Flexible Mold

A hollow shape that is used to enfold the desired object’s real shape is referred to as flexible mold. Usually a liquid is poured into the mold and allowed to solidify in order to create the object. Plastic, molten metal, epoxy resin or the plaster of Paris are the liquids which are included in order to allow the liquid to be solidified.

Molds are generally separated into two different classes namely flexible and solid. There are five types of the flexible mold used today.

Hot-Melt

The first type is the Hot-Melt which is worn molds that are inexpensive. One good thing about this mold is that it can be melted and recast. This mold needs high temperature for melting. So, it is considered to be hazardous to handle. This is restricted to pattern and model materials which are resistant to heat.

Latex

The next mold type is Latex which produces thin walled very elastic strong mold. In this type of mold the shrinkage is very high. In order to prevent distortion these molds are to be supported. There is a need to apply about ten to twenty coats in order to bring about adequate thickness. Making this type of mold is somewhat slow and very time consuming.

Silicone rubbers

The third type of mold is Silicone rubbers. For casting foams and resins this mold is considered to be the excellent ones. One drawback here is the expensive material cost for generating this mold.

The polyurethane flexible mold compounds have got limited shelf stability. The moisture in here is conscious. With good fluidity and simple mixing ratios it is very easy to handle. For casting resin, for the formulation of the foam, for practically pouring any type of cementitious material these compounds can be used. The polyurethanes surpass all other types of the compounds looking at the economy and the general utility.

The accessories

There are quite a number of equipments and accessories that are used in this process. The stirring paddles and the mixing containers which are used in here should be of plastic or metal and it is expected to dry and warm. 1-inch fiber brushes can be used in order to cut down to 1 inch length which would enhance the application of the wax release agent.

For modelling, lying up and for sealing dams and model, the sulphur free plastalina clay is considered to be excellent. The heavy cardboard, linoleum and the lightweight sheet metal are to be used for the irregular or the circular shaped retaining walls.

Questions:

• What is Latex?
• What are silicone rubbers?