Design Nomenclature / Physical Model Making

Mold release

Also called release agent, mould release, parting agent, PVA release

This entry has not been translated yet and is shown in English.

A sacrificial barrier film between mould and casting so the two separate. Wax, PVA and silicone sprays each fail differently: wax builds up and softens detail, PVA leaves a shell that must be washed off, silicone contaminates anything you later intend to paint. Draft does the real work; release only helps it.

A two-column text comparison headed "How the part gets out". Left, in accent: Draft angle — geometry; the walls taper, so the part is clear of the mould after the first millimetre of travel. It does the real work, and it is free. Right: Mold release — a film, which lets a part that is still rubbing let go. It buys friction, not clearance, and contaminates the surface you meant to paint.

In practice

"It needs more release" is nearly always the wrong diagnosis. It needs draft, or it needs the undercut taken out.

Not to be confused with

Draft angleThe taper given to a face so a part can leave a mould or a die along the pull direction — measured from that direction, not from the face. One to two degrees suits smooth plastic; three or more is needed on textured surfaces, because the texture's depth carries its own undercut. Zero draft drags and scores the part.

How this term connects

Related Confused with

In practice

Not to be confused with

Related

How this term connects

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