ACOUSTIC PLASTERBOARD

Abstract

A plaster-based board includes a core made of plaster positioned between two coating layers, in which a textile including fibers of a thermoplastic polymer constitutes at least one of the coating layers and/or the textile is embedded in the plaster constituting the core.

Claims

1. A plaster-based board comprising a core made of plaster positioned between two coating layers, and a textile including thermoplastic polymer fibers, said textile constituting one of the coating layers or the two coating layers and/or being embedded in the core made of plaster.

2. The board as claimed in claim 1, wherein the textile is a nonwoven or a fabric.

3. The board as claimed in claim 1, wherein the textile includes at least 70% by weight of fibers composed of at least one thermoplastic polymer.

4. The board as claimed in claim 1, wherein the thermoplastic polymer is chosen from polyolefins, polyamides, homopolymers and copolymers of acrylonitrile, polyimides, polyesters, poly(lactic acid)s, polyhydroxyalkanoates, vinyl polymers, copolymers of ethylene and of a vinyl compound, (meth)acrylic acid polymers, alkyl (meth)acrylate polymers, polycaprolactones, polystyrenes, polymers of styrene and of an anhydride, copolymers of an olefin and of a fluorinated monomer, polycarbonates, polyketones, polyetherketones, polyethersulfones, polyimides and linear polyurethanes.

5. The board as claimed in claim 4, wherein the thermoplastic polymer is chosen from polypropylene, (meth)acrylic acid or (meth)acrylate polymers, poly(lactic acid)s, polyhydroxyalkanoates, PET, PBT and polyethylene naphthalate.

6. The board as claimed in claim 5, wherein the thermoplastic polymer is polypropylene, a (meth)acrylic acid or (meth)acrylate polymer or PET.

7. The board as claimed in claim 1, wherein the textile includes a mixture of at least two different thermoplastic polymer fibers.

8. The board as claimed in claim 16, wherein the amount of polypropylene fibers represents from 10 to 90% of the total weight of the thermoplastic polymer fibers.

9. The board as claimed in claim 1, wherein the fibers exhibit a linear density which varies from 1 to 25 dtex.

10. The board as claimed in claim 1, wherein the fibers are cut and that their length varies from 0.5 to 15 cm.

11. The board as claimed in claim 1, wherein the thermoplastic polymer fibers have a simple or multilobal section.

12. The board as claimed in claim 1, wherein the textile includes up to 30% by weight of fibers based on a nonthermoplastic polymer or glass fibers.

13. The board as claimed in claim 12, wherein the textile is consolidated by an aqueous binder which contains at least one polymer chosen from copolymers of an olefin and of vinyl acetate, copolymers of vinyl acetate and of (meth)acrylic acid or of acrylate, copolymers of (meth)acrylate and of a monomer other than vinyl acetate, homopolymers of (meth)acrylic acid or of acrylate, terpolymers of vinyl acetate, of an olefin and of a vinyl ester monomer, and acrylonitrile polymers.

14. The board as claimed in claim 1, wherein the textile exhibits a weight per unit area which varies from 50 to 800 g/m.sup.2.

15. The board as claimed in claim 1, wherein the board has a thickness which varies from 6 to 25 millimeters.

16. The board as claimed in claim 7, wherein the textile includes a mixture of polypropylene fibers and of (meth)acrylic acid or (meth)acrylate polymer fibers or of polypropylene fibers and of PET fibers.

17. The board as claimed in claim 8, wherein the amount of polypropylene fibers is at least equal to 50% of the total weight of the thermoplastic polymer fibers.

18. The board as claimed in claim 17, wherein the amount of polypropylene fibers is at least equal to 70% of the total weight of the thermoplastic polymer fibers.

19. The board as claimed in claim 9, wherein the linear density varies from 5 to 12 dtex.

20. The board as claimed in claim 10, wherein the length of the fibers varies from 2 to 8 cm.

21. The board as claimed in claim 14, wherein the textile exhibits a weight per unit area which varies from 80 to 300 g/m.sup.2.

22. The board as claimed in claim 15, wherein the board has a thickness that is of the order of 12.5 millimeters.

Description

EXAMPLES 1 TO 7

[0055] Plaster-based boards comprising one or two textiles in accordance with the invention are manufactured under the following conditions:

[0056] a) a plaster composition is prepared by introducing 1000 g of calcium sulfate hemihydrate, 5 g of starch, 0.1 g of a setting accelerator (gypsum treated with sucrose), 0.05 g of a setting retarder (Plast Retard L, sold by SICIT 2000) and 750 g of water into a mixer provided with a three-bladed stirrer at the speed of 650 rpm for 15 seconds and then 1850 rpm for 45 seconds.

