Mold Release Frequently Asked Questions (FAQ)

Mold Release Frequently Asked Questions

Miller-Stephenson is a pioneer in the mold release agent industry, offering application specific formulations tailored for each individual substrate .  We offer optimized solutions for Polyurethane, Rubbers, Plastics, Composites, Epoxies, etc.  Each mold release agent is designed to deliver superior release and cost effectiveness while also lower mold fouling and scrap rates.  Our team of technical experts and chemists have assembled a list of frequently asked questions about mold release.  If you any additional questions please contact our technical team directly with this link

What does a mold release agent do?

Mold release agents provide the critical barrier between the molding surface and substrate, facilitating separation of the cured part from the mold.  Without this barrier in place the substrate would bond to the mold surface resulting in a scraped part, increased down time, and lost productivity.

What are the benefits of using a Mold Release Agent?

Mold release agents offer enormous value to your production process and generally pay for themselves. Benefits include:

• Reduced scrap rates – Mold release agents eliminate adhesion of the molding substrate to the mold surface, improving part quality and aesthetics
• Cleaner, more productive molds – Release agents eliminate mold build up, allowing molds to produce more parts quicker and without costly downtime due to fouling.
• Higher throughput – Mold Release agents allow cycle times to become shorter and molds to be run hotter, resulting in more parts per shift

What are the different types of Mold Release Agents?

Mold releases can generally be broken down into 5 major categories:

• Wax or Wax-Hybrid
• Silicone oil / Siloxane Resin
• Fluoropolymer
• Boron Nitride / Graphite
• PVA

Each offers their specific pros and cons, Miller-Stephenson focuses on only the most advanced and beneficial to our customers, hence our focus leans more heavily on crosslinking siloxane resins, fluoropolymer, and wax hybrids systems

On what substrates should mold release agents be used for?

Mold release agents can be successfully used on nearly any moldable substrate.  Miller-Stephenson manufacturers application focuses products, designed to meet the specific challenges of each moldable material. Below is a list of materials that benefit from the use of a high-quality, engineered release agent:

• Polyurethane and Thermoplastic Urethanes
• Rubbers and Elastomers
• Silicone Rubbers, LSR, and RTVs
• Plastics (HDPE, Polyacrylate, etc)
• Epoxies, Composites and FRPs
• Concrete and Asphalt
• Glass and Metal

How long does a typical mold release last?

Mold release agents can last for a varying amount of time depending on the type of molding and the quality of mold release agent.  Miller-Stephenson focuses on superior formulations that provide an ideal balance of robust release performance and semi-permanent durability. Typically the mold release should be reapplied just prior to the parts beginning to stick. For instance if you can mold ten parts before the parts begin sticking, we recommend reapplying on cycle 8 or 9 as a preventative measure.

When do you choose a solvent-based release agent vs a water-based release agent?

Miller-Stephenson recommends utilized a solvent-based product if the mold temperature is < 60°C (140°F) and a water-based product for higher temperatures (>60°C).  While a water-based product can be used at lower temperatures, special attention must be given to ensure the product fully dries prior to molding. Also if your process is sensitive to residual moisture, such as Polyurethane molding, than we tend to recommend a solvent based formulation to ensure no unfavorable interactions.  If a water-based product is require due to VOC concerns, than a highly specialized release like our ReleaSys 7200W is the ideal choice.

Why are water-based release agents preferred over solvent-based products?

Water-based release agents do not contain any HAPS or VOC (volatile organic compounds), they do not contain any hazardous shipping or storage requirements, and can be easily diluted with water to adjust product concentration. This translates to a safer production environment for workers and reduced transportation and storage costs. Water-based release are also the ideal product for substrates molded on heated molds and can be used on room temperature or cooler molds if given more time to dry.  On heated molds the dry times and cures time are typically less than 1 minute.

What is the best way to apply a mold release agent?

Mold release agents are ideally applied via a fine atomized spray from a spray gun or aerosol can.  The advantage of the spray method is it allows for a product to be applied very thinly and consistently with excellent uniformity.  Material is applied efficiently and over-application risk is greatly reduced. Mold release agents can also be applied by hand with either a lint-free cotton cloth or a blue shop towel.  This method tends to be less efficiently and can apply the material more unevenly.  Miller-Stephenson recommends you apply 2 coats to ensure a smooth, uniform coating. A light buffing once dried can also help enhance smoothness and uniformity.

What happens if too much release agent is applied?

Applying too much release agent can have several immediate impacts on part release and quality:

• Excessive application will lead to mold release transfer, causing the parts to have a slick, hydrophobic surface. This impedes downstream processing and requiring cleaning to remove
• Repeated overapplication leads to release agent build up on the mold surface and fouling.  This will requiring stopping production to remove the build up.
• Discoloration can occur, specifically on higher temperature molds
• For some sensitive thermoplastics (polycarbonate or ABS), excessive mold release application can lead to stress cracking
• For rubbers, elastomers, or compression molders, excessive application can lead to surface defects such as staining, wavy/knit lines, and non-uniform appearance.

What is Paintable Mold Release Agent?

Paintable mold release agents are release agents formulations specifically designed to not impact downstream processes of a mold part.  These processes can be painting, bonding, gluing, welding, etc.  Special, high performance chemistry is utilized to develop a release coating that provides excellent non-stick behavior while simultaneously not effect post-molding operations.  Miller-Stephenson is a pioneer in paintable mold release agents, our focused release agent formulations balance superior release and compatibility to delivery a superior paintable release agent, such as our ReleaSys 7800 or ReleaSys 7200

How do I extend the life of mold?

Mold surfaces whether made from aluminum, steel, silicone, plastic, etc are all subject to similar punishments during the molding process.  Depending on the temperature and type of substrate you are molding, molds can wear out or become fouled incredible quickly.  Mold releases protects mold surfaces from the harsh chemicals and abrasion that occurs during molding.  Miller-Stephenson mold release agents significantly extends the work life of your molds by forming an inert, lubricious, protective film on surfaces.  The mold surface is completely protected from chemical or physical abrasion and the part is able to easily fill the mold and release cleanly.

Does Miller-Stephenson make custom formulations or work with customers optimize mold release agents?

Miller-Stephenson has built it names on providing robust, high performance release agents.  When our standard products do not meet our customers needs we perfectly equip to make a custom product for any customer, large or small.  Most of greatest innovations started with a unique or difficult customer application where we needed to push the boundaries of our chemistry and mold release knowledge.  Miller-Stephenson will work with all customers to ensure our mold release agents provide the intent release effect inside the parameters the customer dictates.