PI (Polyimide) is one of the organic polymer materials with the highest known heat resistance, belonging to the top of special engineering plastics. Its molecular chain contains a large number of aromatic rings and imide rings, with high base density. Core advantages include unparalleled heat resistance, radiation resistance, chemical corrosion resistance, excellent mechanical properties, and electrical insulation performance, with excellent dimensional stability, can be used for a long time in extreme environments, making it an indispensable key material in aerospace, microelectronics, and high-end equipment fields. The density fluctuation of PI mainly comes from modification types and filling components. Different types and modified versions of PI have slight density variations. Accurate grasp of its density parameters is the key to the design and performance guarantee of core components under extreme working conditions.
Thermoplastic pure PI: 1.38–1.43 g/cm³, typical value 1.40 g/cm³. Amorphous or semi-crystalline structure, with excellent thermal stability and processing performance (thermoplastic PI), suitable for high-end precision molding scenarios.
Glass fiber reinforced PI (10–30%): 1.48–1.65 g/cm³. The higher the glass fiber content, the more obvious the density increase. The material's strength, rigidity, and creep resistance are significantly improved, suitable for ultra-high-load, ultra-high-temperature working conditions.
Graphite/carbon fiber filled PI (wear-resistant self-lubricating type): 1.40–1.55 g/cm³. Filling content is positively correlated with density. The core is to improve wear resistance and self-lubrication, suitable for extreme working conditions of oil-free lubrication and high-speed friction.
Mineral-filled PI: 1.42–1.60 g/cm³. Filling content is positively correlated with density. It mainly adds minerals such as talc and aluminum nitride to focus on improving thermal conductivity, dimensional stability, or reducing production costs.
Flame-retardant PI (natural flame retardant, no need for addition): 1.38–1.43 g/cm³. The material itself has UL94 V-0 flame retardancy, with extremely low smoke generation, density consistent with pure PI, environmentally friendly and stable in performance, suitable for high-end safety scenarios.
Glass fiber + carbon fiber composite reinforced PI: 1.50–1.70 g/cm³. It combines the high strength of glass fiber with the high modulus and lightweight of carbon fiber, with density between single reinforcement systems, ultimate comprehensive performance, suitable for top precision structural components such as aerospace.
This density parameter is the core basis for the design of high-precision products such as aerospace engine components, satellite structural components, microelectronic chip packaging, flexible circuit boards, high-end bearings, seals, and high-temperature resistant insulation films. Its unique molecular structure ensures near-perfect dimensional accuracy under extreme working conditions such as ultra-high temperature, strong radiation, high vacuum, and strong chemical corrosion. Density calculation is also key data for product strength check, mold design, assembly tolerance matching, and special molding process (such as compression molding, injection molding) parameter setting, while supporting the play of its core characteristics of ultra-high heat resistance, radiation resistance, and high insulation.
