Processes for making high-performance polyethylene multi-filament yarn are disclosed which include the steps of a) making a solution of ultra-high molar mass polyethylene in a solvent; b) spinning of the solution through a spinplate containing at least 5 spinholes into an air-gap to form fluid filaments, while applying a draw ratio DR.sub.fluid; c) cooling the fluid filaments to form solvent-containing gel filaments; d) removing at least partly the solvent from the filaments; and e) drawing the filaments in at least one step before, during and/or after said solvent removing, while applying a draw ratio DR.sub.solid of at least 4, wherein in step b) each spinhole comprises a contraction zone of specific dimension and a downstream zone of diameter Dn and length Dn with Ln/Dn of from 0 to at most 25, to result in a draw ratio DR.sub.fluid=DR.sub.sp*DR.sub.ag of at least 150, wherein DR.sub.sp is the draw ratio in the spinholes and DR.sub.ag is the draw ratio in the air-gap, with DR.sub.sp being greater than 1 and DR.sub.ag at least 1. High-performance polyethylene multifilament yarn, and semi-finished or end-use products containing said yarn, especially to ropes and ballistic-resistant composites, are also disclosed.

The present invention relates to knits that can be used to make rip-resistant sheer hosiery or similar garments, using a specific combination of UHMWPE fiber and stretch fiber, such as spandex. The knit has rip-resistant and anti-microbial properties. Details are provided to avoid problems with pilling and the appearance of bald spots during use. A variation of the knit is useful for activewear.

In the present disclosure, there are provided a polyethylene multifilament interlaced yarn having excellent weavability as well as enabling the manufacture of a protective product having high cut resistance and excellent fit by giving sufficient entanglements to the polyethylene multifilament yarn, and a method for manufacturing the same.

High-consistency nonabsorbable braided suture stock of specified size is prepared from twisted multifilament strands braided together with a tightness of weave of less than 60 picks/inch. The suture stock can be cut to provide sutures, which may be combined with needles to provide surgical sutures for wound closure.

This invention relates to eco-friendly solutions and gels for making high strength ultra-high molecular weight polyolefin (UHMWPO) fibers, films, filters, membranes by solution and gel spinning techniques. This invention also makes soft, strong, oriented, and elastic fibers from styrenic block copolymers. The polymers are first dissolved or dispersed in a cyclic terpene. In some embodiments, the fibers are extruded or drawn from the solution or gel, and cooled to form a gel filament. In some embodiments, the fibers and films are soft and elastic by making the spinnable solution or gel from polyolefin and styrenic block copolymers or other elastomeric polymers in cyclic terpene. In some embodiments the fibers and films produced can be oriented by stretching or drawing in the gel state before and/or during and/or after removal of cyclic terpene.

The present application relates to a process for preparing a prepreg by a continuous method, including the following steps: S1: preparing a raw material; S2: heating and stirring the raw material, and spinning in a spinning box to form a semi-finished ultra high molecular weight polyethylene fiber; S3: uniformly laying the semi-finished ultra high molecular weight polyethylene fiber into a layer, performing multistage drafting on the layer while immersing in a liquid matrix; S4: solidifying the matrix on the layer of ultra high molecular weight polyethylene fiber to form an ultra high molecular weight polyethylene fiber prepreg; S5: orthogonally aligning two sheets of the ultra high molecular weight polyethylene fiber prepregs with each other in warp and weft directions, and then performing lamination to form a weft-free fabric; and in step S3, performing multistage drafting by using a drafting device, and immersing by using an immersing device.

Multifilament yarn containing n filaments are provided, wherein the filaments are obtained by spinning an ultra-high molecular weight polyethylene (UHMWPE), said yarn having a tenacity (Ten) as expressed in cN/dtex of Ten(cN/dtex)=f×n.sup.−0.05×dpf.sup.−0.15, wherein Ten is at least 39 cN/dtex, n is at least 25, f is a factor of at least 58 and dpf is the dtex per filament.

In one embodiment, the present invention is a braided filament including a plurality of strands each having at least one ultrahigh molecular weight polyethylene fiber and at least one polyester fiber wherein the quantity of certain types of fibers in a first strand is the same as the quantity of the same type of fibers in a second strand. In a variant, one additional strand of the braided filament is a monofilament strand. In another variant, each strand is homogeneous with respect to the other strands and is made exclusively from ultrahigh molecular weight polyethylene fibers and polyester fibers such that each strand has the same distribution and quantity of fiber types.

Process for spinning multifilament yarn containing n filaments are provided, wherein an ultra-high molecular weight polyethylene (UHMWPE) solution containing UHMWPE polymer and a solvent for the UHMWPE polymer are spun through n spin-holes of a spin plate and drawn before, during or after removal of the solvent to thereby obtain the multifilament yarn containing n filaments, the yarn having a tenacity (Ten) as expressed in cN/dtex of Ten(eN/dtex) = f×n.sup.-.sup.0.05×dpf.sup.-.sup.0.15, wherein Ten is at least 39 cN/dtex, n is at least 25, f is a factor of at least 62.0 and dpf is the dtex per filament.

The present application relates to the technical field of fiber spinning molding, and particularly to a preparation method of an ultra-high molecular weight polyethylene fiber, a spinneret assembly and a multifilament yarn. The spinneret assembly includes a housing, a plate body and an extrusion hole provided in the plate body. The extrusion hole includes a pressurized inlet segment and an outlet segment connected to an end of the pressurized inlet segment. An inner diameter of the pressurized inlet segment is gradually decreased from one end away from the outlet segment to the other end, and the inner diameter of the outlet segment is constant.