Abstract: A continuous process for preparing a polyester shrinkable film includes: pumping an amorphous PET-based polyester melt having a melt viscosity ?1 directly from a polymerization reactor into a first cooling zone; cooling the polyester melt to increase the melt viscosity thereof to a melt viscosity ?2 such that a difference between ?2 and ?1 ranges from 1500 poise to 3500 poise; feeding the polyester melt into a second cooling zone; cooling the polyester melt to increase the melt viscosity thereof to a melt viscosity ?3 ranging from 5000 poise to 12000 poise such that a difference between ?3 and ?2 ranges from 1000 poise to 5500 poise; and pumping the polyester melt from the second cooling zone into a zone for film-forming treatment.

Abstract: A continuous process for preparing a polyester shrinkable film includes: pumping an amorphous PET-based polyester melt having a melt viscosity ?1 directly from a polymerization reactor into a first cooling zone; cooling the polyester melt to increase the melt viscosity thereof to a melt viscosity ?2 such that a difference between ?2 and ?1 ranges from 1500 poise to 3500 poise; feeding the polyester melt into a second cooling zone; cooling the polyester melt to increase the melt viscosity thereof to a melt viscosity ?3 ranging from 5000 poise to 12000 poise such that a difference between ?3 and ?2 ranges from 1000 poise to 5500 poise; and pumping the polyester melt from the second cooling zone into a zone for film-forming treatment.

Abstract: The present invention discloses a heat adhesive biodegradable bicomponent fiber comprising a polylactic-acid-based low melting component and a high melting component, wherein the low melting component constitutes the sheath of the fiber, and the high melting component constitutes the core of the fiber. The material of the low melting component comprises unmodified polylactic acid or a blending with unmodified polylactic acid and modified polylactic acid. The modified polylactic acid is modified by blending unsaturated dicarboxylic acid, unsaturated anhydride or their derivatives with polylactic acid. The bicomponent fiber provided in this invention is biodegradable, environmentally benign and with excellent bonding performance to polylactic acid fibers, chemical fibers and cellulose fibers.

Abstract: The present invention discloses a heat adhesive biodegradable bicomponent fiber comprising a polylactic-acid-based low melting component and a high melting component, wherein the low melting component constitutes the sheath of the fiber, and the high melting component constitutes the core of the fiber. The material of the low melting component comprises unmodified polylactic acid or a blending with unmodified polylactic acid and modified polylactic acid. The modified polylactic acid is modified by blending unsaturated dicarboxylic acid, unsaturated anhydride or their derivatives with polylactic acid. The bicomponent fiber provided in this invention is biodegradable, environmentally benign and with excellent bonding performance to polylactic acid fibers, chemical fibers and cellulose fibers.