What Is a Mold Release Agent?
Mold release agents are necessary when melting metals and other materials for mold forming. You can imagine it as a waffle. Before making a waffle, the mold is coated with oil. That is the mold release agent. Similarly, melted metal is poured into a mold and formed. In other words, it is used to increase the release from the mold when the mold is formed.
Molds are useful for quickly producing large quantities of the same shape. However, simply pouring a liquid material into a mold and molding it will not allow it to be cleanly removed from the mold and it will stick to the mold.
Uses of Mold Release Agents
Mold release agents are always applied when molding. However, there are different types of release agents depending on the form.
One is an external release agent that is applied to the mold, like oil or margarine, used for food, and the other is an internal release agent that is mixed with the material. Other types include water, emulsion, solvent, paste, and oil types, as well as baking and spray types classified by usage.
Among them, ingredients vary greatly in effectiveness. Fluorine-based products require less effort and have lower lubricity. Silicone-based products have good lubricity, but require more time and effort to clean.
Principle of Mold Release Agents
Mold release agents can be roughly divided into wax-related, silicone-related, and fluorine-related.
Wax release agents form layers between the mold and the molded product, causing delamination between the layers. This is called delamination. Although it is characterized by excellent paintability, the amount of transfer is large and the mold can easily become dirty.
Silicone-related products also undergo delamination in the same way as wax-related products. Silicone oil has excellent lubricity, so it has a very high mold release property. However, the amount of transfer is also high, and there is a problem that the molds get dirty easily.
Fluorine-related products utilize the non-adhesiveness of fluorine. Intermolecular contact causes interfacial delamination. This is one of the reasons why the film thickness is thin and the amount of fluorine used is small. Fluorine is often used in combination with silicone because it is difficult to provide high lubricity as a stand-alone material.
As mentioned in the transfer story, the mold release agent may remain in the mold. Moderate cleaning is necessary after a certain amount of use.