China is one of the largest producers and consumers of rubber and plastics in the world. The annual output of rubber and plastic products has long exceeded tens of millions of tons, and the demand for mold release agents is growing accordingly.
In the production of rubber hoses, seals, automotive parts, polyurethane foams, epoxy parts, and even small jewelry pieces made by resin casting, mold release products are applied to the mold surface during mixing, molding, and the curing process. Stable, easy release, and mold surface protection are essential for high-volume production and for fine, small-batch mold making cases.
Traditional “one-shot” release agent systems (waxes, soaps, simple oil-based releases, even hand-applied vaseline) have several common drawbacks:
High consumption, frequent re-spraying or brushing over time
Strong migration onto the finished parts, causing oil stains, gloss differences, pooling marks, or yellowing
Heavy build-up on the mold, requiring frequent shutdown and cleaning to remove residues
Negative impact on downstream bonding, painting, and printing in many applications
As the rubber, plastics, and silicone rubber industries move toward higher automation, efficiency, and environmental compliance, silicone mold release agents that can reduce re-application frequency and contamination are becoming the trend. Among them, the silicone resin release agent is emerging as a key upgrade path in medium- and high-end molding, from industrial components to small epoxy and resin casting parts.
1. Basic Classification of Release Agents: Organic vs Inorganic, One-Shot vs Semi-Permanent
From a composition perspective, mold release agents can be roughly divided into:
Inorganic release agents
Such as mica powder, graphite, talc, and other mineral fillers. These materials offer heat resistance and some lubrication, but the powdery surface often cannot meet modern requirements for smooth and clean forms, especially in fine rubber or jewelry-grade casting.
Organic release agents
Including waxes, fatty acids, organic fluorochemical,s and organosilicone systems based on silicone oil, silicone res,in and modified polymers. Among them, silicone mold release agents are widely used in rubber, plastics, and composite molding thanks to their unique characteristics and excellent resistance to heat and chemicals.
XJY-RA/RAN
Methyl MQ resin is formed by polymerization of tetrafunctional siloxane (Q) and monofunctional methyl siloxane (M). It is widely used in the fields of personal care, adhesives, defoamers, waterproofing agents, etc., and has a good application effect in the fields of high temperature, semi-permanent, or permanent for the silicone release agent.
From the perspective of “service life on the mold,” release agents can be grouped into:
One-shot (migratory) release agents
Must be applied for each molding cycle. They rely on a sacrificial interface layer between the part and the mold. These systems are often diluted oils or waxes, sometimes brushed in quite a thick bit, leading to pooling and non-uniform film thickness.
Semi-permanent (non-migratory) release agents
Typically based on silicone resins or other crosslinkable polymers, which cure on the mold surface to form a stable, crosslinked, thin layer. After initial treatment, only minimal touch-up is needed to support multiple releases.
In the rubber and silicone rubber industries, the share of semi-permanent release agents has significantly increased. Silicone and silicone-resin-based products are gradually becoming mainstream choices for precision parts and long-running molds.
2. Key Advantages of Silicone Resin Semi-Permanent Release Agents
2.1 Crosslinked, Thin Layer for Multi-Release and Lower Cost
Semi-permanent systems built on silicone resin release agent technology use specially designed silicone resins as the film-forming backbone. After the curing process, they form a crosslinked thin layer on the mold surface that:
Shows strong adhesion to the mold, so it does not easily transfer to the part
Has naturally low surface tension, which provides smooth slip and easy release
Maintains structure over many cycles, even at elevated temperatures
For rubber hoses, seals, tire components, PU foam cushions and even epoxy and resin parts, silicone mold release agents can support multiple releases from one treatment. This reduces spray frequency, lowers material usage and labor, and shortens downtime, which is exactly what many customers want when they start comparing products and deciding which release agents to add to their “cart” on an e-commerce site.
2.2 Heat and Chemical Stability from the Silicone Resin Backbone
The heart of the system is the Si–O–Si backbone of silicone polymers, which offers:
Excellent resistance to heat, allowing long cycles at high temperatures
Good low-temperature (cold) flexibility, suitable for thermal cycling of the mold and the rubber or plastic part
Excellent resistance to oxidation, moisture, and some forms of corrosion
Inherent electrical insulation helps keep the mold surface clean and stable in electronic applications
Compared with traditional wax or soap systems, silicone mold release formulations maintain their release performance for a long time, instead of breaking down quickly. In many cases, this means a longer molding run before cleaning or maintenance is needed.
