How deep are you cutting vents on 30% glass-filled nylon before flash becomes a problem? I’m at 0.0008 in (0.02 mm) with a 3 mm land on a 4-cavity injection mold and still getting splay and occasional burn after 250k shots, even with a hot runner and 12 s cycles. Before I reface the parting line, has anyone had better luck adding sub-vents or vacuum at the end-of-fill?
We killed splay/burn on 30% GF nylon by shortening the land instead of going deeper — take it from 3 mm to about 0.5–1 mm and stone a tiny secondary relief right after the land (about 0.0005 in); that kept 0.0009 in vents clean without flash on a 4‑cav at 12 s. @ella2190 > add end-of-fill sub-vents or a small vacuum poppet… Agree, and pairing that with the shorter land made the burn disappear after about 200k; can you try a quick land trim on the next PM rather than refacing the PL?