Why is plastic transparent? How can it be white after being folded?

Plastic is a polymer resin obtained by using oil or natural gas as raw material through synthesis reaction. The so-called polymer resin refers to the polymerization of monomer compounds through polymerization reaction, polymerization into polymer polymers, and its molecular weight can reach thousands or even millions. In the classification of the polymer field, those with a molecular weight of less than 1000 are called low molecules, those between 1000 and 10000 are called quasi-polymers or oligomers, and those with more than 10,000 are called polymers.

Generally, the plastic commonly used for molding processing has a molecular weight of about 10,000 and 1,000,000, and oligomers with a molecular weight of less than 10,000 are commonly used as textile resins, coatings, adhesives, synthetic resins, etc. Therefore, not all polymer polymers can be used as plastics, in fact, it depends on their molecular weight, molecular structure, functional groups, glass transition temperature (TG) and other factors.

Plastics change with temperature and intermolecular structure, such as glass, rubber, and molten glue.

This is determined by the extensibility of the plastic. When folding, the plastic is elongated, and you can carefully measure the length. If it is elongated, the original molecular structure is destroyed, and the color becomes white.

The white color of the plastic fracture surface is related to its internal structure and the scattering and recombination of light on its surface.

The structure of plastic is a pseudocrystalline state, a pure natural form. The internal structure is very complex, and when a beam of light hits its surface, a series of transmissions, reflections, and refractions occur. When the external light shines on the surface of the pseudocrystal, the tiny surface in all directions will transmit, refract and reflect the light, so that the layers of scattered light are formed.

In the world of light, ordinary white light is made up of 7 visible colors of light, which are mixed in proportion. When natural light hits a pseudocrystal, it transmits, reflects and refracts in all directions of the particle aggregate, and the resulting scattered light is recombined and meets the eye, giving the visual perception that plastic is white.

Because the crack in the crease that appears on the surface or inside the polymer material under tensile stress perpendicular to the direction of stress. When the angle of incidence of light hitting the fracture surface exceeds the critical angle, the fracture is silvery due to total reflection.

White is the tiny cracks, also known as silver veins.

Plastic is an organic substance, and there is a certain arrangement in the normal state.

When he bends repeatedly, his spatial regularity is broken.

Its refractive properties are altered.

This is determined by the extensibility of the plastic. When folding, the plastic is elongated, and you can carefully measure the length. If it is elongated, the original molecular structure is destroyed, and the color becomes white.

The problem is not because it is a problem of whether it is a colored plastic, but a problem of plastic polymers.

Today's plastic varieties have two common types of plastics that bleach at the twists and turns.

ABS (acrylonitrile-butadiene-styrene copolymer).

and PVC (polyvinyl chloride).

These two are also things that we can use on a daily basis.

Some plastic musical instruments used in schools are made of ABS.

For example, some shampoo bottles are made of PVC.

That's what I do as a plastic raw material.

If you have any questions, I can answer them for you.

This is determined by the properties of the plastic itself.

The phenomenon of silver streak is a micro-crack-like defect caused by polymer under the action of solvent, ultraviolet light, mechanical force and internal stress, and it shows a silvery-white luster under light irradiation.

Silver streaks are very similar to cracks, except that the cracks are empty in the middle, and the cavities in the middle of the silver veins are connected by silver streaks. The silver grain develops and becomes thicker, and the silver grain breaks down, that is, it becomes a crack.

Transparency means that light can pass through and it looks like no light is reflected in your eyes. There are creases after distortion, and the material is extruded, which causes uneven density, and the light cannot penetrate and causes reflections, so you look white.

If you don't know, you can look at what the letters marked under the cup are, and the PET may appear in the case of what you said.