The so-called 'plastic modification' refers to the method of changing the original performance and improving the performance on one or more aspects by adding one or more other substances to the plastic resin to achieve the purpose of expanding the scope of application. Modified plastic materials are collectively referred to as 'modified plastics'.
There are roughly the following types of plastic modification methods:
1, enhanced: By adding fiberglass, carbon fiber, mica powder and other fibrous or flaky fillers to increase the rigidity and strength of the material, such as glass fiber reinforced nylon used in power tools.
2, toughening: By adding rubber, thermoplastic elastomers and other materials to the plastic to achieve the purpose of improving its toughness / impact strength, such as toughened polypropylene commonly used in automotive, home appliances and industrial applications.
3, blending: Two or more incompletely compatible polymeric materials are uniformly mixed into a macroscopically compatible, microscopically phased mixture to meet certain requirements for physical and mechanical properties, optical properties, processability, and the like.
4, alloy: Similar to blending, but the compatibility between components is good, it is easy to form a homogeneous system, and some properties that cannot be achieved by a single component, such as PC/ABS alloy, or PS modified PPO, can be obtained.
5, padding: Improve physical and mechanical properties or reduce costs by adding fillers to plastics.
6, other modification: Such as the use of conductive fillers to reduce the electrical resistivity of plastics; the addition of antioxidants / light stabilizers to improve the weatherability of materials; the addition of pigments / dyes to change the color of the material, the addition of internal / external lubricants to improve the processing properties of the material, Use nucleating agents to change the crystallization properties of semi-crystalline plastics to improve their mechanical and optical properties.
In addition to the above physical modification methods, there are also methods for modifying plastics by chemical reactions to obtain specific properties, such as maleic anhydride grafted polyolefins, cross-linking of polyethylene, and the use of peroxides in the textile industry. Degrade the resin to improve fluidity / fiberizing properties.
A variety of modification methods are often used together in the industry, such as adding a toughening agent such as rubber in the plastic reinforcement modification process without excessive loss of impact strength; or physical mixing in the production of thermoplastic vulcanizate (TPV). And chemical cross-linking, etc.
In fact, any plastic raw material should contain at least a certain proportion of stabilizers at the factory to prevent its degradation during storage, transportation and processing. Therefore, the 'non-modified plastic' in the strict sense does not exist. However, in the industry, the base resin produced by the chemical plant is usually referred to as 'non-modified plastic' or 'pure resin'.