Characteristics and Application of PBT Plastics
Chemical name: Polybutylene terephthalate (PBT)
Household appliances (food processing blades, vacuum cleaner components, electric fans, hair dryer shell, coffee containers, etc.), electrical components (switches, motor cases, fuse boxes, computer keyboard keys, etc.), the automotive industry (radiator grid , Body panels, wheel covers, doors and windows components, etc.).
Injection molding process conditions:
Drying: This material is very easy to hydrolyze at high temperatures, so the drying process before processing is very important. It is recommended that the drying conditions in air be 120 ° C, 6 to 8 hours, or 150 ° C for 2 to 4 hours. Humidity must be less than 0.03%. If dried with a hygroscopic dryer, the recommended conditions are 150 ° C for 2.5 hours
Melting temperature: 225 ~ 275 ℃, the proposed temperature: 250 ℃.
Mold temperature: 40 to 60 ° C for non-reinforced materials. The mold cavity of the mold is well designed to reduce the bending of the plastic parts. The loss of heat must be fast and uniform. It is recommended that the diameter of the mold cooling cavity be 12 mm.
Injection pressure: medium (up to 1500 bar).
Injection speed: should be used as soon as possible the speed of injection (because PBT solidification quickly).
Runners and gates: It is recommended to use a circular runner to increase the pressure transfer (empirical formula: runner diameter = plastic thickness + 1.5mm). You can use various types of gates. Hot runners can also be used, but care should be taken to prevent leakage and degradation of the material. The gate diameter should be between 0.8 and 1.0 * t, where t is the thickness of the piece. If it is submerged gate, the recommended minimum diameter of 0.75mm.
Chemical and physical properties:
PBT is one of the most tough engineering thermoplastic materials, it is semi-crystalline material, has very good chemical stability, mechanical strength, electrical insulation properties and thermal stability. These materials have very good stability under very wide environmental conditions. PBT moisture characteristics are weak.
The tensile strength of the non-reinforced PBT was 50 MPa, and the PBT tension strength of the glass additive was 170 MPa. Excessive glass additives will cause the material to become brittle. PBT; crystallization is very rapid, which will lead to uneven bending caused by bending deformation. For materials with a glass additive type, the shrinkage in the process direction can be reduced, but the shrinkage in the vertical direction of the process is substantially different from that of the ordinary material. General material shrinkage between 1.5% and 2.8%. The material containing 30% glass additive shrinks between 0.3% and 1.6%. Melting point (225 ℃) and high temperature deformation temperature are lower than PET material. Vicat softening temperature is about 170 C. Because PBT crystallization rate is very high, so its viscosity is very low, plastic parts processing cycle time is generally low.
Asia Billion Industry Co., Limited (ABIL) is a leading qualified plastic injection molding manufacturer, offering a range of products for a variety of industries that include the automotive, home appliance, electronic, electrical, medical, defense, construction and so on. We are also a professional manufacturer of plastic injection tooling and precision-machined products. Based in Shenzhen City of China, we have been engaged in the plastic injection molding manufacturing business for many years. We offer the professional, most cost-effective, quick reaction, high quality molding and tooling services all over the world with different approach to plastic solutions.
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