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Injection moulding is a widely used manufacturing process that is often used to produce plastic products like chairs, toys and enclosures for electronic goods. The process allows even shapes of high-complexity to be produced extremely quickly from both thermoplastic and thermosetting polymers, making it a highly efficient and cost-effective manufacturing option. In addition to plastics, injection moulding can be used with other materials.


How does plastic injection moulding work?

In simple terms, injection moulding  (plastic manufacturing) works by heating the polymer until it becomes liquefied, before injecting the molten plastic into a mould. This is then compressed and cooled to produce the final product.


The injection moulding process

Let’s look in more detail at the injection moulding process and examine the different stages involved in producing the end product:

Stage 1: A moulding in the shape of the product is produced and split into two halves.

Stage 2: At the beginning of the manufacturing process, the two halves of the mould are clamped together tightly by the moulding machine.

Stage 3: Plastic pellets are loaded into the machine via a hopper, which then travel through a heater and are melted down into molten plastic.

Stage 4: The molten plastic is injected into the mould so that it completely fills it, before being cooled and turned into a solid form.

Stage 5: The two clamps are separated, with the finished product then being ejected from the moulding machine.

To see injection moulding in action and get a further feel for how it works, it is well worth watching our Injection Moulding Video showing the production of plastic chairs.



What are the main advantages of injection moulding?

Injection moulding has become one of the most popular manufacturing processes used in the world today. It offers numerous benefits, which we will now look at below:

Fast production speeds

One of the main benefits of injection moulding is that even complex products can be produced at rapid speeds. The process is also largely automated and requires little human interaction.

Low manufacturing costs

Thanks to the automated nature of injection moulding, manufacturing costs are kept low. This makes it especially ideal for use in producing products where low manufacturing costs are important to compete in the market.

Low levels of waste

Injection moulding produces very low levels of waste, whilst any plastic waste that is produced can usually be recycled. This makes injection moulding an extremely environmentally friendly process and therefore a good choice for any organisation looking to limit their impact on the world.

High strength

Don’t think that the high-speeds and low-costs of manufacture have a negative impact on the end product. Fillers can be added during the moulding process to enhance the strength and durability of the product as required.

High levels of flexibility

Another beauty of injection moulding is that the process is extremely flexible. Different materials can be easily injected into the mould to produce different variations – and with co-injection, it’s even possible to simultaneously inject different materials.