Abstract
The present invention relates to an envelope (20) for a laminar structure providing adaptive thermal insulation, the envelope (20) enclosing at least one cavity (16) having included therein a gas generating agent (18) having an unactivated configuration and an activated configuration, the gas generating agent (18) being adapted to change from the unactivated configuration to the activated configuration, such as to increase a gas pressure inside the cavity (16), in response to an increase in temperature in the cavity (16), the envelope (20) being configured such that a volume of the envelope (20) increases in response to the increase in gas pressure inside the cavity (16), wherein the envelope (20) is made of a polymer composite material (8), the polymer composite material (8) including a fluid tight layer which is covered by a reinforcing layer comprising a polymer material, the rein-forcing layer being configured to limit formation of wrinkles in the fluid tight layer (8b) when subjecting the envelope (20) to one, or a plurality of activation/deactivation cycles.
Claims
1. Envelope for a laminar structure providing adaptive thermal insulation, the envelope enclosing at least one cavity having included therein a gas generating agent having an unactivated configuration and an activated configuration, the gas generating agent being adapted to change from the unactivated configuration to the activated configuration, such as to increase a gas pressure inside the cavity, in response to an increase in temperature in the cavity, the envelope being configured such that a volume of the envelope increases in response to the increase in gas pressure inside the cavity, wherein the envelope is made of a polymer composite material, the polymer composite material including a fluid tight layer which is covered by a reinforcing layer comprising a polymer material, the reinforcing layer being configured to limit formation of wrinkles in the fluid tight layer when subjecting the envelope to one, or a plurality of, activation/deactivation cycles.
2. Envelope according to claim 1, comprising a porous layer, in particular an expanded PTFE layer, having a thickness between 30 and 400 m, in particular between 70 and 250 m.
3. Envelope according to claim 1, wherein the reinforcing layer is bonded to the fluid tight layer by a PU resin or by other thermoplastic material, e.g. FEP or PFA.
4. Envelope according to claim 1, wherein the reinforcing layer is configured to provide for additional thermal protection.
5. Envelope according to claim 1, wherein the reinforcing layer comprises a porous polymer material.
6. Envelope according to claim 5, wherein the porous polymer material has a density of 0.2 to 1 g/cm.sup.3.
7. Envelope according to claim 5, wherein the porous polymer material comprises an expanded fluoropolymer material.
8. Envelope according to claim 7, wherein the expanded fluoropolymer material includes expanded PTFE or is expanded PTFE.
9. Envelope according to claim 1, wherein the reinforcing layer has a composite structure including a porous polymer layer (8e) and at least one additional polymer material in contact with the porous polymer layer at least partially penetrating pores formed in the porous polymer layer.
10. Envelope according to claim 9, wherein the additional polymer material penetrates pores of the porous layer up to a penetration depth between 10 and 50 m.
11. Envelope according to claim 9, wherein the additional polymer material forms an essentially homogeneous polymer layer at least on the side of the porous polymer layer facing towards the fluid tight layer.
12. Envelope according to claim 9, wherein the reinforcing layer is bonded to the fluid tight layer by the additional polymer material.
13. Envelope according to claim 1, wherein the envelope is made of a metal/polymers composite material including a fluid tight layer of metallic material.
14. Envelope according to claim 13, wherein the metallic material is Al or an Al based alloy.
15. Laminar structure providing adaptive thermal insulation, comprising a first layer, a second layer, at least one envelope according to claim 1, the envelope provided in between the first layer and the second layer, the first layer, the second layer and the cavity being arranged such that a distance between the first layer and the second layer increases in response to the increase in gas pressure inside the cavity.
16. Fabric with a composite structure, the composite structure comprising a laminar structure providing adaptive thermal insulation or an envelope for a laminar structure providing adaptive thermal insulation according to claim 15.
Description
(1) FIG. 1a shows a simplified and schematic cross-sectional view of a layer used to form an envelope in an embodiment;
(2) FIG. 1b shows a simplified and schematic cross-sectional view of a further layer used to form an envelope;
(3) FIG. 1c shows a simplified and schematic cross-sectional view of a further layer including a polymer reinforcing layer for limiting formation of wrinkles, such layer also used to form an envelope;
(4) FIGS. 2a and 2b show an example of an envelope as described in PCT/EP2011/051265, in an unactivated condition and in an activated condition;
(5) FIGS. 3a-3c show a way how to manufacture envelopes;
(6) FIG. 3d shows a single envelope in a configuration before folding to create first and second sub-cavities;
(7) FIG. 3e shows an embodiment of a sheet layer structure including a three of interconnected sub-cavities of a single envelope, in a configuration before folding;
(8) FIG. 4a shows simplified and schematic cross-sectional views of three different embodiments of an envelope enclosing a cavity which includes a gas generating agent, wherein the envelope laminate layers are welded to each other such as to form the envelope;
(9) FIG. 4b shows simplified and schematic cross-sectional views of three different embodiments of an envelope enclosing a cavity which includes a gas generating agent applied on a dosing aid;
(10) FIG. 4c shows simplified and schematic cross-sectional views of three different embodiments of an envelope enclosing a cavity, which includes a gas generating agent applied on a weldable dosing aid layer;
(11) FIG. 4d shows simplified and schematic cross-sectional views of three different embodiments of an envelope, the envelope enclosing two separated cavities each including a gas generating agent;
(12) FIG. 4e shows simplified and schematic cross-sectional views of three different embodiments of an envelope in an activated condition, with a heat protection shield applied to the heat exposed side of the envelope; as well as a detail showing the heat protection shield in cross section;
(13) FIG. 5 shows an embodiment of an envelope including two sub-cavities connected via a fluid passage, according to an embodiment, in a simplified and schematic plan view in a configuration before folding the envelope along a folding line to superpose the two sub-cavities;
(14) FIG. 6a shows a simplified and schematic cross section of the envelope of FIG. 5 after folding, in a condition with the gas generating agent in the unactivated configuration;
(15) FIG. 6b shows a simplified and schematic cross section of the envelope of FIG. 5 after folding, in a condition with the gas generating agent in the activated configuration;
(16) FIG. 6c shows a simplified and schematic cross section of another envelope including three sub-cavities in folded configuration, in a condition with the gas generating agent in the unactivated configuration;
(17) FIG. 6d shows a simplified and schematic cross section of the envelope of FIG. 6c in a condition with the gas generating agent in the activated configuration;
(18) FIG. 6e shows a simplified and schematic plan view of an envelope according to FIGS. 5, 6a, after folding;
(19) FIG. 7a shows a simplified and schematic cross section of another envelope formed of two identical sub-envelopes bonded together one on top of the other, in a condition with the gas generating agent in the unactivated configuration;
(20) FIG. 7b shows a simplified and schematic cross section of the envelope of FIG. 7a in a condition with the gas generating agent in the activated configuration;
(21) FIG. 8a shows a simplified and schematic cross-sectional view of a laminar structure, according to an embodiment, formed with a plurality of envelopes positioned in between a first layer and a second layer in an unactivated condition;
(22) FIG. 8b shows a simplified and schematic cross-sectional view of a laminar structure, according to a further embodiment, with a plurality of envelopes positioned in between a first layer and a second layer, in an unactivated condition;
(23) FIG. 8c shows a simplified and schematic cross-sectional view of a laminar structure, according to a further embodiment, with a plurality of envelopes positioned in between a first layer and a second layer, in an unactivated condition;
(24) FIG. 8d shows a simplified and schematic cross-sectional view of a laminar structure, according to a further embodiment, with a plurality of envelopes positioned in between a first layer and a second layer and an additional functional membrane laminated onto one of the first and second layers, in an unactivated condition;
(25) FIG. 8e shows a simplified and schematic cross-sectional view of a laminar structure, according to a further embodiment, with a plurality of envelopes and heat protection shields positioned in between a first layer and a second layer, in an activated condition;
(26) FIG. 9a shows a simplified and schematic cross-sectional view of a fabric including a laminar structure;
(27) FIGS. 9b to 9g show other possible configurations of fabrics including the laminar structure providing adaptive thermal insulation according to the invention;
(28) FIG. 10 shows a fire fighter's jacket including a fabric as shown in FIG. 9a;
(29) FIG. 11 shows a schematic sketch of an apparatus to measure increase in distance between the first layer and the second layer when the laminar structure is being brought from the unactivated condition into the activated condition;
(30) FIG. 12 shows a schematic sketch of a laminar structure test piece for measuring the increase in distance between the first layer and the second layer when the laminar structure is being brought from the unactivated condition into the activated condition.
(31) FIG. 13 shows the result of a functionality test for a laminar structure configured to reversibly undergo a plurality of activation/deactivation cycles;
(32) FIG. 14 shows a schematic sketch of an apparatus for carrying out a heat exposure test;
(33) FIG. 15 shows a graph depicting results of heat exposure test carried out with a fabric as shown in FIG. 9g;
(34) FIG. 16 shows in schematic form an apparatus for measuring formation of wrinkles in sheet material 8 used to form the envelope 20; and
(35) FIG. 17 shows photographs of different types of sheet material 8 after a wrinkle formation test has been carried out.
(36) In all Figs. components of respective embodiments being identical or having corresponding functions are denoted by the same reference numerals, respectively. In the following description such components are described only with respect to the first one of the embodiments comprising such components. It is to be understood that the same description applies in respective following embodiments where the same component is included and denoted by the same reference numeral. Unless anything is stated to the contrary, it is generally referred to the corresponding description of that component in the respective earlier embodiment.
(37) FIG. 1a shows a simplified and schematic cross-sectional view of a layer 8 according to an embodiment. Such layer 8 may be used to prepare an envelope. The layer 8 is a laminate comprising a cover layer 8a, a fluid tight layer 8b and a sealing layer 8c. In one example the layer 8 made of an aluminum/plastics composite material comprising a polyethylene terephtalate (PET)-cover layer 8a, an aluminium (Al)-fluid tight layer 8b and a polyethylene (PE)-sealing layer 8c. In order to provide sufficient fluid tightness, a reasonable thickness range for the Al-layer 8b is between 4 m and 25 m. In the example shown the Al-layer 8b has a thickness of at least 12 m. The PE-layer 8c is used as sealing layer by which adjacent laminate layers 8 can be bonded together fluid tightly, in order to create the envelope. The thickness of the PE-layer 8c can be between 20 m and 60 m. A preferable thickness is about 40 m. The PET-layer 8a may be used as a cover layer to provide for desired characteristics of the outer surface of the envelope. In the example a 12 m thick PET-layer 8a is used. The laminate layer 8 as described may be obtained by the company Ko-busch-Sengewald GmbH, Germany.
(38) An alternative layer 8 for forming the envelope is shown in FIG. 1b. This layer 8 also is a laminate including a cover layer 8a made of PE with a thickness of 40 m, an Al layer 8b with a thickness of at least 12 m, and a PE sealing layer 8c with a thickness of 40 m. In this embodiment the cover layer 8a is made of the same material as the sealing layer 8c. The cover layer 8a may be used as an additional sealing layer.
(39) FIG. 1c shows a simplified and schematic cross-sectional view of a further layer 8 including a composite polymer reinforcing layer made of a homogenous polymer material layer 8d and a porous polymer material layer 8e. Such layer 8 is also used to form an envelope 20 in particular embodiments. The composite polymer reinforcing layer is configured to limit formation of wrinkles in the fluid tight layer 8b. A reinforcing layer as shown in FIG. 1c has turned out to be particularly helpful when being intimately laminated together with a metallic fluid tight layer 8b, e.g. a fluid tight layer of an Al or Al alloy.
