What are the processing points of PBT engineering plastics

2019-08-09 1196

Monotonic treatment: this kind of data is easy to hydrolyze under high temperature, so monotonic treatment before processing is very important. It is suggested that the monotonic condition in air is 120 ℃, 6-8 hours, maybe 150 ℃, 2-4 hours. It is necessary that the humidity be less than 0.03%. If the hygroscopic monotone is used, the recommended condition is 150 ℃ for 2.5 hours.

2. Melting temperature: 225-275 ℃, recommended temperature: 250 ℃.

Mold temperature: 40-60 ℃ for unreinforced type. The cooling cavity of the mold should be well designed to reduce the twists and turns of the plastic parts. The loss of heat must be fast and uniform. It is recommended that the diameter of the mold cooling cavity is 12mm.

3 injection pressure: medium (up to 1500bar).

4 injection speed: the injection speed should be as fast as possible (because PBT coagulates quickly).

5 runner and gate: Circular runner is recommended to increase pressure transmission (empirical formula: runner diameter = plastic thickness +1.5mm). Be able to use various types of gates. Warm runner can also be used, but attention should be paid to avoid data leakage and degradation. The gate diameter should be between 0.8-1.0*t, where t is the thickness of the plastic part. For submerged gates, a minimum diameter of 0.75mm is recommended.

Article source: PBT engineering plastics http://www.wywantong.com/