Thermal Insulation Material and Method for Its Production

Abstract

A thermal insulation material is made of a plurality of insulating components. The plurality of insulating components includes a first insulating component made of wood shavings. The plurality of insulating components includes a second insulating component made of cellulose fibers, wherein the cellulose fibers are arranged in voids formed between the wood shavings. The cellulose fibers of the second insulating component are produced from decor paper or sanitary paper.

Claims

1. A thermal insulation material comprising: a plurality of insulating components; wherein the plurality of insulating components includes a first insulating component comprising wood shavings; wherein the plurality of insulating components includes a second insulating component comprising cellulose fibers, wherein the cellulose fibers are arranged in voids formed between the wood shavings; wherein the cellulose fibers of the second insulating component are produced from a paper type selected from the group consisting of decor paper and sanitary paper.

2. The thermal insulation material according to claim 1, wherein the cellulose fibers of the second insulating component comprise a maximum fiber length of 12 mm.

3. The thermal insulation material according to claim 1, wherein the wood shavings of the first insulating component are comprised of wood of the willow family.

4. The thermal insulation material according to claim 3, wherein the wood of the willow family is selected from the group consisting of poplar, aspen, and birch.

5. The thermal insulation material according to claim 1, wherein a fiber length direction of wood of the wood shavings extends primarily in a longitudinal direction of the wood shavings.

6. The thermal insulation material according to claim 1, wherein the wood shavings are produced by chipping a log with a conical face milling cutter.

7. The thermal insulation material according to claim 1, wherein a mass proportion of each one of the plurality of insulating components amounts to 10% to 90%.

8. The thermal insulation material according to claim 1, wherein a mass proportion of the cellulose fibers from sanitary paper or from decor paper amounts to more than 10%.

9. The thermal insulation material according to claim 8, wherein the mass proportion of the cellulose fibers from sanitary paper or from decor paper amounts to 30% to 70%.

10. The thermal insulation material according to claim 9, wherein the mass proportion of the cellulose fibers from sanitary paper or from decor paper amounts to approximately 50%.

11. The thermal insulation material according to claim 1, wherein the plurality of insulating components includes a third insulating component.

12. The thermal insulation material according to claim 11, wherein the third insulating component comprises shavings of wood of coniferous trees; cellulose fibers from a paper type different from the paper type of the second insulating component; or cellulose fibers from natural fibers.

13. The thermal insulation material according to claim 1, wherein at least one of the plurality of insulating components is treated with a flame retardant.

14. The thermal insulation material according to claim 1, wherein all of the plurality of insulating components are treated with a flame retardant.

15. The thermal insulation material according to claim 1, wherein the thermal insulation material is a loose thermal insulation material and the plurality of insulating components are mixed loosely with each other.

16. The thermal insulation material according to claim 1, wherein the thermal insulation material is an insulation mat, and wherein the plurality of insulating components are bonded to each other by a binding agent.

17. The thermal insulation material according to claim 16, wherein the insulation mat comprises a density of 15 kg/m.sup.3 to 120 kg/m.sup.3.

18. The thermal insulation material according to claim 1, wherein the thermal insulation material is an insulation panel and the plurality of insulating components are bonded to each other by a binding agent.

19. The thermal insulation material according to claim 18, wherein the insulation panel comprises a density of not more than 500 kg/m.sup.3.

20. A method for producing a thermal insulation material comprising wood shavings and cellulose fibers, wherein the method comprises: producing the wood shavings by chipping wood in a moist state; and after chipping, mixing the wood shavings, comprising a residual moisture of at least 15%, with the cellulose fibers.

21. The method according to claim 20, comprising: chipping a log with a conical face milling cutter for producing the wood shavings, adjusting an adjusting angle of the conical face milling cutter for chipping to 2 to 45, and positioning an axis of rotation of the conical face milling cutter for chipping aslant at an inclination angle relative to a surface to be worked of the log, when viewed in a viewing direction of a longitudinal center axis of the log, wherein the inclination angle and the adjusting angle together amount to 90.

22. A panel comprising wood shavings that are bonded to each other by a binding agent, wherein the wood shavings are produced by chipping a log by a conical face milling cutter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Embodiments of the invention will be explained in the following with the aid of the drawing.

[0033] FIG. 1 is an illustration of the thermal insulation material according to the invention.

[0034] FIG. 2 is a schematic illustration of a method for producing advantageous wood shavings for the thermal insulation material.

[0035] FIG. 3 is a schematic plan view of the arrangement of FIG. 2 in the direction of arrow III in FIG. 2.

[0036] FIG. 4 is a schematic illustration of a further embodiment of the thermal insulation material according to the invention.