(40) In the embodiment shown in FIG. 1c a reinforcing layer is bonded to the fluid tight layer 8b on the side thereof facing outwards when an envelope is manufactured (upper side in FIG. 1c). The reinforcing layer in this example replaces cover layer 8a. The reinforcing layer has a composite structure with a porous polymer material layer 8e and a homogenous polymer material layer 8d. Porous polymer material layer 8e in this example is made of expanded polytetrafluoroethylene (ePTFE) and has a thickness in the range of 70 to 250 m. in one preferred example the thickness is of 200 m with a density of 0.7 g/cm.sup.3 The porous polymer material layer 8e may have a of 0.2 to 1 g/cm.sup.3.
(41) A polymer material forming a homogeneous polymer layer 8d is applied to the side of porous polymer material layer 8e facing inwards in an envelope, i.e. to the side facing towards fluid tight layer 8b. Homogeneous polymer material layer 8d may be made of polymer materials like PP, PE, PU, or PEK. Homogenoeus polymer material layer 8d may have a thickness between 40 and 300 m. The polymer material of the homogenous polymer material layer 8d, although shown with a sharp boundary to the porous layer 8e in FIG. 1c, in reality does not have such sharp boundary, but penetrates into the pore structure of porous material layer 8e to some extent. Penetration depth of the polymer material may be between 10 and 50 m. Penetration of the polymer material into the pores of porous polymer layer 8e results in a firm and tight bonding between layers 8e and 8d. Moreover, such penetration allows a smooth transition between good stretchability of the reinforcing layer at its side facing outwards in a manufactured envelope (upper side in FIG. 1c), where porous polymer material layer 8e is positioned, and good resistance against compressive loads at the side to which fluid tight layer 8b is bonded (lower side in FIG. 1c), where homogeneous polymer layer 8d is provided.
(42) The reinforcing layer formed by porous material layer 8e and homogeneous polymer layer 8d is bonded to the fluid tight layer 8b of Al using a polyurethane resin. In the embodiment shown in FIG. 1c the same polyurethane resin which is used as a polymer material to form the homogeneous polymer layer 8d is used to bond the reinforcing layer to the fluid tight layer. In other embodiments, an adhesive different from homogeneous polymer layer may be used.
(43) Inner layer 8c is a sealing layer made of PET similar to the embodiments shown in FIGS. 8a and 8b.
(44) FIG. 2a shows a simplified and schematic cross-sectional view of an envelope (generally designated as 20) as disclosed in applicants previous international patent application PCT/EP2011/051265 enclosing a cavity 16 which includes a gas generating agent (generally designated as 18). In FIG. 2a the envelope 20 is shown in an unactivated configuration of the gas generating agent 18, and hence the envelope 20 has an uninflated, essentially flat shape, also referred to as the unactivated condition. In a flat configuration as shown in FIG. 2a, the envelope 20 has a dimension d=d0 in thickness direction being significantly smaller than the dimensions Ax=Ax0, Ay=Ay0 of the envelope 20 directions orthogonal to the thickness direction, i.e. in lateral directions Ax, Ay. Dimension of the envelope 20 in thickness direction is designated by d in FIG. 2a. Dimension of the envelope 20 in lateral directions is designated by A=Ax0 in FIG. 2a. Here, Ax designates the length from one end of the weld to the end of the opposite weld of the envelope 20. In embodiments with a generally round or quadrangular shape of the envelope, dimensions Ax, Ay of the envelope may be substantially equal for all lateral directions. In other embodiments of the envelope with a generally elongate shape, dimension Ax in a width direction may be smaller than dimension Ay in a length direction.
(45) In an embodiment the envelope 20 is made of two envelope layers 12, 14. Envelope layers 12, 14 may each have a configuration as the layers 8 shown in FIG. 1a, 1b or 1c. Particularly, although not explicitly shown, the envelope layers 12, 14 may be each made up of three layers, corresponding to the layers 8 depicted in FIG. 1a, 1b or 1c. The envelope layer 12 forms an upper part of the envelope 20, such upper part enclosing an upper part of cavity 16. The envelope layer 14 forms a lower part of the envelope 20, such lower part enclosing a lower part of cavity 16. In the embodiment shown, the envelope layer 12 and the envelope layer 14 have an identical configuration, e.g the configuration of the layer 8 shown in FIG. 1a. The envelope 20 has an innermost sealing layer, an intermediate fluid tight layer, and an outside cover layer.
(46) Alternatively, the envelope 20 may be made up of two envelope layers 12, 14 configured from a layer 8 as depicted in FIG. 1b, or may be made up of one envelope layer 12 configured from a layer 8 as depicted in FIG. 1a and one envelope layer 14 configured from a layer 8 as depicted in FIG. 1b. Alternative materials, in particular monolayers or laminate layers of more or less complicated configuration, may be used for making the envelope 20, as outlined above, given the materials themselves are fluid tight and bonded together fluid tightly such that a fluid tight envelope 20 is produced. In one embodiment the envelope layers may be made of a fluid tight single layer (monolayer). Said layer might be formed to the envelope by welding or gluing.
(47) The envelope 20 encloses cavity 16 which is filled with gas generating agent 18. Gas generating agent 18 is chosen to be a liquid having a suitable equilibrium vapor pressure at room temperature. Room temperature is considered to define an unactivated configuration of gas generating agent 18. In the unactivated configuration of the gas generating agent 18 shown in FIG. 2a, gas generating agent 18 is substantially in its liquid phase designated by 18. The envelope 20 provides a substantially fluid tight enclosure of cavity 16, and hence cavity 16 contains sufficient amount of gas generating agent 18, and the remaining volume of cavity 16 is filled with gas, in particular with a rest amount of air or other gas having been enclosed in cavity 16 at the time gas generating agent 18 was filled in. In the example disclosed, gas generating agent 18 is a fluid having the chemical formula CF.sub.3CF.sub.2C(O)CF(CF.sub.3).sub.2. Such fluid is typically used for extinguishing fires and is commercially available under the trade name Novec 1230 Fire extinguishing fluid from 3M. Other fluids may be used for the gas generating agent, as set out above.
(48) A first method for producing an envelope 20 as shown in FIG. 2a is as follows:
(49) First Sealing Step:
(50) Two envelope layers 12, 14 made from a material according to FIG. 1a or 1b are put on top of each other, such that their respective sealing layers face each other. For forming a quadrangular envelope 20 a hot bar (sealing width: 2 mm) is brought into contact with the envelope layers 12, 14 such as to bring the sealing layers into contact and to weld the sealing layers together. This procedure is done for three of four sides of the quadrangular envelope 20. Thus an envelope 20 with one side open is formed.
(51) Filling Step:
(52) The envelope 20 is put onto a precision scale and the gas generating agent 18 is filled into the envelope, e.g using a syringe needle. The amount of gas generating agent to be filled in is controlled by the scale.
(53) As an example: A quantity of 0.07 g gas generating agent 18 will be filled into the envelope 20, in case the envelope 20 has the following specification: the envelope 20 is formed from two envelope layers 12, 14 made up of PET/Al/PE as described above, outer size of the envelope 20 is 20 mm length and 20 mm width (corresponding to an inner size of the cavity of 16 mm length and 16 mm width), and gas generating agent 18 is selected as Novec 1230.
(54) Second Sealing Step:
(55) After the filling step is finished the open side of the envelope 20 is closed by a fourth 2 mm sealing line. The envelope 20 is then cut precisely along the sealing line.
(56) Such method is also available for producing any other envelope as shown in FIGS. 4a-4e, 5, 6a/b, 7a/b. In case a dosing aid 19 is used, in the filling step the dosing aid 19 including the gas generating agent applied to the dosing aid is placed inside the envelope, before the second sealing step, or in some cases even before the first sealing step.
(57) Correctness of the filling quantity for envelopes produced as outlined above can be measured as follows:
(58) A predetermined quantity of envelopes 20 (e.g. 10 envelopes) is produced according to the first sealing step, each of these envelopes 20 is marked and weighed individually on a 4 digit scale (e.g. Satorius BP121S). A predetermined quantity of gas generating agent 18 in the form of a liquid is injected through a pipe from a gravity feed reservoir, including a time-triggered valve, through a syringe needle into the interior of the envelope. A predetermined time for valve opening is ensured by an adjustable electrical timer. Each envelope 20 is closed immediately by the second sealing step. Each of the filled envelopes 20 is weighed, and the weight of the empty envelope 20 (measured before filling) is subtracted. A maximum deviation of plus/minus 10% from the mean value of the sample set should be achievable.
(59) A second method for producing an envelope 20 according to FIG. 2a, 2b is shown in FIGS. 3a to 3d. FIGS. 3a to 3e show how such method may be used to produce envelopes 20 as shown in FIGS. 5, 6a-6e. The method is as follows:
(60) First Step (FIG. 3a):
(61) An elongate sheet, e.g. sheet being 65 mm wide and 1.3 m long, made from a laminate material 8 according FIG. 1a is used. Alternatively, a sheet of different size and/or made from another laminate material, e.g. made from a laminate material 8 as shown in FIG. 1b, may be used. The sheet is folded along its long side in such a way that the cover layer 8a of the laminate 8 (see FIG. 1a or FIG. 1b) is located outside, and the sealing layer 8c is located inside. Thereby, an upper envelope layer 12 and a lower envelope layer 14 are formed in such a way that the sealing layers of the envelope layers 12, 14 are facing each other. In this way a pre-envelope 101 is created. The pre-envelope 101 has a width of 32.5 mm and a length of 1.3 m. The pre-envelope 101 is closed at its one long side 102 and is open along its opposite long side 103. Both short sides 104 and 105 of the pre-envelope 101 are open.
(62) Second Step (FIG. 3b):
(63) A rotating ultrasonic welding wheel (e.g. 5 mm wide) is brought into contact with the pre-envelope 101 at the open long side 103, such as to bring the two sealing layers of the envelope layers 12, 14 into contact with each other. The sealing layers are welded together continuously along a sealing line 106 extending parallel to the open long side 103 of the pre-envelope 101. Thereby the long side 103 is closed and the pre-envelope 101 has a tubular shape with two open short sides 104, 105. A hot sealing bar (sealing width: 2 mm) is brought into contact with the pre-envelope 101 at one of the shorter sides 105, such as to bring the sealing layers into contact with each other. The sealing layers are welded together along a sealing line 107 extending parallel to the shorter side 105 such as to close the pre-envelope 101 at the shorter side 105. The pre-envelope 101 then has a shape of a tube with one end closed.
(64) Then, holding open short side 104 higher than closed short side 105, gas generating agent 18 is filled into the open tubular pre-envelope 101 via the open short side 104. As an example, for a pre-envelope 101 as described and forming a cavity with inner size of 23 mm in width and 1 m in length, the pre-envelope 101 being made of a laminate layer 8 made up of PET/Al/PE, as described above and shown in FIG. 1a, and for a gas generating agent 18 being a liquid known as Novec 1230, as described above, a quantity of 4 ml of gas generating agent 18 is filled into the pre-envelope 101.
(65) Third Step (FIG. 3c)
(66) The pre-envelope 101 is held with its open short side 104 facing upwards, and is held in an up-right position, such that the gas generating agent 18 filled in the cavity concentrates at the closed shorter side 105 of the pre-envelope 101. Starting from the closed shorter side 105, the pre-envelope 101 is brought into intimate contact with a second rotating ultrasonic welding wheel 110. Welding wheel 110 is part of an ultrasonic welding machine having a pair of welding wheels 110, 111. The welding wheel 110 has a circumferential face 112 formed with a plurality of circumferential seal contours 114 Each of the seal contours 114 has a shape corresponding to the shape of the sealing line of the envelopes 20 to be produced (FIG. 2d). In this configuration welding wheel 111 has a planar circumferential surface.
