ศึกษาการหดตัวของพลาสติกโพลิเอทิลีนเทเรฟทาเลต ที่ใช้กับแม่พิมพ์เป่า

This research aims to study the shrinkage of plastic polyethylene Terephthalate used with the make blow mold in 2 stages. The shrinkage of work piece was determined in order to design the mold ; Z axis = 1% XY axis = 2.5% . The testing results were as follow. 1. Horizontal shrinkage(Z axis) was 0.85% which differed from the determined shrinkage(1%) at 0.15% 2. Vertical shrinkage(XY axis) was 1.83% that is 0.67% which differed from the determined shrinkage(2.5%) at 0.67%