What Is Transfer Molding?

Transfer molding is also called transfer molding or injection molding.

transfer moulding

Also known as transfer molding or injection molding .

Transfer molding is a molding method of thermosetting plastic. When molding, the molding compound is heated and softened in a heating chamber, and then pressed into a heated mold cavity to be solidified. Transfer molding has different types of work according to equipment: trap type; tank type; plunger type.

The requirements of transfer molding for plastics are: before the curing temperature is reached, the plastic should have greater fluidity, and after reaching the curing temperature, it must have a faster curing rate. Phenolic, melamine formaldehyde, and epoxy resins can meet this requirement.

Transfer molding has the following advantages:

The product has fewer waste edges, which can reduce the amount of post-processing;

Can mold products with fine or fragile inserts and perforations, and can maintain the correct position of inserts and eyelets;

Uniform product performance, accurate size and high quality;

The wear of the mold is small.

The disadvantages are: The manufacturing cost of the mold is higher than that of the compression mold; The plastic loss is large; Fiber-reinforced plastic has anisotropy due to the orientation of the fiber; The plastic surrounding the insert may sometimes cause the product to be welded inadequately. Reduced strength. ^[1]

Transfer molding has different types of work according to equipment: trap type; tank type; plunger type. The most commonly used is trap type. versus

Transfer molding is similar to molding, both relying on a press, but also has the characteristics of injection molding. The mold is equipped with a gate and a runner.

This method requires that thermosetting plastics have greater fluidity before reaching the curing temperature, and have a faster curing rate after reaching the curing temperature, such as phenolic resin, melamine-formaldehyde resin, and epoxy resin. When used in the processing of rubber products, the rubber must have good fluidity and fast vulcanization. Compared with compression molding, this method has the advantages of more uniform curing, short production cycle, good dimensional accuracy, easy flash modification, and easy deformation of inserts and cores, which is especially suitable for the production of inlays. The disadvantage is that the cost of the mold is large, and the remaining material in the mold cavity, the gate and the runner cannot be recovered, so the raw material consumption is slightly higher.