(67) The pre-envelope 101 is transported through the pair of welding wheels 110, 111 starting with its short closed side 105, see arrow B in FIG. 2c indicating the direction of movement of the pre-envelope 101. In this way the welding wheel 110 first contacts first the closed short side 105 of the pre-envelope 101 and finally contacts the open short side 104 of pre-envelope 101.
(68) When the welding wheel 110 contacts the pre-envelope 101, the gas generating agent 18 is pushed away by the rotating ultrasonic welding wheels 110, 111 in areas where one of the sealing contours 114 comes into contact with the pre-envelope 101, since in such areas the sealing layers are brought into contact with each other and are welded together. In this way, a closed sealing contour 116 defining the sealing portion of the final envelope 20 (FIG. 2d) is formed in the pre-envelope 101.
(69) As the pre-envelope 101 travels through the gap between the rotating welding wheels 110, 111 a plurality of consecutive sealing contours 116 are formed in the pre-envelope 101. Each sealing contour 116 encloses a respective cavity 16 including a first sub-cavity 16a and a second sub-cavity 16b filled by a predetermined amount of gas generating agent 18.
(70) It has been found that, following the procedure described above, each sub-cavity 16a, 16b formed in pre-envelope 101 can be filled by the approx. same predetermined amount of gas generating agent 18. Particularly good reproducible results can be obtained by using an ultrasonic welding tool, e.g. in the form of a pair of ultrasonic welding wheels 110, 111, to produce the sealing contours 116 in the pre-envelope 101.
(71) In one example having dimensions as outlined above 20 filled sealing contours 116, each having outer dimensions of 20 mm width and 46 mm length and a sub-cavity size of 16 mm width and 18 mm length, can be created.
(72) Fourth Step (FIG. 3d):
(73) Finally, the final pre-envelope 101 having sealing contours 116 formed therein, is cut, e.g. using a hand operated or automated standard dye cut machine with a cutting dye having the shape of the outer dimensions of the sealing contours 116. In this way individual envelopes 20 having a first sub-cavity 16a and a second sub-cavity 16b as shown in FIG. 3d, are produced.
(74) It is even conceivable to omit or modify the fourth step, i.e. the last cutting step. Then instead of a plurality of single envelopes 20, a sandwich type laminate sheet 20 (see FIG. 3e) is provided. In such sheet layer structure the envelope 20 may be formed by sub-cavities 16a, 16b, 16c aligned along a single line, as indicated for the sheet layer structure of FIG. 3e which is produced from a pre-envelope 101 according to FIGS. 3a to 3c.
(75) Correctness of the filling quantity for envelopes produced according to the second method above can be measured as follows:
(76) A predetermined quantity of envelopes 20 (e.g. 10 envelopes) are produced according to the first to fourth sealing/filling steps above, each of these envelopes 20 is marked and weighed individually on a 4 digit scale (e.g. Satorius BP121S). Each of the envelopes 20 is put on a hot plate with a temperature well above the activation temperate of the gas generating agent 18 to ensure that each of the envelopes 20 will burst and release the gaseous gas generating agent 18 completely. The empty envelopes are weighed individually on a 4 digit scale. The weight loss of each envelope is calculated. In case of humidity pick-up of the envelope material, the envelopes must be conditioned for at least 1 h in the same environment, ideally at 23 C. and 65% relative humidity.
(77) Fluid tightness of the envelope can be measured according to one of the following methods:
(78) Method 1 for Measurement of the Fluid Tightness of the Envelopes:
(79) Each envelope 20 is marked individually. Each envelope 20 is weighed on a 4 digit scale (e.g. SatoriusBP121S). The envelopes 20 are stored under predetermined environmental conditions (20 C., 65% relative humidity). The weighing procedure described is repeated after 1 month of storage. This procedure is continued for at least 6 months. The weight loss after 6 months should be less than 20%, better 10%, ideally less than 1% of the filling weight. Additionally, functionality of each envelope 20 is checked after 6 months on a hot plate or in a water bath. The envelope 20 must show thickness increase when subjected to temperature above activation temperature.
(80) FIGS. 4a to 4e each show three different embodiments of an envelopes 20 enclosing a cavity 16. Each of FIGS. 4a to 4e show in the top a first embodiment in form of a single envelope 20 similar to FIGS. 2a/b, in the middle a further embodiment in form of a folded envelope similar to FIGS. 5, 6a/b, 6c/d, and in the bottom a further embodiment in form of stacked envelopes 20 similar to FIGS. 7a/b.
(81) The three different envelopes 20 shown in FIG. 4a all include a gas generating agent 18 in the form of a liquid, or in the form of a highly viscous liquid, or in form of a coating applied to the inner wall of envelope 20 surrounding the cavity 16 or sub-cavities 16a, 16b. In FIG. 4a the envelopes 20 are all shown in the unactivated configuration of the gas generating agent 18.
(82) The three different envelopes 20 shown in FIG. 4b all include a gas generating agent 18 applied on a dosing aid 19. The dosing aid 19 may be made of any material that is able to absorb gas generating agent 18, e.g. an absorbent paper material, a woven or non-woven textile material, or a sponge-like material. In the embodiments of FIG. 4b a blotting paper or non-woven textile is used as the dosing aid 19. The dosing aid 19 is soaked with a predefined amount of gas generating agent 18, and then is inserted into the cavity 16. This can be done in a way similar to the first method described above. As an alternative to the procedure described above, the dosing aid 19 may be provided with the gas generating agent 18 in a first step, and then the dosing aid 19 may be arranged in between the first and second envelope layers 12, 14, before the first and second envelope layers are bonded together. In FIG. 4b the envelopes 20 are all shown in the unactivated configuration of the gas generating agent 18. Gas generating agent 18, once activated, will be released from dosing aid 19 and inflate cavity 16 or sub-cavities 16a/16b.
(83) In the three different embodiments of FIG. 4b the dosing aid 19 has smaller lateral dimension than the cavity 16 has, or the sub-cavities 16a/16b have, such that the dosing aid 19 does not interfere with the bonding (e.g. along sealing lines) of the first and second envelope layers 12, 14.
(84) Also in the three different embodiments of FIG. 4c the envelope 20 includes a gas generating agent 18 applied on a dosing aid 19. In this embodiment the dosing aid 19 is made of a material that does not interfere with the bonding process used to bond the envelope layers 12, 14 together, or may even be made of material that does support such bonding process as a sealing layer. This allows the dosing aid 19 to be applied in a sandwich type arrangement between the first and second envelope layers 12, 14 before these are bonded together. In case of the embodiment with stacked sub-envelopes 20a, 20b shown in the bottom of FIG. 4c, a respective dosing aid 19a, 19b is placed between the first and second envelope layers 12a/14a; 12b/14b, respectively. For sake of brevity, this not explicitly referred to in the following. The dosing aid 19 may even cover the sealing areas where the first and second envelope layers 12, 14 are to be bonded together. Hence the dosing aid 19 may have a sheet like configuration and be used in the form of a dosing aid layer 19 interposed in between the first and second envelope layers 12, 14 and covering the whole sealing area of the first and second envelope layers 12, 14. The first and second envelope layers 12, 14 are bonded together along the sealing areas, e.g. by welding, with the dosing aid 19 interposed. E.g. the dosing aid 19 may be a sheet made of the above described non-woven textile (PET non-woven, 55 g/cm.sup.2) in which case the dosing aid 19 even provides for an additional sealing layer useful to fluid tightly seal the envelope 20 when welding envelope layers 12, 14 together.
(85) Given the gas generating agent 18 does not interfere with the bonding of the first and second envelope layers 12, 14, gas generating agent 18 may be applied to the dosing aid 19 as a whole. To restrict areas where gas generating agent is applied to the dosing aid in a sealing portion, the gas generating agent 18 may be applied in the form of discrete stripes onto the dosing aid 19. Distance between the stripes can then be selected such that each envelope is crossed by one stripe of gas generating agent. It will generally be more advantageous to apply the gas generating agent 18 only at those portions of the dosing aid 19 which will be inside the cavity 16, i.e. which will be fully enclosed by sealing areas where the first and second envelope layers 12, 14 are bonded together. In this way, the desired predetermined amount of gas generating agent 18 for proper activation and inflating of the envelope 20 can be adjusted more precisely. E.g. the gas generating agent 18 may be applied to the dosing aid 19 in an array of a plurality of discrete spots or areas, all of which are fully enclosed in a respective cavity 16.
(86) In an embodiment where the first and second envelope layers 12, 14 are bonded together by welding having the dosing aid in between, the dosing aid 19 may be made of a textile structure like polypropylene non-woven; or may be made of a porous material like expanded polyethylene (ePE) or expanded polypropylene (ePP). Each of these materials allows welding of the first envelope layer 12 to the second envelope layer 14 with a layer of that material interposed in between.
(87) In a further embodiment, the first envelope layer 12 and/or the second envelope layer 14 may provide the function of the dosing aid 19. This can be achieved by forming the innermost layers of the first envelope layer 12 and/or the second envelope layer 14, which come into contact when welding the first envelope layer 12 to the second envelope layer 14, from a suitable material, e.g. the materials mentioned before.
(88) In the embodiment shown in FIG. 4c the dosing aid 19 is interposed in the form of a further layer in between the first and second envelope layers 12, 14. Gas generating agent 18, once activated, will be released from dosing aid 19 and inflate cavity 16 and sub-cavities 16a and 16b. A dosing aid 19 in form of a layer as shown in FIG. 4c may be used to improve fluid tightness of the seal between the first and second envelope layers 12, 14, e.g. in case the dosing aid 19 is made from material having a sufficiently low melting point interposing dosing aid layer 19 may improve sealing when welding envelope layers 12, 14 together. One example for a suitable material for forming a dosing aid layer 19 is the above mentioned PET non-woven, 55 g/cm.sup.2 material.
(89) FIG. 4d shows three different embodiments of similar envelopes 20 as shown in FIG. 4c. The envelopes 20 of FIG. 4d have first and second envelope layers 12, 14 and an intermediate layer 21 (or sub-envelope layers 12a,14a with intermediate layer 21a; and sub-envelope layers 12b/14b with intermediate layer 21b in the embodiment of FIG. 4d). In the embodiments shown, the intermediate layer 21 (or 21a/21b) has a configuration according to the layer 8 in FIG. 1b, but may have other configuration in other embodiments. The intermediate layer 21 is interposed between layer 12 and layer 14 in a sandwich type arrangement. Gas generating agent 18 is provided as a coating on both sides of intermediate layer 21. The intermediate layer 21 is made of essentially fluid tight material with respect to gas generating agent 18, 18 in the unactivated configuration as well as with respect to gas generating agent 18, 18 in the activated configuration. Intermediate layer 21 may also made of material that provides a fluid tight bonding between first and second envelope layers 12, 14, as described above. A suitable combination of materials in the embodiment of FIG. 3d is: First envelope layer 12: PET/Al/PE (see FIG. 1a); intermediate layer 21: PE/Al/PE (see FIG. 1b); second envelope layer 14: PET/Al/PE (see FIG. 1a).
(90) In the embodiments of FIGS. 4a, 4b, 4c and 4d, the size/volume of cavity 16 or sub-cavities 16a and 16b, and correspondingly the amount of gas generating agent 18, to be filled in the cavity/sub-cavities 16, 16a, 16b can be adjusted as desired.
(91) In the embodiments shown in middle and bottom of FIGS. 4a to 4e, respectively, the thickness d of envelope 20 will be determined by the sum of two distances (thickness of first sub-cavity 16a), and (thickness of second sub-cavity 16b). Both distances will increase in case gas generating agent 18 will change from the unactivated configuration to the activated configuration. Increase in distance between the first layer and the second layer of a laminar structure including such envelopes 20, after activation of the gas generating agent 18 will be substantially identical to the increase in thickness d of the envelope 20, and hence given by increase in thickness of the first sub-cavity 16a plus the increase in thickness of second sub-cavity 16b. In case of the embodiment shown in the middle of FIGS. 4a to 4e, an even larger increase in thickness may be obtained by the hinge-like configuration of the envelope 20.
