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PinWeld Novel Plastic and Composite Parts Joining Technology

PinWeld novel plastic and composite parts joining technology

The innovative PinWeld technology initially made the successful transition from concept to development stage when the collaborating partners behind it, namely TWI Industrial Member company Pinweld Ltd, TWI and Rainbow Medical Engineering Ltd, won funding in 2020 for a project they named ‘PinWeld’, as a result of competitively bidding for an Innovate UK Smart Grant.

Then fast forward to 2023, and post completion of the PinWeld project, PinWeld Ltd are now set to build on the success and future industrial potential of the original PinWeld technology.  Together with consortium partners the Joining 4.0 Innovation Centre (J4IC – a partnership between Lancaster University and TWI), ATS Applied Tech Systems Ltd and Rainbow Engineering Ltd, PinWeld Ltd has won a further Innovate UK Smart Grant for the new DIGIPIPEWELD project: Digital Platform for Defect-free Plastic Pipes Welding.

This case study now takes a deep dive into the original PinWeld project, explaining how it came into being and the partners’ delivery journey, together with its impact and legacy.

Break-through research and development (R&D) initiatives are the life-blood of industrial advancement, however, it can be challenging for organisations with innovative ideas to free up day-to-day operational resources to pursue these activities.  This is where collaboration on R&D, and securing the funding to enable it, come to the fore, both of which TWI has many years’ experience in, through its Collaborative Projects programme that supports new product, system, process or service development, at Technology Readiness Levels (TRLs) 1-7.

 Like its Industrial Member companies, TWI also seeks to innovate as an organisation through collaboration on new engineering-based technologies. Therefore, TWI was delighted to be contacted by Pinweld Ltd who were looking for specialised assistance with accelerating their novel precision welding technology concept and asked TWI if they would like to join the project consortium they had assembled.


The aim of PinWeld was to develop, and create a pre-production prototype of, an electronically controlled plastics and composites repair tool, initially designed for the automotive sector due to its increasing use of plastics, as a means of reducing the environmental impact of vehicle-related production, but also with a view to subsequent application in other relevant industries.  Particularly in automotive, this would address the challenge of being able to effectively repair cracks in plastic without damaging them further; caused by the excessive heat required for existing repair processes, in order to support the sector’s move away from the unsustainable methodology of 'replace not repair'.


Having identified that TWI’s Novel Polymer Technologies (NPT) Section would be the most appropriate to support Pinweld Ltd with their R&D, the NPT team then brought in TWI’s Technology Innovation Management (TIM) team who help SMEs and university partners formulate collaborative proposals to bid for grant (also known as public) funding from European programmes such as Horizon Europe and Government bodies such as Innovate UK.  Part of the TWI Innovation Network (TWIIN), the TIM team takes the lead on the Collaborative Projects programme. Depending on the project, this can include identifying suitable grant funding ‘calls’, creating project consortia, building concepts into competitive proposals, budget management and submitting the final bid documents for consideration.

TWI Industrial Members have the opportunity to both form and join project consortia, and apply for public funding, as part of their membership services. This collaborative approach to technology development enables all parties to maximise their potential for innovation through shared objectives and interests.  On the PinWeld project, the TIM team assisted all partners with preparing their budgets, and managed the submission process to the funding body portal ensuring the bid was successfully entered into the competition.  Consequently, the consortium partners were successful in winning an Innovate UK Smart Grant, enabling the project to go ahead with an 18-month duration.

Industry Relevance

The automotive sector increasingly uses plastics rather than metal for panels, components and bumpers, and this has led to the unfortunate practise of replacing such items when they are damaged rather than repairing them. Over time, this is having a significant, negative environmental impact.

In providing a solution to mitigate this, when the PinWeld project was first conceived, research showed that in the UK, due to their significant number, if just one bumper could be repaired rather than discarded, it would save in excess of 31kg C02e, and this was without incorporating what could be saved on disposal of the damaged bumper, or the packaging, storage and shipping of a replacement.


PinWeld's unique welding tool extends the lifespan of plastic and composite components by quickly and discretely 'removing' almost all traces of cracks. Early weld tests, undertaken at the University of Bath before PinWeld Ltd made contact with TWI, showed that the tool had the potential to achieve a 90% plus increase in weld strength during the component repair process, including without the need for support materials such as meshes and staples to be effective.

The subsequent collaborative work by project partners Pinweld Ltd, TWI and Rainbow Medical Engineering Ltd, backed by the Innovate UK Smart Grant, enabled the novel welding technology to be further optimised and developed for production, with the longer term goal of obtaining a BSI Standard.

This included:

  • Detailed dynamic testing
  • Research into weld compositions to enable the welds within different materials to be augmented
  • Development and testing of prototypes leading to a minimum viable product (MVP) for field testing
  • Identifying the essential information required to create support resources to enable timely commercialisation

The combined experience and expertise of the consortium partners was instrumental in the PinWeld project achieving its objectives, with PinWeld Ltd inventing the unique technology and acting as Project Manager, TWI contributing by stress testing the

the test weld pieces, interpreting and reporting stress-failure data and offering guidance to improve the weld quality, and Rainbow Medical Engineering Ltd manufacturing the prototype welding equipment to facilitate production of accurate test welds, drawing on its extensive knowledge of the design and manufacture of sophisticated plastic welding equipment.

In addition, the project partners were grateful to receive in-kind contributions from a large, UK-based, automotive manufacturer at the forefront of bringing electrification to the delivery van market with its novel, lightweight thermoplastic bodied vehicles, and the Advisory Board: National Body Repair Association (NBRA) representing the UK automotive repair industry.

Benefits and Conclusion

The PinWeld solution solved a number of challenges associated with plastic joining, design, manufacture and repair including its ability to achieve a high integrity weld while reducing the amount of preparation and finishing required before and after welding, and the speed, accuracy, versatility and repeatability of the technology when compared with other welding techniques. Over time, its deployment could support a reduction in material waste, and a much needed increase in the use and re-use of plastics, enabling movement away from traditional, unsustainable forms of material usage.

In automotive specifically, PinWeld will serve to mitigate the practise of ‘replace not repair’, thereby helping to reduce the industry’s negative environmental impact. PinWeld also has the potential for application beyond the automotive parts repair market, for example in the joining and repair of pipes, which are usually done by butt fusion and electro fusion welding, in sectors such as oil and gas, and water transportation, and in advanced manufacturing through the application of automation and robotics.

Additionally, due to the way the technology creates the joint between two components, there is a viable prospect of using it to join short-fibre reinforced composites, where there has always been the challenge of a weaker, resin rich weld zone.

After completing the PinWeld project in 2022, PinWeld Ltd and TWI continued to collaborate on further development of the tool. Subsequent work showed that PinWeld has the potential to enable continuous joining of high performance thermoplastic and thermoplastic composite materials of varying thicknesses, without the need for an additional material at the joint. This alone would be a game-changer for industry and could lead to PinWeld becoming the go-to joining solution for many large, high-performance plastic components and structures in the future.

In addition, the new DIGIPIPEWELD project offers rich industrial potential, seeking to develop a suite of autonomous solutions that will eliminating existing areas of concern in the joining of plastic pipes.

PinWeld secured funding from Innovate UK for collaborative R&D under reference no. 69951.

Plastic pipes
Plastic pipes

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