[0037] FIG. 5 is a schematic illustration of a panel.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0038] FIG. 1 shows thermal insulation material 1 which is present in loose form and, for example, is to be processed as bulk material or is to be blown into the cavities of buildings. In an alternative embodiment, the thermal insulation material 1 can also be an insulation mat, is described in regard to FIG. 4. The thermal insulation material 1 comprises wood shavings 2 and cellulose fibers 3 which are loosely mixed which with each other. The wood shavings 2 form voids in which the cellulose fibers 3 are arranged. The wood shavings 2 form thus a support structure for the cellulose fibers 3. In this way, the settling density of the thermal insulation material 1 is significantly reduced. The wood shavings 2 have a lower density than the cellulose fibers 3. The wood shavings 2 form a first component of the thermal insulation material 1 and the cellulose fibers 3 form a second component of the thermal insulation material 1.

[0039] The wood shavings 2 of the first component in the embodiment are made of wood from deciduous trees. The wood from deciduous trees is preferably wood of the willow family, in particular of poplar (populous), aspen (populus tremula) or birch (betula). In an alternative configuration, the wood shavings 2 can also be made from wood of coniferous trees. The cellulose fibers 3 of the second component are produced from decor paper or sanitary paper. The cellulose fibers 3 of the second component are advantageously comparatively short. In particular, cellulose fibers of sanitary paper have moreover a lower proportion of fillers such as in particular dust.

[0040] The cellulose fibers 3 comprise advantageously a maximal fiber length of 12 mm.

[0041] The wood shavings 2 are designed such that the fiber length direction of the wood extends primarily in the longitudinal direction of the wood shavings 2. The wood shavings intersect therefore only a few tree rings, in particular no tree rings, of the log. Therefore, the wood shavings have a high elasticity and flexibility and at the same time a reduced breaking tendency.

[0042] The manufacture of the wood shavings 2 is schematically illustrated in FIGS. 2 and 3. FIG. 2 shows schematically a log 4 with the longitudinal center axis 5. The log 4 comprises a surface 10 to be worked. For producing the wood shavings 2, a conical face milling cutter 6 is provided which engages the surface 10 to be worked and chips the log 4. The conical face milling cutter 6 is rotatably supported about an axis of rotation 7. The conical face milling cutter 6 comprises a conical surface 8 extending rotation-symmetrical about the axis of rotation 7. In the viewing direction parallel to the longitudinal center axis 5 shown in FIG. 2, the axis of rotation 7 of the conical face milling cutter 6 is slanted at an angle relative to the surface 10 to be worked of the log 4. The angle amounts advantageously to 45 to 88, in particular 60 to 80, and particularly preferred approximately 70. The conical face milling cutter 6 comprises an adjusting angle which corresponds to the inclination of a base surface 9 of the cone relative to the cone surface 8. The base surface 9 is in this context perpendicular to the axis of rotation 7 of the conical face milling cutter 6. The adjusting angle amounts advantageously to 2 to 45, in particular 10 to 30. It has been found to be particularly advantageous when the adjusting angle is approximately 20. The inclination angle and the adjusting angle together amount to 90. The cone angle which is measured between oppositely positioned regions of the cone surface 8 amounts advantageously to 90 to 176, in particular 120 to 160, and particularly preferred approximately 140. The width b of the log 4 in the region in which the wood shavings 2 are produced amounts advantageously to at least 5 mm.

[0043] FIG. 3 shows the arrangement of FIG. 2 in a plan view in a viewing direction parallel to the surface 10 to be worked and perpendicular to the longitudinal center axis 5 of the log 4. In this viewing direction, the axis of rotation 7 is positioned relative to the longitudinal center axis 5 at an angle which amounts to 45 to 135, in particular 75 to 105, and preferred approximately 90.

[0044] The wood shavings 2 have advantageously an average shaving thickness of approximately 0.1 mm to 5 mm. Wood shavings 2 produced by the conical face milling cutter 6 comprise advantageously an average shaving thickness which results from the tooth feed rate multiplied by sink wherein the tooth feed rate is the feeding rate divided by the number of cutting edges and the rotary speed of the conical face milling cutter 6. In this context, a cutting edge can be comprised of a plurality of cutting inserts. A cutting edge which continues across the center of the cone to the opposite side of the cone is regarded as one cutting edge.

[0045] In the embodiment, the cellulose fibers 3 are made from sanitary paper or decor paper. In an advantageous embodiment, the cellulose fibers 3 are treated with a flame retardant. In addition or alternatively, a treatment with other resistance-increasing agents, in particular with fungicides, can be provided.

