PolyGlobal – Injection Moulding

Posted on: 27th Jul 2020

Injection moulding is a manufacturing process used to produce parts by injecting molten plastic into a mould. Used extensively around the world, injection moulding is the most common modern process used for the mass production of identical plastic components.

PolyGlobal & Injection Moulding

For over 34 years injection moulding has been PolyGlobal’s primary manufacturing option. Their injection moulded components are used heavily across all industrial sectors due to the diversity of the base materials they offer including Polyurethane, Nylon, Polypropylene, TPE and TPR, and the variety in size and shape that can be moulded.

PolyGlobal offer injection moulding weights up to a maximum of 2.5kg and dimensions of 1200mm x 500mm and 650mm in diameter, with no upper limit to part quantity. Their precision engineering enables us to work to tight tolerances.

The Injection Moulding Process

In the injection moulding process, the chosen material is introduced into the injection moulding machine via a hopper.  The virgin material starts the process in pellet form. The injection moulding machine consists of a heated barrel from which a reciprocating screw feeds the molten plastic into a temperature-controlled mould.

The screw melts the pellets and acts as a ram during the injection phase. The molten plastic is injected into a mould tool that has been manufactured to the specific design of the moulded part.

Once the part is moulded, the mould opens to release the part. This whole process is then repeated for the entirety of the production run.

After the moulding process, the parts are cooled, before being trimmed/finished if required.

Materials

Working with some of the world’s leading raw material suppliers, such as BASF, PolyGlobal offer a wide range of high-performance injection moulding engineering plastics.

Whilst injection moulding is commonly known for the production of single use plastic items,  PolyGlobal primarily focusses on the production of parts for engineering applications, As such their carefully selected materials are designed to provide toughness and durability, often extending the lifespan of components. Each grade of material has its own qualities and can be selected based on its specific characteristics and suitability for your individual application.

Their material range includes a number of options with a % of recycled content, and the manufactured parts are usually fully recyclable once moulded. In line with their Environmental Policy they regrind production waste whenever possible, and utilise this in production, wherever it is suitable.

PolyGlobal hold in stock a wide range of standard injection colours to suit your requirements and are also able to colour match to RAL or Pantone references, including fluorescent and luminescent colours. Their colour match service is subject to minimum order quantities.

Furthermore, they utilise several specialist additives to enhance the technical performance of your finished part. These are added during the moulding process and include Flame Retardant, UV Stabiliser, Anti-Static and Metal Detectable.

Moulds

PolyGlobal’s bespoke moulds are manufactured on-site by their own engineers. The expertise of their toolmakers, developed over 34 years of excellence in tool engineering, enables them to continually produce new and bespoke moulds to customer designs and concepts, for new and existing applications.

Due to the moulding process, PolyGlobal moulds are subjected to extremely high pressure, facilitating much more detailed and complex parts then other moulding and manufacturing processes.

Multi cavity moulds are a production option that allow 2, 3 or more parts to be produced per production cycle. They are designed to run fully automatic allowing for 24/7 production which makes them ideal for high volume production.

Their experience in tool engineering enables them to identify opportunities for existing tool modifications to improve the finish or performance of existing parts.

The Advantages & Disadvantages of Injection Moulding

Advantages

  • Low cost per part on medium to large production runs
  • Consistency across the full production run
  • Quality control
  • Complex and precision detail
  • Large choice of material options

Disadvantages

  • Higher price per part on small production runs
  • Higher initial costs for moulds and set up processes
  • Fixed designs
  • Weight/thickness/size limitations
  • Simple profile details can cause complex tooling issues
  • Material shrinkage

Summary

Injection moulding is the ideal process if you are looking for an efficient, high volume manufacturing option. PolyGlobal’s full, bespoke service from initial concept or simple sketch, right through to full production runs and delivery, allows them to work collaboratively with you on new or existing projects.

It is important to discuss the key application requirements and critical profile details as there are often numerous material and production options available. High volume parts may be more suited to multi cavity or hardened moulds which may result in higher upfront costs but can result in long term savings in reduced unit costs. Equally where suitable, bigger tolerances and allowances on surface finish may enable more cost-effective production options that suit the required part more appropriately.

Contact sales@polyglobal.co.uk for further details, or for help with your project.

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