High-Temperature Plastics: Types and Heat Resistance Temperatures
High-temperature plastics refer to engineering plastics that can stably maintain mechanical properties, dimensional stability, and chemical resistance at long‑term operating temperatures above 100°C. They are widely used in automotive electronics, mold manufacturing, medical devices, home appliances, and aerospace fields. For mold designers, injection technicians, and product developers, understanding the heat resistance levels and application characteristics of various high‑temperature plastics is critical for material selection, structural design, and process matching. This article classifies common high‑temperature plastics by heat resistance level, provides accurate temperature data, and explains performance characteristics and application scenarios for industrial reference.
Ultra-High-Temperature Plastics
PEEK (Polyetheretherketone)
Long-term heat resistance: 250°CShort-term heat resistance: 300°CPEEK is recognized as one of the most comprehensive high‑performance thermoplastics. It features high strength, excellent wear resistance, outstanding chemical corrosion resistance, and high dimensional stability. It can be processed by conventional injection molding and is widely applied in precision mold components, medical instruments, automotive engine peripherals, and high‑performance electronic parts.
PI (Polyimide)
Long-term heat resistance: above 260°CShort-term heat resistance: above 400°CPI has top‑level thermal stability, electrical insulation, and radiation resistance. It remains stable under extremely high temperatures without decomposition or deformation. However, it is expensive and difficult to mold, usually requiring special processes such as compression molding or machining. It is often used in high‑end mold insulation parts, aerospace components, high‑temperature sensors, and electronic packaging.
PAI (Polyamide-imide)
Long-term heat resistance: 220°C–250°CPAI combines high strength, wear resistance, oil resistance, and dimensional stability. It offers better processability than PI and lower cost, making it suitable for precision mold guiding components, automotive transmission parts, high‑temperature bearings, and precision electrical components.
PPS (Polyphenylene Sulfide)
Long-term heat resistance: 200°C–220°CPPS has inherent flame retardancy, excellent chemical resistance, good dimensional stability, and high flowability. It is easy to injection mold and cost‑effective, making it one of the most commonly used high‑temperature plastics in mass production. Typical applications include electronic connectors, automotive electronics, home appliance components, and mold structural parts.
High-Performance Heat-Resistant Plastics
LCP (Liquid Crystal Polymer)
Long-term heat resistance: 180°C–240°CLCP exhibits extremely high flowability and is suitable for thin‑wall and micro‑precision molding. It provides excellent dimensional accuracy, thermal stability, and electrical insulation. It is widely used in precision connectors, micro parts, camera brackets, and thin‑wall injection products.
PES (Polyethersulfone)
Long-term heat resistance: 150°C–180°CPES is transparent, hydrolysis‑resistant, non‑toxic, and chemically stable. It can be stably injection molded and is widely used in medical consumables, food‑contact components, transparent structural parts, and high‑temperature electronic equipment.
PSU (Polysulfone)
Long-term heat resistance: 150°C–180°CPSU features good impact resistance, hydrolysis resistance, and dimensional stability. It can be used for transparent products and is commonly applied in medical devices, food utensils, electronic housings, and transparent mold components.
PPA (High-Temperature Polyamide)
Long-term heat resistance: 140°C–170°CPPA provides significantly improved heat resistance, rigidity, and oil resistance compared with standard nylons. Glass fiber reinforcement further enhances its comprehensive performance. It is widely used in automotive electronics, gears, connectors, and mold auxiliary components.
PTFE (Polytetrafluoroethylene)
Long-term heat resistance: 260°CPTFE offers exceptional corrosion resistance, self‑lubrication, and thermal stability. It is difficult to injection mold and is mainly used in anti‑corrosion parts, seals, mold insulation components, and high‑temperature insulation parts.
Medium-High-Temperature Engineering Plastics
PC (Polycarbonate)
Long-term heat resistance: 100°C–120°CPC features high transparency, excellent impact resistance, and good dimensional stability. It is suitable for mass injection molding and widely used in home appliance housings, transparent parts, and general high‑temperature components.
PBT (Polybutylene Terephthalate)
Long-term heat resistance: 100°C–130°CPBT has good electrical properties, low warpage, and high molding efficiency. It is widely used in electronic connectors, coil bobbins, and automotive electrical components.
PET (Polyethylene Terephthalate)
Long-term heat resistance: 100°C–120°CPET provides high strength, fatigue resistance, and stable molding performance. It is commonly used in electronic parts, structural components, and heat‑resistant housings.
Reinforced PA66 (Reinforced Polyamide 66)
Long-term heat resistance: 110°C–130°CGlass fiber reinforcement significantly improves rigidity, strength, and thermal stability. It is widely used in automotive parts, gears, bearings, mold peripheral components, and electronic parts.
Material Selection Guidelines
Selection of high‑temperature plastics must be based on actual operating temperature, mechanical load, service environment, molding process, and cost. For long‑term working temperatures above 200°C, PEEK, PPS, PI, and PAI are preferred. For temperatures between 150°C and 200°C, LCP, PES, PSU, and PPA are suitable. For temperatures between 100°C and 150°C, PC, PBT, PET, and reinforced PA66 are commonly selected. Reasonable material selection helps improve product reliability, reduce mold risks, and optimize production efficiency.
