Method for compounding and applying adhesives

Abstract

The invention relates to continuous methods for compounding and applying adhesives, characterized in that (i) a base component of the adhesive is mixed continuously with at least one aggregate so as to produce a compounded adhesive; and (ii) the adhesive compounded in this manner is applied to a substrate. The invention also relates to such methods where a device as described here is used to carry out the method.

Claims

1. A continuous method for compounding and applying a one component hot melt adhesive composition, comprising: providing a solid hot melt adhesive base component, wherein the base component is a reactive hot-melt adhesive composition that is a solid at room temperature or a non-reactive thermoplastic hot melt adhesive composition that is a solid at room temperature; heating the solid base component to a temperature above a melting point of the base component; providing at least one additive; continuously mixing the base component with the at least one additive in a compounding unit to produce the compounded, one component hot melt adhesive; continuously conveying the compounded adhesive from the compounding unit to an application unit having an application roller; and continuously applying the compounded, one component hot melt adhesive from the application unit to a substrate.

2. The method according to claim 1, wherein the base component of the adhesive and/or the at least one additive in step (i) are supplied to a mixer in a controlled manner.

3. The method according to claim 1, wherein the adhesive is applied at a temperature above the melting point of the base component of the adhesive.

4. The method according to claim 1, wherein the at least one additive comprises a material which influences the chemical properties, the biological properties and/or the physical properties of the adhesive.

5. The method according to claim 1, wherein the at least one additive comprises a color pigment, an agent for improving moisture resistance, an agent for improving resistance against mold and/or fungus formation, a biocidal agent, an additive for improved energy absorption, a primer for improved adhesive bonding, an agent for influencing the recrystallization of hot-melt adhesives and/or a reaction accelerator.

6. The method according to claim 1, wherein the at least one additive: (i) is liquid at room temperature and comprises at least one polyol that is liquid at room temperature, at least one color pigment and optionally at least one reaction accelerator; or (ii) is solid at room temperature and comprises at least one polyolefin that is solid at room temperature and at least one color pigment.

7. The method according to claim 1, wherein the at least one additive comprises at least one color pigment and is added in step (i) in a predetermined ratio to the base component of the adhesive to provide the compounded adhesive with a predetermined color that matches that of the substrate onto which it is applied in step (ii).

8. The method according to claim 1, wherein the at least one additive comprises at an agent for influencing recrystallization of the compounded adhesive and, in step (i), is added in a predetermined manner to provide the compounded adhesive with a reworking capability.

9. The method according to claim 1, further comprising: supplying the base component of the adhesive and/or the at least one additive from a supply unit to the compounding unit.

10. The method according to claim 9, wherein: (i) the supply unit has a dosing unit for the dosed supply of the base component and/or the at least one additive, or the compounding unit has a dosing unit for the dosed supply of the at least one additive; and/or (ii) the supply unit allows a manual supply of the base component and/or the at least one additive; and/or (iii) the supply unit allows a controlled supply of the base component and/or the at least one additive; and/or (iv) the compounding unit allows a controlled supply of the base component and/or the at least one additive; and/or (v) the supply unit and/or the compounding unit comprises at least one pump which continuously supplies the base component; and/or (vi) the supply unit and/or the compounding unit comprises a pump which continuously or discretely supplies the at least one additive; and/or (vii) the supply unit and/or the compounding unit has a heater for melting the base component and/or the at least one additive; and/or (viii) the compounding unit has a mixing device comprising a mixing chamber that has a static mixer or a dynamic mixer for mixing the base component and/or the at least one additive; and/or (ix) the compounding unit has a distribution device for the distributed ingress of the base component and/or the at least one additive into the mixing chamber; and/or (x) the application unit has a reservoir for intermediate storage of a defined quantity of the compounded adhesive, the reservoir being used as the supply unit and compounding unit and the mixing taking place in the reservoir by rotation of the application roller.

11. The method according to claim 9, further comprising supplying the base component to the compounding unit through a supply comprising a spiral channel guide.

12. The method according to claim 1 wherein the base component of the adhesive is a non-reactive, thermoplastic hot melt adhesive.

13. The method according to claim 1 wherein the base component of the adhesive is a moisture curing reactive polyurethane hot-melt adhesive composition.

14. A continuous method for compounding and applying an adhesive composition, comprising: continuously providing a supply of an adhesive base component through inlets to a mixer, wherein the base component is a moisture reactive, one component hot-melt adhesive composition that is a solid at room temperature; continuously providing a supply of an additive comprising at least one color pigment, through the inlets to the mixer; continuously mixing the supply of adhesive base component with the supply of additive in the mixer to produce continuous stream of a compounded adhesive; and applying the continuous stream of compounded adhesive to a substrate.