(92) Besides facilitating the accurate dosing of gas generating agent 18, dosing aid 19, as shown in the embodiments of FIGS. 4c and 4d, provides the advantage that it can be applied in a sandwich type configuration as an intermediate sheet in between the first and second envelope layers 12 and 14. This allows for simplified manufacture of the envelopes 20. It is possible to manufacture a plurality of envelopes 20 using only one sheet of envelope layer 12, one sheet of dosing aid layer 19 and one sheet of envelope layer 14.
(93) FIG. 4e shows simplified and schematic cross-sectional views of envelopes 20 according to three further embodiments. In FIG. 4e, each of the envelopes 20 is in an activated condition in which the gas generating agent 18 is in the activated configuration thereof and thus is mostly present in gaseous form. With each embodiment shown in FIG. 4e, the thickness d of the envelope 20 has increased to d=d1, while the lateral extension of the envelope 20, indicated as Ax=Ax1, is still essentially the same as in the unactivated condition of the envelope 20. The envelopes 20 in FIG. 4e each have a heat protection shield 50 applied to the heat exposed side of the envelope 20, respectively. Such heat protection shield 50 is shown in the detail in form a schematic cross section. The heat protection shield 50 is a laminate made up of essentially three layers 52, 54, 56. Layer 52 is a fabric layer, in this example made of non-woven fabric, e.g. non woven polyphenylene sulfide (PPS) imbued with polyurethane (PU) or silicone resin. In other embodiments, layer 52 may be made of other heat resistant material like aramids, glass fibers, melamine, or similar material, or a composition of such materials. Layer 52 provides for a heat resistant and insulating backbone to which two layers 54, 56 of a further insulating material are applied such that layer 52 is sandwiched in between layers 54, 56. In the embodiment of FIG. 4e, layers 54, 56 are both made of an expanded polytetrafluorethylene (ePTFE) membrane. Other membranes, e.g. membranes based on polyolefins and/or polyurethanes, may be conceivable as well with respect to layers 54 and/or 56. The layers 54 and 56 have thicknesses of 30-90 m each. Layer 52 has a thickness in the range of 100-1600 m, in particular in the range of 200 and 800 m.
(94) The heat protection shield 50 is bonded to the outer side of envelope 20 using an adhesive 58. Adhesive 58 is applied in the central region of the envelope 20 and the heat protection shield only, such that a lateral end region or peripheral region 60 of heat protection shield 50 is not bonded to the envelope 20. In the activated condition of the envelope 20, shown in FIG. 4e, such lateral end region 60 of heat protection shield 50 projects from envelope 20, thereby leaving a circumferential air gap 62 in between heat projection shield 50 and envelope 20. The air gap 62 provides for additional thermal insulation, thereby reducing temperature load for the envelope 20 in the activated condition thereof significantly.
(95) The envelopes 20 shown in FIG. 4e each comprise a dosing aid 19 as shown in FIG. 4b. However, alternatively, a dosing aid 19 as shown in FIG. 4c or 4e may be used, or the gas generating agent may be applied without use of a dosing aid as shown in FIG. 4a.
(96) FIG. 5 shows an embodiment of an envelope 20 including two sub-cavities 16a, 16b connected via a fluid passage 34, according to a first embodiment (see the embodiments shown in the middle of FIGS. 4a to 4e, respectively), in a simplified and schematic plan view. The embodiment shown in FIG. 5 has a folded configuration, see FIGS. 6a and 6b. FIG. 5 shows a situation before folding the envelope 20 along a folding line 30 to superpose the two sub-cavities 16a, 16b in direction of thickness d.
(97) FIG. 6a shows a simplified and schematic cross section of the envelope 20 shown in FIG. 5 after folding along the folding line 30, in a condition with the gas generating agent 18 in the unactivated configuration. Gas generating agent 18 is applied by means of a dosing aid 19a, 19b, similar to the embodiment shown in FIG. 4b. In such configuration, the envelope 20 has an essentially thin and flat shape. FIG. 6b shows a simplified and schematic cross section of the envelope 20 shown in FIG. 6a in a condition with the gas generating agent 18 in the activated configuration. The envelope 20 in the condition shown in FIG. 6b has a blown up shape. In particular, the thickness dimension of the envelope 20 has increased dramatically from d=d0 in FIG. 6a to d=d1 in FIG. 6b. Also the angle formed in between the folding line 30 and the welded lateral ends of first and second sub-cavities 16a, 16b, respectively, has increased considerably from =0 in FIG. 6a to =1 in FIG. 6b.
(98) FIG. 6c shows a simplified and schematic cross section of another envelope including three sub-cavities 16a, 16b, 16c in a folded configuration, in a condition with the gas generating agent in the unactivated configuration. FIG. 6d shows a simplified and schematic cross section of the envelope of FIG. 6c in a condition with the gas generating agent 18 in the activated configuration. Similar to the situation in FIGS. 6a and 6b, but even more pronounced, the thickness dimension of the envelope 20 has increased dramatically from d=d0 in FIG. 6c to d=d1 in FIG. 6d, and the angles formed in between a plane including folding line 30a and the welded lateral ends of first sub-cavity 16a, and a plane including both folding lines 30a, 30b, as well as between a plane including both folding lines 30a, 30b, and a plane including folding line 30b and the welded lateral ends of third sub-cavity 16c, respectively, have increased considerably from =0 in FIG. 6c to =1 in FIG. 6d.
(99) Folding line 30 in FIG. 6a/b, as well as each of folding lines 30a, 30b in FIGS. 6c/d, defines a first pivot P1. Two adjacent sub-cavities (first and second sub-cavities 16a. 16b in FIG. 6a/b: first and second sub-cavities 16a, 16b as well as second and third sub-cavities 16b, 16c in FIG. 6c/d) are able to rotate relative to each other around first pivot P1, in response to increase in gas pressure inside the sub-cavities 16a, 16b, 16c.
(100) In the embodiments of FIGS. 6a/b and 6c/d, fluid channels 34, 34a, 34b are located at one lateral end, or both of two opposite lateral ends, of envelopes 20. The fluid channels 34, 34a, 34b cross the folding lines 30, 30a, 30b, respectively and connect the respective adjacent sub-cavities 16a, 16b (FIGS. 6a/6b) and 16a,16b/16b,16c (FIG. 6c/6d) with each other. Therefore, adjacent ones of the sub-cavities 16a, 16b/16a, 16b, 16c formed in the envelopes 20 are connected only in the regions surrounding the fluid channels 34, 34a, 34b, respectively.
(101) With a folded configuration of the envelopes 20 as shown in FIGS. 6a/b, 6c/d, thickness d of the envelope 20 as a whole is not determined by the sum of the thicknesses of the cavities 16a+16b/16a+16b+16c, each of these thicknesses measured in direction orthogonal to the respective lateral plane of these individual cavities. Rather, the thickness d of the envelope 20 is determined by effective thicknesses of the individual cavities. These effective thicknesses are the larger the larger the angle is. The angle will increase when, after activation of the gas generating agent 18 the envelope 20 changes condition from the unactivated condition (envelopes 20 being essentially flat) to the activated condition (envelopes 20 being inflated).
(102) By increasing the angle when changing from the unactivated condition to the activated condition, the envelopes 20 of FIGS. 6a/b, 6c/d provide a function similar to a hinge. This is a very efficient way of increasing the thickness of the envelope 20 after activation of the gas generating agent.
(103) A consequence of this hinge-type behaviour is that the envelopes 20 allow for a large increase in distance between a first layer and the second layer in a fabric or laminar structure having the envelope structure of FIGS. 6a/b, 6c/d sandwiched in between. Alternatively, to achieve a desired increase in distance between the first layer and the second layer, an envelopes of smaller lateral extension can be used covering much less area of the fabric than it would be necessary if envelopes of other type were used.
(104) By using envelopes having a plurality of two or even more sub-cavities arranged on after the other in folded configuration, as just described, very large increase in thickness of the envelope as a whole can be achieved, thereby enabling a very pronounced increase in distance between first layer and second layers. The result is a very effective increase in thermal insulating capability as a result of a temperature change.
(105) FIG. 6e shows another embodiment of an envelope 20 having a folded configuration, in a plan view. FIG. 6e shows the envelope 20 in a configuration after folding along folding line 30 is done, such that first sub-cavity 16a is stacked on top of second sub-cavity 16b. Folding line 30 defines a first pivot P1 allowing rotation of first sub-cavity 16a relative to second sub-cavity 16b around first pivot P1, as explained above. Principally, the envelope 20 may have any configuration as shown in FIGS. 4a to 4e, 5, 6a/b, 6c/d. The envelope 20 of FIG. 6e comprises a connection member 36 which connects first sub-envelope 16a and second sub-envelope 16b at a position distant from first pivot P1. Connection member 36 may be a bonding strip, e.g. adhesive tape, fastened to the outer side of envelope piece 12 in such a way to fix first and second sub-cavities 16a, 16 relative to each other, or at least allow a limit movement of first sub-cavity 16a away from second sub-cavity 16b. Connection member 36 is fixed to envelope at a position distant from folding line 30, thus distant from first pivot P1. Connection member 36 provides for the following functions: First, connection member 36 restricts rotation of the first sub-cavity 16a with respect the second sub-cavity 16b around first pivot P1 to rotational angles smaller than a predetermined threshold angle. Second, connection member 36 itself forms a second pivot for rotational movement of first sub-cavity 16a with respect to second sub-cavity 16b. However, rotational movement of second sub-cavity 16b with respect of first sub-cavity 16a around second pivot is limited by first pivot. Therefore, second pivot P2 in cooperation with first pivot P1 allow a relatively limited rotational movement of first sub-cavity 16a with respect to second sub-cavity 16b around an axis of rotation connecting first and second pivots. Such rotational movement is limited to rotational angles below a maximum threshold rotation angle, because first and second pivots P1, P2 are located on different, particularly adjacent, lateral sides of the envelope 20.
(106) In FIGS. 6a to 6e gas generating agent 18 is applied by means of a dosing aid 19a, 19b as shown in FIG. 4b. The above description also applies with respect to the embodiments shown in the middle of FIGS. 4a, 4c, and 4d using other dosing aids 19, or no dosing aid, for applying gas generating agent 18.
(107) FIG. 7a shows a simplified and schematic cross section of another envelope 20 formed of two sub-envelopes 20a, 20b bonded together one on top of the other, in a condition with the gas generating agent 18 in the unactivated configuration. FIG. 7b shows a simplified and schematic cross section of the envelope 20 of FIG. 7a in a condition with the gas generating agent 18 in the activated configuration. In FIG. 7a/b two identical sup-envelopes 20a, 20b are stacked on top of each other. If desired, it is conceivable to stack envelopes of different size or different shape on top of each other.
(108) In FIGS. 7a/7b two sub-envelopes 20a and 20b are bonded together via a bond 23 to form an envelope 20. Each of the sub-envelopes 20a, 20b encloses a respective sub-cavity 16a, 16b. First sub-cavity 16a includes a dosing aid 19 provided with gas generating agent 18. Also, second cavity 16b includes a dosing aid 19 provided with gas generating agent 18. Other dosing aids 19, as shown in FIGS. 4c, 4d may be used to provide gas generating agent 18. As an alternative to the use of a dosing aid 19, gas generating agent 18 may be provided without using a dosing aid, e.g. in the form of a liquid. Each sub-envelope 20a, 20b is essentially fluid tight.
