There are a number of different ways in which we can mould plastic into our desired shape depending on the end product and its use. Different plastic parts require different moulding methods, and five of the most common are outlined below with the plastic parts they best service.
This process is used for larger plastics such as auto parts. The plastic is compressed into shape, much like the name suggests. The plastic is heated to ensure it will maintain its integrity after the pressure of compression. Once shaped, it is removed from the mould. Any excess plastics from the compression process are cut off once cooled. The strength of the materials used in this moulding process is what makes it great for use with car parts.
For hollow plastics such as straws and tubes, extrusion moulding is used. The plastic is put into a die shape, and this is what determines the final shape rather than the mould. The long tubes are then cut to size.
This is used to manufacture solid plastic parts and can range in component sizes. However, injection moulding is usually used for high volumes of plastic parts and can form part of silicone moulding. It is a versatile technique that can produce very precise parts. This is a flexible process for designers and engineers, such as http://www.meadex.co.uk/silicone-mouldings
High temperatures and a rotation movement are used in this process to make large hollow containers, such as tanks. This is not a quick process, but it can be cheaper than other types of moulding. Very little material is used during this process and the waste plastic can be reused again, making it very economical and having a lower impact on the environment.
Blow Moulding very much follows the techniques used in glass blowing. It is what will form hollow objects, such as plastic bottles. Plastic is heated and air is blown inside until it meets the shape of the mould. Blow moulding is used for high-volume production of identical shapes, such as drinks bottles.
Depending on the use of the plastic, the strength of the material and in what volume it is used will determine the moulding process required. Each of the processes has strengths and weaknesses.