15. The method according to claim 14, further comprising applying the compounded adhesive to the substrate using an application roller.

16. The method according to claim 14, wherein the adhesive base component is supplied to the mixer through three spaced inlets.

17. The method according to claim 14, wherein the base component is supplied to the mixing chamber through three inlets, with each inlet offset by about 120°.

18. A continuous method for compounding and applying an adhesive composition, comprising: continuously providing a supply of an adhesive base component through inlets to a mixer, wherein the inlets provide a spiral channel guide and the base component is a reactive hot-melt adhesive composition or a non-reactive thermoplastic hot melt adhesive composition; continuously providing a supply of an additive comprising at least one color pigment, through the inlets to the mixer; continuously mixing the supply of adhesive base component with the supply of additive in the mixer to produce continuous stream of a compounded adhesive; and applying the continuous stream of compounded adhesive to a substrate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a first embodiment of a device for compounding and applying adhesive, which can be used in the methods according to the invention.

(2) FIG. 2 shows a further embodiment of a device for compounding and applying adhesive, which can be used in the methods according to the invention,

(3) FIG. 3 shows a further embodiment of a device for compounding and applying adhesive, which can be used in the methods according to the invention.

(4) FIG. 4 is a sectional view of one embodiment of a compounding device.

(5) FIG. 5 is a sectional view of the compounding device according to FIG. 4.

(6) FIG. 6 is a sectional view of a further embodiment of a compounding device.

(7) FIG. 7 is a sectional view of the compounding device according to FIG. 6.

(8) FIG. 8 is a sectional view of a further embodiment of a compounding device, and

(9) FIG. 9 is a sectional view of the compounding device according to FIG. 8.

(10) FIG. 1 shows a first embodiment of a device 1 for compounding and applying adhesive, comprising a supply unit 2, a compounding unit 3 and an application unit 4, which device can be used in the methods according to the invention.

(11) The supply unit 2 is used to supply the base component of the adhesive, it being possible for the base component of the adhesive to already be provided in a liquid or fluid state.

(12) The base component of the adhesive can also be provided as a solid, granulate, powder or the like, and can be poured into the supply unit 2. For this purpose, the supply unit 2 can have a melting unit 5 which is used to melt the base component. The base component is supplied from the supply unit 2 to the compounding unit 3, to which additives can in turn be supplied.

(13) The base component and the additive/s are then mixed in the compounding unit 3. For this purpose, a non-driven rotating mixer, a driven rotating mixer or a static non-rotating mixer can be provided in the compounding unit 3, which mixer mixes the components to be mixed in the compounding unit 3. The mixed components of the adhesive are then guided from the compounding unit 3 into the application unit 4, from which unit the adhesive can be applied onto a substrate. For this purpose, the application unit 4 has a means for carrying out the application to the substrate, for example an application roller 6.

(14) However, the supply unit 2 can also be used to supply the base component of the adhesive and at least one additive, meaning that the supply unit 2 is already supplied with the base component and the at least one additive and forwards said component and additive on to the compounding unit, for example to mix the components.

(15) The supply of the base component to the supply unit and/or the compounding unit preferably take places in a controlled, automated manner. In a further embodiment of the invention, one component or the other can also be supplied manually.

(16) The compounding unit 3 continuously mixes the base component of the adhesive with the supplied additive/s in order to form the compounded adhesive, and also continuously conveys the compounded adhesive. For this purpose, the compounding unit preferably has a pump which conveys the base component or the mixed adhesive. If only the base component is conveyed by the pump, the mixed adhesive is also conveyed because the base component constitutes the main portion of the mixed adhesive.

(17) FIG. 2 shows a further embodiment of a device 11 according to the invention for compounding and applying adhesive, comprising a supply unit 12, a compounding unit 13 and an application unit 14. The supply unit 12 is again used to supply the base component 16 of the adhesive, it being possible for the base component 16 of the adhesive to already be provided in a liquid or fluid state, as stated above. The base component 16 of the adhesive can also be provided as a solid, granulate, powder or the like and can be poured into the supply unit 12. For this purpose, the supply unit 12 can optionally have a melting unit 15 which is used to melt the base component 16. The base component 16 is supplied from the supply unit 12 to the compounding unit 13, to which additives 17 can optionally also be supplied. Alternatively, the additives 17 can also be supplied to the supply unit 12, as shown in FIG. 2.

