PEI (Polyetherimide) is an amorphous high-performance special engineering plastic. Its molecular chain combines the flexibility of ether bonds with the rigidity of imide rings, with high base density. Core advantages include excellent heat resistance, mechanical strength, electrical insulation, and dimensional stability, along with natural flame retardancy, excellent chemical corrosion resistance, and hydrolysis resistance, can withstand high-temperature steam sterilization, non-toxic, making it a core material in aerospace, high-end electronics, and medical fields. The overall density of PEI is stable, with fluctuations mainly coming from modification types and filling components. Different types and modified versions of PEI have slight density variations, which are directly related to the design, processing, and performance guarantee of high-end precision components.
General-purpose pure PEI: 1.27–1.29 g/cm³, typical value 1.28 g/cm³. The amorphous structure gives it excellent toughness and dimensional stability, good processing performance, suitable for various high-end basic precision components.
Glass fiber reinforced PEI (10–40%): 1.36–1.58 g/cm³. The higher the glass fiber content, the more obvious the density increase. The material's strength, rigidity, and creep resistance increase step by step, suitable for ultra-high-load, ultra-high-temperature working conditions.
Mineral-filled PEI: 1.33–1.50 g/cm³. Filling content is positively correlated with density. It mainly adds minerals such as talc and glass beads to focus on improving dimensional stability, reducing warpage, and controlling production costs.
Flame-retardant PEI (natural flame retardant, no need for addition): 1.27–1.29 g/cm³. The material itself has UL94 V-0 flame retardancy, no need to add additional flame retardants, density consistent with pure PEI, meeting high-end electronic safety standards, environmentally friendly and residue-free.
Medical/food-grade PEI: 1.27–1.29 g/cm³. Passed FDA and USP Class VI certifications, with minimal density fluctuation. The core guarantee is hygiene and safety and resistance to steam sterilization, non-toxic, no odor, suitable for medical and food contact scenarios.
Glass fiber + mineral composite PEI: 1.38–1.60 g/cm³. It combines the high strength of glass fiber with the dimensional stability of minerals, with density between single reinforcement systems, more balanced comprehensive performance, suitable for complex high-end precision structural components.
This density parameter is the core basis for the design of high-precision products such as aerospace structural components, high-end electronic connectors, printed circuit boards, medical surgical instruments, automotive engine peripheral parts, and semiconductor processing equipment. The amorphous structure and excellent comprehensive performance ensure stable dimensional accuracy under extreme temperature, strong chemical corrosion, and high-load conditions. Density calculation is also key data for product lightweight design, mold cavity design, assembly gap matching, and injection molding process parameter setting, while supporting the play of its core characteristics of ultra-high heat resistance, high rigidity, and natural flame retardancy.
