The benefits provided by polybutylene terephthalate include:
1.Good creep resistance over steady and elevated temperatures
2.Blocks UV radiation and excellent heat aging behavior
3.Meets numerous agency and regulatory approvals for food, medical and potable water applications, as well as specialized performance specifications
4.It has robust chemical resistance to a wide range of chemicals such as diluted acids, alcohols, aromatic hydrocarbons, ketones etc., solvents, oils and greases. This makes it suitable for use to produce plastic parts that are exposed to organic solvents,gasoline, oils and hence avoid erosion after period of time.
5.By incorporating fillers, reinforcing materials, and additives during compounding, material properties can be tailored to
requirements. A benzotriazole-type UV stabilizer is generally used with PBT because it offers low initial color and good color stability.
PBT Injection Molding Conditions
Before injection molding, predrying is recommended to control moisture content below 0.02%
Mold Temperature: 40-80°
Mold Shrinkage: Higher the mold temperature, greater is the shrinkage
Unfilled: 1.4-2.0%
Glass-fiber Reinforced: 0.4-0.6%
Injection Pressure: 100-140 MPa / 1000-1400 Bar
Screw: Graded three-zone screw with L/D ratio of 15-20 & compression ratio of 2.5-3.0