Handbook  of  Cable & Wire  Producer                                 


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[Most Recent Quotes from www.kitco.com]



SingleTwist generates one twist per rotation of flying arm.  Wingding distribution is handled by moving  take-up spool back and forth.  Both Take-up spool and flying arm rotates in same direction. Twisting pitch is adjusted via difference in rotation speed between flying arm and take-up spool.  SingleTwist buncher is the second  fastest twisting machine in cable production.  single twist can be use for bunching bare conductors, insulated cores for grouping. Twinning is possible but productivity is much less than doubletwist. Strands  are pulled through twisting plate over flying arm. There are two flying arms on singletwist machine.  One for twisting , the other one is for weight balancing.  Could be only one flying arm as well as long as balance issues are solved.  Twisting occurs at the entrance of flying arm. Singletwist machine may be used for several different applications.  Bare conductors and insulated cable cores can be twisted at comparingly high speed level.  Twist per minute equals the rotation of flying arm.  The fastest can be fairly 800-1000rpm. In General, singletwist machines are referred by the size of Take-up spool. "ST800" for example, points that take-up spool flange size is 800mm.

Singletwist machine relays fine electronic measurement devices during process. Speed of take-up drum changes continuously during process. Twisting construction is better than a doubletwist machine but still "flower effect" needs to be solved with rotating pay-off units.

Singletwist is a compact and reliable but still not best solution for large solid bare conductors. Construction of bundle better than a doubletwist but not as good as a rigid strander or a planetary.  Total weight of take-up spool is limited.  Therefore, over 1600mm flange size is not productive. Also,  Production speed is decreased drastically by spool size.  Vibration is an obstacle for singletwist bunching. Machine manufactuers use various solutions to that.

Best For:  A singletwist machine is best for grouping telephone & data signal cables.

Versatility: SingleTwist buncher is versatile in compare to doubletwist machine.  Number of strands has no limit as long as finished overall diameter stays within in the range of machine.  Total weight of take-up spool is limited. Size of take-up spool is fixed by barrel length.  Using diffeent flange size spools are possible .Application of  foil or other wrapping materials is  possible while twisting process which makes Singletwist more productive. Changing processed material may require adjustments to flying-arm.

Flower Effect :


When bunching insulated cores,  round shape of insulation is ruined because of torsion. In this case,  insulation thickness is not constant and cores not circular anymore.  Impedance and capacity of the final assembly would not be a constant value by length.  Such default bears impedance, capacity and cross talk problems for Communications cables working over 600Mhz.  Solution is back-twist or pre-twist  depending on what type of twisting machine is used.