2.3 Low Surface Tension and Wetting: Smooth Surface and Fine Detail
The combination of silicone oil and silicone resin gives very low surface tension and good wetting. This means the spray or wipe-on coating can flow into fine features and form a very thin, even layer:
It creates a smooth surface on the mold, allowing air to escape and avoiding bubbles at the interface
It replicates fine details in molds used for jewelry, small decorative parts, and other high-detail casting cases
It reduces pooling, streaks, and uneven thickness that are common when using simple oils or vaseline-like materials
For resin casting with epoxy, polyurethane, or unsaturated resins, a properly formulated silicone mold release works as a clean barrier layer: the material doesn’t react with the mold, and the cured part can be demolded easily without damage, saving time and scrap cost.
2.4 Water-Based and “Non-Toxic” Directions
As environmental regulations tighten, many producers are moving away from highly flammable or strongly solvent-based mold release agents. Newer generation silicone mold release agents can be:
Low-VOC or water-based, with silicone resin and silicone oil emulsified into a stable dispersion
Designed to be as non-toxic as possible for operators and for contact with sensitive materials
Formulated with controlled viscosity so they can be applied by spray, brush or wiping, then dry quickly without pooling
For factories that once started with very simple, home-made mixes (like mineral oil + a bit of wax), a modern silicone resin system offers a cleaner, more professional solution that works reliably across many different applications and materials.
3. Insights from Research for Silicone Resin Formulation Design
Recent studies and technical papers show several trends in the design of silicone resin release agent systems:
Room- or medium-temperature curing silicone resins
Used to form durable film layers in semi-permanent molds for rubber, plastics, and silicone rubber parts
Designed to give a good balance between flexibility and hardness for long mold life
Hybrid systems with silicone + fluoropolymer components
Further reduce surface energy and increase release cycles
Provide additional resistance to chemicals and heat in demanding cases
Improved emulsification and dilution behavior
Allow diluted concentrates to be shipped for easier delivery and on-site mixing
Help the product work well both in industrial presses and in smaller shops doing mold making, resin casting, or jewelry work
These developments mean silicone resin technology is not limited to big automotive rubber plants; it also works in smaller “craft” environments where people need a reliable release agent for silicone mold and epoxy casting, but still expect professional performance.
4. How Silicone Resin Suppliers Can Support Release-Agent Customers
From the viewpoint of a silicone resin manufacturer, supporting release agent formulators and end customers involves several tasks:
4.1 Resin Structure and Crosslink Design
Offer different silicone resin grades for high-heat rubber molding, low-temperature casting, and long-cycle PU foaming
Tailor the curing process and hardness so that the film forms a long-lasting, semi-permanent barrier on the mold
4.2 Compatibility with Silicone Oils and Other Materials
Provide silicone resins that blend cleanly with silicone oil, modified oils and other additives without phase separation
Ensure the final material forms a stable, uniform thin layer on steel, aluminum, and silicone molds alike
4.3 Application Support and Product Documentation
Supply TDS, application guides, and example formulations for different applications (rubber, plastics, resin casting, jewelry, prototype mold making)
Explain clearly how to apply (brush, spray, dip), how to dilute concentrates,and how much time is needed for proper drying and curing
4.4 Communicating Real-World Benefits
Emphasize that a good silicone mold release agent system works over many cycles, reducing cleaning time and scrap
Show customers that “more releases per application” plus easier part removal means smoother production and fewer defects in the final product
When these points are explained in simple language, customers better understand why a modern silicone resin release agent is not just more expensive chemistry, but a product that saves time and cost in the long run.
5. How to make silicone resin release agent perform better?
Semi-permanent silicone resin release agent technology has moved mold release from simple waxes and vaseline-like films to engineered coatings that really protect the mold. By using silicone mold release systems based on silicone resin and silicone oil, manufacturers can:
Achieve easy release and smooth surfaces in rubber parts, plastic components, and fine resin casting
Reduce build-up, improve mold life, and cut cleaning time
Offer cleaner, lower-VOC, often non-toxic solutions to operators
For suppliers, this means helping customers choose the right silicone, resin, and formulation for their specific molds and materials, then delivering reliable product and technical support. In many cases, that is the difference between a release system that “sort of works” and one that becomes the perfect standard solution customers keep buying for a very long time.
XJY Silicones is one of the leading silicone MQ resin and VMQ silicone manufacturers in China, with more than 30 years of R&D and manufacturing experience in the silicone industry, as well as more than 15 related patents and technical support. Our silicone raw material products can meet the needs of the silicone mold release field and support the provision of diversified customized solutions.
