24-07-2026 Because every machine and material is different, you can’t blindly copy exact numbers. Here’s a rule‑of‑thumb rhyme to judge if your back pressure is right: “Smooth charging, no slipping; stable cushion, small deviation. Check the surface for smoke—smooth, bubble‑free, no drooling.” Next time you run into dimensional instability, surface gas marks, or color‑change issues, don’t rush to tweak injection speed. Calm down, look at the back pressure gauge first, adjust back pressure, and the problem that’s been haunting you for days might just solve itself.