UHMWPE Specific Gravity (Density)
UHMWPE (Ultra-High Molecular Weight Polyethylene) is a linear polyethylene with an extremely high molecular weight (typically over 1,000,000). Its ultra-long, highly entangled molecular chains provide exceptional wear resistance, impact resistance, low-temperature resistance, and chemical resistance. With a slightly higher density than ordinary HDPE, it is a core specialty material for wear, impact, and low-friction applications, widely used in machinery, mining, textiles, medical, and sports industries. UHMWPE density is primarily affected by molecular weight, polymerization process, and filler modification. Virgin material density is stable, with a slight increase after glass or carbon fiber filling. Accurate density is critical for wear-resistant component and impact-resistant structural part design.
Virgin UHMWPE: 0.930–0.940 g/cm³, typical value 0.935 g/cm³. It has the highest wear and impact resistance among thermoplastics, with low-temperature and chemical resistance and moderate density, suitable for wear-resistant liners, bearings, gears, artificial joints, and anti-collision components.
Wear-Resistant Modified UHMWPE: 0.935–0.950 g/cm³. Fillers like graphite and molybdenum disulfide slightly increase density, further reducing friction coefficient and improving wear life for high-frequency friction components.
Glass Fiber Reinforced UHMWPE: 1.00–1.15 g/cm³. Glass fiber filling increases density, enhancing rigidity and dimensional stability for high-load wear-resistant structural parts.
Conductive/Antistatic UHMWPE: 0.935–0.955 g/cm³. Conductive fillers increase density slightly above virgin material, providing antistatic and conductive properties for electronic and mining explosion-proof components.
Medical-Grade UHMWPE: 0.930–0.938 g/cm³. Purity optimization ensures stable density, primarily improving biocompatibility and wear life for artificial joint prostheses and orthopedic implants.
