Mold Release Agent Chemistries: Which is right for you?

Mold Release Agent: Which is right for you?

Miller-Stephenson’s exclusive mold release product lines offer advanced chemistry and modern, eco-friendly formulations for the molding industry.

Mold release agent application provide the critical barrier between the molding surface and substrate, facilitating separation of the cured part from the mold. Without such a barrier in place the substrate would become fused to the mold surface, resulting in difficult clean-up and dramatic loss in production efficiency. Even when a mold release agent is used, factors such as irregular applications or improper release agent choice will have a dramatic effect on the quality and consistency of your finished product. It is therefore critical that  engineers understand what types of mold release agent are available and which variant would compliment their production method.  There are several distinct release agents categories: Sacrificial, PVA (polyvinyl alcohol), PTFE (polytetrafluoroethylene), and Reactive polysiloxanes.  Critical criteria for each release agent to meet is the following:

  • Surface adhesion and durability
  • Ability to form a thin-film
  • Sufficient surface slip
  • Chemical inertness to the molding process and molding substrate
  • Number of releases per application

Release agents types and individual products within those types, vary significantly in regard to slip, application methods, production efficiency and cost. For that reason, manufacturers who invest time researching and testing release agents will see a return on that investment once an optimized agent is found.  Sacrificial (typically waxes and silicone oils) and PVA release agents are the lowest cost materials, offering adequate slip and chemical inertness.  Unfortunately these agents must be re-applied after each molding cycle, and will transfer to the molding part.  This result in time-consuming cleaning of the molded part.  Interestingly, while the initial cost may be lower for the sacrificial and PVA release agents, the overall cost is substantially more as one can expect  more releases per application and little to no post-operation cleaning with PTFE and reactive polysiloxanes.

Miller-Stephenson specializes in providing only the highest performing and cost-effective mold release agent solutions for it customers, hence our companies specializes in providing advanced release chemistry. Our company is 100% back-integrated meaning our manufacturing, inventory, and quality are maintained regardless of fluctuations in the market.  In an effort to help guide process engineers in selecting which agent would work best for their molding application we have summarized the leading attributes for each of our agents.

PTFE Dry Film Mold Release Agent

Intricate molding die, an ideal application of the Miller-Stephenson’s MS-122AV

Miller-Stephenson’s PTFE mold release agent solutions (MS-122 and MS-143) utilize low-molecular weight and particle size fluoropolymers to achieve ultra-uniform dry, thin films that exhibit excellent surface adhesion and durability. Miller-Stephenson PTFE release agents contain no silicones, surfactants, or waxes and are thermally stable up to 600F.  These release agents generate a dry film on the mold surface, which is chemical inert, non-migrating and non-staining.  Formulations for this class of mold release agent can be solvent or water-based and application is typically performed with brushing or aerosolization. Once the solvent is dried, the release coating is ready for operation, no additional cure time is needed. PTFE dry film release agents are particularly useful in rubber-to-metal bonding operations or when molding silicone or fluorosilicone polymers and elastomers. PTFE has exceptional utility and can be use in compression and transfer molding operations, however due to its relatively low slip, it can be ineffective with injection molding operations.

Production engineers will typically choose PTFE-based release agents if they are looking for a non-silicone, chemical inert, and non-transferable release agent that is applicable across a broad range of substrates. Our PTFE release agents are particular effective in potting and casting molding operations, specifically with electronic potting and casting as PTFE’s chemical inertness and low-transfer will not interfere with sensitive electronics. PTFE, on a release per application basis is significantly more efficient and cost-effective than sacrificial or PVA alternatives.  Miller-Stephenson’s MS-122AV and MS-122SE are formulations which increase the durability and cost-effectiveness even further by addition of proprietary surface activation chemistry.

Reactive polysiloxanes (ReleaSys™) Mold Release Agent

ReleaSys excels are molding of large composite structures, yielding efficient release, cycle after cycle.

Reactive polysiloxanes are the newest generation of mold release agent, designed to crosslink and bind to the mold surface.  These semi-permanent mold release agent chemistries generate robust thin-films onto the mold surface, enabling numerous molding cycles to be completed with a single application.  Typically, thermosets require a cure-time to allow sufficient crosslinking and surface adhesion. Cured films are extremely durable, chemically-resistant, have high surface slip, and have temperature stability up to 550-600 F. Other reactive siloxanes provide a rapid cure, even at room temperature, with a minimum reduction in durability and abrasion resistance.  Properly applied as a thin film, the release agent will not transfer to parts and therefore will not interfere with secondary adhesive bonds or coating operations.  Over application, however, may result in irregular curing and transfer can occur.  Miller-Stephenson generally recommends training in the product’s use by one of our technical staff.   Semi-permanents polysiloxanes can be designed to exhibit varying levels of slip, durability, and cure times.

Miller-Stephenson’s new ReleaSys™ product line offers the most advanced semi-permanent thermoset mold release agents available.  ReleaSys excels in compression, transfer, and injection molding and is compatible with a broad range of resins and elastomers. Our formulations are particularly useful in geometrically complex molds or when using abrasive molding substrates.  ReleaSys should not be used to mold any silicone or fluorosilicone based products.  Application can be performed via aerosolization or brushing/wiping and formulations come as either solvent or water-based.  ReleaSys™ is Miller-Stephenson’s most cost-effective, highest performing release agent capable of dramatically reduced re-application frequency, greater product throughput, and lower rejection rates.

Innovative Chemistry, Superior Cost-Effectiveness, and Unmatched Technical Service

Miller-Stephenson mold release agents are backed by over 40 years of research and development and are relied upon by global industries to ensure efficient, cost effective, and high quality release of their molded parts. By pioneering release agent solutions for many of the largest manufacturing organizations, Miller-Stephenson understands what it takes to release the most complex materials in the most demanding molding applications. We have solutions which are optimized for your molding operations; from airplane stow bins to O-rings, carbon-fiber bike frames to tires, Miller-Stephenson has a solution for your molding operation.

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The recommendation made here with and the information set forth with respect to the performance or use of our products are believed, but not warranted to be accurate. The products discussed are sold without warranty, as to fitness or performance, express or implied and upon condition that purchasers shall make their own test to determine suitability of such products for their particular purposes. Likewise, statements concerning the possible uses of our products are not intended as recommendations to use our products in the infringement of any patent.