Polybutylene Terephthalate (PBT) is a semi-crystalline, white or off-white polyester it is resistant to solvents, shrinks very little during forming, is mechanically strong, heat-resistant up to 150 °C (or 200 °C with glass-fibre reinforcement) and can be treated with flame retardants to make it noncombustible.
4DUR® is the registered trade mark for Polybutylene Terephthalate (PBT) compounds produced by 4PLAS. We offer a wide range of PBT compounds as well as a range of PBT/PET, PBT/ASA and PBT/PC blends.
4DUR® compounds offer the following key properties:
- Excellent stiffness and hardness
- Good mechanical strength
- Good creep and fatigue behaviour
- Very good thermal stability
- Excellent flammability resistance
- Good electrical properties
- High wear resistance and low friction
- Good dimensional stability
- Very good chemical resistance
- Excellent flow and processing properties
- Low moisture absorption
- Very good surface finish
With the addition of a wide range of modifiers, stabilisers, speciality additives and customised colours, 4DUR® can be compounded as:
- Impact modified
- Glass fibre reinforced
- Glass bead reinforced
- Mineral filled and reinforced
- Carbon fibre reinforced
- Flame retardant including UL listed grades
- Low warpage
- Heat stabilised
- Surface modified
- UV/ light stabilised
- Electrically conductive
- High tracking resistance
- Laser markable
For individual grades or to search using a wide range of criteria please use our interactive material selector.
Our standard range is comprehensive, however should you not find what you are looking for within the data available on this website, we offer Custom Compounds to suit the requirements of specific applications.
If you would like advice on selecting suitable materials, or you cannot find what you are looking for, please contact us and one of our team will be pleased to assist you.
4DUR® grades are supplied in pellet form and packed in moisture proof 25kg multi-layer bags. Other forms of packaging such as octabins and big- bags with PE or Aluminium liners are also available.
For PBT compounds, moisture content should be less than 0.04%, blends less than 0.02%. Moisture causes immediate hydrolytic degradation during processing, therefore 4DUR® grades should be dried at 120°C for 2 to 4 hours.
It is highly recommended that drying is conducted using desiccant driers. The performance of the desiccant drier depends on the dew point that indicates air moisture content. In order to obtain sufficient drying dew point values should be set below -20°C.
As the atmospheric humidity levels cannot be controlled the use of air circulating ovens or driers are not recommended.
4DUR® compounds can be processed on all commercial injection moulding machinery.
It is necessary to have precise temperature control for processing PBT compounds. The temperature of the nozzle is also very important in order to avoid thermal loss or overheating.
Short open nozzles are recommended to reduce shear. In general nozzle diameters should be 3 to 6mm.
For more information on this product, see our processing guides, troubleshooting guides and chemical resistance charts.
Regrind levels up to 25% can be used depending on the application and requirements. However, for flame retardant grades a maximum 10% addition rate is recommended. Regrind should be free of contamination, should not be thermally degraded and must be dry as moulded, or be dried prior to reuse.
Under normal conditions 4DUR® is not a toxic or hazardous material. During processing preventative action should be taken to avoid direct contact with the polymer melt or inhalation of any gases produced. Processing temperatures above 300°C should be avoided. Detailed safety information can be found in our material safety data sheets (MSDS).