(109) In the embodiment of FIGS. 7a/7b both sub-envelopes 20a, 20b have an essentially identical size, however it also conceivable to use sub-envelopes 20a, 20b of different size. Further, more than two sub-envelopes 20a, 20b may be arranged on top of each other.
(110) In the embodiment of FIGS. 7a/7b the sub-envelopes 20a, 20b are bonded together by a bond 23 located in a central region of the sub-envelopes 20a, 20b, where each sub-envelope 20a, 20b has the largest increase in thickness in response to activation of gas generating agent 18 (see FIG. 7b). Hence, thickness d of the envelope 20 as a whole is determined by the sum of the two thicknesses of the individual sub-envelopes 20a, 20b. Increase in thickness of the envelope 20 after activation of the gas generating agent 18 will be substantially identical to the increase in thicknesses of the individual sub-envelopes 20a, 20b.
(111) Bonding of the sub-envelopes 20a and 20b can be effected by suitable adhesives, adhesive layers, by welding or by glueing (in the case of glueing, proper measures should be taken to maintain fluid tightness).
(112) Importantly a fluid passage 22 is provided in the region where sub-envelops 20a, 20b are bonded together. Fluid passage 22 is formed by an opening 28a formed in first sub-envelope 20 and a corresponding opening 28b formed in second sub-envelope 20b. Since both sub-envelops 20a, 20b are bonded only in the region around fluid passage 22, both sub-envelops 20a, 20b can increase their respective thickness effectively in response to activation of the gas generating agent.
(113) Each of the envelopes shown in FIGS. 5, 6a/b,6c/d, and 7a/b may be provided in combination with a respective heat protection shield 50 assigned thereto, similar to the heat protection shield of FIG. 4e.
(114) FIGS. 8a to 8d show exemplary embodiments of a laminar structure 100 according to the invention.
(115) The embodiment of FIG. 8a comprises a plurality of envelopes 20. In FIGS. 8a to 8e, as well as in FIGS. 9a to 9f, three different types of envelopes according to the embodiments shown in FIG. 4b, above are shown, respectively. This illustration is for the purpose of indicating that envelopes according to each of these embodiments may be used alternatively. It be understood that typically envelopes 20 of a same configuration will be used for a laminar structure. It also be understood that any of the other envelopes described herein may be used alternatively to the three embodiments shown exemplary in FIGS. 8a to 8e, 9a to 9g. In the laminar structure 100, the envelopes 20 are positioned in between a first layer 122 and a second layer 124. Both the first and second layers 122, 124 may be textile layers. In a possible configuration the textile layers 122, 124 may be connected via stitches 127 in the form of a quilted composite. In this way, pockets 125 are formed by the first and second layers 122, 124. In this embodiment, each of these pockets 125 receives a respective one of the envelopes 20. Other embodiments are conceivable in which each pocket 125 receives more than one envelope 120, or where part of the pockets 125 do not receive any envelope 20. The envelopes 20 are thus fixed by their respective pocket 125 with respect to movement in the length/width plane defined by the layers 122, 124.
(116) In a possible configuration, the first layer 122 may be a textile having flame resistant properties. In one example the first layer 122 is made of 55 g/m.sup.2 spun-laced non-woven of aramid fiber (available as Vilene Fireblocker from the company Freudenberg). In the embodiment shown in FIG. 8a, the second layer 124 is made of the same material as the first layer 122. In other embodiments, the second layer may be made of a fire resistant textile liner made of 125 g/m.sup.2 aramid viscose FR blend 50/50 woven (available from the company Schueler), as shown in FIG. 8b. Both, the first layer 122 and the second layer 124 may be either a non-woven or a woven, depending on the application.
(117) Activation of the gas generating agent 18 provides for a volumetric increase (inflation) of the envelopes 20 in the pockets 125. Such inflation of the envelopes 20 induces movement of the first layer 122 and second layer 124 away from each other and increases the distance D between the first layer 122 and the second layer 124 from a first distance D0 to a second distance D1. In case the first layer 122 and/or the second layer 124 have a structure with embossments and depressions, it may be convenient to measure the distance D with respect to reference planes of the first and second layers 122, 124 respectively. In the example shown the distance is measured by using reference planes touching the most distant points of the first and second layers 122, 124 respectively.
(118) FIG. 8a further shows that the envelopes 20 are received in the pockets 125 in such a way that gaps remain free in between each two neighbouring envelopes 20. The distance of these gaps is indicated by X. It can be seen that this distance X remains nearly constant or even increases slightly, when the gas generating agent 18 in the envelopes 20 changes from the unactivated configuration to the activated configuration. Further, thermally triggered shrinkage of the laminate structure 100 is advantageously reduced.
(119) FIG. 8b shows a simplified and schematic cross-sectional view of a laminar structure 100 according to a further embodiment. The laminar structure 100 is similar to FIG. 8a with a plurality of envelopes 20 positioned in between a first layer 122 and a second layer 124 in an unactivated condition. In the embodiment of FIG. 8b the envelopes 20 are fixed to layer 122 by means of adhesive spots 129. Such adhesive spots 129 may provide fixation of the envelopes 20 only temporarily for mounting purposes. In such case, typically additional measures for fixing the envelopes 20 in position will be provided, e.g. stitches 127 to form pockets in the type of a quilted composite structure as shown in FIG. 8a.
(120) Alternatively, the adhesive spots 129 may be formed of an adhesive providing durable fixation of the envelopes with respect to either first layer 122 (see FIG. 8b) or second layer 124, or to both of them (see FIG. 8c). In such case, additional stitches 127 are not absolutely necessary. In all embodiments shown, the envelopes 20 may be connected with the first layer 122 and/or the second layer 124 via stitches, instead of adhesive spots 129.
(121) In FIG. 8c the first layer 122 and the second layer 124 are not fixed to each other. Only the envelopes 20 are fixed to the first layer 122, and may optionally be fixed to the second layer 124. With respect to the single envelope 20 shown in left part of FIG. 8c, it be understood that such envelope may be fixed to first layer 122 and/or second layer 124 (as indicated by adhesive spots 123a). The gap shown between envelope 20 and adhesive spots 123a in the single envelope embodiment 20 in FIG. 8c does not exist in reality, of course, but is a consequence of the schematic drawing. The laminar structure 100 in such embodiment as shown in FIG. 8c provides a relatively loosely coupled structure. Such arrangement facilitates assembly of the laminar structure 100 and provides for flexibility. In case a tighter connection between the first and the second layer 122, 124 is desired it is possible to additionally provide stitches joining the first and second layers 122, 124 with each other. Generally such additional stitches will be provided with larger distances to each such as to form rather large pockets. In a further embodiment it is possible to connect a plurality of envelopes 20 such as to form a chain of envelopes 20, and to connect the first layer 122 and the second layer 124 via a plurality of parallel stitches running parallel to each other. The first and second layers 122, 124 thus will form a plurality of channels in between each two adjacent stitches. Into such channels a respective chain of envelopes 20 may be introduced.
(122) FIG. 8d shows a laminar structure 100, according to a further embodiment in an unactivated condition. The laminar structure 100 of FIG. 8e is similar to the embodiment shown in FIG. 8b and has an additional functional layer 140 attached to at least the first layer 122 or the second layer 124. In the embodiment of FIG. 8d the functional layer 140 is attached to the second layer 124. The additional functional layer 140 may include a water vapour permeable and waterproof membrane, as described above, and thus provide for water proofness of the laminar structure 100, and also for a barrier against other liquids and gases, while still maintaining the laminar structure 100 water vapor permeable. For a more detailed description of the functional layer, see the description above.
(123) The additional functional layer 140 is applied to the second layer 124 in a low temperature bonding process by using adhesive spots 144, in order to avoid activation of the laminar structure 100 when the functional layer 140 is applied. A functional layer 140 may be attached to the first layer 122 and/or to the second layer 124. Such first and/or second layer 122, 124 may be made of a woven material as shown in FIG. 8d, or may be made of a non-woven material, e.g. as shown in FIG. 8a.
(124) FIG. 8e shows a simplified and schematic cross-sectional view of a laminar structure 100 according to a further embodiment. The laminar structure 100 is similar to FIG. 8a with a plurality of envelopes 20 positioned in between a first layer 122 and a second layer 124. Again, the first layer 122 and/or second layer 124 may be made of a woven or non-woven material. FIG. 8e shows the laminar structure 100 in an activated condition in which the gas generating agent 18 included in the envelopes 20 is in the activated configuration thereof. The envelopes 20 of the embodiment in FIG. 8e are assigned to respective heat protection shields 50. These heat protection shields 50 are provided on the heat exposed side of the envelopes 20, in such way that the heat protection shields 50 are bonded to the respective envelope 20 in a central region only. In the activated condition shown in FIG. 8e, an insulating air gap 62 is formed in between a peripheral region of a respective heat protection shield 50 and the envelope 20 assigned to it.
(125) Also, in the embodiment of FIG. 8e the laminar structure 100 has the configuration of a quilted blanket with the first layer 122 and the second layer 124 attached to each other via stitches 127 such as to form pockets 125. The envelopes 20 together with their respective heat protection shields 50 are inserted into these pockets 125. In other embodiments, the envelopes 20 including heat protection shields 50 may be fixed to first layer 122 and/or second layer 124 by means of adhesive spots 123, 129, in a manner similar as shown in FIGS. 8b to 8d.
(126) In the embodiment of FIG. 8e the heat protection shields 50 are bonded to the respective envelopes 20. In other embodiments it may be possible to provide the respective envelopes 20 and heat protection shields 50 assigned thereto separately, e.g. by inserting a respective envelope 20 and heat protection shield 50 into a pocket 125 of suitable shape.
(127) The envelopes 20 having assigned a heat protection shield 50 thereto may be used in any other laminar structure as shown in FIGS. 8a to 8d. Further, any form of envelopes, as shown in FIGS. 2a,b, 4a-e, 5, 6a,b, 7a,b may be provided in combination with a heat protection shield 50.
(128) FIG. 9a shows a simplified and schematic cross-sectional view of a fabric composite 150 including a laminar structure 100 as shown in FIG. 8a. The fabric composite 150 comprises a plurality of layers arranged to each other, seen from an outer side A of a garment made with such fabric composite 150: (1) an outer heat protective shell layer 136 having an outer side 135 and an inner side 137; (2) a laminar structure 100 providing adaptive thermal insulation as shown in FIG. 8a, the laminar structure 100 is arranged on the inner side 137 of outer heat protective shell layer 136, and (3) a barrier laminate 138 comprising a functional layer 140, the barrier laminate 138 is arranged on the inner side laminar structure 100.
(129) The outer side A means for all the embodiments in the FIGS. 9a to 9g said side which is directed to the environment.
(130) The barrier laminate 138 includes a functional layer 140 which typically comprises a waterproof and water vapor permeable membrane for example as described above. The functional layer 140 is attached to at least one layer 142 via an adhesive layer 144 (two layer laminate). Layer 142 may be a woven or non-woven textile layer. Adhesive layer 144 is configured such as not to significantly impair breathability of the barrier laminate 138. In further embodiments the barrier laminate 138 comprises two or more textile layers wherein the functional layer is arranged between at least two textile layers (three layer laminate). Other configurations of fabrics 150 to which the laminar structure 100 can be applied are shown in FIGS. 9b to 9g:
(131) In FIG. 9b the fabric composite 150 includes an outer layer 136 with an outer side 135 and an inner side 137. A laminar structure 100 providing adaptive thermal insulation is positioned on the inner side 137 of the outer layer 136. The laminar structure 100 comprises a barrier laminate 138 having a functional layer 140 adhesively attached to a textile layer 142 for example by adhesive dots 144, an inner layer 124 and envelopes 20 arranged between the barrier laminate 138 and the inner layer 124. The envelopes 20 of the laminar structure 100 are bonded to the inner side of functional layer 140 via a suitable discontinuous adhesive 129, e.g. silicone, polyurethane. The inner layer 124 may comprises one or more textile layers. In this embodiment barrier laminate 138 has the function of the first layer of the laminar structure providing adaptive thermal insulation. On the inner side of inner layer 124 there is provided an inner layer 148 of woven material.
