Processing of various engineering plastics

1. Material properties

Engineering plastics possess outstanding mechanical properties, heat resistance, chemical stability and dimensional stability. Compared with general-purpose plastics such as PP and PVC, they can better meet the demanding industrial requirements.

High strength/rigidity: For instance, PA (nylon) and POM (polyoxymethylene) have high tensile strength.

Temperature resistance: The long-term service temperature can reach 80°C to 150°C (for example, PEEK can withstand 260°C).

Chemical resistance: Resistant to oil, acid, alkali, etc. (For example, PTFE is resistant to strong acid).

Wear resistance: POM and PA66 are suitable for gears and bearings.

Insulation property: Widely used in electronic components (such as PC, PBT).

2. Common types of engineering plastics

Typical applications of material name characteristics

PA (nylon) wear-resistant, high toughness, moisture-absorbing gears, pulleys, and housings

POM (polyoxymethylene) high-rigidity, low-friction bearings, valves, and fasteners

PC (polycarbonate) transparent, impact-resistant lenses, protective covers, electronic housings

PBT/PET dimensionally stable, electrically insulated connectors, switches

PEEK is heat-resistant and high-strength, suitable for aerospace and medical implants

PTFE (Teflon) self-lubricating and corrosion-resistant seals and gaskets

3. Processing technology

Injection molding: Mass production of complex-shaped parts (such as gears and housings).

CNC machining: Small-batch high-precision parts (such as PEEK bearings).

3D printing: Rapid prototyping (materials such as nylon powder, PC filament).

Extrusion/Blow molding: Pipes, films (such as PTFE pipes).

4. Typical application scenarios

Automotive industry: Fuel system components (PA), interior parts (PC/ABS).

Electronic and electrical appliances: sockets (PBT), insulating enclosures (PEI).

Mechanical Engineering: Wear-resistant gears (POM), Bearings (PI).

Medical equipment: Surgical instruments (PPSU), sterilized trays.

Aerospace: Lightweight structural components (PEEK).

5. Advantages vs. Metal parts

Lightweight: The density is only 1/4 to 1/8 of that of metal.

Self-lubricating: Self-lubricating materials (such as PTFE) reduce maintenance.

Design freedom: Complex geometric shapes can be formed.

Cost-effectiveness: Lower cost during mass production.

6. Precautions for Selection

Environmental factors: humidity (PA absorbs moisture), ultraviolet rays (stabilizers need to be added).

Load requirement: For dynamic loads, high fatigue strength materials (such as POM) are needed.

Tolerance control: Some materials have a large shrinkage rate (such as PA which requires post-treatment).