[0057] b) a foam is prepared by introducing 138.5 g of water and 1.4 g of foaming agent (Milifoam, sold by Huntsman) into a mixer provided with a three-bladed stirrer at the speed of 3300 rpm for 1 minute.

[0058] c) the plaster composition obtained in stage a) and 30 g of foam obtained in stage b) are introduced into a mixer provided with a planetary paddle operating at the speed of 250 rpm for 50 seconds, in order to obtain a paste.

[0059] d) the paste is poured into a brass mold comprising 4 parallelepipedal cavities (length: 300 mm; width: 30 mm; depth: 13 mm), the internal walls of which are coated with a layer of oil and the bottom of which is coated with a sheet of cardboard or of the textile according to the invention.

[0060] When a textile in accordance with the invention is incorporated in the paste, the paste is first poured into the mold over a thickness of 6 mm, then the textile, cut to the size of the mold, is deposited and the mold is filled with the paste.

[0061] A sheet of cardboard or a textile, having the size of the mold, is deposited over the paste and the mold is closed with a board on which two weights each of 5 kg are placed.

[0062] The boards are removed from the mold after 20 minutes, left in the open air for 10 minutes, then placed in a first drying oven at 180 C. for 35 minutes and in a second drying oven at 100 C. for 25 minutes. The boards are stored in a dry chamber at 40 C.

[0063] Example 1 comprises, on one face of the board, a nonwoven composed of polypropylene fibers (80% by weight) and of poly(acrylic acid) fibers (20% by weight) with a weight per unit area equal to 100 g/m.sup.2 (sold under the reference Fibertex F-80 Extra by Fibertex Nonwoven) and, on the other face, a sheet of cardboard (V5, sold by Saint-Rgis).

[0064] Example 2 comprises a nonwoven (Fibertex F-80 Extra, sold by Fibertex Nonwoven) on each face of the board.

[0065] Example 3 comprises, on one face of the board, a nonwoven consisting of multilobal PET fibers (sold under the reference 4DG by Fiber Innovation Technology) with a weight per unit area equal to 50 g/m.sup.2 and, on the other face, a sheet of cardboard (V5, sold by Saint-Rgis).

[0066] Example 4 comprises, on one face of the board, a nonwoven consisting of multilobal PET fibers (sold under the reference 4DG by Fiber Innovation Technology) with a weight per unit area equal to 150 g/m.sup.2 and, on the other face, a sheet of cardboard (V5, sold by Saint-Rgis).

[0067] Example 5 comprises a nonwoven composed of polypropylene fibers (80% by weight) and of PET fibers (20% by weight) with a weight per unit area equal to 100 g/m.sup.2 (sold by Fibertex Nonwoven) in the core made of plaster and a sheet of cardboard (V5, sold by Saint-Rgis) on each face of the board.

[0068] Example 6 comprises a nonwoven composed of polypropylene fibers (80% by weight) and of PET fibers (20% by weight) and including from 4 to 6% by weight of carbon black with a weight per unit area equal to 100 g/m.sup.2 (sold by Fibertex Nonwoven) in the core made of plaster and a sheet of cardboard (V5, sold by Saint-Rgis) on each face of the board.

[0069] By way of comparison, a board comprising two sheets of cardboard (V5, sold by Saint-Rgis) and not including any textile in accordance with the invention in the core made of plaster was prepared under the same conditions (comparative example 7).

[0070] The acoustic performance levels of the boards are evaluated by measuring their mechanical impedance MIM (Measurement of Mechanical Impedance) under the conditions of the standard ISO 16940:2008(E). The dynamic Young's modulus (in GN/m.sup.2) and the loss factor (in %) are calculated from the curve of the acceleration frequency (dB) as a function of the frequency (Hz). The acoustic gain with respect to the board of (comparative) example 7 is also calculated.

[0071] The results are given in table 1.

TABLE-US-00001 TABLE 1 Ex. 7 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6 (comp.) Weight per unit 9.30 9.00 10.00 9.80 9.40 9.13 9.11 area (kg/m.sup.2) Dynamic Young's 2.95 2.61 3.17 2.01 0.90 2.11 3.58 modulus (GN/m.sup.2) Loss factor (%) 0.75 1.01 0.88 3.72 7.59 4.70 0.30 Acoustic gain (%) 17.60 27.09 11.45 43.85 74.86 48.60