In the plastic packaging industry, the plastic products in the same batch of delivery, some plastic product color yellowish, very ugly, especially in the end of the packaging, which greatly affected the sales and beauty of the product, thus causing a certain loss to the enterprise. However, Xiaobian feels that there are many main reasons for the discoloration of plastic products.

1. Equipment

(1) the equipment is not clean. The dust or dust on the equipment will cause the blister sheet to pollute, which will cause plastic discoloration.

(2) the imbalance of thermocouple, temperature controller or heating system results in imbalance of temperature, which will also make plastic packaging discolouration.

2, mold aspect

(1) the venting holes of the moulds are not good, causing the plastics to react violently under high temperature and high pressure and oxygen, burn plastics and so on.

(2) to absorb the sheet or to say that there are too many lubricants and demoulding agents in the mold, so we should clean it on schedule, and then we should remove some additives such as anti static.

3, sheet material aspect.

(1) the content of water and volatiles is high.

(2) high temperature decomposition of coloring agent and additive.

(3) the sheet was polluted.