High-temperature engineering plastics that can also be used in hot runner systems include polyetherimide (PEI), polysulfone (PSU), polyarylethersulfone (PES), and modified polyphenylene ether (PPO). These materials possess excellent heat resistance, dimensional stability, and processing performance, making them suitable for demanding injection molding environments.
1. Polyetherimide (PEI)
Heat Resistance: Glass transition temperature up to 215℃, short-term resistance to 220℃
Advantages: Excellent electrical insulation and flame retardancy (UL94 V-0 rating) Low molding shrinkage (0.5%～0.7%), suitable for precision parts Can be injection molded and extruded, easy post-processing
Applications: Heating component supports, sensor sleeves, insulating terminals in hot runner systems
Processing Recommendations: Pre-drying to moisture content <0.02% is required; recommended mold temperature 170～190℃
2. Polysulfone (PSU)
Heat Resistance: Long-term operating temperature up to 180℃, retaining over 80% of mechanical strength at 150℃
Advantages: High creep resistance, excellent dimensional stability
Resistant to hydrolysis and steam, suitable for high-temperature sterilization environments
Can be metallized (e.g., electroplating) to improve thermal conductivity or shielding performance
Applications: Hot runner manifold supports, high-temperature connector housings
Notes: Stress cracking may occur under high temperature and high humidity loads, requiring optimized structural design
3. Polyarylene ether sulfone (PES)
Heat resistance: Continuous use temperature above 200℃, heat distortion temperature up to 210℃
Advantages: Good light transmittance, facilitating integration into visual inspection systems
High rigidity, low creep, excellent fatigue resistance
Radiation resistant, suitable for medical and aerospace applications
Applications: Transparent observation windows and precision guide sleeves for high-end hot runner systems
Processing requirements: Drying temperature 140℃, time 4-6 hours, preventing bubbles and degradation
4. Modified Polyphenylene Oxide (PPO/M-PPO)
Heat Resistance: Glass transition temperature reaches 210℃, one of the highest among thermoplastics.
Advantages: Stable dielectric properties, suitable for high-frequency electrical environments. Dimensionally stable, low water absorption, suitable for long-term operation. Can be blended with HIPS (e.g., NORYL™) to improve processing flowability.
Applications: Hot runner temperature control module housing, electronic control box.
Limitations: Poor resistance to organic solvents, prone to stress cracking, contact with oily substances should be avoided.
