Development of Impregnation Technology
Ultraseal International Limited, Guernsey, pioneered the introduction of the first thermal curing methacrylate sealant in the 1980’s. The company continued to develop both the chemical and equipment side of impregnation technology throughout the decade. It was a unique period of development for the Guernsey Company being able to parallel both sides of the equation of both plant and equipment and sealant technology, each putting pressure on the other in elevating the expectations of product development.
During this period, PC504 continued to be developed, resulting in the introduction of PC504M, PC504/66 and eventually recycling MX sealant alongside plant and equipment research and manufacture.
The most significant machine to be conceived and built by the Guernsey company was known simply as ‘The In-line Machine’. Although, at the time it wasn’t apparent how important this new technology was to become, it was at this point that traditional impregnation batch processing took on a new meaning in design and concept.
The machine incorporated four important features, never before encompassed on one machine.
- The workload and sealant remained in the same chamber throughout the impregnation cycle. The workload was suspended above the sealant in a trigger mechanism that allowed it to descend into the sealant once both had been degassed. Descent was controlled by using the sealant as a hydraulic cushion to control the fall of the workload.
- Following the transfer of the workload to a drain station, it was rotated about a horizontal axis to remove surplus sealant before entering the wash station.
- Washing was achieved by rotating the workload beneath a cascade of water for the removal of sealant.
- The workload was transferred into an enclosure where it was rotated in a hot air stream to effect the cure.
The machine was totally automatic and transfer between the stations was made by a moving beam.
Following on from the In-line Machine was the ‘Shuttle’. Patents: UK Feb 1986. No: 8602540. USA Feb 1988. No: 4,722,295.
This machine was especially designed for TRW power steering castings and was a variation on the theme, as it was ‘In-line’ but had the distinction of being a row of stations resembling oyster shells. This machine won the British Engineers Design Award in 1987 and was the only one of its kind to be built.
In-line Machines in the Motor Industry
In contrast a number of the previous design of ‘In-line Machines’ were built. Toyota Motor Company in Japan embraced the In-line technology and had eight such machines installed for sealing engine components. These continued to operate for the next 20 years. Other In-line machines were supplied to Austin Rover, Longbridge and Ford Motor company in Geson, Melbourne, Australia which is believed to be still in operation.