Polymeric plastics material and manufacture thereof

Abstract

A polymeric plastics material having a composition which includes a wax, the material having a reduced propensity to absorb moisture. The material is manufactured in multifilament form, particularly in the form of a fabric. A method of manufacturing the polymeric plastics material is also disclosed.

1 . A polymeric multifilament fibre formed from a multitude of filaments, the fibre having a plurality of capillaries, each fibre comprising: 
 a polymeric composition comprising a mixture of a polymer, copolymer or combination thereof of propylene and a wax in an amount between 0.5 and 5% by weight of the composition; and    a surface coating of an oil lubricant in an amount between 0.5 and 5% by volume of the filaments,    wherein the combination of the wax and oil lubricant substantially prevents the fibre from absorbing moisture by capillary action.    
   
   
       2 . A polymeric multifilament fibre as claimed in  claim 1 , wherein the wax is present in an amount of about 1% by weight of the polymeric composition.  
   
   
       3 . A polymeric multifilament fibre as claimed in  claim 1 , wherein the oil lubricant is present in an amount of about 2% by volume of the filaments.  
   
   
       4 . A polymeric multifilament fibre as claimed in  claim 1 , wherein the wax is at a surface of each filament.  
   
   
       5 . A polymeric multifilament fibre as claimed in  claim 4 , wherein the wax is intermittently distributed over a surface of each filament.  
   
   
       6 . A polymeric multifilament fibre as claimed in  claim 5 , wherein the wax is distributed in globules over a surface of each filament.  
   
   
       7 . A polymeric multifilament fibre as claimed in  claim 1 , wherein the wax is a hydrocarbon compound or mixture selected from one or more of the Fischer-Tropsch range of hydrocarbons.  
   
   
       8 . A polymeric multifilament fibre as claimed in  claim 7 , wherein the wax is Ad Sperse 868.  
   
   
       9 . A polymeric multifilament fibre as claimed in  claim 1 , wherein the oil lubricant is present as a film on the surface of each filament.  
   
   
       10 . A polymeric multifilament fibre as claimed in  claim 1 , wherein the oil lubricant is a hydrocarbon white oil.  
   
   
       11 . A fabric manufactured from a multitude of fibres as claimed in  claim 1 .  
   
   
       12 . A method of manufacturing polymeric multifilament fibre, the fibre having a plurality of capillaries, the method comprising the steps of: 
 preparing a polymeric plastics composition comprising a mixture of a polymer, copolymer or combination thereof of propylene and a wax in an amount between 0.5 and 5% by weight of the composition;    forming the composition into two or more filaments;    lubricating a surface of the filaments with an oil lubricant in an amount between 0.5 and 5% by volume of the filaments; and    forming the filaments into a multifilament fibre,    wherein the combination of the wax and oil lubricant substantially prevents the fibre from absorbing moisture by capillary action.    
   
   
       13 . A method as claimed in  claim 12 , wherein the wax is added to the polymeric composition in an amount of about 2% by volume of the polymeric composition.  
   
   
       14 . A method as claimed in  claim 12 , wherein the lubricant is applied in an amount of about 2% by volume of the filaments.  
   
   
       15 . A method as claimed in  claim 12 , wherein forming the composition into filaments comprises allowing the wax to migrate to a surface of the filaments.  
   
   
       16 . A method as claimed in  claim 15 , wherein the wax is intermittently distributed over the surface of the filaments.  
   
   
       17 . A method as claimed in  claim 12 , wherein the wax is distributed in globules over the surface of the filaments.  
   
   
       18 . A method as claimed in  claim 12 , wherein preparing the polymeric plastics composition comprises preparing a polypropylene base batch and adding a wax or a mixture including a wax to the base batch.  
   
   
       19 . A method as claimed in  claim 12 , wherein the filaments are formed by extrusion of the composition.  
   
   
       20 . A method as claimed in  claim 12 , wherein lubricating the formed filaments comprises applying a hydrocarbon white oil to a surface of the filaments.  
   
   
       21 . A method as claimed in  claim 12 , wherein the oil lubricant is applied by passing the filaments through lubricant drops so as to form a film of lubricant on surfaces of the filaments.  
   
   
       22 . A polymeric multifilament fibre formed from a multitude of filaments, the fibre having a plurality of capillaries, each fibre comprising: 
 a polymeric composition comprising a polymer, copolymer or combination thereof of propylene mixed with a wax selected from one or more of the Fischer-Tropsch range of hydrocarbons in an amount between 0.5 and 5% by weight of the composition; and    a surface coating of an oil lubricant between 0.5 and 5% by volume of the filaments, the oil lubricant being a hydrocarbon white oil,    wherein the wax is distributed in globules over a surface of each filament and the oil lubricant is present as a film on the surface of each filament, this combination of the wax and oil lubricant substantially preventing the fibre from absorbing moisture by capillary action.    
   
   
       23 . A method of manufacturing polymeric multifilament fibre, the material having a plurality of capillaries, the method comprising the steps of: 
 preparing a polymeric plastics composition comprising a mixture of a polymer, copolymer or combination thereof of propylene and a wax selected from one or more of the Fischer-Tropsch range of hydrocarbons in an amount between 0.5 and 5% by weight of the composition;    forming the composition into two or more filaments;    lubricating a surface of the filaments with an oil lubricant in an amount between 0.5 and 5% by volume of the filaments, the oil lubricant being a hydrocarbon white oil; and    forming the filaments into a multifilament fibre,    wherein the wax is distributed in globules over a surface of each filament and the oil lubricant is present as a film on the surface of each filament, this combination of the wax and oil lubricant substantially preventing the fibre from absorbing moisture by capillary action.