The disclosure provides a method for preparing a hollow fiber membrane by melt spinning-stretching and selective swelling, including: preparing a nascent hollow fiber by melt spinning in an inert gas protective atmosphere by using an amphiphilic block copolymer as a film forming material, and stretching the nascent hollow fiber in the cooling process, a stretch rate being controlled at 200-540 mm/min, and a stretch ratio being controlled at 150-600%; immersing the obtained hollow fiber in a swelling solvent, and treating the hollow fiber in a water bath at 65° C. for 1 h; and then transferring the hollow fiber into a long-chain alkane solvent, treating the hollow fiber at the same temperature for 1-12 h, and after the completion of the treatment, immediately taking out the hollow fiber and drying the hollow fiber to obtain the hollow fiber membrane with a bicontinuous porous structure. By combining the melt spinning-stretching and the selective swelling, the method of the disclosure can synchronously and continuously improve the permeability and selectivity of the hollow fiber membrane. The treatment in the long-chain alkane solvent can make the polar chain excessively enriched on the surface of the membrane migrate inward, thereby improving the performance of the hollow fiber membrane.

A method for producing a polyacetal fiber that presents an improved whiteness unevenness is provided. According to one embodiment, there is provided a polyacetal fiber production method that yields a polyacetal fiber using an oxymethylene copolymer having a melt index, at 190° C. under a load of 2.16 kg, of 5-60 g/10 min, wherein the production method includes taking off the polyacetal fiber from the discharge nozzle of a spinning apparatus, and drawing the taken-off polyacetal fiber. The tensile elongation E1 of the polyacetal fiber after the taking off is 20%-500%; the tensile elongation E2 of the polyacetal fiber after the drawing is 10%-100%; E1≥E2; and the single fiber thickness of the polyacetal fiber after the drawing is 0.7-5.0 denier.

A method for producing a polyurethane elastic fiber according to the present invention contains the steps of: [1] producing a polyurethane urea polymer (A) having a number average molecular weight ranging from 12,000 to 50,000, and represented by general formula (1); [2] preparing a spinning dope by adding the polyurethane urea polymer (A) to a polyurethane urea polymer (B); and [3] spinning a polyurethane elastic fiber using the spinning dope.

##STR00001##

In the formula, R.sup.1 and R.sup.2 are an alkyl group or a hydroxyalkyl group, R.sup.3 is an alkylene group, a polyethyleneoxy group or a polypropyleneoxy group, R.sup.4 is a diisocyanate residue, X is a urethane bond or a urea bond, R.sup.5 and R.sup.6 are a diisocyanate residue, P is a diol residue, Q is a diamine residue, UT is a urethane bond, UA is a urea bond, each of k, 1, m and n is 0 or a positive number.

A method for producing a polyurethane elastic fiber according to the present invention contains the steps of: [1] producing a polyurethane urea polymer (A) having a number average molecular weight ranging from 12,000 to 50,000, and represented by general formula (1); [2] preparing a spinning dope by adding the polyurethane urea polymer (A) to a polyurethane urea polymer (B); and [3] spinning a polyurethane elastic fiber using the spinning dope.

##STR00001##

In the formula, R.sup.1 and R.sup.2 are an alkyl group or a hydroxyalkyl group, R.sup.3 is an alkylene group, a polyethyleneoxy group or a polypropyleneoxy group, R.sup.4 is a diisocyanate residue, X is a urethane bond or a urea bond, R.sup.5 and R.sup.6 are a diisocyanate residue, P is a diol residue, Q is a diamine residue, UT is a urethane bond, UA is a urea bond, each of k, 1, m and n is 0 or a positive number.

A fused filament fabrication filament, method and process, for layer-wise formation of a component, wherein the filament, method and process comprise feedstock material comprising a polyaryletherketone, PAEK and optionally, one or more filler means.

A support garment may have a seamless support garment configured for use by a person. The garment may have first and second arm openings configured to be about 0.5 to 1 times greater than a diameter of an average user's arms; a neck opening configured to be about 2 to 4 times greater than a diameter of an average user's neck; a portion of the arm openings and neck opening opposite each other form integral shoulder straps; a band configured to fit at an under bust of the user defining a torso opening; two cup regions positioned above the band to receive the user's breasts, two cup regions positioned above the band to receive the user's breasts, the cup regions being 100-200 percent thicker at a portion of the cup configured for placement of the user's nipple and tapering to a garment body thickness as the taper extends away from the nipple portion; wherein, the support garment is configured from a material having between 50-200 percent elasticity.

A support garment may have a seamless support garment configured for use by a person. The garment may have first and second arm openings configured to be about 0.5 to 1 times greater than a diameter of an average user's arms; a neck opening configured to be about 2 to 4 times greater than a diameter of an average user's neck; a portion of the arm openings and neck opening opposite each other form integral shoulder straps; a band configured to fit at an under bust of the user defining a torso opening; two cup regions positioned above the band to receive the user's breasts, two cup regions positioned above the band to receive the user's breasts, the cup regions being 100-200 percent thicker at a portion of the cup configured for placement of the user's nipple and tapering to a garment body thickness as the taper extends away from the nipple portion; wherein, the support garment is configured from a material having between 50-200 percent elasticity.

A polyurethaneurea composition comprises a reaction product of at least one diisocyanate compound, a polymeric glycol, a poly(tetramethylene-co-ethyleneether) glycol comprising constituent units derived by copolymerizing tetrahydrofuran and ethylene oxide (EO) wherein the portion of the constituent units derived from ethylene oxide is present in the poly(tetramethylene-co-ethyleneether) glycol from greater than about 37 to about 70 mole percent, at least one diamine chain extender, and at least one chain terminator. The invention further relates to the use of blends of polymeric glycols and poly(tetramethylene-co-ethyleneether) glycols as the soft segment base in spandex compositions. The invention also relates to new polyurethane compositions comprising polymeric glycols and poly(tetramethylene-co-ethyleneether) glycols, and their use in spandex.

A polyurethaneurea composition comprises a reaction product of at least one diisocyanate compound, a polymeric glycol, a poly(tetramethylene-co-ethyleneether) glycol comprising constituent units derived by copolymerizing tetrahydrofuran and ethylene oxide (EO) wherein the portion of the constituent units derived from ethylene oxide is present in the poly(tetramethylene-co-ethyleneether) glycol from greater than about 37 to about 70 mole percent, at least one diamine chain extender, and at least one chain terminator. The invention further relates to the use of blends of polymeric glycols and poly(tetramethylene-co-ethyleneether) glycols as the soft segment base in spandex compositions. The invention also relates to new polyurethane compositions comprising polymeric glycols and poly(tetramethylene-co-ethyleneether) glycols, and their use in spandex.

The present invention provides a method for manufacturing a polyacetal fiber in which whiteness irregularity is improved. One embodiment of the present invention provides a method for manufacturing a polyacetal fiber, wherein the method includes a discharge step, a takeup step, a stretching step, and a winding step, the steps being continuously performed, an oxymethylene copolymer being used as the raw material of the polyacetal fiber, the oxymethylene copolymer having an oxymethylene unit and an oxyethylene unit, the content of the oxyethylene unit being 0.5-7.0 moles to 100 moles of the oxymethylene unit, the roller temperature of a stretching unit used in the stretching step being 130-155° C., and operation parameters of the method being set so as to satisfy a prescribed numerical formula.