(132) In FIG. 9c the fabric composite 150 includes a laminar structure 100 providing adaptive thermal insulation forming the outer fabric layer. The laminar structure 100 comprises an outer layer 136 with an outer side 135 and an inner side 137 and a barrier laminate 138 having a functional layer 140 adhesively attached to a textile layer 142 for example by adhesive dots 144. The laminar structure 100 further comprises envelopes 20 which are arranged between the inner side 137 of the outer layer 136 and the barrier laminate 138. In particular the envelopes 120 are adhesively bonded to the outer side of the textile layer 142 by adhesive dots 129. In this embodiment barrier laminate 138 has the function of the second layer of the laminar structure 100 providing adaptive thermal insulation and outer layer 136 has the function of the first layer of the laminar structure 100 providing adaptive thermal insulation. The composite 150 further comprises an inner layer 148 which may comprise one or more textile layers.
(133) In FIG. 9d the fabric composite 150 includes a laminar structure 100 providing adaptable thermal insulation. The laminar structure 100 comprises an outer layer 136 with an outer side 135 and an inner side 137 and a barrier laminate 138 having a functional layer 140 adhesively attached to a textile layer 142 for example by adhesive dots 144. The laminar structure further comprises envelopes 20 which are bonded to the inner side 137 of the outer layer 136 for example by a discontinuous adhesive in the form of adhesive dots 129. In this embodiment barrier laminate 138 has the function of the second layer of the laminar structure 100 providing adaptive thermal insulation and outer layer 136 has the function of the first layer of the laminar structure 100 providing adaptive thermal insulation. The composite 150 further comprises an inner layer 148 which may comprise one or more textile layers.
(134) The insulation capability of the individual layers can be adjusted as required for a particular application, e.g. by area weight, thickness, number of layers.
(135) In FIG. 9e the fabrics composite 150 comprises a laminar structure 100 including a first layer 122 and a second layer 124 with a plurality of envelopes 20 in between as shown in FIG. 8a, with the second layer 124 having the configuration of a woven layer. Further the fabric composite 150 includes a barrier laminate 138 forming the outer shell of the composite 150 and being positioned on the outer side of the laminar structure 100. The barrier laminate 138 comprises an outer layer 136 and a functional layer 140 adhesively attached to the inner side of the outer layer 136 for example by polyurethane adhesive dots 144.
(136) The fabrics composite 150 in FIG. 9f is similar to the fabric composite of FIG. 9e. In this embodiment the barrier laminate 138 has an additional inner textile layer 142 attached to the functional layer 140 such that the functional layer 140 is embedded between outer textile layer 136 and textile layer 142. The textile layer 142 might be for a fire resistant liner made of 125 g/m.sup.2 Aramide Viscose FR blend 50/50 woven.
(137) In all embodiments shown in FIGS. 9a to 9e the laminar structure 100 has the configuration of a quilted blanket with the first and second layers being connected by stitches 127 such as to form pockets 125.
(138) The fabrics composite 150 shown in FIG. 9g is similar to the fabric composites of FIGS. 9a-9f. In this embodiment the laminar structure 100 has the configuration of a quilted blanket and is provided with envelopes 20 each combined with a heat protection shield 50, as described above and shown in FIG. 8e. The laminar structure 100 is positioned adjacent to the inner side 137 of an outer heat protective shell 136 as described above. Thus, the laminar structure 100 is expected to be exposed to relatively high temperature in case the fabric is exposed to a source of heat, as indicated by 700 in FIG. 9g. On the inner side of the laminar structure 100 there is provided a barrier laminate 138 similar to the barrier laminates described above. On the inner side of barrier laminate 138 there is an insulating lining 148.
(139) The envelopes 20 having assigned a heat protection shield thereto may be used in any other laminar structure as shown in FIGS. 8a to 8e, or fabric as shown in FIGS. 9a to 9e, or in laminar structures or fabrics of other configuration.
(140) FIG. 10 shows a fire fighter's jacket 152 including fabric composite 150 as shown in FIGS. 9a-9f. Other garments which may comprise fabrics 150 according to invention include jackets, coats, trousers, overalls, shoes, gloves, socks, gaiters, headgear, blankets, and the like or parts of them. The fabric composite may be used in other articles as well, for example in tents or the like.
(141) The following is a description of a method for determining thickness d of an envelope 20, in particular applicable to an envelope 20 as described with respect to FIGS. 5, 6a/b and 6c/d.
(142) The envelope was produced as described above with respect to FIGS. 3 to 3e (Second method 2 for producing envelopes), The welding wheel 110 was provided with sealing contours 116 of a shape to form envelopes 20 as shown in FIG. 5 with Ax=22.5 mm, and Ay=21 mm. The sealed envelope 20 was folded at the middle along folding line 30 to produce an envelope 20 having two sub-cavities 16a, 16b stacked on top of each other. Then an adhesive tape 36 was fixed to envelope 30 such as to fix the first sub-cavity the second sub-cavity. The adhesive strip 36 thus provided a second pivot P2 essentially oriented rectangular to folding line 30 forming a first pivot P1. Such envelope 20 is shown in FIG. 6e.
(143) Method for Measuring Thickness Change of Envelopes:
(144) A method for measuring thickness change of such envelope is as follows:
(145) A heating plate is connected to a heating apparatus (heating plate 300 mm500 mm out of a Erichsen, doctor blade coater 509/MC/1+heating control Jumo Matec, with controller Jumo dtron16, connected to 220V/16 A).
(146) An envelope 20 is placed onto the center of the heating plate in switched off mode, at ambient temperature of 23 C. The height d=d0 of the unactivated envelope 20 is measured by placing a temperature resistant ruler rectangular to the heating surface of the heating plate and observing the thickness d as a function of time by looking parallel to the heating plate surface onto the ruler scale. Thickness d is measured relative to the surface of the heating plate.
(147) Then, the temperature is increased in steps of 5K starting 5K below the activation temperature. After each temperature increase the thickness d is measured. This procedure is repeated until no further increase in thickness d is observed. This thickness d is reported as the final thickness d=d1 of the envelope 20 in the condition with the gas generating agent 18 in the activated configuration thereof.
Examples for Envelopes
Example 1 (Single Envelope)
(148) Single envelopes 20 as shown in FIG. 4a have been produced and used to carry out the test measurements. Such envelopes 20 have a slightly elliptical shape when seen from above with larger axis of ellipse b1=23 mm, and smaller axis of ellipse b2=20 mm).
(149) Each of the envelopes is filled with 0.03 g of 3M NOVEC 1230 Fire Protection Fluid (chemical formula: CF.sub.3CF.sub.2C(O)CF(CF.sub.3).sub.2) as gas generating agent according to method described above with respect to FIGS. 3a to 3e. Gas generating agent 18 is applied using a dosing aid layer 19, as shown in FIG. 4c, made of 50 g/m.sup.2 non woven polypropylene.
(150) The area covered by the envelope 20 in the unactivated condition with the gas generating agent 18 in the unactivated configuration thereof is 394 mm.sup.2.
Example 2 (Envelope with Folded Configuration)
(151) Single envelopes 20 as shown in FIGS. 5, 6a and 6b have been produced and used to carry out the test measurements. Such envelopes 20 have in unfolded condition a shape as shown in FIG. 5 with Ax=22.5 mm and Ay=21 mm. Width of the envelopes at the folding line 30 is Ay (folding line)=15 mm. After folding the envelope 20 of example 2 has a similar shape in the lateral plane as the envelope 20 in example 1. The area covered by the folded envelope 20 of example 2 is 380 mm.sup.2. Each of the envelopes 20 is filled with 0.06 g of 3M NOVEC 1230 Fire Protection Fluid (chemical formula: CF.sub.3CF.sub.2C(O)CF(CF.sub.3).sub.2) as gas generating agent. Production of these envelopes 20 follow the method described above with respect to FIGS. 3a to 3d. Gas generating agent 18 is applied using a dosing aid layer 19, as shown in FIG. 4c, made of 50 g/m.sup.2 non woven polypropylene.
(152) A strip of adhesive tape 36 (Tesafilm, order number 57335 at www.tesa.de) is attached to the outer side of envelope 20 at a lateral side of the envelope essentially rectangular to the folding line 30. The adhesive strip 36 has a width of 19 mm and a length of 8 mm, and is attached with its longer side being is on the outer sides of the envelope 20. Thus, the adhesive strip 26 fixes the first and second sub-cavities 16a, 16 to each other, against movement away from each other. Provided in such way, adhesive strip 36 restricts rotation of first sub-cavity 16a with respect to second sub-cavity 16b to rotation angles avoiding complete unfolding of the envelope 20 (into a state where the envelope 20 is not able to recover its original folded state in response to decrease of gas pressure inside the sub-cavities 16a, 16b)
Example 3 (Envelope with Sub-Envelopes Stacked on Top of Each Other)
(153) 2 sub-envelopes 20a, 20b, each having a configuration of the single envelope 20 shown in FIG. 4a, with a square size of 40 mm40 mm side length, have been made according the first method for producing an envelope described above. The filling step was omitted. In each of the sub-envelopes 20a, 20b a circular opening 28a, 28b having a diameter of 1.5 mm was formed in one lateral wall 14a, 12b thereof. The openings 28a, 28b were formed in the central region of one lateral side 14a, 12b of the sub-envelopes 20a, 20b, such that the openings 28a, 28b formed in each sub-envelope 20a, 20b fit together when stacking the first and second sub-envelopes 20a, 20b on top of each other. An adhesive, e.g. adhesive film available from 3M, article number 9077, was applied to at least one sub-envelopes 20a, 20b around the openings 28a, 28b in a circular pattern with an inner diameter of 3 mm and an outer diameter of 12 mm. Novec 1230 Fire fighting fluid was injected into the first and second sub-envelopes 20a, 20b via the openings 28a, 28b by a syringe, and very quickly afterwards the two sub-envelopes 20a, 20b were attached to each other in a fluid tight manner by placing the openings 28a, 28b on top of each other. 0.024 g of 3M Novec 1230 was measured as a filling amount of gas generating agent 18. This was measured by weight as a difference of the empty envelope parts and the final filled envelope.
(154) The sub-envelopes 20a, 20b were made of envelope pieces 12a, 14a; 12b, 14b of the following configuration: PET 12 m, Al 12 m, PE 40 m
(155) The gas generating agent in all three examples has been placed on a dosing aid as described with respect to FIG. 4c.
(156) Results of thickness measurements, following the procedure described above, were as follows:
(157) TABLE-US-00001 Example 3: Envelope with sub- Example 2: envelopes Example 1: Envelope stacked on Single with folded top of each envelope configuration other: Covering area [mm.sup.2] 394 380 1600 mm.sup.2 Initial thickness d0 [mm] 0.4 1.2 1.5 Thickness in activated 8 12.5 22 condition d1 [mm]
Measurement of Reversibility
(158) The above described method for measuring the change of thickness d of envelopes 20 can be also used for checking the reversibility of the change from unactivated condition of the envelope 20 to activated condition (activation cycle) and reverse (deactivation cycle). As a baseline the thickness d=d0 of the unactivated envelope 20 is measured, when the heating plate is switched off and its surface is at room temperature. For the continuation of the procedure the temperature of the heating plate is then set to the lowest temperature at which the maximum increase in thickness of envelopes 20 has been obtained in previous tests. After a waiting time required for the heating plate to the temperature of the hot plate the procedure is stated.
