The density (specific gravity) of PBT resin is an industry-recognized standard physical parameter. As a general-purpose engineering plastic with fast crystallization and excellent moldability, it has stable base density values tested in accordance with international standards such as ASTM D792 and ISO 1183.

Density varies slightly across different grades and modified types of PBT, with all values being industry-recognized measured data:

Pure PBT resin: 1.30～1.35 g/cm3, typical value 1.31～1.33 g/cm3

Glass fiber-reinforced PBT (10% glass fiber): 1.38～1.42 g/cm3

Glass fiber-reinforced PBT (20% glass fiber): 1.45～1.49 g/cm3

Glass fiber-reinforced PBT (30% glass fiber): 1.50～1.55 g/cm3

Flame-retardant reinforced PBT: 1.52～1.60 g/cm3, with halogen-free flame-retardant systems showing smaller density increases than halogenated systems

Inorganic-filled PBT: 1.55～1.70 g/cm3, with higher filler ratios leading to greater density

This density parameter is a core reference for the design of connectors, relay housings, and automotive functional parts. Density changes after modification directly affect product weight and assembly accuracy, and it also serves as an auxiliary reference for mold cooling and injection process parameter setting.