Home page > Case studies > How Abakus Okna accelerated production by 15% thanks to Alumaster’s COMBI threshold technology
17
+Years of experience in the industry
3000
Satisfied customers per year
15
%Productivity gains in this case study

Abakus Okna (Choroszcz) is an experienced manufacturer of PVC and aluminum joinery, known for its high quality and modern production organization.
The company needed a reliable and repeatable threshold solution for complex door structures — especially double doors with a movable mullion and side lights.
Key requirements: high tightness, ease of installation, and compatibility with the existing process, without slowing down the line or increasing the risk of complaints. It was at this point that Abakus invited Alumaster to collaborate.
In the threshold area of doors with movable posts and side lights, the continuity of the seal is most often interrupted and thermal bridges are formed. The point of contact between the threshold and the movable post requires many precise manual operations — installation differences and micro-shifts are easy to occur, resulting in leaks and, consequently, the ingress of water and cold air. In addition, narrow side lights limit the working space, making it difficult to cut and apply waterproofing correctly. Abakus needed a solution that would simplify installation and standardize this area so that the effect would be repeatable on every shift.
In response to these challenges, we conducted a process and design audit at Abakus, and then proposed the COMBI threshold system – tailored to Rehau, also for doors with movable posts and transoms. The implementation included standardization of the sequence of operations and accessories, as well as support from an advisor on the shop floor, which simplified installation and ensured a repeatable, tight threshold zone.

Key elements of implementation
Why COMBI proved to be the right choice
The result: simpler assembly, stable tightness, and 15% faster production.
We are happy to share our experience and help you choose a solution tailored to your door designs.