(18) The base component 16 and the additive/s 17 are then mixed in the compounding unit 13. For this purpose, a non-driven rotating mixer, a driven rotating mixer or a static non-rotating mixer can in turn be provided in the compounding unit 13, which mixer mixes the components 16, 17 to be mixed in the compounding unit 13. The mixed components 16, 17 of the adhesive are then guided from the compounding unit 13 into the application unit 14, by means of which the adhesive can be applied onto a substrate. For this purpose, the application unit 14 in turn has a means for applying the adhesive onto the substrate, for example an application roller 18.

(19) As shown in FIG. 2, in addition to the supply of the base component 16 of the adhesive, at least one additive is also supplied by means of the supply unit 12, meaning that the supply unit 12 is already supplied with the base component 16 and also the at least one additive 17 and forwards said component and additive onto the compounding unit 13, for example to mix the components.

(20) The supply of the base component 16 to the supply unit 12 and/or the compounding unit 13 preferably take places in a controlled, automated manner. Alternatively, the base component 16 can also be supplied manually. The additives 17 are advantageously supplied manually. Alternatively, said additives 17 can also be supplied in an automated manner.

(21) The compounding unit 13 in turn continuously mixes the base component 16 of the adhesive with the supplied additive/s 17 in order to form the compounded adhesive, and also continuously conveys the compounded adhesive.

(22) For this purpose, the compounding unit optionally and preferably has a pump (not shown) which conveys the base component or the mixed adhesive. If only the base component is conveyed by the pump, the mixed adhesive is also conveyed because the base component constitutes the main portion of the mixed adhesive.

(23) FIG. 3 shows a further embodiment of the device 21 according to the invention for compounding and applying adhesive. The device contains a supply unit 22, a compounding unit 23 and an application unit 24, which are all integrated in a housing 25 or in a vessel.

(24) The supply unit 22 is again used to supply the base component 26 of the adhesive, it being possible for the base component 26 of the adhesive to already be provided in a liquid or fluid state, as stated above. The base component 26 of the adhesive can also be alternatively provided as a solid, granulate, powder or the like and can be poured into the supply unit 22. For this purpose, the supply unit 22 can optionally have a melting unit (not shown in FIG. 3, however) which is used to melt the base component 26. The base component 26 and the at least one additive 27 are supplied from the supply unit 22 to the compounding unit 23. The base component 26 and the additive/s 27 are then mixed in the compounding unit 23.

(25) For this purpose, a non-driven rotating mixer, a driven rotating mixer or a static non-rotating mixer can in turn be provided in the compounding unit 23, which mixer mixes the components 26, 27 to be mixed in the compounding unit 23.

(26) The application roller 28 can also be used, albeit indirectly, as the mixer, which roller, on account of the rotation thereof in the compounding unit, brings about a flow that mixes the base component and the at least one additive.

(27) The mixed components 26, 27 of the adhesive are then discharged from the application unit 24 and applied to a substrate by means of the application roller 28.

(28) As shown in FIG. 3, in addition to the supply of the base component 26 of the adhesive, at least one additive is also supplied by means of the supply unit 22. The base component 26 is preferably supplied to the supply unit 22 manually, but this can alternatively also be performed in a controlled manner. The additives 27 are advantageously supplied manually. Alternatively, said additives 27 can also be supplied in an automated manner.

(29) FIGS. 4 to 6 show embodiments of compounding units that are designed so as to have different mixers.

(30) FIG. 4 shows a compounding unit 50 that has a housing 51 in which a volume 52 is designed as a mixing chamber. A pump 54 is provided in the upper region 53 of the housing 51 and conveys the base component and/or the additive/s into the mixing chamber 52 of the housing 51. For this purpose, the base component enters the mixing chamber 52 by means of a supply 55 having inlets 56 into the mixing chamber; see FIG. 5. The supply 55 distributes the base component in the mixing chamber 52 by means of the spiral channel guide. Three channels are formed for this purpose in the embodiment, which channels allow the base component to enter the mixing chamber at an angle of approximately 120°, each of the inlets 56 being arranged so as to be offset by 120°. The pump 54 can preferably be a gear pump.

(31) The pump 54 is used as a dosing unit for the dosed supply of the base component into the mixing space 52.

