Biodegradable formable filament nonwoven fabric and method of producing the same
AssigneeUnitika Ltd.
InventorsKoichi Nagaoka, Fumio Matsuoka, Naoji Ichise
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Abstract
A formable biodegradable filament nonwoven fabric and a production method therefor are provided. A biodegradable polymer comprising a thermoplastic aliphatic polyester as its principal component is melted and extruded through a spinneret into filaments. While being quenched with quench air blow, the extruded filaments are drafted at a drafting speed of 1,000 to 2,500 m/min by means of a suction device disposed below the spinneret. The drafted filaments are spread and accumulated on a movable collector surface thereby to be formed into a web, which is then treated for formation of a nonwoven fabric. The constituent filaments of the nonwoven fabric has a polymer supercool index of 0.3 to 0.6.
Claims12
A thermoformable nonwoven fabric composed of filaments of a biodegradable polymer, wherein
- the biodegradable polymer is a copolymer of D-lactic acid and L-lactic acid in which the copolymerization molar ratio of either one of D-lactic acid in which the copolymerization molar ratio of either one of D-lactic acid and L-lactic acid is 90% or more and that of the other is 10% or less,
- the nonwoven fabric is a spun bonded nonwoven fabric in which the filaments are bonded to each other only in spot fusion-bonded areas partially formed in the nonwoven fabric,
- the filaments have a polymer supercool index of 0.3 to 0.6,
- the filaments have a birefringence of 3×10−3 to 15×10−3,
- the filaments have a polymer crystalline size of 15 to 20 angstroms as measured axially thereof, and
- the nonwoven fabric has a boiling water shrinkage percentage of 10 to 40%.
A thermoformable nonwoven fabric composed of filaments of a biodegradable polymer, wherein
- the biodegradable polymer is a copolymer of D-lactic acid and L-lactic acid in which the copolymerization molar ration of either one of D-lactic acid and L-lactic acid is 90% or more and that of the other is 10% or less,
- the nonwoven fabric is a spun bonded nonwoven fabric and has temporary fusion-bonded spots preliminarily formed in parts of a web of the filaments in which the filaments are partially de-bonded through a three-dimensional entanglement process, and non-fusion areas in which the filaments are three-dimensionally entangled with each other for integration of the filaments,
- the filaments have a polymer supercool index of 0.3 to 0.6,
- the filaments have a birefringence of 3×10−3 to 15×10−3,
- the filaments have a polymer crystalline size of 15 to 20 angstroms as measured axially thereof, and
- the nonwoven fabric has a boiling water shrinkage percentage of 10 to 40%.
A thermoformable nonwoven fabric composed of filaments of a biodegradable polymer, wherein
- the biodegradable polymer is a copolymer of D-lactic acid and L-lactic acid in which the copolymerization molar ratio of either one of D-lactic acid and L-lactic acid is 90% or more and that of the other is 10% or less.
- the nonwoven fabric is a spun bonded nonwoven fabric, and the filaments are integrated by completely de-bonding temporary fusion-bonded spots once formed in parts of a web of the filaments and three-dimensionally entangling the filaments through a three-dimensional entanglement process,
- the filaments have a polymer supercool index of 0.3 to 0.6,
- the filaments have a birefringence of 3×10−3 to 15×10−3,
- the filaments have a polymer crystalline size of 15 to 20 angstroms as measured axially thereof, and
- the nonwoven fabric has a boiling water shrinkage percentage of 10 to 40%.
Dependencies are inferred from the claim text.