The roller, which consists of a roller body and cap and made from glass-filled polypropylene (PP), cannot be manufactured in one piece.
In response, a team of engineers at TWI investigated the use of a 20 KHz ultrasonic welding machine to attach the PP can to the PP roller body.
The team designed a bespoke 20KHz sonotrode and holding nest for welding the two parts before beginning a series of trials. Once sample welds on a number rollers had been completed, the team was also able to check weld quality using X-ray computed tomography.
Following the successful trials, Hayter is now using the technique in production, with the reinforced polymer rear roller delivering strength, rigidity and resistance to chemical fertilisers and corrosion.
Hayter Ltd kindly donated a Harrier 41 Pro lawnmower to TWI, which can be seen in the atrium at TWI Cambridge.
For more information, please contact us.
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