PBT/PET Conjugated Fibers:Melt Spinning,Fiber Properties,and Thermal Bonding

摘要

This work examines the PBT/PET sheath/core conjugated fiber,with reference to melt spinning,fiber properties and thermal bonding.Regarding the rheological behaviors in the conjugated spinning,PET and PBT show the smallest difference between their melt-viscosity at temperatures of 290 deg C and 260 deg C respectively,which has been thought to represent optimal spinning conditions.The effect of processing parameters on the crystallinity of core material-PET was observed and listed.In order of importance,these factors are the draw ratio,the heat-set temperature,and the drawing temperature.The crystallinity of sheath material-PBT,however,can be considered to be constant,independent of any processing parameters.The bulk orientation,rather than the crystallinity of PET core,dominates the tenacity of PBT/ PET sheath/core fiber.Moreover,heat-set treatment after drawing is recommended to yield a highly oriented conjugated fiber.With respect to thermal bonding,PBT/PET conjugated fibers processed via high draw ratio but low-temperature heat setting can form optimal thermal bonds at a constant bonding temperature of 10 deg C above the T_m of PBT.