(159) An envelope 20 in a condition with the gas generating agent 18 in the unactivated configuration thereof, is placed on the hot surface of the heating plate, and the change of thickness d of the envelope 20 is observed until the maximum thickness d=d1 is reached. Then the activated envelope 20 is placed with pincers on a surface at room temperature, e.g. a metal plate for quick heat transfer. Here the deactivation of the envelope 20 will be observed. The final thickness of the envelope d=d0 is measured with an equal ruler in the same procedure as on the hot plate and reported.
(160) For obtaining not only minimum thickness d=d0 and maximum thickness d=d1 of the envelope 20, the heating plate and the unheated metal plate with the rulers mounted are placed next to each other and the envelope 20 will be placed repeatedly on the heating plate and on the unheated metal plate. Such back and forth placement of the envelope 20 will be then recorded by a video recording device, which is looking in the same direction onto the rulers as the observer does in the manual procedure described above. With almost continuous thickness data a graph can be printed similar to FIG. 13. (with the ordinate showing thickness d of an envelope 20 instead of thickness D of a laminar structure 100).
(161) Example for a Laminar Structure Using Envelopes as Described Herein
(162) FIG. 12 shows a schematic sketch of a laminar structure in the form of a test piece 70 to be used with the apparatus of FIG. 11 for measuring the increase in distance D between the first layer 122 and the second layer 124 when the laminar structure 100 is being brought from the unactivated condition into the activated condition. The test piece 70 is shown in plan view in FIG. 12. A cross-sectional view thereof corresponds to the cross sections shown in FIG. 8a. FIG. 12 shows the laminar structure 100 in the unactivated condition.
(163) The test procedure as described herein is carried out using a laminar structure 70 including envelopes 20 as shown in FIG. 4a. The same test procedure is applicable to other test pieces 70 in the form of any other laminar structure 100 including envelopes 20 as shown in any of FIGS. 4a to 4e, 5, 6a-e, 7a, 7b as well.
(164) The test piece 70 used in the test described below has the following configuration:
(165) The test piece 70 forms a quilted structure with: (a) a first layer (122) made of 55 g/m.sup.2 spun-laced nonwoven of aramid fiber (available as Vilene Fireblocker from the company Freudenberg, Germany) (b) a second layer (124)(not visible in FIG. 11), arranged underneath the first layer (122), made of 55 g/m.sup.2 spun-laced nonwoven of aramid fiber (available as Vilene Fireblocker from the company Freudenberg, Germany)
(166) The first and second layers 122, 124 have a size of 140 mm (length L)140 mm (width W). The first and second layers 122, 124 are connected by a plurality of stitched seams 72a-72d, 74a-74d, thus forming a quilted composite. The stitched seams are formed by a single needle lock stitch. In this way, 9 pockets 125 are formed by the quilted composite 70. The pockets 125 each have the shape of a square with a side length of a=40 mm. Each of these pockets 125 receives a respective one of the envelopes 20 made as described above. Single envelopes 20 as shown in FIG. 7a, 7b have been used to carry out the test measurements. Such envelopes 20 have a slightly elliptical shape when seen from above with larger axis of ellipse b1=23 mm, and smaller axis of ellipse b2=20 mm). 9 envelopes 20 are arranged between the first and the second layers 122, 124 such that a single envelope 20 is spaced to at least one neighbour envelope 20 by one of said stitched seams 72a-72d, 74a-74d. Each of the pockets 125 receives one envelope 20. The envelopes 20 are inserted into the pockets 125 without being fixed to the first layer 122 or second layer 124.
(167) Each of the envelopes is filled with 0.03 g of 3M NOVEC 1230 Fire Protection Fluid (chemical formula: CF.sub.3CF.sub.2C(O)CF(CF.sub.3).sub.2) as gas generating agent according to method 2 described above with respect to FIGS. 3a to 3d
(168) A method for measuring thickness change of such test piece 70 is as follows:
(169) Setup of Measurement Apparatus:
(170) The arrangement for measuring a thickness change of the test piece 70 in response to a change in temperature is shown in FIG. 11. The arrangement comprises a apparatus 300 with a base 302, a heating plate 304, a top plate 306, and a laser based distance measuring device 314.
(171) The heating plate 304 is connected to a heating apparatus (plate 300 mm500 mm out of a Erichsen, doctor blade coater 509/MC/1+heating control Jumo Matec, with controller Jumo dtron16, connected to 220V/16 A).
(172) Test piece 70 is laid flat on the heating plate 304.
(173) Top plate 306 has the form of a flat disk with a diameter of 89 mm and is made of Monolux 500 (available from Cape Boards & Panels, Ltd., Uxbridge, England) or an equivalent material. Top plate 306 has a weight of approx 115g. Top plate 306 is laid flat on top of the test piece 70.
(174) Laser based distance measuring device 310 includes a frame 312 and a distance laser device 314 (laser sensor: Leuze ODSL-8N 4-400-S 12 which is connected to a A/D converter Almemo 2590-9V5 having a reading rate of 3 measurements per second, the A/D converter translates the 0-10 V output of the laser sensor into a 0-400 mm distance reading, accuracy: 0.2 mm on a plain plate). The frame 312 is mounted to the base 302. The distance laser device 314 is and has mounted to a top arm of the frame in such a way that the distance laser device 314 emits a laser beam 316 towards the top surface of the top plate 306 and receives a reflected beam 318. The distance laser device 314 is able to detect a distance h between the distance laser device 314 and the top surface of top plate 306. Preferably, laser beam 316 is emitted orthogonally to top surface of top plate 306.
(175) Temperature gradient of plate 304 is lower than 2K across the plate in the range of the measurement.
(176) Measurement Procedure:
(177) Test is done at room temperature, i.e. controlled climate of 23 C. and 65% relative humidity. (a) Top plate 306 is placed directly onto heating plate 304 (without test piece 70) to obtain a zero reading h_0. (b) Then, test piece 70 is placed in between heating plate 304 and top plate 306. Heating plate 304 is heated to a temperature above ambient temperature and 5K below the expected activation temperature of the gas generating agent (e.g up to 44 C. in case of 3M Novec 1230 Fire Protection Fluid as gas generating agent) to obtain an initial height reading h_1. Thickness of test piece 70 (corresponding to distance between first layer 22 and second layer 24 in unactivated condition) is D0=h_0h_1. (c) Temperature of heating plate is increased in steps of 5K, after each new step is adjusted, distance h is read after 1 minute to calculate a thickness change h_1h. This procedure is repeated until the maximum expansion of the test piece 70 is reached. Maximum expansion is considered to be reached if thickness change h_1h in at least two consecutive 5K steps is identical within 0.4 mm (which is twice the accuracy of the distance measurement tool). Reading h_max is obtained. Thickness of test piece 70 (corresponding to distance between first layer 22 and second layer 24 in activated condition) is D1=h_0h_max. Increase in thickness of test piece 70 (corresponding to increase in distance between first layer 22 and second layer 24 in activated condition with respect to unactivated condition) is D1D0=h_1h_max.
(178) In the example of test pieces that are able to undergo a plurality of activation/deactivation cycles the following test procedure is available:
(179) Thickness Reversibility Method:
(180) Set-up of thickness measurement apparatus, as described above, is used. (a) Top plate 306 is placed directly onto heating plate 304 (without test piece 70) to obtain a zero reading h_0. (b) Then, test piece 70 is placed in between heating plate 304 and top plate 306. Heating plate 304 is heated to a temperature above ambient temperature and 5K below the expected activation temperature of the gas generating agent (e.g up to 44 C. in case of 3M Novec 1230 Fire Protection Fluid as gas generating agent) to obtain an initial height reading h_1. Thickness of test piece 70 (corresponding to distance between first layer 122 and second layer 124 in unactivated condition) D0=h_0h_1. (c) Heating cycle: Target temperature of heating plate 304 is set to a temperature 30 C. above the boiling point of the gas generating agent in the envelope 20 and heating plate 304 is heated with a heating rate of 1 K/min. Increase in thickness (corresponding to increase in distance D between first layer 122 and second layer 124) is measured by distance laser device 314 every 10 s. When heating plate 304 reaches target temperature this temperature is maintained for about 10 min and reading of increase in thickness is continued. After 10 min final increase in thickness is measured (corresponding to distance between first layer 122 and second layer 124 in activated condition of gas generating agent). (d) Cooling cycle: Target temperature of heating plate 304 is set to room temperature and heating plate 304 is cooling down by the environment within 1 hour. Decrease in thickness (corresponding to decrease in distance D between first layer 122 and second layer 124) is measured by distance laser device 314 every 10 s. When heating plate 304 reaches target temperature this temperature is maintained for about 10 min and reading of decrease in thickness is continued. After 10 min final decrease in thickness is measured (corresponding to distance between first layer 122 and second layer 124 in unactivated configuration).
(181) Heating cycle (c) and cooling cycle (d) are repeated 3 times. Each time thickness increase at topmost temperature and thickness decrease at lowermost temperature are measured.
(182) A result of the thickness reversibility test for one heating cycle and one cooling cycle is shown in FIG. 13 in the form of a distance D vs. temperature T diagram. It can be seen that a hysteresis loop is produced. From the topmost plateau of this hysteresis loop the distance D1 between the first layer 122 and second layer 124 in the activated configuration, and from the lowermost plateau distance D0 between the first layer 122 and second layer 124 in the unactivated configuration can be inferred.
(183) For reversible envelopes with a liquid gas generating agent, the following functionality test is available for single envelopes 20: (a) 2 buckets are prepared. Each bucket is filled with 2 liters of liquid. The first bucket acts as a cold bath and the second bucket acts as a hot bath. The temperatures for the cold bath and the hot bath should be chosen with respect to the activation temperature of the gas generating agent and the onset temperature of condensation/freezing of the gas generating agent. If in one example the gas generating agent is a liquid and the boiling/condensing temperature range is from 47 to 52 C. then a cold bath temperature of 25 C. and a hot bath temperature of 80 C., using water as the liquid in the hot bath and the cold bath, is preferred. (b) The envelope 20, filled with the gas generating agent 18, is held with a pincer and put it into the hot bath, until the envelope 20 will inflate. (c) After inflation is complete, inflated envelope 20 is removed from the hot bath immediately and the thickness of the inflated envelope is estimated using a frame with an opening of the expected thickness. Such frame should be made of a material with a low thermal conductivity. As an example, in case the expected thickness of the inflated envelope is 5.5 mm, then using a frame with an opening of 5 mm height and 30 mm width can show that the envelope has reached at least 5 mm (d) The envelope is then put into the cold bath, until it collapses it again. Cycles (b) to (d) are repeated until the inflation is no longer reaching the gap of the frame indicating that functionality of the envelope becomes impaired. After every 10 repetitions the temperature of the liquids inside the 2 buckets is controlled and adjusted to the target, if necessary.
Example of a Fabric Composite
Fabric Example 1
(184) As fabric example 1, a fabric composite sample 150, according FIG. 9a was produced, comprising an outer shell in the form of a heat protective layer 136 made of 200 g/m.sup.2 Nomex Delta T woven available from company Fritsche, Germany; a laminar structure 100 in the form of the fabric composite sample 70 according to FIG. 12. a barrier laminate 138 in the form of a Fireblocker N laminate (145 g/m.sup.2) available from company W.L. Gore & Associates GmbH, Germany an inner lining made of 125 g/m.sup.2 aramid viscose woven (available as Nomex Viscose FR blend 50/50 woven from the company Schueler, Switzerland)
(185) A reference fabric sample was produced using the same set-up as fabric example 1 without the envelopes 20.
