Production of yarns with reduced residual extension after repeated loading, e.g. for carpets, uses mixture of polyethylene or polybutylene terephthalate with polytrimethylene terephthalate

摘要

A mixture of polyethylene or polybutylene terephthalate with polytrimethylene terephthalate (PTT) is spun and drawn to produce yarns of breaking extensions of 15 - 35%. Unexpectedly low residual extension after one, five and ten loading cycles to 5% and 10% extension is defined by formulae involving the concentration of PTT. A mixture of polyethylene or polybutylene terephthalate with polytrimethylene terephthalate (PTT), especially with up to 90% of either component, is spun and drawn to produce yarns of breaking extensions of 15 - 35%. The unexpectedly low residual extension after one, five and ten loading cycles to 5% and 10% extension is defined by formulae involving the concentration of PTT. The values apply to untwisted yarn, yarns with producer twist and yarns with metric twist factors up to 130. Most of the effect is produced by PTT concentrations of about 10% with little further improvement beyond that value. A residual extension of less than 0.1% is obtained over a wide range of conditions.