Plastics are made of synthetic resin. The main component of plastics is resin. Resin refers to polymer compounds that have not been mixed with various additives.
The basic properties of plastics mainly depend on the nature of resin, but additives also play an important role. Some plastics are basically composed of synthetic resin without or less additives, such as plexiglass, polystyrene, etc.
Plastics can be divided into thermosetting and thermoplastic. The former cannot be re molded and used, and the latter can be re produced. Thermal plasticity has a large physical elongation, generally 50% ~ 500%. The force is not completely linear at different elongation.
The different properties of plastics determine their use in industry. With the progress of technology, the research on the modification of plastics has not stopped. It is hoped that in the near future, plastics can be used more widely after modification, and can even replace materials such as steel and no longer pollute the environment.
Plastic packaging materials have the advantages of light weight, high strength, good impact resistance, transparency, moisture resistance, beauty, stable chemical properties, good toughness and anti-corrosion. They have widely replaced metals, wood, paper, glass and leather in the field of packaging. Therefore, plastic packaging plays an irreplaceable role in reducing the pressure of resources and energy in China.
However, plastic packaging materials have a fatal weakness, that is, their natural degradation time is long, some of which are more than 100 years. The non degradability of plastics leads to the long-term existence of its waste. Therefore, the recycling of plastic packaging waste is imminent.