PBT

Polybuthyleneterephtalate is a semi-crystalline polyester. It is an
engineering plastic with high stiffness and strength with a very low
moisture absorption (an important difference with polyamides).
It is often applied in glass fiber filled compounds to gain a much higher
stiffness and strength. Due to the excellent electrical insulating properties,
also in wet conditions, it is mainly applied in electronics.
PBT has a good chemical resistance and a good long term high
temperature stability, important for electronics and automotive
applications. Many flame retardant grades are available (UL-V0).

Specific properties
Density: 1.30 g/cm3. (Higher for glass filled PBT).

Mechanical properties: Young´s Modulus ca 2.7 GPa and strength ca. 55 MPa,
both much higher in glass filled compounds. Low coefficient of friction
and high wear resistance. Good fatigue resistance.

Thermal properties: Tg around 50-60 °C, Tm ca. 225 °C.
Good resistance against continuous use at high temperatures.

Chemical resistance: very good resistance against many organic solvents,
oils and greases, and weak acids. Is attacked by strong acids and bases.

Colour/surface
White opaque with glossy surface. Can be coloured in any colour.

Processing
Easily injection moulded and extruded. Needs to be dried very well to
prevent degradation. Due to the crystallinity the shrinkage is around 2%.

Applications
- Electronics: connectors, switches, coils, bobbins, capacitors,
relays, circuit breakers.
- Automotive sector: electronic connectors, door handles,
windscreen wipers, headlamp units.
- Consumer products: oven knobs, handles, housings (iron),
lighting fixtures.
- Industry: gears, pump housings, impellers, fan blades.