Release agents play a critical role in enabling efficient and defect-free manufacturing operations for molded rubber and plastic parts. In industries like aerospace to automotive, release agents are formulated into release coatings that prevent molded materials from adhering to molding surfaces. This lack of adhesion preserves the shape and integrity of the molded part and enables the quicker release of parts from their molds, leading to increased manufacturing speed and efficiency.
Selecting the best mold release agent is one of the most important decisions that release coating formulators make. The best mold release agents are consistent and effective in reducing adhesion, efficient to apply and cure on molds, and do not migrate to the molded parts.
DryFilm Mold Release Agents
DryFilm products from Chemours are dispersions of small-sized PTFE (polytetrafluoroethylene) polymers used extensively as mold release agents in release coatings for molded rubber and plastic parts. DryFilm can be applied on molding surfaces through several spray methods and forms a thin film made of PTFE with excellent lubricity and release properties. While many mold release agents exist on the market, the following qualities are unique to DryFilm and provide the greatest competitive advantage as a mold release agent.
Extremely low coefficient of friction and low migration
Excellent surface coverage, owing to smaller particle sizes
Lasting durability, chemical inertness, and ease of drying
Low Migration and Coefficient of Friction
The active ingredient in a DryFilm dispersion is PTFE, which has an extremely low static coefficient of friction and is renowned for its excellent nonstick properties in many commercial and consumer applications. By extension, DryFilm dispersions also have an extremely low coefficient of friction, measured to be as low as 0.06. When applied to molds, DryFilm provides excellent mold release performance, even allowing molded parts to eject at rates up to four times faster when compared to other release agents, such as silicone oil-based agents. Using DryFilm also makes the release easier for even the most difficult-to-release materials, such as epoxy resins.
As PTFE is also chemically inert, the chance of DryFilm migrating onto parts during molding is minimized. This means parts that come in contact with DryFilm require less cleaning after molding. As a result, applying adhesives or paints to these parts can be subsequently conducted with less downtime.
Small Particle Size and Enhanced Coverage
Compared to other PTFE-based mold release agents, DryFilm is unique in that its PTFE polymers are polymerized in a solvent-based process that forms small, soft, sponge-like particles. The PTFE particles in DryFilm typically have a molecular weight between 3,000 and 40,000 g/mol. Other PTFE-based mold release agents are polymerized in water-based processes that yield PTFE particles with molecular weights ranging from 100,000 g/mol to millions of grams per mole. Although molecular weight isn’t always directly related to particle size, this data indicates DryFilm PTFE particles tend to be smaller than the competition.
The small, soft particles of DryFilm are advantageous for several reasons. Smaller particle sizes can cover a larger surface area with less material, making them more efficient than larger particles. The soft, sponge-like, malleable shape of DryFilm particles also provides enhanced surface coverage compared to the hard, sphere-like particle characteristics of other PTFE-based release agents. Thus, films formed with DryFilm tend to be thinner, on the order of 0.2-0.5 mils, compared to the typical 1.0-mil-thick films made with other PTFE release agents. Since DryFilm accomplishes better surface coverage using less material, it offers cost advantages over other PTFE-based mold release agents.
Ease of Drying and Durability
DryFilm is available as a dispersion in various solvents, providing versatility when formulating into sprayable release coatings. Unlike other release agents that need to be cured by using heat, DryFilm release agents can be air-dried, saving time after application. Furthermore, air-dried coatings using DryFilm provide multiple releases between moldings, extending the efficacy of each application.
As mentioned, DryFilm dispersions are chemically inert and extremely temperature stable. This provides for a release agent that is more durable under diverse operating conditions, where DryFilm will not degrade due to chemical attack or exposure to high operating temperatures in molds.
How to Use and Select a DryFilm Grade
The DryFilm release agent is supplied as a concentrate that can be extended and formulated into release coatings by increasing the base solvent in each DryFilm grade. A typical concentration for application as a release coating is 2–5 wt%. Starting at a concentration of 2.5 wt%, the performance evaluation of higher and lower concentrations will allow for discovering the optimal concentration for each customer's specific mold release application.
Below is a list of available grades. Selecting a grade may be based on a formulator’s preference for a solvent carrier and its compatibility with the rest of the release coating formulation.
DryFilm formulations may be applied to surfaces by conventional air spray, airless spraying, or aerosol spraying equipment. In the case of airless spraying, applying a succession of thin coats is recommended, allowing the surface to dry between applications. Drying should be done in an area that is relatively free of dust.
Summary
DryFilm dispersions are the highest-performing release agents in release coatings for rubber and plastic part molds and surfaces that require antistick properties. Compared to other release agents, DryFilm offers mold release coating manufacturers better performance and efficiency. DryFilm accomplishes this through an extremely low coefficient of friction, excellent coverage, lower use rates, air-drying ability, and outstanding durability that provides multiple uses per application. Click below to discuss your release coating application with us and request a sample or quote of DryFilm.