(32) A dosing unit 57 is further provided, which brings about the feed-in of at least one additive component. For this purpose, the dosing unit 57 can have a reservoir 58 and a valve 59, such that the feed-in can be performed by actuation of the valve 59. The pump 54 can be used for this purpose, in order to convey the additive into the mixing chamber 52. Alternatively, the dosing unit 57 can have its own pump or it can have an injector, by means of which the at least one additive can be dosed into the mixing chamber 52.

(33) The housing 51 can advantageously be heated, meaning that a melted base component and/or a melted additive can be further processed in a melted state.

(34) The compounding unit 50 has a mixing device 60 for mixing the base component and/or the at least one additive. For this purpose, a rotatable mixing element 61 is arranged in the mixing chamber 52, which element can be driven by a drive motor 62, by means of the shaft 63, in order to mix the base component and/or the at least one additive. Accordingly, the mixing element 61 is a dynamic mixing means which can be rotated in a controlled manner. In this case, the drive motor 62 is preferably an electric motor or a motor driven by other means. In addition to driving the mixing element 61, the motor 62 can also be used to drive the pump 54. A drive would thus be omitted, because one drive could be used simultaneously for two purposes. Alternatively or additionally, the drive motor 62 can also be provided in order to drive the pump for conveying the additives.

(35) The mixing chamber 52 preferably has an opening 65 in the bottom face 64 thereof, by means of which the mixed adhesive can be discharged from the compounding unit 50.

(36) FIGS. 6 and 7 show a further embodiment of a compounding unit 70 according to the invention which is designed so as to be substantially similar to the compounding unit 50 in FIGS. 4 and 5.

(37) In contrast to the example in FIGS. 4 and 5, the device 70 is provided with a non-driven mixing element 71 which, although rotatably mounted in the mixing chamber 52, is not designed to be driven by the drive 62. The shaft 63 does not drive the mixing element 71. However, on account of the flow of the adhesive in the mixing chamber, the mixing element 71 can rotate and thus mixes the adhesive that is composed of the base component and/or at least one additive.

(38) FIGS. 8 and 9 show a further embodiment of a compounding unit 90 that is designed so as to be substantially similar to the compounding unit 50 in FIGS. 4 and 5 and can likewise be used in the methods according to the invention.

(39) In contrast to the example in FIGS. 4 and 5, the device 90 is provided with a static mixer 91. The static mixer 91 is composed of a hollow cylinder 92 into which a coil 93 is placed in order to form a spiral flow path 94. The fluid base component and the additives flow along the flow passage and mix therein.

(40) The mixer 91 is therefore a static mixing means which is formed as a stationary mixing means in the mixing chamber or on a wall of the mixing chamber. For this purpose, the mixing chamber is altered so as to create a spiral flow passage that is formed by a hollow cylindrical chamber having a spiral flow passage formed therein.

LIST OF REFERENCE SIGNS

(41) 1 device 2 supply unit 3 compounding unit 4 application unit 5 melting unit 6 application roller 11 device 12 supply unit 13 compounding unit 14 application unit 15 melting unit 16 base component 17 additive 18 application roller 21 device 22 supply unit 23 compounding unit 24 application unit 25 housing 26 base component 27 additive 28 application roller 50 compounding unit 51 housing 52 volume, mixing chamber 53 upper region 54 pump 55 supply 56 entry 57 dosing unit 58 reservoir 59 valve 60 mixing device 61 mixing element 62 drive motor 63 shaft 64 bottom face 65 opening 70 compounding unit 71 mixing element 90 compounding unit 91 mixer 92 hollow cylinder 93 coil 94 flow path

EXAMPLES

Example 1

(42) Technomelt PUR 270/7 (Henkel AG & Co. KGaA, DE) was used as the adhesive base component, into which yellow, magenta and blue color pastes were stirred, each in an amount of 0.1, 0.5 or 1.0 wt. % based on the total weight of the adhesive. For this purpose, the adhesive base component was melted for 45 minutes in a convection oven at 140° C. 200 g thereof was transferred into a reactor (160° C.) and the color paste was added in and stirred for 10 minutes in a vacuum.

(43) On the basis of the adhesives compounded in this way, a visual inspection was carried out, the viscosity was determined (Brookfield, spindle 28, 150° C., 5 rpm) and a rheometer oscillatory test was carried out, from which the temperature of the crossover of the storage and loss modulus (tan δ=1) and the temperature at which the storage modulus G′ reaches the value of 10.sup.6 Pa are analyzed. The results are shown in Table 1.

