Mold release agents for rubber and tire manufacturing
Rubber release agents are chemical products applied to the mold to make part extraction easier and to protect the mold from the attack of highly aggressive compounds. At AITANACHEM, we have developed a complete release system for the rubber and elastomer industry, based on high-performance water-based semi-permanent release agents. A single application allows multiple consecutive releases, with minimal transfer to the part and no build-up in the mold. They are suitable for both metal and polymer molds.
The twofold challenge of demolding in the rubber industry
Rubber has a feature that sets it apart from almost any other molding process: the compounds are designed precisely to withstand abrasive environments, which makes them chemically very aggressive towards the mold. During vulcanisation, that chemical aggressiveness adds to the mechanical wear. This is why a rubber and tire release agent has to overcome two challenges at once:
- Make the part easy to extract, providing anti-stick properties and high lubricity to the mold surface.
- Protect the mold from the twofold attack, chemical and mechanical, forming a barrier able to withstand the aggressiveness of the compound cycle after cycle.
Our release agents are based on high-performance polymers that create that effective barrier against chemical and mechanical attack, protecting the mold while ensuring clean demolding. To formulate them correctly, both the potential wear of the release film and the geometry of the part must be assessed in advance.
Compatible rubber sectors and parts
The rubber and elastomer industry covers a wide range of applications, each with its own demolding requirements. Our release agents are designed for the production of:
- Tires, both for new manufacturing and retreading.
- Automotive parts: seals, gaskets, dust covers and technical components.
- Conveyor belts, where clean demolding conditions production throughput.
- Pipes, hoses and tubing made of technical rubber.
- Footwear and engineering parts made from elastomers.
What a rubber release agent must deliver
If you are evaluating suppliers for your rubber or elastomer process, these are the criteria that make the difference in this industry:
Abrasion and chemical attack resistance
This is the requirement specific to rubber. The release film must resist the wear caused by a compound formulated to be abrasive, without breaking down after each cycle. A release agent that withstands this twofold attack maintains the number of releases per application and, above all, protects the tire mold — the most expensive and hardest-to-replace investment in your plant.
High sliding power (lubricity)
Rubber molds, and tire molds in particular, have complex geometries with tread patterns, ribs and tight angles. In these cases a high degree of sliding is needed for the part to release without catching or deforming. For the most demanding applications there are graphite-reinforced formulations that provide very high doses of lubricity to the release process.
Low transfer to the part
The release agent must not transfer to or contaminate the molded part, which is especially important for parts that will be painted or that have a high likelihood of self-release. In tire production, transfer is often linked to the use of mica; that is why we also offer mica-free formulations, suitable when this filler could be harmful in the process.
No colour degradation and no high-temperature activation
A good rubber release agent must not cause colour degradation in Teflon coatings, vulcanised silicones or other elastomers, nor require a high activation temperature. An activation temperature that is too high creates downtime and reduces the number of release cycles over the working day.
Water-based release agents for rubber
At AITANACHEM, we encourage our customers to use water-based release agents. Developments in this technology over recent years have brought it on a par with solvent-based release agents in terms of performance, and its advantages fit the rubber industry particularly well: healthier and safer working environments, non-flammable behaviour (an advantage in a process that runs at high temperature) and lower transport and storage costs, as it is not classified as dangerous goods (ADR). You can see the full comparison between technologies in our guide to mold release agents
Mold preparation and maintenance
The performance of any release agent depends on the condition of the mold. A rubber mold with accumulated residue reduces the number of releases per application and worsens the finish of the part. Before implementing a semi-permanent system, we recommend that you:
- Carry out a thorough cleaning using mold cleaners suited to the type of residue.
- Apply a sealer as part of mold treatment and maintenance, which closes the micropores in the surface and multiplies the effectiveness of the release agent.
Frequently asked questions about rubber and tire release agents
Why does rubber need such a resistant release agent?
Because rubber compounds are formulated to withstand abrasive environments and, as a result, are chemically very aggressive towards the mold. During vulcanisation, the mold endures both the chemical attack of the compound and the mechanical wear of demolding. If the release film does not resist this twofold attack, it breaks down within a few cycles and the mold is left unprotected. A well-formulated rubber release agent combines lubricity to extract the part with the resistance needed to protect the mold.
Which release agent is used for tire manufacturing?
Tire manufacturing uses release agents with high sliding power, able to reproduce the mold’s tread pattern and detail without the part catching. For the most demanding applications, graphite-reinforced formulations are used to increase lubricity. They are suitable both for new tire manufacturing and for retreading. We analyse your process before recommending a specific formulation.
Is it possible to demold rubber without transferring mica to the part?
Yes. Mica transfer is a common problem in tire production and in other rubber parts. We offer mica-free formulations, suitable for cases where this mineral filler could be harmful in the process or contaminate the final part. This avoids subsequent cleaning of the molded part.
How many releases can you get from a single application?
It depends above all on the geometry of the part, the rubber compound and the vulcanisation temperature, so we do not give a fixed figure: it would be misleading. The real difference lies in the technology: a semi-permanent release agent allows several consecutive releases after a single application, whereas traditional continuous-application systems require reapplication on every cycle. We determine the specific figure for your process during the trial phase at your premises.
How should a water-based release agent be applied correctly?
Application determines a large part of the performance. Water has a high surface tension, so spraying must be very fine: the technique involves several light passes rather than one thick coat, so that product does not accumulate or form droplets on the mold. Applying more product does not guarantee better release — quite the opposite. We explain this step by step, video included, in our guide on how to apply water-based release agents
We adapt the release agent to your rubber process
The type of compound, the geometry of the mold, the vulcanisation temperature and the required finish completely change the requirements of the release system. That is why, rather than selling an off-the-shelf product, we have a highly qualified technical team that analyses your process and adjusts the level of release power required. We send you the product that best suits your needs so that you can test it at your premises, always with our technical support throughout the trial phase. Depending on the results, we assess adjusting the formulation to the specific characteristics of your production.
Are you experiencing mold attack, transfer to the part or demolding issues on complex geometries?
Get in touch with us and we will look at your case with no obligation.
👉 Looking for general information on release technologies, types of release agents and other application sectors? Take a look at our complete guide to industrial mold release agents