Plastic Parts Design Guide-Material Selection
publisherkarl
time2025/05/20
- Plastic injection manufacturers will show you different plastic raw materials and choose the right material to start your project.
一. Plastic
1. Definition of Plastic
Plastic: Mainly composed of carbon, oxygen, hydrogen, nitrogen and other organic or inorganic elements. The finished product is solid, and it is a molten liquid during the manufacturing process. Therefore, it can be formed into various shapes by heating to melt it, applying pressure to make it flow, and cooling to solidify it. This large and varied group of materials is called plastics.
For plastic custom factories, injection molding is already a very mature process, and more and more customers choose this process, but they seem to be a little hesitant about the choice of materials.
If you happen to encounter this problem, you can also contact me. I will analyze how to choose from multiple dimensions.
2. Characteristics of plastics
1) Low strength and toughness
2) Abundant raw materials, low price
3) Easy to form, easy to process into complex shapes, and can be mass-produced
4) Lightweight, low density (plastic specific gravity 0.9~2, aluminum 2.7, iron 7.8)
5) Easy to produce continuous deformation when subjected to external force
6) Bright colors, easy to color, and appropriate addition of colorants can change its color
7) Good insulation
8) Good corrosion resistance, water resistance, oil resistance, acid resistance, chemical resistance, and no rust
9) Poor heat resistance, most plastics have a heat resistance temperature of about 150℃ or below
10) Non-conductive and non-thermal
11) Can have other special properties, such as transparency, elasticity, etc.
3. Injection Molding
A typical injection molding machine mainly includes five units: mold system, injection system, hydraulic system, control system, and door lock system.
二. Choice of plastic material
| Classification | Concept | Example | Application |
| General Plastics | Good molding performance, low price and wide application | PE、PP、EEA、PVC | Film, pipe, shoe material, basin, barrel, packaging material |
| Ordinary engineering plastics | Refers to materials with medium comprehensive mechanical properties and used as non-load-bearing materials in engineering | PS、HIPS、ABS、AAS、ACS、MBS、AS、PMMA | Various product shells and housings |
| Structural Engineering Plastics | Refers to materials with high comprehensive mechanical properties, used as product structural parts in engineering, and capable of bearing high loads. | PA、POM、NORYL、PC、PBT、PET | Various product shells |
High temperature resistant engineering plastics | Refers to plastics that can still maintain high mechanical properties under high temperature conditions, high temperature resistance and high rigidity | PI、PPO、PPS、PSF、PAS、PAR | Automobile engine parts, oil pump and air pump covers, high temperature sockets for electronic and electrical instruments |
Plastic alloy | Refers to a class of high-performance, functional, and specialized new materials obtained by physical blending or chemical grafting. | PC/ABS、PC/PBT、PC/PMMA | Automobiles, electronics, precision instruments, office equipment, packaging materials, building materials |
Thermoplastic elastomer | Refers to a class of polymer materials with physical properties between rubber and plastic. It has both the elasticity of rubber and the processability of plastic. | Automobile, electronics, electrical, construction, engineering and daily necessities | |
Modified plastics | Refers to adding various additives, fillers and reinforcing agents (such as glass fiber, conductive fiber, flame retardant, impact agent, flow agent, light stabilizer) to plastic raw materials. | Automobile, machinery, electrical appliances, ships, aerospace and other fields |
