Why are OPP and PE bags transparent? Recently, Xiaobian learned that some friends have doubts about the transparency of the plastic bags, OPP plastic bags and Po Plastic bags we usually use. Today, Xiaobian will explain one by one. Why the plastic bags in use are transparent? This is mainly because any crystal type opening agent has a certain negative impact on the transparency of the plastic bags, that is, a kind of mist will be formed in the film. However, due to the variety of the opening agent used in the product, the degree of influence will be different. However, the main factors affecting the transparency of the plastic bag are as follows:

1. Chemical purity of the opening agent. The purity of chemically synthesized crystals is much higher than that of natural minerals. Therefore, the transparency of the opening agent made by the chemical synthesis process is obviously higher than that of the natural mineral.

2. Optical refractive index of the opening agent. When the direct light passes through the contact interface of two different substances, if two different substances have the same refractive index, the loss of the direct light passing through is the smallest in the linear range of the original incidence angle. If the refractive index difference between two different materials is larger, the loss of direct light passing through in the linear range of the original incidence angle is larger. Therefore, the natural talcum powder and silica have great attenuation on the direct light, and have obvious influence on the transparency of OPP bag.

3. Dosage of opening agent. Because of the different sources of crystal type opening agent, the heavy crystal refers to the natural mineral type opening agent, and the light crystal refers to the chemically synthesized opening agent. The difference between the two is that there is a significant difference in weight under the same volume.