What is transfer moulding?

Transfer moulding, also known as transfer pressing, is an established process for manufacturing rubber parts. In this process, the Rubber-The raw material is placed in a separate chamber of the mould and, when the mould is closed, is fed from there via channels into the Cavities pressed. In the cavities, targeted temperature control is used to Vulcanisation.

 

Transfer compression moulding process

  1. Inserting the Rubber-Raw material: Raw material is inserted into the transfer chamber as strips or discs
  2. Closing the mould halves and transferring the material into the mould. CavitiesMould is force-locked and raw material is pressed into the cavities via pistons through a channel system
  3. Temperature control and VulcanisationDepending on the material and the desired degree of cross-linking, the material is heated to 120-220°C, held for a defined time and vulcanised in the process
  4. Opening, demoulding and post-processing: The component is removed from the mould and generally post-processed, e.g. Deburred or coated

 

Advantages

  • Good dimensional accuracy and reproducibility
  • Wide range of materials can be processed
  • Well suited for thick-walled components
  • Low burr content

 

Disadvantages

  • Longer cycle times than Injection Molding with comparable component complexity
  • Material losses due to sprue in the runner system and remaining raw material residues in the transfer chamber
  • Manual effort for insertion / removal

 

Processed materials

Transfer compression moulding is suitable for processing almost all Elastomers suitable. The only exceptions are thermoplastic elastomers (TPE) or elastomers with particularly short pot lives. These are usually used in Injection moulding process processed. In contrast to the Compression Molding are also low-viscosity Rubbers processable.

 

Typical applications

Transfer moulding is a standard process in rubber production. It is the right strategic choice especially for:

  • Series sizes of approx. 1,000 to 100,000 units per year, in which the ratio of Tool costs remains economical at part price,
  • Rubber composite parts, such as Rubber-metal compounds, and
  • Materials used for Injection Molding are not or only limitedly suitable