Partners develop composite stone sill with high insulation value.

At Aliplast Aluminum Systems, they do everything as much as possible in-house to minimize reliance on third parties. Thanks to their own R&D departments in several European locations, they can also respond to local needs. From the Netherlands there was an increasing demand for a hardstone sill to replace the standard aluminum version. Stone may be beautiful, but it does not have a good insulation value. That is why Aliplast, together with Holonite, developed an innovative circular composite stone sill with the appearance of bluestone, but excellent in terms of insulation.

Fast response through vertical integration

Aliplast, part of the Corialis Group, makes aluminum systems for windows, doors, sliding doors, curtain walls, fireproof solutions, conservatories and cladding. As much as possible is done in-house. At the production site in Lokeren, Belgium, the profiles are extruded. But there is more, because the manufacturer also takes care of development and engineering, insulation, powder coating, packaging and even transport to customers in the Benelux, France, Germany, Sweden, Norway and Switzerland.

"This vertical integration allows for short lines of communication. We don't need the approval of dozens of people to develop new solutions or adjust things. We switch quickly and flexibly, saving valuable time to respond to questions from architects, for example," explains sales manager for the Netherlands Marc Mulders. "We also have our own R&D departments in several places in Europe, which also allows us to act quickly to respond to local needs. A good example comes from the Netherlands, where there was more and more demand to replace the existing aluminum sills with models in bluestone. These do look nice, however, but they invariably create a thermal bridge. We were looking for a partner with whom we could develop a new solution with the appearance of bluestone, but one that scored highly in terms of insulation, fit neatly with our window and door systems and was easy to install."

Circular sill made of quartz and synthetic resin

In their search, Aliplast's team came across Holonite, a composite stone specialist that has already developed and produced many sills for wood frame manufacturers. This time, they were working on a solution for aluminum windows and doors. It was a choice between a fiberglass-reinforced sill or a version made of composite stone, specifically a bond of quartz with synthetic resin.

"We carry the Cradle-to-Cradle label, which means that our systems are sustainable and circular as well as free of toxic substances. Holonite also has this certificate for the composite stone sill. The biggest advantage, however, is the insulation value, which is many times higher with composite stone than with natural stone. Moreover, thanks to the accessories we developed, this sill fits perfectly with our profiles of the Star 75 windows and doors, making the construction water- and wind-tight. This sill can be combined with inside and outside hinged doors and can also be extended for the side light without any problems," Mulders points out. "Finally, there is also the color, as this sill can be supplied in about twenty standard colors. Holonite uses a casting process for production, which means that even for one door, for example, a green, a blue or a red sill can be made."