OPP bottles are becoming popular

In recent years, two-way polypropylene (OPP) transparent bottles have become the preferred choice for PET bottles. This is because OPP bottles are particularly suitable for hot filling because of their light weight, low cost, improved transparency and heat resistance.

The new metallocene PP developed by Basell features low migration and improves the performance of OPP bottles in food and pharmaceutical packaging. Milliken's 4th generation Millad 3988 antireflective agent, combined with a metallocene random copolymer, reduces the haze to 1.5 and is very close to PET. Material development also improved the processing window by about 5°C.

Equipment manufacturers have also redesigned the performance of the one-step and two-step injection stretch blow machines to overcome the problems of early PP preform heating and cooling. At present, OPP bottles can be produced on high-speed, rotary heated stretch blow molding machines.