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.

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.

A process for the preparation of plexifilamentary film-fibril strands of polymer. The process includes the steps of generating a spin fluid containing (a) 5 to 30 wt. % containing one or more polymer types, (b) a primary spin agent selected from the group consisting of dichloromethane, cis-1,2-dichloroethylene and trans-1,2-dichloroethylene, and (c) a co-spin agent comprising 1H,6H-perfluorohexane or 1H-perfluorohexane or 1H-perfluoroheptane. The spin fluid is flash-spun at a pressure that is greater than the autogenous pressure of the spin fluid into a region of lower pressure to form plexifilamentary film-fibril strands of the polymer. The co-spin agent is present in the spin fluid in an amount sufficient to form an azeotrope-like composition with the primary spin agent in the presence of the one or more polymer types. The polymer may be selected from the group consisting of high density polyethylene, polypropylene, polybutene-1, polymethylpentene, polyvinylidene fluoride, poly (ethylene tetrafluoroethylene), and blends of the foregoing.

The present disclosure relates to knits that can be used to make rip-resistant garments using an ultra-high molecular weight polyethylene (UHMWPE) fiber and a companion fiber such as a stretch fiber or a memory fiber. The UHMWPE fiber includes a monofilament or multiple microfilaments, each of the microfilaments has a denier of 5 or less.

The present disclosure relates to knits that can be used to make rip-resistant garments using an ultra-high molecular weight polyethylene (UHMWPE) fiber and a companion fiber such as a stretch fiber or a memory fiber. The UHMWPE fiber includes a monofilament or multiple microfilaments, each of the microfilaments has a denier of 5 or less.

A polyolefin material that comprises a thermoplastic composition is provided. The composition contains a continuous phase that includes a polyolefin matrix polymer and a nanoinclusion additive dispersed within the continuous phase in the form of discrete domains. The composition further includes a butene polymer. A porous network is defined within the thermoplastic composition that includes a plurality of nanopores.

A hollow fiber that extending along at least a portion of the fiber along a longitudinal axis thereof and is defined by an interior wall is provided. Through selective control over the manner in which it is formed, the present inventors have discovered that the hollow fiber can exhibit a unique combination of a high void fraction and small fiber size that makes it particularly suitable for use in certain applications, such as in nonwoven webs for absorbent articles.

The invention relates to a multifilament yarn having a tenacity of at least 30 cN/dtex, and comprising a plurality of spun ultrahigh molecular weight polyolefin filaments characterized in that the titer of any one of said spun filaments is at least 10 dtex.

The invention relates to a multifilament yarn having a tenacity of at least 30 cN/dtex, and comprising a plurality of spun ultrahigh molecular weight polyolefin filaments characterized in that the titer of any one of said spun filaments is at least 10 dtex.

Disclosed is an ethylene polymer having a viscosity-average molecular weight (Mv) of 3,000,000 or more and 15,000,000 or less.