At first sight, the term mould release agent might suggest someone who comes around to eliminate furry growth from around a bath or sink. In reality, of course, it is a product that is essential in the design and manufacture of any pre-shaped part - whether it be rubber, plastic, thermoplastic or an advanced carbon-fibre composite. A mould release agent works as a coating to create a very low surface energy on a substrate. When applied to a substrate that forms the mould for a particular component, it allows the moulded material to be released quickly and easily.
Henkel produces a range of such products under the Frekote brand name that fit into three main industry categories - advanced composites, polyester and rubber. Within each of these classifications there are products to meet a wide variety of application needs such as gloss finish levels, slip properties, temperature considerations and material usage. In addition, there are self-glossing wipe-on and spray-on versions and both water and solvent-based formulae.
The way these agents are applied is important. Taking time to prepare the surface of the mould correctly, ensuring it is clean and the right amount of agent is applied is vital. When that happens, the user will achieve a high level of releases before a further coating will be needed. The following examples are illustrative.
The designer of recreational boats specified using a paste wax to release hulls. Preparing one boat hull mould with paste wax took up to eight man-hours. A switch to Frekote enabled the manufacturer to prepare its hull moulds in just one hour. Furthermore, as many as 30 releases between touch-ups is achieved. By reducing the length of time it takes to prepare the mould initially and eliminating two re-coats, the manufacturer now saves many hours of preparation time per mould.
Then there’s the case of a major bath and shower manufacturer who applied four coats of paste wax to its moulds. The total time taken for each mould preparation took 2.5 to 3 hours, and then an additional coat of wax had to be applied after each release. With Frekote, the total mould preparation time was decreased to just 1.5 hours. More importantly, by obtaining more releases per application of mould release, the frequency of the preparation cycles was reduced by up to 80%.