Production of custom doors and windows at the KAV plant

Most domestic companies selling aluminium doors and windows do not have their own production capacity. However, in KAV’s imposing manufacturing plant, they are able to resolve even seemingly impossible profile connections. This is where further thought-out versions of Schüco or Reynaers profile elements and completely unique door and window solutions are manufactured, designed and developed by KAV engineers. We talked to Albert Herbut, the head of KAV’s Kisbér plant, about the production processes and the operation of the plant.

What does the production process for aluminium doors and windows look like?

At KAV, all processes start in our Budapest office. They consult with the customer, based on which they send us the needs: designed manufacturing material that includes what aluminium structures they want and what the structures should look like. We order the material for these. Pending the arrival of the material, we will prepare the product plans (cutting plans, milling patterns and 3D CAD plans on how to assemble them), then we can find out what other fittings and seals are still needed. Our colleagues in Pest calculate the price using the same software, from where we then prepare the production plans. So they’ll already explore 99 percent of what the customer wants in the calculation phase, based on which we start the production process. We group together to produce the aluminium doors and windows simultaneously, with an identical type of production. There are many different processes performed in the plant, so we try to simplify the tasks to some extent. We tend to sort by profile group: let’s say we first manufacture tilt-and-turn and fixed components and lifting-sliding structures; aluminium doors are manufactured separately; if there are curtain walls and/or glass roofs, they again belong to a separate group. We work with dedicated software and CAD software, which we verify at the end, but we can usually maintain 99 percent preparation accuracy. After tailoring, a barcode label is fixed to the profile, based on which the machining centre can identify the profile. They perform the machining operations: they mill the special connection points and glue injection gaps and holes and prepare the place for the lock, rivet holes, dewatering holes and milling.

Where is the biggest challenge, or even the biggest chance of making a mistake in this process? Does it matter how thin or large an aluminium window or door is?

The biggest possibility of error, I think, comes during the planning process: how can we implement what was requested? At KAV, we usually always have some extra and unique knowledge, a special solution in any aluminium door and window system. Something the customer has dreamed of, and our sales colleague may not spot that it’s not feasible that way. There may also be errors in the software, which, if left unnoticed, can even go through, all along the machining process, and then we have to start the process all over again. The biggest challenge is that KAV engineers combine a lot of things that are not included in any given system; in other words, that aren’t basic solutions. This is what we are famous for: we do something that others can’t. However, these custom solutions must always be reconciled with the standard components. We manufacture quite a lot of parts for ourselves, such as custom corner elements that are not provided as accessories in the relevant system. If an aluminium sliding door, window or door component has a connection at the corner other than 90-degrees, we always have to manufacture custom corner elements for it. In such a case, the milling and the connection point are redesigned. And if a thermal bridge-free extension or special fastener is needed, we design a 3D printable component – these are still manufactured by third parties – and then add it to our structure.

You have worked in many places in the profession. How does KAV differ from a factory producing standard doors and windows?

Mainly that we don’t only try but also meet special needs. An aluminium system supplier such as Reynaers or Schüco came up with a solution that has a glass-to-glass connection at right angles to the corner, with no other profile component. This in itself is quite a special structure; it counts as rarity that we produce anything like this. However, we further develop this, by saying that the two glass planes should meet at, say, 112.3 degrees rather than 90 degrees. In such a case, completely new corner elements must be manufactured; completely different milling patterns must be brought together. But it also happens that we try to put together two mismatched profiles that basically wouldn’t be able to meet in reality, so a 3D printed component is used. For example, a four-rail sliding door is now combined with a three-rail sliding door in a corner-opening design. These are just two examples, but I think it is clear that we are able to solve the almost-impossible.

Do you like these challenges?

I think I would have a hard time if I only had the task of how I could better optimise production, packaging and delivery. I really enjoy what I’m doing now. It’s hard when they try to have these special aluminium doors and windows designed and manufactured by us to a schedule, as if they were system structures. We need to factor into the process that we have to figure these out, and we may not succeed at first, and we need to adjust the a bit more. We may not always be able to estimate the lead time for everything perfectly, especially the time for preparing and manufacturing custom goods. But I love that we create something unique, that no one else does.

During the production of custom aluminium doors and windows, will you also need to test to see if a solution really works in the way the engineers and the software designed it?

We know about many things by experience, that it will work. The more custom windows we make, the more we are able to assess which solution works, what can be solved, or how a standard Schüco or Reynaers component can be improved. But a pitfall can occur at any time: we don’t notice that two mechanical components don’t fit precisely, or if something has to stand at a different angle. Fortunately, it occurs very rarely that we have to completely re-manufacture a structure.

Is aluminium, as a raw material, really capable of such miracles that almost anything can be made out of it?

Aluminium is a relatively lightweight but very robust material. It can be used to create thinner door and window structures that cover less of the view. However, we need to adjust to the system suppliers’ profile connections, i.e. those of Schüco or Reynaers. For example, we can’t fit the sash profile of one manufacturer into the casing of the other manufacturer,. We need to adjust to the basic concept of the profile system suppliers and be able to push the limits with them, as this is the basis for factory production control as well as having a declaration of performance issued. But we are already working on the big dream that KAV will have its own system solutions, even within another product range of our suppliers.

How does the supplier process work? Is there any element that can only be purchased from abroad?

Our main suppliers, Schüco and Reynaers, have their representatives in Hungary. The former even has a warehouse in Hungary. If, in addition to the system components, we also need a more special component, which may be a handle, a motor, a door closing device or any device that increases the technical content of the door and window, they should contact their factories and suppliers separately. Most of them also have representation in Hungary. If not, we get it from abroad. There are oversized glass planes that we can exclusively get abroad, because there aren’t enough curing ovens in Hungary to prepare them. But we’ve done a lot of research on accessories, like the black cylinder liner, for example.

How do you work here at the plant?

The most spectacular is our machining centre. Although the cutting machine is already interesting, too, as we send it the cutting list and the machine can cut the profiles automatically. We also usually give a cutting list on paper, so that the cutter can also check that the machine is setting what we want. The door and window profile is then identified by a barcode; ten years ago it was still completely unimaginable. The milling machine and machining centre then identify the profile, based on its barcode. We can’t automate many things, because the aluminium windows and doors we manufacture are so unique. We don’t have series production; it’s rare for us to produce two identical structures for a project. Do colleagues also ask you if you indeed need to make two copies of something? We work with large glass surfaces, two of which would be too much on a family home.

How many of you work here?

The production office employs three engineers. Engineering preparation, material ordering, physical stock management, checking the software communication of the machines, organising the delivery belong to us. For example, we have a lot of plate orders – cornices, covers – documenting these with accurate colour coding, data, ordering, and order tracking is already a lot of tasks, although I’ve only highlighted a tiny part of our work. But if we need a longer screw then we’ll also find out where to get it. And there are 9 or 10 people working in the factory; we know who is better in which work phase, and they usually work there, but everyone has to know everything. A cutter also needs to know what kind of door, window or glass wall is created ultimately, for which he cuts the first component, and he rotates and cuts the component accordingly. The tasks are very diverse, multifaceted; it isn’t possible for someone to be able to complete just one task consisting of 5 to 10 operations, they have to understand the whole process.

How unique is what is happening here at KAV’s Kisbér plant?

Significantly fewer sliding doors and large glass structures are produced anywhere else. They focus more on the production of strip windows, curtain walls and façades. Because we go beyond standard solutions, we push the size limits and meet individual needs, it isn’t possible to standardise our production. Series production is much more typical at other manufacturers, while we are better at custom aluminium doors and windows.