Lifting bags, developed and manufactured by Trelleborg Engineered Systems, are unique reinforced polymer bags that when inflated can lift huge weights. Used for three decades in rescue work they are now being launched to a broader range of applications in the industrial market.
“In our new range, the smallest lifting bag is 150mm long and wide and only 22mm thick, but it can lift up to a ton – the weight of a car,” says Jacco Vonk, sales manager at the Trelleborg Engineered Systems manufacturing facility in Ridderkerk, the Netherlands, where the lifting bags were developed. “Compressed air provides enormous power. The largest of our bags can move up to 67t, the weight of a military tank, with compressed air at a pressure of only eight bars.”
Lifting bags are expected to be used mainly instead of hydraulic jacks or cranes. They are much thinner than jacks – between 22mm and 25mm – which means they can be inserted into small spaces. And while cranes are heavy pieces of equipment that need to be specially transported to where they are needed, a lifting bag can be carried under your arm and moved around in any type of vehicle, even a car. In addition, the bag also inflates quickly, in a matter of seconds, while a hydraulic jack will take longer. In addition, there are no moving parts in a lifting bag, so no maintenance is required.
Trelleborg’s lifting bags are made of natural rubber reinforced with aramid fibers, which are stronger, lighter and more flexible than steel. Made like a car tire, there is an airtight inner rubber bag; then on top is an aramid layer absorbing the force and an outer rubber bag protecting it.
The larger the contact area, the greater the lifting power of the bag. There are eight sizes of lifting bags available. The smallest, with a maximum lifting height of 80mm, can move a ton. The largest can lift an object of up to 67t up to 520mm. Two lifting bags can be used together to double the lifting height, and a range of accessories is available.
The lifting bags have four different functions:
- Lifting: to raise a load vertically
- Pushing: to push a load sideways
- Spreading: to spread two things apart when inserted in a gap between them
- Fixing: to fix a part in place