[0046] When producing the thermal insulation material 1, the wood shavings 2 are advantageously produced by chipping moist wood, in particular wood fresh from the forest, and in particular by means of a conical face milling cutter 6. In this way, a very smooth surface and high elasticity of the wood shavings 2 result. After chipping, the wood shavings 2 are mixed in the moist state with the second component, i.e., the cellulose fibers 3, as well as with possible further components of the thermal insulation material 1. At the time of mixing, the wood shavings 2 comprise a residual moisture of at least 20%. It has been found that by mixing the cellulose fibers 3 with moist wood shavings 2, a simpler migration of the flame retardant from the cellulose fibers 3 to the wood shavings 2 is realized. In case of dry components, this migration is slower so that greater quantities of flame retardant must be added in order to achieve the desired fire resistance of the thermal insulation material 1 already shortly after mixing. By mixing the components in the moist state, the required quantity of flame retardant can be reduced without the duration until use of the thermal insulation material 1 being extended. The total moisture of the thermal insulation material when mixing the components amounts to at most 15%. The components are therefore not wet. In particular, the shavings of wood fresh from the forest are mixed without further drying or wetting steps with the dry cellulose fibers with addition of flame retardant diluted with water.

[0047] For an alternative advantageous composition of the thermal insulation material 1, it is provided that the thermal insulation material 1 comprises a third insulating component in addition to the wood shavings 2 and the cellulose fibers 3. Advantageously, the mass proportion of the wood shavings 2, of the cellulose fibers 3, and of the third insulating component amounts to 10% to 80% in each case. In particular, the mass proportions of the three components differ by less than 30%, in particular by less than 20%, from each other.

[0048] The third component can advantageously be formed by cellulose fibers wherein the cellulose fibers of the third component are produced from another raw material than the cellulose fibers of the second component. For example, the second component can be formed by cellulose fibers of another type of paper. It is particularly advantageous when the cellulose fibers of the second component are from sanitary paper and the cellulose fibers of the third component from decor paper. A thermal insulation material of the wood shavings, cellulose fibers from decor paper, and cellulose fibers from sanitary paper is provided with particularly advantageous properties when the thermal insulation material has a mass proportion of approximately 40% to 60%, in particular of approximately 50%, of wood shavings and a mass proportion of approximately 40% to 60% of cellulose fibers from sanitary paper and decor paper. Preferably, the mass proportion of the cellulose fibers from sanitary paper and the mass proportion of cellulose fibers from decor paper amount in particular to approximately 20% to 30%, in particular approximately 25%. Other proportions of cellulose fibers from sanitary paper and cellulose fibers from decor paper can also be advantageous however.

[0049] It can however also be provided that the cellulose fibers of the third component are produced, for example, from recycled paper. The third component in an alternative embodiment can be comprised, for example, of cellulose fibers from natural fibers such as wood, jute, hemp, flax or miscanthus. An advantageous composition of a thermal insulation material comprises a mass proportion of approximately 30% to 70%, preferably approximately 30% to 60%, of shavings. The thermal insulation material comprises in addition cellulose fibers from wood and cellulose fibers from paper, at least partially from decor and/or sanitary paper, in arbitrary mass proportions. In an alternative embodiment, a component of the thermal insulation material can be formed by feathers.

[0050] It can also be provided that the third component is formed by natural fibers themselves, i.e., not of cellulose fibers from the natural fibers. In this way, the density of the thermal insulation material 1 relative to the density of the cellulose fibers is reduced. The third component can also be formed by shavings of another type of wood than the wood shavings of the second component. For example, the wood shavings of the second component can be made from a willow family member and the wood shavings of the third component from wood of coniferous trees. The wood shavings of a willow family member have a particularly low settling-safe density. The shavings of wood from coniferous trees have a characteristic wood odor. By use of shavings of different types of wood, a thermal insulation material with particularly advantageous properties can be provided. An advantageous composition comprises a mass proportions of approximately 40% to 45% of shavings of wood of deciduous trees, in particular from the willow family, preferably from poplar, a mass proportion of less than 10%, in particular of 5% to 10%, of shavings of wood of coniferous trees, and cellulose fibers from sanitary or decor paper as well as further components in arbitrary composition. Already by a comparatively minimal proportion of shavings of wood of coniferous trees, a thermal insulation material with characteristic wood odor can be produced. It can also be provided that all shavings of the thermal insulation material are produced from wood of coniferous trees.

[0051] In a further advantageous embodiment, the thermal insulation material comprises at least one further fourth component in addition to the first, the second, and the third components. Additional components may be advantageous also.

[0052] The thermal conductivity of the loose thermal insulation material 1 amounts advantageously to less than 0.040 W/(m*K), in particular 0.036 W/(m*K) to 0.040 W/(m*K).

