Tyres and rubber products stick to the mould when the release film has worn off or rubber residue has built up on the surface. The fix is to clean the mould and apply a light, even coat of a tyre mould treatment such as Micron 1150 Tyre Mould Treatment Spray, a silicone-based treatment specially formulated for tyre moulds and rubber moulding. Reapply as the mould condition needs.
Why it happens
Tyre and rubber moulds run many cycles at temperature, and the release surface degrades over time. The usual causes are:
- Release film worn off across cycles. Each cure cycle takes a little of the film with it.
- Rubber compound residue build-up. Residue collects in vents and pattern detail and gives fresh rubber something to grip.
- Mould not clean before treatment. Treating over dirt or residue gives an uneven film that releases poorly.
On the floor you see tyres sticking on demoulding, rubber build-up in mould vents and pattern, and frequent stoppages for mould cleaning.
How to fix it
The 1150 page gives directions. In short:
- Make sure the mould surface is clean, dry and free from excessive rubber residue, dirt or contamination.
- Shake the can thoroughly.
- Hold the can about 20–30 cm from the mould surface and spray a light, even coat. Avoid excessive application.
- Let the treatment film settle and flash off before you start moulding.
- Reapply as required, depending on mould condition, rubber compound and production cycle. Use the minimum effective quantity that gives the release you need.
Micron notes that the right frequency and quantity vary with mould design, rubber compound, mould temperature and processing conditions, so set your own reapplication interval by watching how parts release.
If grease, wax or old release agent needs removing before treatment, Micron 1220 Mould Cleaner is stated to remove grease, silicones, waxes and mould-release agents. Use it on a cool mould, let it evaporate fully, then apply 1150.
What to avoid
- Avoid excessive application. The 1150 page says so directly, and excess treatment can build up in fine detail.
- Apply only on clean moulds. Treating over residue traps it under the film.
- 1220 Mould Cleaner is a solvent cleaner. Treat it as flammable until the SDS says otherwise: keep it away from sparks, flames and hot surfaces, use ventilation, and let the mould cool before cleaning.
- Do not use a treatment spray to cover up a mould that needs deep cleaning.
When to ask an expert
Talk to your tyre process engineer if:
- build-up persists despite cleaning and treatment;
- sticking appears suddenly with a new compound;
- vents are blocked or the pattern is damaged.
Persistent build-up may need dry-ice or blast cleaning of the mould, or a review of the compound. A treatment spray supports release; it does not remove baked-on deposits.
FAQ
How often should I apply tyre mould treatment?
There is no fixed number. Micron says frequency depends on mould design, rubber compound, mould temperature and processing conditions. Reapply when release starts to drop off, and use the minimum effective amount.
Can I use it on retreading moulds?
The 1150 page describes it as formulated for tyre moulds and rubber moulding applications. If your retreading process is unusual, check with Micron first.
Do I need to clean the mould every time?
The directions say the surface should be clean, dry and free from excessive rubber residue before you spray. How often you deep-clean depends on how fast residue builds up in your process.
Why do my vents keep blocking?
Rubber residue and excess treatment both collect in vents. Keep the coat light and clean vents as part of mould maintenance. If they block quickly, ask your process engineer to check the compound and venting.
See the product: Micron 1150 Tyre Mould Treatment Spray. Related: 1220 Mould Cleaner. More moulding fixes: moulding hub.