Breakthrough in the production process of packaging materials: two-stage stretch blow molding process

At present, a new breakthrough has been achieved in the production process of packaging materials, namely the preparation of polyethylene terephthalate (PET) beverage cups through a two-stage stretch blow molding process. The first FRC-12 unit developed by Japan's Fron-tier company has been put into commercial production at Japanese packaging material maker Seiyu.

The device is special in that it operates and optimizes heating in 10 heating zones on the FRC-12 rotary reheat blow molding machine. The FRC-12 has 12 blow mold cavities. The number of cavities depends on the operating conditions of the machine and the shape of the blown beverage cup. Blow mold slots can be added according to actual needs, up to 240.

Compared with a stretch blow molding machine, the former produces beverage cups with a reject rate of about 1%, while the latter, due to unstable mold cooling, typically has a reject rate of 20-30%; while the former produces a cup with an elongation of 3.2. The latter has an elongation rate of only 2.2; the former guarantees that the thickness of the cup wall does not change by more than 0.06 mm, and the diameter of the cup mouth varies by about 0.01 mm, while the cup produced by the latter has uneven wall thickness and is easily broken at the outlet.

Some experts believe that since the two-stage stretching process can produce most of the sizes of products that can be produced by the thermoforming and injection molding processes and have excellent performance, it may become a major production process for plastic containers in the future.