If plastic parts stick in the cavity or core, the usual fix is a fresh, even film of mould release agent. For general moulding of PVC, ABS, PP or nylon with no finishing afterwards, use a silicone release such as Micron 1100 Silicon Mould Release Agent. For clear parts, or parts that will be painted, printed, chromed or glued, choose the non-silicone Micron 1110 Non Silicon Mould Release Agent and run a trial part first.
Why it happens
Sticking is rarely down to one thing. The common causes on the shop floor are:
- The release film has worn off. Release agents give a number of shots per application, then the film thins and parts start to grip.
- Mould design. Undercuts and low draft angles make parts hard to eject however much release you use.
- Mould surface condition. Scratches, polishing marks or a build-up of old residue give the plastic something to key into.
- Process settings. Mould temperature or cooling time that is wrong for the material can leave parts soft or shrunk onto the core.
You will usually see it as parts that need force to eject, drag marks or scuffing on ejection, and cycle times creeping up because an operator is pulling parts out by hand.
How to fix it
Start with the part, then pick the release:
- General moulding of PVC, ABS, PP or nylon, no painting or printing later: Micron 1100 Silicon Mould Release Agent. Its page lists PVC, ABS, polypropylene and nylon, and says one spray delivers multiple releases.
- Part will be painted, printed, chromed or glued later: Micron 1110 Non Silicon Mould Release Agent. It is a non-silicone formula. Micron's page does not state paint, print or plating compatibility, so put a trial part through your finishing process before you switch the line.
- Transparent polycarbonate or acrylic parts: Micron 1110. Its page describes the film as crystal clear and non-staining and says grades are available for polycarbonate and acrylic. Confirm the right resin grade with Micron before ordering.
- High-volume line that needs bulk: the 5 L pack of the silicone release (1108). The non-silicone release also comes in a 5 L pack (1148).
Before applying any release, make sure the mould is clean. If old release or grease has built up, clean it off first so the new film goes on evenly.
Neither the 1100 nor the 1110 product page gives step-by-step directions. Follow the instructions on the can and the TDS. Apply a light, even coat and do not over-apply.
What to avoid
- Do not use silicone release (1100) on parts that will be painted, printed or bonded. Silicone left on the surface can interfere with later finishing.
- Do not over-apply release. Excess can transfer onto parts and show up as marks or haze.
- Do not assume more release will fix a design problem. If parts stick at the same spot every time, look at draft, undercuts and surface finish.
- Keep the can label and SDS to hand. These are pressurised aerosols; handle and store them as the label says.
When to ask an expert
Ask a toolroom or process engineer if:
- parts still stick with a fresh release film on a clean mould;
- the part tears or deforms on ejection;
- sticking started after a change of material grade, mould temperature or cycle time.
These point to mould design, draft or temperature, which a release agent cannot fix. If you need help choosing between 1100 and 1110 for a specific resin or finishing process, you can also ask on Calchemi and we will route it to Micron's technical team.
FAQ
What is the difference between silicone and non-silicone mould release?
Both put a thin film between the mould and the part. Silicone release (1100) is listed for a wide range of plastics and gives multiple releases per application. Non-silicone release (1110) avoids silicone on the part, which matters if the part is finished later, and is described as crystal clear and non-staining.
Can I use the same release agent for every plastic?
Not always. The 1100 page lists PVC, ABS, polypropylene and nylon. The 1110 page says grades are available for polycarbonate, acrylic, nylon, PP, HDPE and ABS. Tell Micron your resin so you get the right grade.
How often should I reapply mould release?
It depends on the resin, mould and cycle. Reapply when parts start to grip again, and follow the can and TDS. Watch for over-application, which causes marks on parts.
Is 1110 safe to use before painting?
It is non-silicone, but Micron's page does not state paint compatibility. Run a trial part through your paint or print process before switching production.
See the products: Micron 1100 Silicon Mould Release Agent and Micron 1110 Non Silicon Mould Release Agent. More moulding problems and fixes: moulding hub.