[0053] In a further alternative configuration, the thermal insulation material 1 is in a bonded form, as is illustrated schematically in FIG. 4. The components of the thermal insulation material 1 are advantageously bonded to each other by a binding agent, in particular by an adhesive or hot melt fibers such as, for example, bi-component fibers. The binding agent advantageously produces a flexible connection between the components of the thermal insulation material 1.

[0054] The thermal insulation material 1 illustrated in FIG. 4 is in particular an insulation mat. The insulation mat comprises advantageously a comparatively minimal density. The density of the insulation mat amounts to in particular 15 kg/m.sup.3 to 120 kg/m.sup.3, preferably 30 kg/m.sup.3 up to 60 kg/m.sup.3. The components and the composition of the components of the insulation mat correspond to the compositions described in regard to the loose thermal insulation materials 1 wherein the insulation mat additionally contains the binding agent. The insulation mat is advantageously flexible and comprises a plurality of voids between the components. The voids are not filled with the binding agent. The thermal conductivity of the thermal insulation material 1 embodied as an insulation mat amounts advantageously to less than 0.040 W/(m*K), in particular 0.036 W/(m*K) to 0.040 W/(m*K).

[0055] In an alternative embodiment, the thermal insulation material 1 illustrated in FIG. 4 is embodied as an insulation panel. The insulation panel comprises in this context a comparatively minimal density. The density of the insulation panel amounts advantageously to not more than 500 kg/m.sup.3, in particular not more than 400 kg/m.sup.3. The insulation panel is advantageously shape-stable and compact and comprises only very few or only negligibly small air-filled voids.

[0056] Preferably, the mass proportion of each insulating component of the thermal insulation material amounts to 10% to 90%. In case of a thermal insulation material 1 of at least three insulating components, the mass proportion of each of the insulating components advantageously amounts to 10% to 80% and for a thermal insulation material of four components advantageously 10% to 70%. Preferably, the mass proportion of each insulating component amounts to at least 10%, in particular at least 20%. Mass proportions which differ from each other by at most 30%, in particular at most 20%, are considered similar mass proportions. In case of a thermal insulation material 1 of two components, the mass proportion of each component amounts advantageously to 35% to 65%, in particular 40% to 60%. In case of a thermal insulation material 1 of three components, the mass proportion of each component amounts advantageously to 20% to 50%, in particular 25% to 45%. Advantageously, no component has a mass proportion of more than 90%.

[0057] The mass proportion of the cellulose fibers 3 from sanitary paper or decor paper amounts advantageously to more than 10%, in particular 30% to 70%, preferably approximately 50%. Particularly advantageously, the thermal insulation material comprises a mass proportion of 40% to 60%, in particular of approximately 50%, of shavings, independent of the further components of the thermal insulation material.

[0058] FIG. 5 shows an embodiment variant of a panel 11 comprising wood shavings 2. The wood shavings 2 are bonded to each other by a binding agent. The binding agent can be, for example, an adhesive, in particular resins, or hot melt fibers such as, for example, bi-component fibers. As binding agents, conventional binding agents used for OSB panels can be provided. The binding agent provides advantageously a fixed connection between the components of the thermal insulation material 1.

[0059] In an advantageous embodiment variant, the panel 11 comprises no cellulose fibers 3. In an alternative variant, it is provided that the panel 11 comprises cellulose fibers 3, in particular cellulose fibers 3 from sanitary paper or decor paper. The panel 11 can be designed as a thermal insulation panel. The wood shavings 2 are produced by means of a conical face milling cutter 6 (FIGS. 2 and 3). In this way, the wood shavings 2 are very elastic and flexible.

[0060] The fiber length direction of the wood extends primarily in longitudinal direction of the wood shavings 2. The density of the panel 11 amounts advantageously to not more than 500 kg/m.sup.3, in particular not more than 400 kg/m.sup.3. The thermal conductivity of the panel 11 is advantageously less than the thermal conductivity of OSB panels. The panel 11 is advantageously shape-stable and compact and comprises only very few or negligibly small air-filled voids.

[0061] The wood shavings 2 of the panel 11 are in particular made of wood of deciduous trees, preferably of wood of the willow family, in particular wood of poplar (populus), aspen (populus tremula), or birch (betula). The wood shavings 2 of the panel 11 can however be produced also partially or exclusively from wood of coniferous trees. Advantageously, the wood shavings 2 of the panel 11 are produced by chipping moist wood fresh from the forest. The wood shavings 2 of the panel 11 are advantageously produced as described above in connection with the wood shavings 2 of the thermal insulation material 1. The wood shavings 2 are in particular produced by a conical face milling method, as described above.

[0062] The specification incorporates by reference the entire disclosure of European priority document 18 166 567.0 having a filing date of Apr. 10, 2018.

[0063] While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.