There are a variety of silicone products that can be used to mould things in. Silicone is an excellent choice for moulding as it is always elastic and has very good resistance to moisture, vibrations, chemicals and is a good insulator.
The vast majority of moulding silicones provide very good protection, so what determines the choice of moulding compound is instead how the moulding itself should look - i.e. the choice becomes a question of achieving good productivity and finding a suitable curing system.
The first thing to do is to reconcile which geometry the moulding should have: large, small, narrow channels? In the pictures below shows examples of mouldings and the curing systems that can be considered. In general, the thermosetting variants work for all types of geometries, whether they are of 1-component or 2-component type. Thermosetting in this case means going up to at least 80°C for the 2-component and 105°C for the 1-component, but preferably 105°C for both.
Small moulding with silicone
For a small pour, any type of RTV silicone will work: 1-component moisture curing, 2-component room temperature curing, 1-component heat curing, 2-component heat curing and UV curing.
Deep and complex moulding
In larger mouldings, the moisture-curing silicones do not work very well, as they require moisture from the environment to cure and are therefore not recommended when the contact surface with the surrounding air is very small. This is especially true for one-component moisture-curing silicones. There is a risk that it will not cure at all in the long term. All other types of moulding silicone, however, work well.
Large moulding
Larger castings can be made with essentially the same products as those used for deep and complex castings, i.e. 1-component thermosetting, 2-component room temperature curing and 2-component thermosetting silicones. The choice of product can instead be determined by other factors, such as viscosity. A larger moulding obviously takes longer to make. A low viscosity product fills the space faster.
Fully enclosed moulding compound
If the grout becomes completely enclosed during curing, only the addition-curing silicones can be used; no moisture-curing ones will work, whether 1- or 2-component. Instead, choose between 1- and 2-component thermosets, as well as 2-component addition-curing ones that can cure at room temperature.
In addition to the geometry, there are other important factors to be reconciled and prioritised, and for a fast and intelligent solution: contact us at Tribotec early in your project. We have extensive experience in moulding and in-depth knowledge of all the properties of our silicones. Together we can solve the vast majority of requests.
