LIGHTWEIGHT CARPET PRODUCTS AND METHOD OF MANUFACTURE THEREOF
A lightweight carpet product includes a greige carpet having a primary backing and tufted fibers, a secondary backing including a nonwoven textile of synthetic fibers, and a thermoplastic adhesive composition adhered to the greige carpet and the secondary backing. The thermoplastic adhesive composition includes a modified polyethylene terephthalate (PET) having a crystallinity less than unmodified PET and a melting point from about 90° C. to about 150° C., and a particulate filler. Methods of manufacture include using a thermoplastic adhesive composition to adhere a greige carpet to a secondary backing to form a lightweight carpet product.
1 . A carpet product comprising:
a greige carpet which comprises a primary backing and tufted fibers;
a secondary backing which comprises a nonwoven textile of synthetic fibers; and
a thermoplastic adhesive composition adhered to the greige carpet and the secondary backing, the thermoplastic adhesive composition comprising:
a modified polyethylene terephthalate (PET) having a crystallinity less than unmodified PET and a melting point from about 90° C. to about 150° C.; and
a particulate filler.
2 . The carpet product of claim 1 , wherein the carpet product has a basis weight of less than 60 ounces per square yard.
3 . The carpet product of claim 1 , wherein the carpet product has a basis weight from about 50 ounces per square yard to about 60 ounces per square yard.
4 . The carpet product of claim 1 , wherein the thermoplastic adhesive composition has a viscosity from about 5,000 centipoise at 325° F. to about 10,000 centipoise at 325° F.
5 . The carpet product of claim 4 , wherein the thermoplastic adhesive composition has a viscosity from about 6,000 centipoise at 325° F. to about 8,500 centipoise at 325° F.
6 . The carpet product of claim 1 , wherein the modified PET has a melting point from about 100° C. to about 115° C.
7 . The carpet product of claim 1 , wherein the particulate filler is present in an amount less than 43 percent by weight of the thermoplastic adhesive composition.
8 . The carpet product of claim 7 , wherein the particulate filler has a specific heat from about 0.15 kcal/kg° C. to about 0.25 kcal/kg° C.
9 . The carpet product of claim 1 , wherein the particulate filler is present in an amount from about 37 to about 41 percent by weight of the thermoplastic adhesive composition.
10 . The carpet product of claim 1 , wherein the particulate filler comprises glass, ceramic, barite, calcium carbonate, magnetite, stone, or a combination thereof.
11 . The carpet product of claim 1 , wherein the particulate filler has a particle size smaller than 60 mesh.
12 . The carpet product of claim 1 , wherein the particulate filler has a particle size from about 80 mesh to about 60 mesh.
13 . The carpet product of claim 1 , wherein the synthetic fibers comprise polyester fibers.
14 . The carpet product of claim 13 , wherein the secondary backing comprises a spunlaid nonwoven textile of polyester fibers.
15 . The carpet product of claim 1 , wherein the secondary backing has a basis weight of less than 6 ounces per square yard.
16 . The carpet product of claim 1 , wherein the secondary backing has a basis weight from about 2.5 ounces per square yard to about 6 ounces per square yard.
17 . The carpet product of claim 1 , wherein the secondary backing has a porosity such that the thermoplastic adhesive composition will not substantially penetrate through the secondary backing.
18 . The carpet product of claim 1 , wherein the carpet product is a carpet tile.
19 . A carpet tile comprising:
a greige carpet which comprises a primary backing and tufted fibers;
a secondary backing which comprises a spunlaid nonwoven textile of polyester fibers; and
a thermoplastic adhesive composition adhered to the greige carpet and the secondary backing, the thermoplastic adhesive composition comprising:
a modified polyethylene terephthalate (PET) having a crystallinity less than unmodified PET and a melting point from about 90° C. to about 150° C.; and
a glass particulate filler in an amount from about 37 to about 41 percent by weight of the thermoplastic adhesive composition,
wherein the carpet tile has a basis weight from about 50 ounces per square yard to about 60 ounces per square yard.
20 . A method of making a carpet product comprising:
providing a thermoplastic adhesive composition which comprises:
modified PET having a crystallinity less than unmodified PET and a melting point from about 90° C. to about 150° C.; and
a particulate filler;
providing a greige carpet which comprises a primary backing and tufted fibers;
providing a secondary backing which comprises a nonwoven textile of synthetic fibers; and
using the thermoplastic adhesive composition to adhere the greige carpet to the secondary backing to form a carpet product.
21 . The method of claim 20 , wherein the thermoplastic adhesive composition is dispersed onto a surface of the secondary backing to form an adhesive-loaded secondary backing and then the greige carpet is brought into contact with the adhesive-loaded secondary backing to adhere the greige carpet to the secondary backing.
22 . The method of claim 21 , further comprising applying a nip pressure to the carpet product with a press roll.
23 . The method of claim 22 , wherein a gap between the carpet product and the press roll is from about 185 mm to about 285 mm.
24 . The method of claim 20 , wherein the greige carpet is adhered to the secondary backing by a process which comprises:
dispersing the thermoplastic adhesive composition on a surface of the secondary backing to form an adhesive-loaded secondary backing;
passing the adhesive-loaded secondary backing under a heated doctor bar; and then contacting the greige carpet with the adhesive-loaded secondary backing to form the carpet product.
25 . The method of claim 20 , further comprising cutting the carpet product to form a plurality of carpet tiles.
26 . The method of claim 20 , wherein the carpet product has a basis weight of less than 60 ounces per square yard.
27 . The method of claim 20 , wherein the carpet product has a basis weight from about 50 ounces per square yard to about 60 ounces per square yard.
28 . The method of claim 20 , wherein the particulate filler is present in an amount from about 37 to about 41 percent by weight of the thermoplastic adhesive composition.
29 . The method of claim 20 , wherein the secondary backing comprises a spunlaid nonwoven textile of polyester fibers.
30 . The method of claim 20 , wherein the secondary backing has a basis weight from about 2.5 ounces per square yard to about 6 ounces per square yard and has a porosity such that the thermoplastic adhesive composition will not substantially penetrate the secondary backing.
31 . A method of making a thermoplastic adhesive composition comprising:
transesterifying raw PET with a monomer mix to produce modified PET and non-modified PET reaction products; and
removing at least a portion of the non-modified PET reaction products to produce a modified PET composition,
wherein the modified PET composition has a crystallinity less than unmodified PET and a melting point from about 90° C. to about 150° C.
32 . The method of claim 31 , wherein the transesterifying is performed at a temperature from about 200° C. to about 270° C.
33 . The method of claim 31 , wherein the portion of the non-modified PET reaction products removed is effective to give the modified PET composition a viscosity from about 11.5 poise to about 12 poise.
34 . The method of claim 31 , wherein the non-modified PET reaction products are removed under vacuum.
35 . The method of claim 31 , wherein the monomer mix comprises a glycol.