GeminiPrototyping · Manufacturing+44 (0)1844 339857
Gemini injection moulding machine on the shop floor
Home/Manufacturing/Injection Moulding

UK Plastic
Injection Moulding

Gemini are experts in custom plastic injection moulding of complex components in a variety of materials for industries in the UK and worldwide. Our injection moulding services run from prototype to production, with finishing and assembly under the same roof so a single part can go from first-off to boxed dispatch without leaving the site.

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What Gemini

Why choose Gemini for custom plastic moulding?

01 / Overview
01

26 years of injection moulding

Custom injection moulding is the discipline Gemini was built on. We have delivered custom plastic injection moulding for over 26 years, right here in our UK facilities. No outsourcing to Europe or the Far East.

02

Everything manufactured in the UK

Among UK injection moulding companies, Gemini is unusual in keeping tooling, moulding, finishing and assembly on one site. You no longer need to maintain complicated supply chains; it all collapses to a single accountable source. That means shorter lead times, fewer hand-offs, and one team answerable for the quality of the part on your line.

03

Low, medium or high volume

From single-cavity bridge tools to fully automated multi-cavity production, we scale the process to your volume needs, not the other way around.

Discuss Your Part
02 / Process

Our Process

Every part of the injection moulding process, all under one roof.

From the first sketch to the final boxed part, every stage runs in our own UK facilities. Nothing is subcontracted, one team, one site, and full accountability from enquiry to dispatch.

1Design & Development

We refine your concept with in-house CAD and design-for-manufacture, then cut and prove the tooling on site, before a single part is made.

2Manufacture

Your part is injection moulded in our own UK facilities, from first-off samples through to full production volumes, on our own presses.

3Finishing & Assembly

Finishing, decoration, sub-assembly and packing all happen under the same roof, leaving us ready to dispatch a complete, inspected product.

In-House Capability

A complete moulding capability.

03 / Capability

Precision injection moulding

High-precision injection moulding of all thermoplastic materials, from commodity polymers to engineering-grade and high-performance grades.

Additives & colour matching

Components produced in a wide range of additives and colour-matched to your exact specification.

Initial field trials

Initial field trials to validate form, fit and function before committing to full-volume production.

Part assembly

Post-moulding part assembly available in-house, delivering complete, ready-to-use components.

Part finishing

Full part finishing in-house, VDI texture, polished finishes, spray painting and pad printing.

Over-moulded components

Multi-material overmoulding and insert moulding to produce robust over-moulded components with bonded substrates.

Prototype injection moulding

Prototype injection moulding on aluminium and bridge tooling, so you can prove a moulded part in the real production material before committing to hardened steel. Injection moulding prototypes run from 5 to 500 parts, with a clean route into full production on the same site.

Material Selection

Choosing the right material.

Material choice shapes how a part performs, how it looks and what it costs. These are the five factors we weigh with you before a tool is cut, mapped to the plastics we mould most.

04 / Materials

Mechanical strength

High strength: Nylon (PA), Polycarbonate (PC)

Impact resistant: ABS, Polycarbonate (PC)

Flexible: Polyethylene (PE), Polypropylene (PP)

Temperature resistance

High heat: Nylon (PA), Polycarbonate (PC)

Moderate heat: ABS

Low heat: Polyethylene (PE), Polypropylene (PP)

Chemical resistance

Good resistance: Polypropylene (PP)

Moderate resistance: Polyethylene (PE)

Low resistance: ABS

Appearance

High gloss: ABS

Transparent: Polycarbonate (PC), Acrylic (PMMA)

Matte: High-density polyethylene (HDPE), Polypropylene (PP)

Cost

Low: Polypropylene (PP), Polyethylene (PE)

Mid-range: ABS

High: Polycarbonate (PC), Nylon (PA)

Have a part to injection mould?

Send us details about your part and we'll get back to you within 24 hours.

Industries We Serve

Our injection moulding expertise has taken us into many markets.

05 / Markets

Consumer Packaging

Hair careLaundryBeverageFloor careAir careDevices

Medical

Drug delivery devicesDiagnosticsGene therapyDentalCardiovascularOrthopaedic

Automotive & Transport

Air induction hosesInterior coolingFuel systemsFluid reservoirsSteering & suspension bootsInterior & exterior trimElectric propulsion

Industrial & Construction

RespiratorsCable managementTemporary hoardingFence capsIce packsCold-chain transport

Aerospace & Defence

Classified

Inside Gemini

Injection moulding services in action.

06 / Video

Case Studies

Examples of our injection moulding work.

07 / Case Studies
Automotive · Case StudyBlow- and injection-moulded parts for the Ricardo hydrogen Toyota Hilux

A prototype hydrogen Toyota Hilux

Blow- and injection-moulded parts treated as production by Toyota — strong quality and timing, in a six-week turnaround.

Read Full Case Study

The nominally prototype parts were treated by Toyota as if they were actual production parts, and performed very well throughout test and validation. The overall quality and timing have been very strong.

Our Clients

Trusted by the best

BMW
Rolls-Royce
Airbus
Bentley
GSK
Novartis
Unilever
Mondelez
Kraft Heinz
Bacardi
3M
Veolia
Sharp

Keep Exploring

Related capabilities.

08 / Related
Manufacturing

Liquid Silicone Rubber

LSR moulding for seals, valves and medical-grade parts.

View Service
Manufacturing

Blow Moulding

Hollow parts, bottles and ducting, ISBM included.

View Service
Tooling

Tooling

Design, manufacture and maintenance of production tooling.

View Service
Prototyping

Rapid Prototyping

Fast iterations before you commit to steel.

View Service