Injection moulding is the preferred manufacturing process when you talk about of the same plastic product. The injection moulding involves heating up the plastic raw material (small plastic beads or pellets) to a liquid or near liquid state and injecting it under pressure into the cavity of a steel mould.
Once you have finalised the design of the plastic part, the first step to getting the part injection moulded is to build the mould. This requires precision using a CAD design programme on a CNC machine. Moulds can vary in price depending on;
- The size of the mould
- The number of cavities in the mould
- The material the mould is made from
- The texture or finish of the moulded article
As can be seen the initial set-up cost to make an injection mould is quite high. That is why injection moulding processes are usually the preferred methods when you need to produce high volumes of the same products. A well designed mould should make several hundred thousand plastic parts before needing any major refurbishment.