Warm-Edge for Insulating Glass Production

The new curving unit makes it possible to automate curving of Swisspacer and therefore also speed up insulating glass production even further.
Photos: Swisspacer

Spring 2008 saw Saint-Gobain Glass Solutions Suisse AG present its familiar warm-edge spacer system Swisspacer, now with curved edges.

So-called warm edge technology is gaining noticeable importance in insulating glass production. Due to the increasing energy saving demands placed on windows, doors and insulating glass, today even the minutest improvement in the heat transfer coefficient of construction components counts. By using Swisspacer, Saint-Gobain Glass Solutions Suisse AG says, the U value of a window (Uw (window)) can be lowered by at least 0.1 W/m2K according to the German energy saving ordinance (“Energiesparverordnung”). In detail they say up to 0.3 W/m2K is possible.

Two Models in 17 Colours

Swisspacer is a thermally-improved spacer made of highly insulating composite plastic with a 35% fibreglass content giving the spacer its high rigidity and long life. Extremely thin metal foils made of aluminium (standard) or stainless steel (Swisspacer V) ensure tightness for gas fill and water vapour as well as very good adhesion for all insulating glass sealants. Swisspacer has the same exterior geometry as conventional aluminium spacers and is mechanically and thermally resistant up to 100°C. The range is rounded off by the Georgian Bar ‘Vienna’ made of the same material. Swisspacer comes in a Standard and V model in 17 different colours.

Top-Ranking amongst Warm-Edge Spacers

With Psi values of 0.032 W/m2K with double, and 0.031 W/m2K with triple, insulating glass Swisspacer ranks amongst the top-rated warm-edge spacers on the market. The value represented by the Greek letter y (Psi) describes the linear transfer of heat at the glass edge according to EN ISO 10077-2, 10/2003. This value gained importance with the introduction of the energy saving ordinance EnEV 2002. Since then it has been obligatory for the transition level between the frame and the pane of glass to be included in the total calculation for a construction component.

The background here being: the heat transfer coefficient Ug of the glass relates to the middle section of the pane and does not take the impact of the spacer in the insulating glass at the edge into consideration. This also applies to the heat transfer coefficient decisive for the frame of a construction component Uf (frame). The Psi value relating to the length of the entire glass edge of a glazed window fills this gap and describes the thermal bridge situation in the transition area of the frame, the pane and the spacer. All three values are used to calculate the total U value (Uw)) of a window.

Considerable Acceleration of Insulating Glass Production

In view of the continuing automation of insulating glass production Saint-Gobain Glass Solutions Suisse AG has consistently continued to develop its Swisspacer and now also offers the warm-edge spacer with curved edges. In future, it will be possible to automate the production of highly insulated multiple insulating glass in combination with the Swisspacer using a new curving unit. With the curved edge version the production of insulating glass panes is reduced to 31 seconds. Saint-Gobain Glass Solutions Suisse AG says this represents an enormous improvement in the production process. The curved version is made possible thanks to the new curving unit from Saint-Gobain Seva, the mechanical engineering subsidiary of the Saint-Gobain Group. The company will also market the new curving unit in future. Alongside the curved version of the Swisspacer, Saint-Gobain Glass Solutions Suisse AG says the version with corner keys will continue to be available.

More on Warm Edge Technology at glasstec 2008

All leading manufacturers of insulating glass now offer highly insulating functional glass. See who is opting for warm-edge technology and how far the developments of various manufacturers of innovative spacers has advanced in Düsseldorf from 21 to 25 October 2008 at the world’s largest glass trade fair.