Process for making a monofilament-like product

Abstract

The invention relates to a process for making a monofilament-like product from a precursor containing at least one strand of a spun yarn made from polyolefin staple fibres, comprising the steps of a) exposing the precursor to a temperature within the melting point range of the polyolefin for a time sufficient to at least partly fuse adjacent fibres and b) simultaneously stretching the precursor at a draw ratio of at least 1.0. The invention further relates to a monofilament-like product obtainable by said process showing improved abrasion resistance, and to the use of said monofilament-like product for making various semi-finished and end-use products.

1 . Process for making a monofilament-like product comprising the steps of:
 a) exposing a precursor of indefinite length containing at least one strand comprised of a spun yarn of polyolefin staple fibres to a temperature within the melting point range of the polyolefin fibres for a time sufficient to soften the staple fibers without partial melting and allow adjacent staple fibers to at least partly fuse to one another, and   b) simultaneously with step a) stretching the precursor at a draw ratio of at least 1.0.   
     
     
         2 . Process according to  claim 1 , wherein the draw ratio is from 1.2 to 25. 
     
     
         3 . Process according to  claim 1 , wherein the polyolefin is ultra-high molar mass polyethylene. 
     
     
         4 . Process according to  claim 1 , wherein the staple fibres have been obtained by stretch-breaking of a polyolefin multifilament yarn. 
     
     
         5 . Process according to  claim 1 , wherein the precursor contains plied and twisted strands. 
     
     
         6 . Process according to  claim 1 , further comprising a step preceding step a) of pretreating the precursor in order to enhance inter fibre bonding. 
     
     
         7 . Process according to  claim 6 , wherein pretreating comprises applying an oil to the precursor. 
     
     
         8 . Process according to  claim 6 , wherein pretreating comprises applying a polyurethane composition to the precursor. 
     
     
         9 . Process according to  claim 1 , further comprising a step of applying a coating composition to the product after steps a) and b). 
     
     
         10 . Monofilament-like product comprising an at least partly fused spun yarn made from polyolefin staple fibres made by the process according to  claim 1 . 
     
     
         11 . A fishing line which comprises a monofilament-like product according to  claim 10 . 
     
     
         12 . A cut-resistant article which comprises a monofilament-like product according to  claim 10 . 
     
     
         13 . Monofilament-like product according to  claim 10 , comprising an outer surface layer in which the polyolefin staple fibers are at least partly fused to one another. 
     
     
         14 . Monofilament-like product according to  claim 13 , wherein the polyolefin staple fibers are at least partly fused to one another in both the outer surface layer and an inner layer of the product. 
     
     
         15 . Monofilament-like product comprising a spun yarn made from polyolefin staple fibers, wherein adjacent ones of the staple fibers are at least partly fused without being partially melted. 
     
     
         16 . Process according to  claim 1 , wherein step a) is practiced such that adjacent polyolefin staple fibers in at least an outer surface layer of the monofilament-like product are at least partly fused to one another without partial melting. 
     
     
         17 . Process according to  claim 16 , wherein step a) is practiced to at least partly fuse staple fibers to one another without melting in both the outer layer and an inner layer of the monofilament-like product.