| abstract |
A type of high-modulus-low-shrinkage activated PET industrial yarn and preparing method thereof are disclosed. The preparing method is to manufacture filament from a modified polyester, which is the product of the esterification and the successive polycondensation reactions of evenly mixed terephthalic acid, ethylene glycol and tert-butyl branched heptanediol, through a series of processes composed of viscosity enhancing by solid state polycondensation, melting, metering, extruding, cooling, oiling, stretching, heat setting, relaxation heat-treating, oiling with activation oil, winding and pre-activation treatment. The relaxation heat-treating indicates passing the modified polyester yarns through a space with a certain temperature within 200-220° C. under a proper relaxation state; and the proper relaxation state means a 3.0-5.0% of overfeed for the winding. The improvement of activator efficiency by importing the tert-butyl branched diol into the polyester, together with the synergistic effect of heat setting temperature and high winding overfeed rate, will reduce the fiber thermal shrinkage. |