What are the pros and cons of using internal release agents in the pressing of engineered wood/wood composites?
Because much more of the wood is treated when using internal release agents, the consumption of the internal release agent is typically much greater than an external release agent. However, internal release agents provide an added layer of security because the entire wood particle, fiber, or strand is treated, thus enhancing the potential for the desired release quality. If the wood mat is disturbed before it enters the press, such as in OSB strand flipping or shifting of particleboard furnish particles, internal release agents help prevent untreated binder-coated wood materials from contacting the pressing surface, thus increasing the potential for a clean release.
To help reduce costs, internal release agents can be used only in the face layers of the wood panel when that is an option. Use of wax-based internal release agents may also lower the amount of sizing wax (“slack wax” or “e-wax”) needed to achieve desired board properties. Used as directed, internal release agents have been proven not to affect the internal bond strength of a panel. Internal release agents can be used alone, but are found to be most effective when used in combination with a specialized external release agent.