(44) TABLE-US-00001 TABLE 1 Viscosity 0% color 0.1% color 0.5% color 1.0% color (Pas) paste paste paste paste Yellow 34 40 44 47 paste Magenta 34 40 43 46 paste Blue paste 34 40 42 46 T [° C.] when tan (δ) = 1.00 Yellow 49.3 50.4 52.4 53.3 paste Magenta 49.3 53.4 55.4 56.4 paste Blue paste 49.3 54.4 55.4 56.4 T [° C.] when G′ = 1,000,000 Pa Yellow 46.0 46.3 47.3 47.3 paste Magenta 46.0 48.4 49.0 49.4 paste Blue paste 46.3 49.4 49.4 50.4

Example 2

(45) Technomelt PUR 270/7 (Henkel AG & Co. KGaA, DE) was again used as the adhesive base component, into which black color pastes were stirred in amounts of 1, 2, 3 or 5 wt. % based on the total weight of the adhesive. For this purpose, the adhesive base component was melted for 45 minutes in a convection oven at 140° C. 200 g thereof was transferred into a reactor (160° C.) and the color paste was added in and stirred for 10 minutes in a vacuum.

(46) On the basis of the adhesives compounded in this way, the viscosity (Brookfield, spindle 28, 150° C., 5 rpm), the initial strength, the strength build-up and the viscosity stability and color stability at the application temperature were determined, and a rheometer oscillatory test was carried out, from which the temperature of the crossover of the storage and loss modulus (tan δ=1) and the temperature at which the storage modulus G′ reaches the value of 10.sup.6 Pa are analyzed. The results are shown in Table 2.

(47) TABLE-US-00002 TABLE 2 270-7 + 270-7 + 270-7 + 270-7 + 1% 2% 3% 5% black black black black 270-7 paste paste paste paste After 2 h EMod 42 40 43 48 41 [N/mm.sup.2] σ − max 2.2 1.9 2.2 2.7 3.1 [N/mm.sup.2] ε-fracture — 43 134 127 538 [%] After 2 days EMod 85 89 85 83 56 [N/mm.sup.2] σ − max 7.9 18.4 16.9 15.9 13.0 [N/mm.sup.2] ε-fracture 842 752 822 768 907 [%] After 7 days EMod 116 99 79 94 63 [N/mm.sup.2] σ − max 21.5 14.2 14.7 19.1 13.4 [N/mm.sup.2] ε-fracture 922 599 675 759 851 [%] Viscosity (Pas) After mixing 29 45 54 58 153 After 1 h 36 46.2 57.2 64.4 183 After 2 h 41.3 50.1 68.7 77.8 212 After 3 h 45.3 54.6 78.4 88.8 251

(48) TABLE-US-00003 TABLE 3 0% 0.1% 0.5% 1.0% 5.0% color color color color color paste paste paste paste paste Viscosity 29 45 54 58 153 (Pas) T [° C.] when 49.4 50.4 57.5 55.4 63.5 tan (δ) = 1.00 T [° C.] when 45.6 46.3 45.3 45.3 46.3 G′ = 1,000,000 Pa

Example 3

(49) An adhesive base component (Technomelt PUR 270/7 Henkel AG & Co. KGaA, DE) together with a color paste as described in examples 1 and 2 was applied to the straight edge of a chipboard (IKEA, 19.00 mm thick) by means of a HOMAG POWERLINE KRF 620 edge-banding machine having an application roller (Nordson MC Series) and a melting device (Nordson MC Series); an ABS edge band (Giplast Sincro, Sitech) having a thickness of 0.9 mm was then adhered to said chipboard. The conditions were as follows:

(50) Conditions A: temperatures: premelter: 130° C., tube: 130° C., head: 140° C.; roller: 144° C. Nordson premelter pump: 80 rpm pump of the mixing head for the additive: 3 rpm (rotations per minute) 80-100 boards can be produced in approximately 3 hours without difficulty no threading, no smearing, no adhesive joint very high initial adhesion

(51) Conditions B: temperatures: premelter: 130° C., tube: 140° C., head: 140° C. Nordson premelter pump: 80 rpm pump of the mixing head for the additive: 2.8 rpm 4 sample cartridges were filled

(52) Conditions C: temperatures: premelter: 130° C., tube: 140° C., head: 140° C. Nordson premelter pump: 80 rpm pump of the mixing head for the additive: 2.4 rpm 4 sample cartridges were filled

(53) Further reducing the power of the pump of the mixing head for the additive resulted in uncolored adhesive. It was observed that the colored adhesives could be processed just as effectively as the adhesive without an additive.