Three-dimensional striped structure
A three-dimensional striped structure is provided which is formed by bonding continuous filaments in random in loops, has a longitudinal direction corresponding to an extruding direction, a lateral direction and a thickness direction perpendicular to the extruding direction, and is comprised of a polyethylene thermoplastic resin, a polyester thermoplastic elastomer or a mixture of a polyethylene thermoplastic resin and a polyethylene thermoplastic elastomer. The three dimensional striped structure has an impact resilience of not lower than 13 cm, a hysteresis loss of not higher than 34% and not lower than 13%, and a thermal expansion rate of 0 to 8% in the longitudinal direction before and after a hot-air drying test, and does not shrink during high-temperature sterilization.
1. A three-dimensional striped structure that is formed by bonding continuous filaments partly at random in loops,
the three-dimensional striped structure has a longitudinal direction corresponding to an extrusion direction, a lateral direction and a thickness direction perpendicular to the extrusion direction and is comprised of a polyethylene thermoplastic resin, a polyester thermoplastic elastomer or a mixture of a polyethylene thermoplastic resin and a polyethylene thermoplastic elastomer, wherein
the three-dimensional striped structure has an impact resilience of not lower than 13 cm, a hysteresis loss of not higher than 34% and not lower than 13%, and a thermal expansion rate of 0 to 8% in the longitudinal direction before and after a hot-air drying test that is performed at a temperature of 90° C. for 30 minutes with regard to the polyethylene thermoplastic resin, that is performed at a temperature of 130° C. for 30 minutes with regard to the polyester thermoplastic elastomer and that is performed at a temperature of 90° C. for 30 minutes with regard to the mixture of the polyethylene thermoplastic resin and the polyethylene thermoplastic elastomer.
2. The three-dimensional striped structure according to claim 1 , wherein the three-dimensional striped structure has a thermal expansion rate of 0 to 8% in the lateral direction before and after the hot-air drying test that is performed at the temperature of 90° C. for 30 minutes with regard to the polyethylene thermoplastic resin, that is performed at the temperature of 130° C. for 30 minutes with regard to the polyester thermoplastic elastomer and that is performed at the temperature of 90° C. for 30 minutes with regard to the mixture of the polyethylene thermoplastic resin and the polyethylene thermoplastic elastomer.
3. The three-dimensional striped structure according to claim 1 , wherein the three-dimensional striped structure has an anisotropic thermal expansion characteristic providing different thermal expansion rates in the longitudinal direction and in the lateral direction.
4. The three-dimensional striped structure according to claim 1 , wherein the three-dimensional striped structure has an impact resilience change rate of not higher than 25% with regard to the polyethylene thermoplastic resin after a repeated load test, and not higher than 20% with regard to the polyester thermoplastic elastomer after a repeated load test.
5. The three-dimensional striped structure according to claim 1 , wherein the three-dimensional striped structure has an apparent density of 0.025 g/cm 3 to 0.2 g/cm 3 , a thickness of 5 mm to 500 mm in each layer and a filament diameter of 0.1 mm to 1.5 mm.
6. The three-dimensional striped structure according to claim 1 , wherein the polyethylene thermoplastic resin is selected from polyethylene or an ethylene/α-olefin copolymer resin that is mainly made of ethylene and an α-olefin containing 3 or more carbon atoms.
7. The three-dimensional striped structure according to claim 1 , wherein
the mixture of the polyethylene thermoplastic resin and the polyethylene thermoplastic elastomer is a mixture of an ethylene/α-olefin copolymer resin, which is mainly made of ethylene and an α-olefin containing 3 or more carbon atoms, and the polyethylene thermoplastic elastomer; and
a content of the polyethylene thermoplastic elastomer in the mixture is not higher than 45% in weight ratio.
8. The three-dimensional striped structure according to claim 1 , wherein the three-dimensional striped structure is used for cushions, cushion seats, Japanese floor cushions, pillows, nursing care products, or cushions or mattress for beds.
9. The three-dimensional striped structure according to claim 1 , wherein the three-dimensional striped structure has a plurality of surfaces, among which two surfaces, three surfaces or four surfaces are molded or a curved surface is molded.
10. The three-dimensional striped structure according to claim 1 , wherein the three-dimensional striped structure has a multi-layer structure of a three-dimensional net-like structure made of polyethylene thermoplastic resin and a three-dimensional net-like structure made of polyethylene thermoplastic elastomer.
11. The three-dimensional striped structure according to claim 10 , wherein the three-dimensional net-like structure has stripe sparse and dense portions arranged alternately in an extruding direction, the ratio of the number of bonding points of the dense portion to that of the sparse portion per unit weight is 0.96 to 1.33, and the apparent density of the dense portion is larger than the apparent density of the sparse portion by not less than 0.005 g/cm 3 .