In the blister product packaging industry, in the same batch of products delivered, some of the blister products are yellow in color and very ugly, especially when used for the final packaging, which greatly affects the sales and beauty of products, thus causing a certain loss to enterprises. However, the blister packaging manufacturers feel that there are many main reasons for the discoloration of the blister products. The main reasons are as follows:

1. Equipment

(1) the equipment is not clean. Dust or dust on the equipment will cause the blister sheet to be contaminated, which will cause the blister discoloration.

(2) the imbalance of thermocouple, temperature controller or heating system causes the temperature imbalance, which will also change the color of the blister package.

2. Mold

(1) the vent hole of the mold is not good, which leads to the dramatic reaction of the plastics under high temperature and pressure and oxygen, the burnt plastics and so on.

(2) the blister sheet material or the mold contains too much lubricant and mold release agent, so we should clean it on time, and then some additives like anti-static should be removed.

3. Sheet.

(1) high water content and volatile content.

(2) high temperature decomposition of stain and additive.

(3) the sheet is contaminated.

The reason why the thick film blister production material is recognized by the vast number of merchants in the field of packaging, among which the most important factor is that the plastic packaging material has the same excellent transparent characteristics of glass material, which can better display the packaged goods and improve the image and level of the goods. However, in the production and processing of blister packaging materials and blister packaging products, there are many factors affecting the transparency of the finished products of blister packaging, which is not conducive to the packaging display of products. For this, blister processing small make up for everybody introduced the factor that has an effect on transparency, in order to promote the transparency of packing material better.

The standard for judging the transparency of blister packaging materials usually includes transmittance, fog, refractive index, birefringence and dispersion. According to the light transmittance of the blister packaging materials, it can be divided into: transparent plastic packaging materials, the light transmittance of the visible light with a wavelength of 400nm-800nm is more than 80%; Translucent plastic packaging material: the transmittance of visible light of 400nm-800nm is between 50% and 80%; Opaque packaging material: the refractive index of visible light at 400nm-800nm is below 50%.

After knowing the factors that affect the transparency of the finished products of blister packaging, of course, the editor below introduces the methods to improve the transparency of blister packaging materials, mainly including: reducing crystallinity, controlling the purity of plastic production, improving refractive index and reducing birefringence.

1. Increase the light transmittance of transparent resin by adding nucleating agent, and promote the crystallization of small molecules to play the role of crystal nucleus;

2. Improve the transparency of plastics by bidirectional stretching, which can break the original crystal particles in the products, make the crystal size smaller, and achieve the purpose of improving the transmittance;

3. Improve the transparency of plastics through blending, that is, adding other resins to the transparent resin to improve the transparency.