Why Use Plastic Injection Moulding

Mar 15, 2024

When it comes to manufacturing a plastic product, there are different options and processes to consider; it is a huge part of the initial concept creation, and the design process as a product must be designed with the suitable manufacturing process in mind. If you are looking to produce high volumes plastic products, there is a process that stands out above the rest, and that is plastic injection moulding.

As plastic injection moulding experts here at Pentagon, we see the wide variety of technical components that can be produced using this manufacturing method. There are so many reasons to use plastic injection moulding, and in this article, we will be sharing the main ones with you.

What is plastic injection moulding?

Plastic injection moulding is the manufacturing process that is used to create formed plastic products. This process starts by heating granulated thermoplastic material until it is liquified. The molten plastic is then injected into a mould, and once it is cooled it creates a hard, formed plastic component. Examples of a product made through plastic injection moulding are storage containers, phone cases, light switches, medical devices, electrical product housing, automotive components, and some forms of plastic packaging.

Why use plastic injection moulding?

High precision

Plastic injection moulding is a particularly popular production method for parts that are being produced to tight tolerances, moulds can be made with multi cavitation and complex forms to reproduce an exacting product. The level of engineering knowledge and the high accuracy of plastic injection moulding does require expert mould design to ensure that the finished part meets the design specifications.

A variety of colours

The thermoplastic materials used in the moulding process are available in a wide range of grades and raw materials can be compounded or mixed to produce specific colour pallets where necessary, this can reduce the need for post-production finishing processes once the product has been moulded.

Low cost per part

Beyond the initial investment in mould tool manufacture the cost per part can be low compared to other plastic processing techniques.


The beauty of plastic injection moulding is that one mould tool will produce multiple and repeatable product with great efficiency. With a well-made mould tool, you can expect to carry out many production runs manufacturing a high volume of products.

A wide choice of materials

When it comes to plastic injection moulding, there are numerous material options that your final component can be moulded from. When considering a suitable thermoplastic for your product you may consider elements such as strength, durability, flexibility, and resistance to external environments that will meet your design specifications and products end use.

For example, Low-Density Polyethylene (LDPE) is great for softer, more flexible items such as food trays or computer components, whereas Polycarbonate (PC) gives strength, and favoured for parts used in engineering.

A quick manufacturing process

Initial mould tool manufacture can be a lengthy process and will depend heavily on the complexity of the parts that it will manufacture but once complete the production process itself is quick and straightforward, making for speedy production runs depending on the processing parameters of the thermoplastic material being used. In comparison to other production methods, plastic injection moulding wins the race by miles.

Surface finish options

The finish of a product is important and can vary depending on the requirements of a products end use, whether it will be externally visible or form part of a larger assembly of products. The surface finish requirements are taken into account at both the material selection and mould tool design phase of a project.

Different raw materials will deliver different surface finishes and by either highly polishing the mould faces or texturing it to produce a specific surface finish to ensure the final product meets the design specification.  It is possible to carry out post moulding operations to deliver the surface finish required and this may consist of bead blasting, engraving, painting or printing.

Little plastic waste

Due to the considered mould tool design very little plastic is wasted in the production process injection moulding. When plastic waste is produced, it can often be reground and reprocessed.

Need the help of plastic injection moulding experts?

We know how important it is that your plastic product is perfect every time. We also know that a perfect product relies on expert mould design, excellent mould manufacture, state-of-the-art plastic injection moulding equipment, excellent finishing, and a knowledgeable team working on every stage of the process. That is what we provide here at Pentagon Plastics, a full turnkey solution.

We will support you through every stage of the process, from full design for manufacturing assistance, to mould tool manufacture and injection moulding production. We also offer a range of post operations including insert fitting, machining and finishing, so that your final product meets your exact specification.

Whatever the stage of your injection moulding project, if you need our support give us a call and we will be only too happy to help.

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