Process and apparatus for making alternate s/z twist plied braid or joined alternate s/z twist plied yarns

Abstract

The present invention provides an improved method and device for producing an alternate S/Z twist plied braid and joined alternate S/Z twist plied yarns. The invention further provides an alternate S/Z twist plied braid and joined alternate S/Z twist plied yarns produced according to a process of the invention.

1 . A method for making an alternate S/Z twist plied braid, comprising the steps of:
 a) separately providing at least four strands, divided over at least two groups;   b) alternately applying S and Z twist to the strands; thereto zone of S- twist are alternated with zones of Z-twist and vice versa, with an intervening zone with approximately no twist, wherein these reversal zones are called “nodes”;   c) per group the alternately S/Z twisted strands, are brought together via a narrowing;   d) connecting the nodes of all strands within a group;   e) allowing the strands of a same group to self-twist thereby providing an alternate S/Z twist plied yarn;   f) alternately imparting additional twist to the alternate S/Z twist plied yarn, wherein the alternation of the direction of twist coincides with the nodes of the alternate S/Z twist plied yarns;   g) combining the alternate S/Z twist plied yarns via a narrowing;   h) connecting the nodes of the alternate S/Z twist plied yarns;   i) allowing the alternate S/Z twist plied yarns, to self-twist, thereby providing an alternate S/Z twist plied braid,   j) leading away the braid produced,   
       wherein, 
       tension of the alternately S/Z twist plied yarns is reduced between the step f) of imparting additional alternate twist to the alternately S/Z twist plied yarns and the step g) of combining these yarns. 
     
     
         2 . The method according to  claim 1 , wherein step c) comprises bringing together the alternately S/Z twisted strands via a narrowing, in phase: all nodes coinciding, and with zones of equal twist direction next to each other. 
     
     
         3 . The method according to  claim 1 , wherein step g) comprises combining the alternate S/Z twist plied yarns via a narrowing in phase: all nodes coinciding, and with zones of equal twist direction next to each other. 
     
     
         4 . A method for making joined alternate S/Z twist plied yarns, comprising the steps of:
 k) separately providing at least four strands, divided over at least two groups;   l) alternately applying S and Z twist to the strands, wherein zone of S-twist are alternating with zones of Z-twist and vice versa, with an intervening zone with approximately no twist, wherein these reversal zones are called “nodes”;   m) then subsequently per group the alternately S/Z twist plied strands, are brought together via a narrowing;   n) connecting the nodes of all strands within a group;   o) allowing the strands of a same group to self-twist thereby providing an alternate S/Z twist plied yarn;   p) alternately imparting additional twist to the alternate S/Z twist plied yarn, wherein the alternation of the direction of twist coincides with the nodes of the alternate S/Z twist plied yarns;   q) combining the alternate S/Z twist plied yarns, via a narrowing;   r) connecting the nodes of the alternate S/Z twist plied yarns, thereby providing joined unbalanced alternate twist plied yarns comprising at least two unbalanced alternate S/Z twist plied yarns, connected with each other in the nodes,   s) leading away the yarns produced,   
       wherein, tension of the alternately S/Z twist plied yarns is reduced between the step p) of imparting additional alternate twist to the alternately S/Z twist plied yarns and the step q) of combining these yarns. 
     
     
         5 . The method according to  claim 4 , wherein step m) comprises bringing together the alternately S/Z twist plied strands
 via a narrowing, in phase: all nodes coinciding, and with zones of equal twist direction next to each other.   
     
     
         6 . The method according to  claim 4 , wherein step q) comprises combining the alternate S/Z twist plied yarns via a narrowing in counter phase: all nodes coinciding, and with zones of opposite twist direction next to each other. 
     
     
         7 . The method according to  claim 1 , wherein the tension of the alternate S/Z twist plied yarns is reduced in a controlled manner with a closed circuit system on the basis of the measured tension of the alternate S/Z twist plied braid respectively the joined alternate S/Z twist plied yarns. 
     
     
         8 . The method according to  claim 1 , wherein the tension of the alternate S/Z twisted yarns is reduced in a controlled manner with a closed circuit system on the basis of the amount of yarn between the step of connecting the nodes of the alternate S/Z twist plied yarns (h, r), and the step of leading away the yarn produced (j, s). 
     
     
         9 . The method according to  claim 1 , wherein the fibers or filaments of the alternate S/Z twisted yarns are preheated prior to imparting additional alternate twist to said yarns. 
     
     
         10 . The method according to  claim 1 , wherein the fibers or filaments of the alternate S/Z twist plied yarns are heated using a hot fluidum at the imparting of additional alternate twist of said yarns. 
     
     
         11 . The method according to  claim 1 , wherein the fibers or filaments of the alternate S/Z twist plied yarns are heated using a hot fluidum when connecting their nodes. 
     
     
         12 . The method according to  claim 1 , wherein inter-fiber or -filament friction of the alternate S/Z twist plied yarns is reduced by the addition of liquid additives prior to or during imparting additional alternate twist of said yarns. 
     
     
         13 . The method according to  claim 1 , wherein inter-fiber or -filament friction of the alternate S/Z twist plied yarns is reduced by the addition of liquid additives during the connection of their nodes. 
     
     
         14 . An apparatus for making an alternate twist plied braid or joined alternate twist plied yarns formed from a plurality of at least four strands, comprising:
 a source of supply for the separate feeding of individual strands, at least four, spread over at least two groups;   a means for tensioning each strand;   a first twisting means for alternatingly applying a S respectively Z twist in at least one strand of each group thereby obtaining alternate S and Z twisted strands;   a first fixation means for combining the alternately S/Z twisted strands of each group and connecting these at their nodes;   a second torsion means for imparting additional alternate twist to at least one of the alternately S/Z twisted strands;   a second fixation means for connecting the alternately S/Z twist plied yarns with each other;   a means to remove the yarn produced;   a steering means for the coordinated control of all the above mentioned means, characterized in that the means for reducing the tension in the alternate S/Z plied yarns is provided between the second torsion means and the second fixation means.   
     
     
         15 . Apparatus according to  claim 14 , wherein a means for measuring the tension of the yarn is provided after the second fixation means. 
     
     
         16 . Apparatus according to  claim 14 , wherein a means for yarn accumulation is provided after the second fixation means. 
     
     
         17 . Apparatus according to  claim 14 , wherein a means for heating the alternate S/Z twist plied yarn is provided before the second torsion means. 
     
     
         18 . Apparatus according to  claim 14 , wherein a means is provided for the addition of liquid additives to the yarns before the second torsion means. 
     
     
         19 . Apparatus according to  claim 14 , wherein a means is provided for the addition of liquid additives to the second torsion means. 
     
     
         20 . Apparatus according to  claim 14 , wherein a means is provided for addition of liquid additives in the second fixation means. 
     
     
         21 . An alternate S/Z twist plied braid obtained by the method of  claim 1 . 
     
     
         22 . A joined alternate twist plied yarn obtained by the method of  claim 4 .