Injection Moulding Services

Injection Moulding Services

This is a great process! The range of materials and colours is huge and there is no “abs like’ that we get in 3D Printing, its the real thing. Parts are repeatable and tight tolerance.

Injection Moulding

Visual Appearance

When moulding, the visual appearance of the part is governed by the surface finish in the tool and this can be anything from a course spark finish to a fine spark (almost matt), to a gloss.

There will always be certain marks on a moulding that originate from the tooling, ejector marks from the core side of the tool, a gate mark or scar where the plastic is injected and a split line that defines where the core stops and the cavity starts. These cannot be avoided so it is worth ensuring they are positioned appropriately and not on a cosmetic surface.

Mouldflow analysisMouldflow Analysis

There may also be marks from the way the material flows. Consider for example a picture frame where the plastic is injected from a single point. It will flow around the frame cavity and meet, typically on the far side. This can leave a visible line in the moulding as well as a potential weakness.

Good tool design and moulding practice will help to reduce or eliminate such issues but at Plunkett Associates we also run Moldflow to simulate such issues at the outset so they can be avoided.

Injection Moulding Gloucester100,000 vs 100 parts

Moulding a handful of parts is very different from 100,000 parts. Usually small batch work is on tight deliveries as it is often associated with development work. For small batches it is usually necessary to buy a minimum of 20/25 kg of material and the associated masterbatch for the specified colour.

Delivery on either of these can exceed the moulding time and sometimes the tooling time if there is none in the UK at the time of order! So planning ahead to ensure availability is very important.

Why use injection moulding?Why use Injection Moulding?

A frequent question is “why would anyone use injection moulding to make just a handful of parts?” There are several answers, but the ones we come across most frequently relate to materials.

For example we have moulded in PP and PE for a client who found that his test fluid dissolved all available plastic 3D Printing materials!

In another application we needed to manufacture parts in electrically conductive plastics. Whilst there is an FDM material that is ESD compliant, there are no 3D Printing materials that are conductive, so we moulded.

Some applications are strictly development, whilst others are production, just in very low quantities with unusual characteristics.

Plunkett Associates deliverDelivery to meet client objectives

When moulding 100,000 parts material is being bought by the ton, the tooling is likely to be multi cavity and the injection moulding will run for weeks, with staged deliveries to meet client objectives.

This is about consistency, repeatability and standardisation to ensure that every box of parts is the same as the one before.

Injection moulding GloucesterPricing and costs

It is worth noting that the unit prices of parts in these two situations will vary considerably. Injection moulding is often regarded as a ‘cheap’ method of manufacture, which is potentially true if the quantity is there.

The price point on a batch of 100 mouldings will be very different from 100,000 due to the setup time and material costs. That said, even at 100 parts it can be competitive with other prototyping options.

So whether we are moulding for you in the Far East, or locally in the UK we can supply you with injection mouldings in any quantity you require, in a wide range of materials and colours and do our best to achieve your timescales.

Adept Precision is our dedicated tooling and moulding sister company in the UK. All it takes is a call, or you can upload an enquiry here. We will be happy to help.Adept Precision

More information about injection moulding and comparisons between this and other processes, can be found within our Processes and FAQ sections.

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  • Plunkett Associates worked on the design and production of titanium frames for an artificial heart valve where precision and consistency was paramount. Communications were efficient and productive with concepts readily incorporated into the final design, and suggestions for improvements all highly appropriate. The quality of the end product was ideal and I have no doubt that I will use the advice and expertise of Plunkett Associates again.
    David Wheatley, Wheatley Research Ltd
  • “Doing business with you has been an absolute pleasure. You have made my goals a reality. You have been patient, helpful and above all, responsive. Best service that I have experienced in ages. I consider Plunkett Associates to be an integral part of my business plan moving forward.”
    Jet Cooper, Sculptor
  • Thanks for the present that arrived this morning, as promised. Parts look first class, as always.
    Jon Todd, Design Manager, PHS Group
  • Plunketts developed a solution that met our precision requirements at a cost significantly lower than alternative manufacturing approaches we had investigated
    Nick Skaer, CEO, Orthox Ltd
  • Plunkett Associates have excellent breadth of experience, work with high quality partners and have a flexibility that we have found enables challenges to be met successfully, cost effectively and in a timely manner.
    Nick Skaer, CEO, Orthox Ltd
  • Interestingly, people who look at it in its own right with little knowledge of what it does, just like it! It’s tactile and it looks good…
    Tim Collings, Operations Director, Troika Systems Ltd
  • To create such a consistent quality finish in chrome was an amazing achievement and the prototypes really gave our stand the wow factor.
    James Clark, Group Commercial Director, The Airdri Group
  • I can’t recommend Tim and his team highly enough. We ended up with a design which can be produced and assembled quickly, efficiently and reliably, in volumes that make sense
    Simon Leggett, Director, Olivewood Technology
  • Kirintec were thrilled with Plunketts. They made a complex process simple and we were just amazed at the lead times achieved. Plus, every single deadline was met without any drama.
    Penny While, Marketing Director, Kirintec
  • Plunkett Associates truly offer a complete turnkey solution with Speed, Effectiveness and Precision.
    David Harden, Director, Enica Ltd
  • Thanks to Plunkett Associates flexible, bespoke and cost effective service I was able to produce the objects that I had originally had in mind.
    Simon Ryder, Artist
  • Plunkett Associates have a fantastic supply chain, work with all sorts of production processes and will always do their utmost to solve a problem.
    Naim Audio
  • We always know exactly what we’re getting and we know we won’t be let down on quality, price or lead times.
    Mark Williams, Research and Development Director, Johnson Safety Products
  • "With their simple to understand language, willingness to go the extra mile and approachability, Plunkett Associates were a great partner for our company. We couldn’t be happier with the results of our project. (A working prototype that they got right first time, by the way). Thank you!"
    Carolina Ballon-Forrester, Director, Kittyrama Ltd
  • “We use Plunkett Associates because we want someone we can trust, that knows what they’re talking about, has all the contacts, will provide reliable advice and feedback and will get the right result for us.”
    Jim Copestick. Design Manager, Thorlux Lighting
  • “Accuracy, finish and delivery all first class.”
    Andrew Peters, JMDA Ltd
  • “We were really surprised at how quickly they turned round such a high quality prototype and the parts certainly proved their worth. They were of high enough quality to provide a fantastic visual representation and to undergo rigorous testing."
    Stuart Wilson, Design Director, TRT Lighting
  • "Tim's experience, expertise and supplier base have been fundamental to us getting this project off the ground."
    Sam Pearce, Jelly Products Ltd
  • Plunkett associates always find a solution. Whatever we need to prototype, they have a great grasp on the technologies available, costs and lead-times so we get the right solution tailored to the project needs. Have always delivered and never let us down.
    Naim Audio

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