Question

For silicone rubber clearly states the possibility or impossibility of each process and includes the pros and cons for each possible for mold process.

Answer 1

Name	Molding process	Pros	Cons	Possibility level
Lost wax/Investment moulding	Wax injection mold is created to form a wax pattern and is dipped in ceramic slurry and dried,the wax is later removed.	* Has good finish. * Ferrous and non ferrous metals can be molded. * Close dimensional tolerance is possible in this method. *Alloys difficult in machines can be used too. * Flexible design.	* Cost is high. * Limitation in size of mold.	Medium
Sand casting	Finely ground grains of spherical shapr is tightly packed into smooth surface for molding.	*Low cost *Large sized molds are created.	*Casting produced has higher weight than expected. * It required large tolerance. * Accuracy of dimention is less.	Medium
Plaster casting	Mixture of gypsum ,water and strengthening compounds are tightly packed in the mold.	*Dimentional tolerance is good. *Smooth finish. *Thin. *Mold with fine details can be made. *Larger parts are made with less expence.	*Frequent replacement of plaster molding is required. * Requires a minimum of 1 degree draft	Medium
Permanent mold	Metal die blocks with mold cavities are used.	*Less expensive. *Density and pressure tight is more. *Can be repeatedly used. *Close dimentional tolerance.	*Toling cost is high. *Can cast only non-ferrous metals. *Only simple designs can be used. Small castings.	Medium
Die casting	Materials to be molded are put under high pressure and casted.	*Metals with low melting points are also used. *Good dimensional tolerance. *Low cost. *Ideal for large scale production. *Post machining is minimum.	*Not good for hydrostatic pressure applications. *Suitable for casting upto 75 pounds.	High
Room temperature vulcanization	Material is injected using hand and is made to cure.	*Capital eqipment requirement is less	*Slow process	Medium
3D printing	The mold is formed layer by layer.	*Runs unattended. *Machining of mold is not needed.	*Unit cost is more. *Large batches are not possible. *Precision is low.	Low
Injection molding solution	The injection molding press is molded in soft metal tooling.	*Quick tooling. *Production of parts is fast. *Close approximation.	*For small runs,cost is more.	High
Transfer press molding	Transfer molding is used to make parts and the cavity is then cooled.	*Little process development. *Simple tools.	*Cycle time is long *Complex molds are not possible.	Medium