Pentagon, putting the positivity in to plastics manufacture

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Leading Plastic Injection Moulding Services UK

We offer a complete plastic injection moulding service from initial design to development and onto tooling, production and post production support. Our team are highly experienced and dedicated, offering a plastic injection moulding service that is truly world leading. We are able to offer mould tooling solutions as well as repeat production of injection moulding components and thermoplastic moulding.

We have a range of cutting edge tools and technology at our disposal to deliver moulding and tooling. We work very closely with our customers to make sure we fulfil their requirements to the letter and beyond.


Design For Manufacture or DFM will focus on ease of manufacture and optimal mould tool configuration.
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We draw on our experience and technical knowledge to support you at this early stage.
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Moulding Division

Our ISO 9001:2015 certified moulding division is the core of our manufacturing facility and capabilities.
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Tooling Division

We provide manufacturing support our customers mould tooling requirements including mould tool design.
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UK Plastics Manufacturer and Tooling Division

We operate two companies from our UK site, Pentagon Plastics Ltd and Pentagon Tooling Ltd and have traded in the sector since 1972.  The companies complement each other operating as two supporting divisions in the plastics industry specifically in the sectors of plastic injection moulding and tool manufacture.

Pentagon Tooling

Pentagon Tooling is a centre of excellence for mould tool servicing, repair, modification, pre-production development and production mould tools.

Specialising in all forms of mould tool services, we provide extensive tooling services to our diverse customer base spanning a wide range of industry sectors. This compromises complex multi-cavity tooling for industries including medical, aviation, caps & closure and packaging markets amongst others.

Pentagon delivers comprehensive mould tool manufacture and supports bespoke in-house moulding for a range of customers. As well as an outsourced service to other plastic injection moulders.

Pentagon Plastics

The technical expertise in our plastics division enables us to provide a wealth of knowledge and experience to a diverse customer base spanning many industries. Our services include design for manufacture, development, tool trials, low to medium volume repeat production and post moulding operations. A wide range of injection mould tooling can be accommodated including basic development tools, single impression and family moulds through to multi-cavity. Tools are processed on a range of clean, efficient and well maintained electric, hybrid and hydraulic moulding machines.

Post Moulding

Our post injection moulding services provide added value to customers and include finishing of parts, inserting, waxing and light assembly. Specialist services such as painting, coating and marking are subcontracted to approved suppliers.

Plastic Injection Moulding Manufacturer

If you want to start a project or just have a question, we are always here to help.

What is Plastic Injection Moulding?

Plastic injection moulding is a manufacturing process that involves melting plastic pellets and injecting them into a mould under high pressure. This process creates a wide range of plastic parts and products to exact specifications. The plastic is then cooled and solidified, and the finished product is removed.

The process starts with a mould designed to the exact specifications of a product. The mould is designed with features like cavities, cores, and ejector pins before being mounted onto a plastic injection moulding machine. The plastic pellets are melted and then injected into the mould under high pressure to create the desired shape.

This process can be repeated thousands or millions of times making it great for mass production of high-quality plastic products. Plastic injection moulding is widely used in industries like automotive, medical, electronics and more.

Furthermore, there are different types of thermoplastics moulding and variations in the technical process that allow us to fulfil a wide range of product requirements. This includes the size of the press and the configuration of the mould tool.

At Pentagon, we have successfully manufactured many hundreds of parts including non-invasive medical, aircraft seating components and electrical housings. Our expertise allows us to produce components across a range of industries and product requirements.

Plastic Injection Moulding Vs Vacuum Forming

When deciding between plastic injection moulding and vacuum forming, it’s important to consider factors such as the complexity of the parts, the desired level of precision and accuracy, the production volume and your budget.

Plastic injection moulding is generally more expensive due to the upfront costs, however, it offers the advantage of producing high-quality parts with consistent dimensions and minimal waste. On the other hand, vacuum forming is a relatively inexpensive process, but it may not be able to produce parts with the same level of precision and accuracy as plastic injection moulding.

Ultimately, the decision between these two processes depends on the specific needs of the product being manufactured. In some cases, it may be necessary to use a combination of both to achieve the desired outcome.

In-House Mould Tooling

Pentagon is unique in that, unlike UK competitors, we provide mould tooling in-house from our facilities in Horsham, West Sussex. Not outsourcing production means we have direct on-site control over every element of a project.

Why Choose Pentagon Plastics

  • ISO 9001:2015 certified for tooling and moulding.
  • UK designed and manufactured tooling.
  • Design for manufacture support.
  • One site of manufacture for both Tooling and Production.
  • Full tool preventative maintenance and service program.
  • Experienced in processing commodity through to high end engineering thermoplastics.
  • Full 360˚process control at each stage of manufacture.
  • Full process traceability.
  • Production fully optimised.
  • 24-hour production capacity.
  • Mould Tool and Production trials
  • Post moulding added value services.
  • Supply options to meet customer requirements.
  • Managed investment program.

50 Years of Experience in the Plastics Industry!

We have been trading in the industry since 1972 and under the Pentagon Name since 1979. Our many years of experience mean we understand the challenges, methods and have the know-how to take on and deliver any project. Whilst we have years of experience, we are also highly focused on keeping up to date on the latest tools and manufacturing methods.

Sectors We Work In

We have worked on projects across a vast array of sectors over the years and our experience allows us to take on projects in new sectors with ease.

Here are just a few common sectors we work in:

- Medical non-invasive products

- Medical devices

- Aviation and aerospace

- Security, sensor and control

- Construction and electrical

Tooling Capabilities

  • Fully equipped tooling facility
  • ISO 9001:2015 certified quality control process
  • Experienced tooling staff
  • EDM, CNC and manual machines
  • Laser welding
  • CMM Inspection
  • Development and production mould tools
  • Service, repair and modification service
  • Tool preventative maintenance program
  • Single, family and multi-cavity tools
  • Up to 2 tonne weight

Tooling Lead Times


3-6 Weeks from date of order

Basic Production

6-10 Weeks from date of order

Complex Production

8-12 Weeks from date of order


10-18 Weeks from date of order

Moulding Capabilities

  • Fully equipped moulding facility
  • Experienced processing staff
  • 12 x injection moulding machines
  • Moulding range from 22 tonne to 280 tonne
  • Shot weights from 0.5 grams to 500 grams.
  • Supporting ancillary equipment
  • On-site material stores
  • Development and production service
  • Production optimisation program
  • ISO 9001:2015 certified quality control process
  • Process Control – first off, patrol and final release
  • Material and Production Trials
  • Post moulding and packing services

Moulding Lead Times

Production Orders

3-6 Weeks from date of order

Production Batch Volumes

Low 1- 2,000

Medium 2,000– 20,000

High 20,000– 250,000

Materials Used in Plastic Injection Moulding

At Pentagon Plastics, we have extensive experience in processing a wide range of high-engineering grades of thermoplastics. Our expertise includes working with materials such as:

For a comprehensive overview of the thermoplastics we mould, take a look at our material considerations. If you have any additional questions, please don’t hesitateto let us know.

Download Our Brochure

Click the button below to download our brochure and to find out more about Pentagon Plastics and how we can help you and your business


Interested in working with us?
Get in touch today to get started.

If you want to start a project or just have a question about our plastic injection moulding services; we are always here to help.
Visit our work with us page for estimated tooling costs.