含水量对饮料瓶片挤出产物特性黏度的影响

Effect of Water Content on Intrinsic Viscosity of Extrusion Product of Bottle Flakes

研究了不同含水量饮料瓶片在单螺杆、双螺杆等挤出机中的挤出现象及含水量对挤出产物特性黏度的影响。结果表明:所有饮料瓶片材质均为聚对苯二甲酸乙二醇酯(PET);不同含水量的饮料瓶片,使用单螺杆挤出机或双螺杆挤出机挤出时都难以牵引成条,挤出产物的特性黏度均低于0.60dL/g;使用带有真空除气装置的反应挤出机挤出时,都能牵引成条,挤出产物的特性黏度较高;提高反应挤出机除气段真空度或降低饮料瓶片的含水量均有利于提高挤出产物的特性黏度,反应挤出机螺杆转速最佳范围为70~80r/min。

Effect of water content of bottle flakes on extrusion phenomenon and intrinsic viscosity of extrusion product is studied with single-screw extruder, twin screw extruder and so on. Experiment results show that the material of bottle flakes is polyethylene terephthalate （PET）. Extrusion product is difficult to mould into line shape and the intrinsic viscosity of extrudate is all below 0. 60 dL/g when bottle flakes are extruded with single-screw extruder or twin-screw extruder. Bottle flakes can be mould into line shape and its intrinsic viscosity is obviously higher by reactive extruder with vacuum degassing section. The intrinsic viscosity of extrudate increases when vacuum degree increases or water content of bottle flakes reduces. The optimal screw speed of reactive extruder is 70-80 r/min.