
How to choose the Engineering Plastic ?
1.Identify Key Operating Conditions
First, define the critical parameters of your working environment:
Mechanical loads: Tensile/compressive strength, impact resistance, flexural modulus.
Thermal conditions: Operating temperature range (continuous vs. intermittent), thermal expansion, heat deflection temperature (HDT).
Chemical exposure: Resistance to solvents, acids, bases, oils, or fuels.
Electrical requirements: Dielectric strength, volume resistivity, arc resistance (for electrical applications).
Environmental factors: UV radiation, moisture/humidity, outdoor weathering.
Friction/wear: Coefficient of friction, abrasion resistance, need for lubrication.
**Example Workflow**
Suppose you need a plastic for an automotive engine component exposed to oil (chemicals) at 180°C (high temp) with moderate mechanical stress:
1. Prioritize **thermal stability** (HDT > 180°C) and **oil resistance**.
2. From the table, PPS (polyphenylene sulfide) or PEEK are top candidates.
3. Compare cost: PPS is more affordable than PEEK for this scenario.
4. Verify processability (PPS is injection-moldable) and confirm regulatory compliance (automotive OEM standards).