Frequently Asked Questions
How does it actually work?
Essentially it employs a computer-controlled oscillating and heated pin. The forces at the tip recreate conditions of the polymer within the original mould, millimetre by millimetre. This promotes low temperature fusion and thorough polymer bonding at the joint.
How long do the pins last
Longevity of the pins are a function of the abrasiveness and ductility of the material being welded similar to the nozzles on Additive Manufacturing equipment.
How hot do the pins get?
The temperature of the pin is accurately controlled by the software to remain at an optimised setting just below the level where the polymer suffers degradation. This obviously varies between polymer types and even production batches. Hence why we are focussing intensely on developing our control algorithms.
What material is the pin?
This is dependent on the application and the chosen polymer. Pins range from steel and tungsten to co-extruded alloys and other speciality metals.
What is the maximum thickness you can work/weld?
The range we have successfully welded on the development machines covers 0.7mm – 12mm. However, the process can be scaled, hence the physical properties aren’t known to be bounded by thickness. Worthy of note is the optimisation for thin sheet materials, where we have successfully butt-welded 1.5mm polypropylene with astonishing results.
How long before the process is proven/ready?
The process is very much proven and is recognised as a bona fide plastic welding technology by the experts as TWI - Cambridge. The equipment could’ve been made available before now, but as an Research and Development company the team behind the technology, with grant support from Innovate UK who identified it’s inherent commercial and sustainability benefits, are taking it to a level where it can enter industry as an advanced automated manufacturing technology. The collaborative team on the project agree the date for this rollout is forecast to be in the Spring of 2025.
Will this process work on the latest polymer types designed to work in extremes, materials such as PEEK or PEK?
Early tests in our lab indicate that these materials will be fully weldable. We’re currently working with the polymer manufacturers and TWI to understand the post welding chemistries and characteristics of these materials.
Will the process work on recycled/bioplastics?
Yes indeed. Bio-plastics like any other chemical make-up can be used with the process. As long as the material is a thermoplastic, there’s a high chance that we will have a design solution. Regarding recycled materials, our AI supported system is being developed to be able to work with a range of polymer types, where the chemistry and quality can change within a short distance. Constant automatic adjustment of the force and temperature settings allows the weld to be optimised for every millimetre of travel.
Is the process protected?
Yes, we have a strong series of broad technology and process patents across multiple territories. These are maintained for us across the globe by Murgitroyd based here in the UK.
How much force is required to achieve a strong weld?
This is highly dependent on the polymer and the characteristics the designer is looking for. A thicker material with inclusions such as short fibre reinforcement, will require more force if the design calls for a high-speed weld. Conversely, very little force is required to create a good weld in a thin sheet laminar assembly of polypropylene.
Can you join two dissimilar materials?
Yes we have successfully joined materials not supposed to be compatible with alternative welding techniques. The team are planning to investigate this in some detail in a proposed paper later in 24/25.
What BS standards have the welds achieved so far?
(Info to follow)
How fast can the process run at?
This metric is highly variable. The team at TWI Middlesborough ran one prototype machine at very high linear speeds and produced good results. However, the AI as of today would probably not be able to control the quality of that weld. However, a customer may require high speed for an application and be more than happy with visual inspection.
How is machine learning and AI contributing to the weld process (Trials with Lancaster, ATS, TWI, Rainbow)?
Science forcing/propelling the technology onto a new level. In the early days weld samples would be created, data recorded and then the samples would be tested at TWI by the polymer experts. The new machines are digitally connected to both TWI and the University of Lancaster robotics department. This leads to much faster development of the control algorithms, as each sample is monitored as it undergoes the process, every parameter is recorded and available for analysis. So as test data becomes available the system becomes closed loop. At this point for a given polymer and setting, the machine becomes self-governing continually adjusting its own settings to optimise the weld. This feature will allow designers to monitor these joints for production specification, but also tune the parameters to achieve desired characteristics. For example, one manufacturer for a particular application may opt for ductility in a joint, but another using an identical polymer might select settings for outright tensile strength.
What TRL are you at now and how long before you are close to ‘market ready’ position?
On the basic Pinweld technology we are at TRL 5/6 and have achieved excellent results that are feeding into the development of the next generation of development. These 3rd generation machines will allow the fast tracking of the ML/AI algorithms for various commodity plastics which will inform the first actual production designs. In short we have operator-controlled equipment that can be used successfully today, but within the next year we will have intelligent systems that will weld plastic products independently.
Unit 4A Fourbrooks Business Park
Stanier Road
Porte Marsh Industrial Estate
Calne
Wiltshire
SN11 9PP
United Kingdom