Plasticventing system design and manufacturing
What is injection mold venting and why vent?
Mold venting is a process that is used to remove trapped air from the closed injection mold and volatile gas from the processed melting plastic. Without mold venting, the trapped air will compress as plastic tries to force it out of the mold and the air will ignite, burning the surrounding plastic and causing charred areas on the plastic molded part. Trapped air also keeps the plastic from filling in those areas of the mold cavity where the air is trapped so a non-filled (or short) part is molded. Volatile gases will be absorbed by the plastic and will cause voids, blisters, bubbles, and a variety of other defects.
SEASKYTOOLING plastic injection mold venting system design and manufacturing
- All of the end of the and runner slag have to be vented.
- There should be enough venting for cavity; Also there should be venting at the opposite side of the , air trapped area and aftermost plastic resin flow.
- To lead the venting on core pin and inserts out of injection mold.
- Preferentially use grinding machine or EDM machine to manufacture venting.
- Venting require as below, different resin with different venting depth.
MATERIAL Venting Min. Max. ABS 0.025 0.04 POM 0.015 0.025 PMMA 0.035 0.05 PA 0.01 0.015 PA+GF 0.035 0.05 PS 0.015 0.025 PC 0.04 0.06 PBT 0.01 0.02 PE 0.015 0.03 PP 0.02 0.05