Mark Jones
Compression moulding is a process which allows various natural and synthetic materials to replace metal components. Using heat and force, compression moulding shapes a pre-heated polymer into a mould tool cavity. The technique is one of the earliest means to manufacture rubber and plastic components and is now used across a number of industries worldwide. Here we’ll run you through how it works, what it’s used for and the advantages of compression moulding.
The raw material is heated to make it more pliable, then it is weighed so that the correct quantity will be used to fill the mould. The material is placed in the open heated mould cavity, and then the mould will be closed to begin the compression moulding process.
With a combination of heat and pressure over time, the raw material forms the desired shape. The mould is only opened once the raw material has cured, and any excess product can be cut away.
The amount of material, heating and cooling time, and force applied in the process will affect the outcome of the compression moulding. The amount of material will be determined by the shape and size of the tool cavity, whilst the length of time needed for the material to shape and cure will depend upon the type of material, the temperature that it is moulded at, and the size of the tool cavity.
The three main types of material used in compression moulding are rubber, thermoplastics, and thermoset plastics. These will generally be in the form of granules or preforms. Rubber commonly used for bespoke rubber mouldings include Neoprene, Natural, Silicone and EPDM rubber. Common plastics used for the process include polyester, polyamide-imide, polyphenylene sulfide, polyetheretherketone and fibre reinforced plastics.
● Fast set-up time and short cycle time
● Capable of producing high volumes
● Suitable for moulding complex, high-strength and large objects
● Generally good consistent surface finish
● Less fibre degradation than other processes such as injection moulding
● Relatively low-waste process
● Low initial setup costs
Compression moulding has varied uses - electrical parts, buttons, gears etc. - and is typically employed in the production of weather, dust and moisture seals for indoor and outdoor lighting, vibration mounts for commercial and specialist vehicles, or in door and window seals. Because of its high production rate, many companies in the automotive industry use compression moulding to manufacture parts.
To find out more about compression moulding and to discuss compression moulding for your project, please visit the CB Frost website. CB Frost are specialists in the manufacture of rubbers and plastics, and offer a comprehensive range of bespoke rubber mouldings for all your technical and commercial needs.
C B Frost & Co is an innovative and highly experienced rubber and plastics manufacturer and converter. Established in 1921 we have earned a reputation for our extensive product range, comprehensive...
