Indicator yarn construction

Abstract

The present invention is related to a yarn construction comprising fibres A and at least one indicator fibre, wherein the indicator fibre comprises fibre B and an elemental metal at least partially coating the surface of the fibre B, wherein fibre A and fibre B are dissimilar ultra high molecular weight polyethylene (UHMWPE) fibres. The yarn constructions may be available in different forms, amongst others in ropes, straps, slings, fabrics and synthetic chains.

1 . A yarn construction comprising fibres A and at least one indicator fibre, wherein the indicator fibre comprises fibre B and an elemental metal at least partially coating the surface of fibre B, wherein fibre A and fibre B are different ultra high molecular weight polyethylene (UHMWPE) fibres. 
     
     
         2 . A yarn construction according to  claim 1  comprising at least one yarn A and at least one indicator yarn, wherein the yarn A comprises fibres A and the indicator yarn comprises the indicator fibre. 
     
     
         3 . The yarn construction of  claim 1  wherein the fibres A and fibre B differ by at least one property, the property being selected from the group consisting of filament titer, fibre tenacity, fibre elongation at break, fibre tensile modulus and intrinsic viscosity of the UHMWPE. 
     
     
         4 . The yarn construction of  claim 3  wherein at least one ratio of a property of fibre B to the corresponding property of fibre A is at most 0.95, preferably at most 0.9, even more preferably 0.80. 
     
     
         5 . The yarn construction of  claim 1  wherein at least fibre B comprises a filler and wherein fibre B comprises at least 2 wt % more filler than fibre A wherein wt % is the weight ratio of filler present in a fibre to the total weight of said fibre including the filler. 
     
     
         6 . The yarn construction of  claim 5  wherein the fibre B comprises filler with a hardness higher than the hardness of the fibre measured in the absence of the filler. 
     
     
         7 . The yarn construction of  claim 1  wherein the fibre B is inferior to the fibre A in terms of withstanding a stress. 
     
     
         8 . The yarn construction of  claim 7  wherein the inferiority is expressed either in that the flexural fatigue strength of the fibres B is inferior to the flexural fatigue strength of the fibres A,
 in that the elongation at break of the fibres B is inferior to the elongation at break of the fibres A, 
 in that the resistance to abrasion of the fibres B is inferior to the resistance to abrasion of the fibres A, or 
 in that the creep rupture of the fibres B is inferior to the creep rupture of the fibres A. 
 
     
     
         9 . The yarn construction of  claim 1  wherein the weight ratio of indicator fibres to fibres A is less than 0.1, preferably less than 0.05, more preferably less than 0.02 and most preferably less than 0.01. 
     
     
         10 . The yarn construction of  claim 1  wherein the indicator fibre or indicator yarn is twisted, laid or braided with fibre A, with fibre B or with fibre A and fibre B to form an assembled yarn. 
     
     
         11 . The yarn construction of  claim 1  wherein fibre B is a continuous filament. 
     
     
         12 . The yarn construction according to  claim 1  being a rope, a sling, a fabric or a synthetic chain link. 
     
     
         13 . The yarn construction according to  claim 12  comprising a load carrying core comprising at least one indicator fibre or indicator yarn. 
     
     
         14 . The yarn construction of  claim 1  comprising at least 2 indicator fibres or yarns asymmetrically positioned within the yarn construction. 
     
     
         15 . The yarn construction of  claim 1  comprising at least 2 distinct indicator fibres or indicator yarns.