Available from Anglo Design , Anglomoil mould release oil has been formulated especially to ensure clean concrete release from steel, aluminum, plywood or composite forms. The mould release oil reduces voids, minimises surface irregularities and helps protect forms and formwork from rust.
Concrete is alkaline, having a pH of 11 to 12. As the concrete reacts with atmospheric carbon dioxide, the pH decreases but seldom falls below 9. When damp concrete comes into contact with organic acids a soap-like film is formed, which prevents the concrete sticking in the form.
As well as preventing the concrete sticking in the form the mould release oil must itself stick firmly to the surface of the form, so that it does not run off before the concrete is poured in. In the case of metal moulds this is particularly important and it can be difficult to get a release agent to remain in place, especially if the form is exposed to strong vibrations. A mechanical strain may also be placed on the release agent when placing concrete in the mould.
Anglomoil form release oil is usually applied by spraying around the surfaces of the mould, which means the viscosity must be correct. If the mould release oil is to be used in cold climates it must also be fluid in the winter.
To produce the right properties a functioning release agent is created by using the mould release oil as a base and adding various substances. The desired acid value is obtained by adding fatty acids. To get the right stickiness, wetting agents are added that reduce the surface tension on the mould release oil.
Other additives are needed for a range of functions, including preventing air holes forming in the concrete and counteracting corrosion.