PET bottle plasma coating technology

PET bottle is widely used because of its light weight, transparency, and no breakage. It has a variety of bottle shapes, easy to seal and store, and the material can be recycled. The current PET bottle consumption has approached 800 billion. However, the air permeability of a thick PET bottle generally results in the oxidation of vitamin C in the content or the loss of CO2 in the nitrogen-filled beverage. Therefore, the improvement of the barrier performance of the PET bottle has attracted attention in various countries.

The specific method of plasma coating technology to improve the barrier properties of PET bottles introduced by Mr. Chen Juntian of SIG Cooperas Corp. is: placing PET bottles in a closed coating chamber, exhausting to a vacuum state, and injecting a type containing Si atoms. The chemical gas is injected into O2 at the same time, and the microwave is applied to make the gas pulse and chemical reaction so that SiO2 is deposited on the wall of the bottle and its thickness is only 15 Nm. Visually observing the transparency of the coated PET bottle before coating was no different.

The first rotating multi-station plasma coating equipment produced by the Cooperras company has been put into commercial operation at the Bischofszell Foods plant in Switzerland. The machine is used to produce 0.4-1L of fruit juice beverage in line with the bottle blowing machine and aseptic filling machine. The output reaches 10000BPH. The coated bottle can be used for hot filling at 95°C and aseptic cold filling; it can be filled with juice drinks, carbonated beverages such as beer. The coated PET bottle had a 27-fold improved barrier factor and a 17-fold cold-filled juice. After being stored at 20°C for 26 weeks, the vitamin C in the juice dropped from 450 ppm to 220 ppm. After the fruit juice was hot-filled at 89°C, the barrier element was improved 7-10 times. This technology has been approved by the US Food and Drug Administration FDA and the European Union.