Rotate 150kg on a cent coin

Previously, metallic bearings were used in the hinge systems. These require a relatively large installation space. Another negative effect was that the bearings had a clearly noticeable breakaway torque. This was accompanied by a squeaking noise.

Our material iglidur® Q290 offers a very good coefficient of friction for this case and thus also a smooth swivelling of the door. Another advantage here is that the bearings have a thinner wall thickness and require less space in the hinge system.

The Belgian company has been developing innovative door systems under the name ANYWAYdoors since 1995 with a focus on the Benelux countries and began selling its products online to global B2B customers around a year ago. "We sell our pivot door hinges as self-assembly kits that can only be purchased online via our website, where they can be configured exactly to customer requirements," explains Rudi Dies, co-founder of PortaPivot. "In this way, we combine our own product, engineering and experience in assembly and installation with our customers' local network, their expertise and their local suppliers."

PortaPivot's door systems have already won a number of prestigious awards in recent years, including the Reddot award and iF Design Award. They have also been honoured with the "Best Architectural Product" (AZ awards), the Muuuz International Award design & innovation, the Archiproducts design award, the Iconic Award ('innovative interior') and the "Best products award" from the Architects newspaper.

In addition to the design aspect that the doors equipped with the Stealth Pivot hinges do not require a door frame at all and can be swivelled open 90 degrees in one direction or 180 or 360 degrees in both directions as required, the feel is a very special experience. Much less force is required to swing the door open and, despite the door's high dead weight, it can be moved with ease.

In addition to adjustable gas pressure springs, there are two plastic plain bearings from motion plastic specialist igus® inside the hinges, which enable the doors to move smoothly and securely support the glass panels weighing up to 150 kilograms. "Although these plain bearings are only very small components, they are among the most important in our doors," admits CEO Rudi Dries. "It's amazing to see what these bearings can do." Before the door hinges with the igus® bearings were used, they were extensively tested by Wood.be in a specialised Belgian test centre. "Our requirement was for the doors to complete 200,000 cycles with a 90° opening process and for the hinges to be able to withstand this without failure," recalls Rudi Dries. "In our own tests, we then proved that they can even withstand 248,000 cycles with swivelling movements of 180° with the plain bearings from igus®."

PortaPivot also wanted its own products to make service calls obsolete. In addition to their low friction and wear values, the plastic plain bearings from igus® have another major advantage here - they are maintenance-free. The plain bearings consist of a mixture of base polymers, fibres and fillers as well as solid lubricants. The latter are embedded millions of times in the solid material as microscopically small particles. This is sufficient to adequately lubricate their immediate surroundings and makes external lubricants such as oils and greases superfluous. This dry operation means that dust and dirt cannot adhere to the bearing points and there is no risk of contaminating doors and floors with greasy lubricants.

"Bearings made of the material iglidur® Q290 are now used in the hinges," explains Lars Butenschön, Product Manager iglidur® bearings, from igus®. "This material was originally developed for applications in agricultural engineering and is designed for medium to high load and abuse forces." PortaPivot was pleased with this recommendation, recalls Rudi Dries: "We are product developers, not engineers. That's why we are always on the lookout for partners who can provide us with reliable support and help us find solutions. This always works very well with igus®."

The special thing about the PortaPivot application and the main reason for switching to the robust material is that the entire force of the doors - up to 150 kilograms - is only exerted on the flange of the bearing. In other applications, this is usually only used to hold the bushing in place and not to absorb the entire force. In relation to the load-bearing surface, this application results in a surface pressure of 20 MPa. Most iglidur® materials can withstand this pressure without any problems. However, edge loads, which occur due to the leverage effect when the door swings open, in conjunction with the load applied via the flange and the cylindrical part of the bushing, additionally stress the material, which could lead to the flange of the bearing tearing off. In more than four years of PortaPivot applications, however, there have been no significant failures, which proves the reliability of the iglidur® bearings from igus®.

In older generations of door hinges, metallic alternatives were used at the bearing points. However, they required more installation space due to the thicker wall thickness of the bearing, and also created an unpleasant "stick-slip effect", in which a clear breakaway could be felt and a squeaking could be heard when the doors were moved. Thanks to the iglidur® plain bearings from igus®, these problems are a thing of the past and even after years of use, smooth movements of the heavy but very stylish doors are guaranteed.