Hi all,

I’m currently running a 16 cavity hot runner mold with acetal. We ran the first lot of material and all the QC came back good. We swapped to another lot and now we’re having parts coming out way smaller than before. I’m also getting a cavity that’s coming out decently larger than all the others.

I’ve never run a hot runner mold before, thus I’m not sure how sprue, manifold, or cavity temps would play a role in some of the issues I’m having. We have not adjusted anything from the last lot of materials. I’m also having an issue with getting consistent parts from the same cavities as well.

For information sake, currently running the barrel from (Rear) 375-400 (nozzle). Sprue - 450. Manifold - 450. Cavities – 470. This information is per our customers setup sheets as well. Leaving around 6.75 mm of cushion during holding.

Any and all suggestions would be greatly appreciated. I’m at a loss here (probably mostly from frustration).