久久久性生活视频_国产免费内射又粗又爽密桃视频_欧美区在线播放_久久精品成人欧美大片

How to classify Jiangmen engineering plastics?

1. Classification by application characteristics

According to the different application characteristics of famous plastics, plastics are usually divided into three types: general plastics, engineering plastics and special plastics.

(1) general plastic

Generally, it refers to plastics with large output, wide use, good formability and low price, such as polyethylene, polypropylene, phenolic resin, etc.

(2) engineering plastics

General grease can bear external force, has outstanding mechanical function, high and low temperature resistance function, and has good dimensional stability. It can be used as plastics for engineering structures, such as polyamide, polysulfone, etc.

In engineering plastics, it is divided into general engineering plastics and special engineering plastics.

(3) special plastics

Generally, it refers to plastics with special functions that can be used in special application fields such as aviation and aerospace. For example, fluoroplastics and organosilicon have outstanding high-temperature resistance, self-lubricating and other special functions, while reinforced plastics and foamed plastics have high strength, high cushioning and other special functions. These plastics belong to the category of special plastics.

2. Classification by physical and chemical characteristics

According to the different physical and chemical properties of various plastics, plastics can be divided into thermosetting plastics and thermoplastics.

(1) thermosetting plastics

Thermosetting plastics refer to plastics that can cure or have insoluble (melting) properties under heating or other conditions, such as phenolic plastics, epoxy plastics, etc. Thermosetting plastics are divided into formaldehyde crosslinking type and other crosslinking type.

Formaldehyde crosslinked plastics include phenolic plastics and amino plastics (such as urea formaldehyde melamine formaldehyde, etc.).

Other cross-linked plastics include unsaturated polyester, epoxy resin, o-phthalic diallyl resin, etc.

Jiangmen engineering plastics

(2) thermoplastics

Thermoplastics refer to plastics that can be repeatedly heated, softened and cooled and hardened within a specific temperature range, such as polyethylene, polytetrafluoroethylene, etc. Thermoplastics are divided into hydrocarbon, vinyl containing polar genes, engineering, cellulose and other types.

3. Classification by processing method

According to different molding methods of various plastics, they can be divided into film pressing, laminating, injection, extrusion, blow molding, casting plastics and reaction injection plastics.

Source: Jiangmen engineering plasticshttp://www.jxrytd.com/