Modern plastic injection moulding is one of the most efficient and widely used methods of producing complex parts from thermoplastics. This technology used for moulding plastics is a method known since the first half of the last century. Since then, however, it has been constantly improved due to ever newer types of plastics. It is therefore worth learning more about this technology as the subject is really interesting.
High precision and aesthetics
Plastic injection moulding is a method of producing articles of high quality, high precision of workmanship, aesthetics and repeatability of the dimensions of the products obtained. The technology of injection moulding is one of the most common methods used in the plastics processing industry. It allows you to get ready-made elements of virtually any shape. That is why it is eagerly used by manufacturers not only of children’s toys and medical equipment, but also of elements for the automotive or aviation industry. The fast and efficient nature of this type of production makes it the most popular method of large-series production of plastic items for both everyday use and highly specialized purposes. However, the actual creation time for each element will vary depending on the complexity of the injection mould itself.
The process of injection moulding is based on the interaction of the injection moulding machine and the injection mould attached to it. The injection moulding machine is a machine which is designed to press the plastic mass into the mould socket. Nowadays, screw injection moulding machines are mostly used, which have effectively displaced piston injection moulding machines (their use was associated with the problem of obtaining
a temperature-homogeneous plasticized material). Plastic injection moulding of plastics in injecting a mass of plastic, plasticized under the influence of high temperature, into the mould cavity under a certain pressure, in which, after it solidifies, the material is given the desired shape. As a result, virtually any shape of a plastic product can be obtained. An important element of the process is the duration of the so-called pressure, i.e. the material remaining in the mould under high pressure when it solidifies. It usually takes a few to about 20 seconds and usually depends on the type of material, but also on the size and weight of the product. Too short pressure may lead to the collapse of the product surface or its other damage. Also, too long is not beneficial.
In this method, injection moulds can be made of cheaper materials than steel (e.g. aluminium or nickel castings). Thanks to these features, the forming process is also cheaper, which is influenced by less energy used.