The modern world is filled with ‘extrusions’. They are all around us, where they form seals between the components of complex machinery, and work to keep the machines themselves functional. There are many different types, and they are all important in some way, but of all the core products Viking Extrusions makes, inflatable seals are arguably one of the most valuable. Matthew Bishop, operations manager, explains why...
Inflatable seals are important components in the function of equipment used in many industries – from food processing, the medical and pharmaceutical sectors, and powder processing production lines, to the marine industry, life sciences, and more.
Such seals serve an important role in the function of air and watertight doors, with environments ranging from luxury yachts to sterile laboratory environments. In fact the same properties that make them ideal for sealing doors also translate into a practical means to handle items on production lines, where the seals can expand or inflate to pick up or stop components, staggering out item production.
Because of their ability to inflate in this way, the production process behind them is more complex than with the manufacturing and development of other types of silicone extrusions. There are many additional steps involved, such as joining, the manufacturing and assembling of the inflation valves, and pressure testing.
How inflatable seals work
Inflatable seals are the ideal solution for difficult sealing situations – especially if there are different parts moving in relation to one another which are frequently connected and disconnected. This is what makes them useful for doors with sealing surfaces, and also for processing equipment where rapid sealing and unsealing is required.
To actually inflate, the seals can be pumped with either an air or a liquid via a pressure regulated supply system. This allows the seal to conform even to
uneven surfaces, where it acts as a reliable barrier against moisture, dust and other contaminants – and even germs.
Fighting the coronavirus with inflatable seals
Their ability to be used to limit the spread of germs has placed inflatable seals in even more demand. In the panic of March and April last year,
there was a rush for more silicone extrusions, including for peristaltic pumps for ventilator systems, and silicone inflatable seals for use in decontamination systems.
As part of the wider effort to deal with the coronavirus pandemic, inflatable seals are also commonly sought after for use in clean room doors, autoclaves, assembly lines and other pieces of essential equipment frequently used in laboratories and vaccine-research.
Inflatable seals are one of our core products and, if anything, we want them to be at the heart of our business service. We have over two decades of experience making them, and they are manufactured right here at our factory in the United Kingdom. Our facilities, plus the equipment we have managed to accrue over the years, puts us in a great position to deliver inflatable seals with very competitive tooling costs and lead times.
Because inflatable seals are used in so many industries, we are often requested to make lots of different types, to solve a variety of problems. In the process we are always pushing the boundaries of inflatable seal design, and continuously review and improve our production processes in order to improve durability and quality.
One of the best ways to make different inflatable seals for different purposes is to manufacture them out of different grades of silicone. For this, we develop and test our own grades of silicone specifically for the manufacture of unique inflatable seals. As an example, some of the requirements we get are
for inflatable seals to be made out of a grade of silicone with especially high tear-strength properties, or to have good bonding properties for creating especially strong joints in seals.
Silicone is also a great material because it is resistant to extremely high or low temperatures. As such, silicon inflatable seals can function at temperatures of +200°C, and even higher for shorter periods of time.
Other requests include for specific classes, such as USP Class VI, for FDA-approved materials (for food and medicinal where freedom from germs is important) and more. Furthermore, our seals are individually part numbered so every seal can be traced back to its material batch origins.
A crucial solution
Inflatable seals perform crucial functions all over the modern technological world, and most people are probably unaware of their existence or do not give them much thought. Yet, as we have seen, where they are needed, they have a key role to play. And because inflatable seals are so important, that is why we work so hard to make them of the best quality we possibly can.
This article first appeared in the Dec/Jan issue of Design Solutions. To subscribe to the printed or digital issue, please click here.