The doubling machine TD688 used in the production of various kinds of cone yarn, for warping machine, knitting machine, tatting machine and hosiery machine.Vertical yarn path design, no inflection point, yarn friction is small, less hairiness, equipped with led light.double points tension control system with micro motors, uniform yarn tension. Using high quality alloy drums with optimized groove shape, good anti-patterning, good wear resistance.Easy to adjust yarn tension by changing tension slices We use pneumatic technology for yarn package to go up when the tube is full or yarn break comes.