Knitted heat shrink tubing and method for the production thereof

Abstract

The invention relates to a protective tubing produced using a heat-shrinkable yarn in the circular knitting method, and to a method for producing a protective tubing of this kind.

1 . Protective tubing produced using a heat-shrinkable yarn, wherein the protective tubing is produced using a circular knitting method. 
     
     
         2 . The protective tubing according to  claim 1 , wherein, in a non-shrunk state of a knitted fabric, the ratio (P/M−Ø eff ) of the length of a stitch period (P) in the peripheral direction of the knitted fabric to the difference (M−Ø eff ) between the outer width (M) of narrower stitches, measured in the peripheral direction, minus the effective thread diameter (Ø eff ), is between approximately 1.49 and approximately 1.78. 
     
     
         3 . The protective tubing according to  claim 1 , wherein, in the non-shrunk state of the knitted fabric, the ratio (p/M−Ø eff ) of the length of the stitch period (P) in the longitudinal direction of the knitted fabric to the difference (M−Ø eff ) between the outer width (M) of the narrower stitches, measured in the peripheral direction, minus the effective thread diameter (Ø eff ), is between approximately 0.65 and approximately 0.76. 
     
     
         4 . The protective tubing according to  claim 1 , wherein the yarn has an effective thread diameter (Ø eff ) of between approximately 0.15 mm and approximately 0.40 mm. 
     
     
         5 . The protective tubing according to  claim 1 , wherein the yarn comprises at least one monofilament and at least one multifilament. 
     
     
         6 . The protective tubing according to  claim 5 , wherein at least one monofilament and/or at least one multifilament and/or at least a portion of the filaments of at least one multifilament is produced from heat-shrinkable polyester. 
     
     
         7 . The protective tubing according to  claim 1 , wherein the knitted fabric is coated by a varnish. 
     
     
         8 . The protective tubing according to  claim 1 , wherein a strip of a material which is not heat-shrinkable is arranged on an outer surface and/or an inner surface thereof at at least one point. 
     
     
         9 . A method for producing a protective tubing according to  claim 1 , wherein the protective tubing is produced on a circular knitting machine. 
     
     
         10 . The method according to  claim 9 , wherein the ratio of the needle width of needles of the circular knitting machine to the needle spacing, measured from needle center to needle center, of the needles is between approximately 0.31 and approximately 0.37. 
     
     
         11 . The according to  claim 9 , wherein the diameter of a circle of needles of the circular knitting machine is between approximately one quarter and approximately half larger than the diameter of the protective tubing in a state in which said tubing is removed from the circular knitting machine and is not shrunk.