Open doors for a deeper partnership

Kiiltonians regularly visit Pihla Group’s door factory, helping optimise adhesive-related processes and testing samples in climate chambers. The door factory’s production quality has improved even further since Kiilto’s service was introduced.

Pihla Group is a window and door manufacturing company that is part of Inwido AB, the largest window and door manufacturer in Europe. Pihla Group’s Ruovesi door factory in Finland has relied on Kiilto adhesives for a long time. Over the last couple of years, the companies have further deepened their partnership.

“We have switched to using a service where Kiiltonians visit our factory four times a year and make sure that certain adhesive-related processes are implemented as agreed. During these visits, they also take samples that are then tested in Kiilto’s own laboratory,” says Pihla Group Maintenance Supervisor Hanna Savolainen.

Everything is connected

During their visits, Kiiltonians study things such as the press pressure, the amount of glue, the mixture ratio and the press temperature used in the bonding processes.


“Bonding layered structures is a multi-dimensional process where everything affects everything. For example, the open time and materials to be bonded, as well as their constancy of size, are very significant for the whole process,” says Kiilto Regional Manager Erkki Kivimäki.

In the climate chambers of Kiilto’s laboratory, the sample pieces are wet, frozen, dried and heated.

“We can simulate ten years’ worth of weather conditions in two weeks,” says Kiilto Solutions Manager Tero Mäkinen.

For example, in Finland, external doors are exposed to extreme weather conditions.

“The temperature difference between the outer surface of the door and the inner surface, which is at room temperature, may be as much as 50 °C. This means that the layered structures and gluing of the door have to be able to withstand a lot,” Savolainen says.

Supporting product development

Kiilto’s service has also proved useful in the door factory’s product development processes.

“We can also utilise the information gained through Kiilto’s climate chamber testing when looking for new materials,” says Savolainen.


Pihla’s doors consist of a high-density fibreboard (HDF), an aluminium stiffener, a wooden frame filled with insulation material, another aluminium stiffener and a second HDF.

Savolainen says that the industry is currently evolving, and new regulations are introduced all the time. These may be related to factors such as soundproofing, heat transfer coefficients (U-values), or even fire safety.

“The door is an invention that never seems to be quite finished,” she points out.

Savolainen says she is very satisfied with the partnership with Kiilto.

“The service – the inspections, testing and proposed measures – help us ensure the uniform quality of our products. It has helped us enhance our production quality even further.”