Stretchable multiple component nonwoven fabrics and methods for preparing
View Patent ↗A method for preparing stretchable bonded nonwoven fabrics which involves forming a substantially nonbonded nonwoven web of multiple-component continuous filaments or staple fibers which are capable of developing three-dimensional spiral crimp, activating the spiral crimp by heating substantially nonbonded web under free shrinkage conditions during which the nonwoven remains substantially nonbonded, followed by bonding the crimped nonwoven web using an array of discrete mechanical, chemical, or thermal bonds. Nonwoven fabrics prepared according to the method of the current invention have an improved combination of stretch-recovery properties, textile hand and drape compared to multiple-component nonwoven fabrics known in the art.
1. A nonwoven fabric comprising multiple-component fibers with three-dimensional spiral crimp after heating having no greater than about 5% permanent set wherein when bonded after heating the highest level of stretch of the fabric is at least 12% and wherein the bonds are spaced at about 4 to 8 bonds per cm and have a density of about 16 to 62 per cm 2 ; wherein the multiple component fibers comprise bicomponent fibers including two distinct polymers selected from the group consisting of poly(ethylene terephthalate), poly (cyclohexyl 1,4-dimethylene terephthalate), copolymers of poly(ethylene terephthalate) and poly (cyclohexyl 1,4-dimethylene terephthalate), copolymers of ethylene terephthalate and the sodium salt of ethylene sulfoisophthalate; poly(trimethylene terephthalate), poly(tetramethylene terephthalate), poly(trimethylene dinaphthalate), poly(trimethylene bibenzoate), and copolymers poly(trimethylene terephthalate), poly(tetramethylene terephthalate), poly(trimethylene dinaphthalate), and poly(trimethylene bibenzoate) with ethylene sodium sulfoisophthalate, crystalline polypropylene, high density polyethylene, ethylene-vinyl acetate copolymers, nylon 66, and nylon 6;
said bicomponent fibers having an arrangement selected from eccentric sheath-core and side-by side.
2. The nonwoven fabric of claim 1 , wherein the highest level of stretch of the fabric is at least 20%.
3. The nonwoven fabric of claim 1 , comprising least 30 weight percent of multiple-component fibers.
4. The nonwoven fabric of claim 3 , comprising least 40 weight percent of multiple-component fibers.
5. The nonwoven fabric of claim 1 , wherein the multiple-component fibers comprise bicomponent fibers of poly(ethylene terephthalate) and poly(trimethylene terephthalate).
6. The nonwoven fabric of claim 1 , comprising a blend of multiple-component fibers with fibers that are not three dimensionally spirally crimped selected from the group consisting of cotton, wool, and silk and synthetic fibers including polyamide, polyester, polyacrylonitrile, polyethylene, polypropylene, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, and polyurethane.
7. The nonwoven fabric of claim 1 , wherein available stretch in the machine direction and cross direction are at least 10% and the fabric growth is no greater than 20% of the available stretch.
8. A nonwoven fabric comprising multiple-component fibers with three-dimensional spiral crimp after heating having no greater than about 5% permanent set wherein when bonded after heating the highest level of stretch of the fabric is at least 12% and wherein the bonds are spaced at about 4 to 8 bonds per cm and have a density of about 16 to 62 per cm 2 ; wherein the multiple component fibers comprise bicomponent fibers including two distinct polymers selected from the group consisting of poly(ethylene terephthalate), poly(trimethylene terephthalate), poly(tetramethylene terephthalate),
said bicomponent fibers having an arrangement selected from eccentric sheath-core and side-by side.