Aicaigou LogoB2B Wiki

PBT Material Properties Table

Updated: 2026-07-15

Overview

Polybutylene Terephthalate (PBT) is a semi-crystalline thermoplastic polyester renowned for its balanced mechanical, thermal, and electrical properties. Developed as an engineering plastic, PBT combines the rigidity of PET (Polyethylene Terephthalate) with enhanced processability, making it a versatile material for injection molding and extrusion applications. PBT is particularly valued in industries requiring dimensional stability and resistance to harsh environments. Its molecular structure contributes to low moisture absorption, which is critical for maintaining performance in humid conditions. The material is available in various grades, including glass-fiber reinforced and flame-retardant versions, to meet specific industry requirements.

Physical and Chemical Properties

PBT exhibits a density range of 1.31-1.38 g/cm³, with a melting point between 220-230°C. Its semi-crystalline nature provides good stiffness and strength, while additives like glass fibers can further enhance these properties. The material's low moisture absorption (typically <0.1% after 24 hours) ensures minimal dimensional changes in wet environments. Chemically, PBT demonstrates excellent resistance to oils, greases, and aliphatic hydrocarbons, though it may degrade when exposed to strong acids or bases. Its electrical insulation properties remain stable across a wide temperature range, making it suitable for electronic components. PBT's UV resistance is moderate but can be improved with stabilizers for outdoor applications.

Main Applications

In the automotive sector, PBT is used for under-the-hood components like sensor housings and connector systems due to its heat resistance (up to 150°C continuous use). Electrical applications include circuit breakers, switchgear, and LED housings, where its dielectric strength and flame retardancy (in modified grades) are critical. The consumer goods industry utilizes PBT for kitchen appliance parts, power tool housings, and IT accessories. Its ability to withstand repeated sterilization makes it suitable for certain medical device components. Industrial applications encompass pump impellers, gear wheels, and conveyor system parts where wear resistance and low friction are required.

Safety and Storage

PBT is generally considered safe for handling under normal conditions, classified as non-hazardous under OSHA standards. However, processing at high temperatures (above 300°C) may release terephthalic acid and butanediol vapors, requiring adequate ventilation systems in manufacturing environments. Storage recommendations include keeping PBT pellets in their original packaging at temperatures below 40°C with relative humidity under 50%. Prolonged exposure to moisture can lead to hydrolysis during processing, so drying at 120°C for 3-4 hours is advised before molding operations. Bulk storage should use sealed containers with desiccants to prevent moisture absorption.

B2B Procurement Guide

When sourcing PBT, buyers should specify required certifications such as UL recognition, RoHS compliance, or FDA approval for food-contact applications. Technical datasheets should be reviewed for key parameters: tensile strength (typically 50-60 MPa for unfilled grades), impact resistance (5-7 kJ/m² Charpy notched), and thermal deflection temperature (55-205°C depending on reinforcement). For large-volume procurement, consider suppliers with ISO 9001 certification and material traceability systems. Price negotiations should account for grade variations – glass-filled (30% reinforcement) commands approximately 15-20% premium over standard grades. Lead times vary from 2-6 weeks for standard formulations, with custom-compounded versions requiring longer.

Related Manufacturers