(186) Fabric example 2 envelopes 20 having a folded configuration, according FIGS. 5, 6a and 6b, instead of the single envelopes 20 of fabric example 1. Otherwise fabric example 2 is identical to fabric example 1. Each of the envelopes 20 is filled with 0.06 g of 3M NOVEC 1230 Fire Protection Fluid (chemical formula: CF.sub.3CF.sub.2C(O)CF(CF.sub.3).sub.2) as gas generating agent according to the second method for producing envelopes, described above with respect to FIGS. 3a to 3d.
(187) The following test results were obtained with fabric examples 1 and 2, and with the reference fabric sample
(188) TABLE-US-00002 Example 2 (Envelopes with Example 1 Reference 80 kW/m.sup.2 folded configuration) (Single envelopes) example EN367 HT124 34.2 29.3 17.0 mean [s] weight per 667 632 600 area [g/m.sup.2]
(189) Surprisingly if the heat flux is lowered from 80 kW/m.sup.2 as used in the maximum configuration of EN367 to a much lower, but in firer fighting relevant, heat flux of 5 kW/m.sup.2 by putting the flame from a larger distance onto the fabrics composite sample 150, the following results are obtained:
(190) TABLE-US-00003 Example 2 (Envelopes with Example 1 Reference 5 kW/m.sup.2 folded configuration) (Single envelopes) example EN367 HT124 397.3 246.3 175.5 mean [s] weight per 667 632 600 area [g/m.sup.2]
(191) EN367-HTI24-mean refers to heat transfer index at 80 kW/m.sup.2, as defined in DIN EN 367 (1992). This quantity describes the time it takes to obtain an increase of 24 K in temperature at the second side (inner side) of a sample fabric as shown in FIG. 11 when the first side is subject to a heat source of 80 kW/m.sup.2 with a flame.
(192) Heat Exposure Test Showing Effect of Protection Shield
(193) FIG. 14 shows the results of a heat exposure test made on a fabric as in principle shown in FIG. 9g. A layered structure as shown in FIG. 9g was prepared using the methods and materials described below. The fabric included one envelope combined with a heat protection shield 50, as shown in FIG. 4e.
(194) The Envelope was Produced as Follows:
(195) Two envelope layers 12, 14 made from a material according to FIG. 1a or 1b wherein the material is a laminate with a cover layer 8a made of polyethylene-terephtalate (PET) with a thickness of 12 m, a fluid tight layer 8b made of aluminum with a thickness of 9 m and a sealing layer 8c made of polyethylene-terephtalate (PET) with a thickness of 23 m, are put on top of each other, such that their respective sealing layers face each other. For forming a quadrangular envelope 20 a hot bar (sealing width: 2 mm) is brought into contact with the envelope layers 12, 14 such as to bring the sealing layers into contact and to weld the sealing layers together. This procedure is done for three of four sides of the quadrangular envelope 20. Thus an envelope 20 with one side open is formed.
(196) The envelope 20 is put onto a precision scale and the gas generating agent 18 is filled into the envelope, e.g using a syringe needle. The amount of gas generating agent to be filled in is controlled by the scale.
(197) A quantity of around 0.07 g gas generating agent 18 will be filled into the envelope 20, in case the envelope 20 has the following specification: the envelope 20 is formed from two envelope layers 12, 14 made up of PET/Al/PET as described above, outer size of the envelope 20 is 30 mm length and 30 mm width (corresponding to an inner size of the cavity of 26 mm length and 26 mm width), and gas generating agent 18 is selected as Novec 1230.
(198) After the filling step is finished the open side of the envelope 20 is closed by a fourth 2 mm sealing line. The envelope 20 is then cut precisely along the sealing line.
(199) The configuration of the heat protection shield is as shown in FIG. 4e. The heat protection shield 50 is a laminate made up of three layers 52, 54, 56. The layer 52 is a fabric layer made of non woven polyphenylene sulphide (PPS) with a textile weight of 65 g/m.sup.2. The layer 52 is sandwiched in between layers 54, 56; both are made of an ePTFE membrane. The thickness of the laminate is 0.5 mm. A piece with the dimensions of 30 mm in length and 30 mm in width has been cut out of the laminate.
(200) Heat protection shield has been attached to one surface of envelope using a silicone adhesive in the centre of the surface area.
(201) The configuration of the laminar structure was: (a) a first layer (122) made of 55 g/m.sup.2 spun-laced nonwoven of aramid fiber (available as Vilene Fireblocker from the company Freudenberg, Germany) (b) a second layer (124), arranged underneath the first layer (122), made of 55 g/m.sup.2 spun-laced nonwoven of aramid fiber (available as Vilene Fireblocker from the company Freudenberg, Germany)
(202) One Envelope was Put in Between the Two Textile Layers
(203) A fabric composite, according FIG. 9g was produced, comprising an outer shell in the form of a heat protective layer 136 made of 200 g/m.sup.2 Nomex Delta T woven available from company Fritsche, Germany; a laminar structure as described above a barrier laminate 138 in the form of a Fireblocker N laminate (145 g/m.sup.2) available from company W.L. Gore & Associates GmbH, Germany and a lining layer made of 125 g/m.sup.2 aramid viscose woven (available as Nomex Viscose FR blend 50/50 woven from the company Schueler, Switzerland)
(204) Further, a fabric according to a comparative example was prepared which was identical to the fabric described above, except that the envelopes 20 were not provided with any heat protection shield.
(205) The fabric according to the example, as well as the fabric according to the comparative example, were subjected to a source of heat in such a way that the heat flux arriving at the outer surface of the fabric was 20 kW/m.sup.2.
(206) The Configuration of the Source of Heat was as Follows:
(207) An apparatus as defined in DIN EN 367 (1992) was used, see FIG. 14 for a schematic sketch of the measurement apparatus 400. The thermocouple 416, the calorimeter block 418 and the specimen 420, as described in DIN EN 367 (1992), were placed at a distance from the burner 410 that a heat flux density of 20 kW/m.sup.2 was produced, instead of the standard heat flux of 80 kW/m.sup.2. 20 kW/m.sup.2 corresponds to the heat flux of a severe fire fighter activity in which the envelopes 20 should sustain several activation/deactivation cycles.
(208) Reference signs 412 and 414 refer to a frame 312 and a distance laser device 314 of a laser based distance measuring device as shown in FIG. 11. These parts are present only for the purpose of monitoring thickness changes during the flame test and during activation and deactivation cycles, but not absolutely necessary for carrying out the tests according to DIN EN 367 (1992).
(209) For the measurement of the comparative example a NiCrNi wire thermocouple (Thermo ZA 9020-FS from ALHBORN) was connected to a A/D converter Almelo 2590-9V5 having a reading rate of 3 measurements per second) and placed between the first layer 122 of the laminar structure 100 and the heat exposed surface of the envelope 20, see reference symbol T in FIG. 9a.
(210) For the measurement of the fabric composite with an envelope 20 combined with the heat protection shield 50, the thermocouple was placed between the shield 50 and the heat exposed surface of the envelope 20, see reference symbol T in FIG. 9g.
(211) FIG. 15 shows a graph with results of the heat exposure test. The abscissa denotes the time of exposure to the source of heat of the test pieces. The ordinate denotes temperature as measured at the heat exposed outer surface of an envelope for the above example (temperature was measured in between the outer surface of the envelope 20 and the heat protection shield 50, as indicated by T in FIG. 9g) and for the comparative example.
(212) Curve 80 in FIG. 14 denotes the temporal profile of temperature at the outer surface on the heat exposed side of the envelope 20 for the comparative example (without heat protection shield 50). Temperature increased relatively fast, i.e. within about 30 s to about 300 C. Such temperature is too high for the envelope 20 to withstand without damage. As a result, the increasing insulation provided by the envelope 20 by activation of the gas generating agent will be lost within a minute.
(213) In contrast, for the fabric according to the example (provided with heat protection shield 50 on the heat exposed side), increase in temperature turned out to much slower, as indicated by curve 82 in FIG. 14. The slower increase in temperature is still sufficient to allow for fast activation of the gas generating agent and adaptive increase in thermal insulation capability of the envelope. It turned out that with the fabric according to the example escape time can be increased by at least 40 s with respect to a conventional product not having an adaptive thermal insulating structure including envelopes as described herein. For the example provided with a heat insulation shield 50, escape time is still longer for about 10 s compared to an embodiment where the envelopes 20 are not provided with a heat insulation shield 50.
(214) Wrinkle Formation Test
(215) FIG. 16 shows in schematic form an apparatus for measuring formation of wrinkles in sheet material 8 used to form the envelope 20. Such test apparatus and the test procedure carried out is a standard procedure used for testing of resistance of sheet materials with respect to wrinkling, known as Gelboflex-test (ASTM F 392-93 (2004). A sample 8 with a size of 200 mm by 280 mm was formed into a tube shape and then attached to the tester mandrels.
(216) Samples were flexed at standard atmospheric condition (23 C. and 50% relative humidity). The flexing action consists of a twisting motion combined with a vertical motion, thus, repeatedly twisting and crushing the film. The frequency was at a rate of 45 cycles per minute. In this case, 50 cycles were performed for each sample.
(217) Three sample sheets 8 of a sheet material as shown in FIG. 1c were tested for wrinkle formation (test example). Also, three sample sheets 8 of a sheet material made up from an Al layer and an PET sealing layer were tested (comparative example).
(218) Configuration of the sample sheets was as follows:
Test Example
(219) Reinforcing layer: ePTFE layer with a thickness of 200 m
(220) Fluid tight layer: Al-layer with a thickness of 9 m
(221) The fluid tight layer is sandwiched between a layer of polypropylene (PP) with a thickness of 70 m and a PET sealing layer with a thickness of 12 m.
Comparative Example
(222) A laminate according to FIG. 1a or 1b, with a fluid tight layer made of Al with a thickness of 9 m, sandwiched between a layer of polypropylene (PP) with a thickness of 70 m and a PET sealing layer with a thickness of 12 m.
(223) The sample sheets according to the test example as well as three sample sheets according to the comparative example were Subject to 50 bending cycles. Afterward, the sample sheets were inspected visually. The result is shown in FIG. 17. FIG. 17 shows drawing of all six sample sheets after having been subject to the Gelboflex test described above. The top row shows the three sample sheets according to the test example, the bottom row shows the three sample sheets according to the comparative example. It is clearly visible that almost no wrinkles are present in the sample sheets according to the test example. In contrast, the sample sheets according to the comparative example show significant formation of wrinkles, some of them being relatively severe and deep.
(224) An oxygen gas transmission test using the manometric method as described in ASTM D 1434-82 has been carried out using the sample sheets 8 before and after being subject to the Gelboflex test. The sample has to be mounted between two sealed chambers whose pressure are different. The gas molecules will pass through the film from the higher pressure side (1 bar pressure) to the lower pressure side (vacuum) under the influence of a pressure difference (gas concentration difference). The detected pressure change of the lower side will provide the transmission rate.
(225) Gas transmission rate is the volume of gas which, under steady conditions, crosses unit area of the sample in unit time under unit pressure difference and at constant temperature. This volume is expressed at standard temperature and pressure.
(226) The rate is usually expressed in cubic centimeters under standard atmospheric pressure per square meter 24 h under a pressure difference of 1 atm (cm.sup.3/m.sup.2.Math.d.Math.atm).
(227) It turned out that the three sample sheets according to the test example showed a practically unchanged oxygen permeation rate before and after being subject to the Gelboflex test. In contrast, with the sample sheets according to the comparative example oxgen permeation rate increased dramatically after being subject to the Gelboflex test. This is a clear indication that the fluid tight Al layer lost its fluid tight characteristics by formation of wrinkles.
