Tue, 15 October, 2024
We are pleased to announce the launch of the Innovate UK-funded ‘DigiPipeWeld’ project, which is based on the Pinweld joining process.
Pinweld is a novel process for joining plastics that uses a metal pin travelling with out-of-plane oscillating movement between two surfaces to be welded.
This is a novel technique, invented by Pinweld Ltd, that is being developed in the DigiPipeWeld Innovate UK project, in cooperation with TWI Ltd, Lancaster University, Rainbow Medical Engineering Ltd, and ATS Applied Tech Systems.
Figure 1. Pinweld
The process can be automated to suit a variety of applications and become a standard in welding sheets, pipes or even more complex geometries. One of the objectives of the DigiPipeWeld project is to enable real-time monitoring of all of the essential welding parameters and to use AI to provide real-time control of the welding process and, if required, to generate a digital twin.
The method uses a heated metallic pin attached to a machine that makes it oscillate perpendicularly to the joint. The plastic is heated locally by both conduction and friction, which generates precise melting of the polymer and subsequent fusion between two parts. This process has been termed Dynamic Plastic Deformation Welding. The Pinweld machine comprises the following components:
- Clamps for the two plastic parts to be welded together that press them against one another
- Robot arm or gantry for mounting the welding head
- Heating system for the pin
- Electric or fluidic motor to generate oscillations
- The tuned application-specific welding pin and its holding fixture (the welding head).
The main parameters that control the process are:
- Pin temperature – the pin is heated by a resistive heating element or by induction, and heat is also generated by friction against the material surfaces. The pin can be controlled to a specific temperature, depending on the polymer being welded
- Frequency – the oscillating movement can be faster or slower, which means that precise temperature control of the melt zone can be achieved
- Weld speed – the welding head with the pin advances across the weld
- Weld pressure – the pressure exerted on the plastic parts perpendicular to the joint
- Penetration depth – the pin can either penetrate through all the plastic to be welded or stop within its thickness
- Amplitude of vibration – the distance the pin travels through the welded part.
All these parameters can be digitally monitored and recorded for real-time control of the process or later evaluation.
For more information on Pinweld or DigiPipeWeld, please contact us using the email address, below.