Plastic Injection Moulding Services

Injection moulding is used to manufacture various plastic products, ranging from engineering components to consumer goods. It involves heating thermoplastic polymers until they are liquid and injecting them into a mould under pressure. This method allows for the production of complex shapes quickly. Injection-moulded parts typically feature a gate point, where the plastic was injected, and a split line where the mould halves meet.

We can produce plastic parts ranging from a few grams up to 750 grams (unfilled) or 1000 grams (filled).

PNP's Plant List

Once the tooling is made, we can produce single one-off components if required, though at a premium. For cost-effective unit prices, quantities of 1,000-10,000 are typically recommended.

The primary methods are compounding and using masterbatch. Compounding colours the base material before moulding, while masterbatch involves adding concentrated pigments to the base material during the injection moulding process.

Compounding provides the greatest level of colour consistency, maintains material purity, and maximizes the performance of structural parts. It ensures uniformity and repeatability, especially for custom colours and base polymers that are strongly self-coloured or don’t mix well with pigments.

Compounded materials increase the unit price in small quantities due to the additional process involved. However, this method becomes more economical as production volumes increase.

Masterbatch can be universal (usable with a broad range of plastics) or polymer-specific (tailored to not affect the physical properties of specific materials). They can also produce various effects, such as metallic, sparkle, or marbling.

Yes, masterbatch can also include additives to enhance properties such as flame retardance, UV resistance, anti-static properties, anti-sink, and fragrances.

For more information refer to our 'Colours and Additives for Plastic Injection Moulding' Blog

In most cases, yes, depending on the base material used.

The pigments or additives are measured by weight and mixed with the base polymer at specific ratios to ensure the desired properties and colour consistency.

The surface finish and wall thickness of the part can significantly affect how the colour appears, even if the same colour is used.

A process that involves moulding a secondary material over a pre-existing part, often to add functionality, improve ergonomics, or enhance aesthetics. Common in creating multi-material components.

Similar to overmoulding, insert moulding involves placing a pre-formed insert (often metal or another plastic) into the mould before injecting the plastic. This creates a single part with integrated components.