Certified material compatibility

In this article we’ll be revealing to you why we dedicate a lot of time to testing the material compatibility of the glazing blocks in the Glas-Tec range. The focus is on their compatibility with the edge composite materials and laminated safety glass films (LSG films) on panes of insulating glass.

Creeping process

Glazing blocks prevent the glass edges and edge composite from coming into contact with the profile, which could cause damage to the glass edge. So far, so clear. However, creeping quality loss can be dangerous for the glazing and the window.

If there is a lack of material compatibility between the edge composite of the pane or the LSG film and the glazing block, this makes a window less secure and durable. A phenomenon known as migration occurs. Low-molecular-weight materials like plasticisers “migrate”, which can alter the properties of glazing blocks, edge composite materials and LSG films.

The direct consequences of incompatible materials include deformation or even disintegration of the glazing block or reduced effectiveness of the edge composite. This leads to cracks in the glass and glass breakage, but also condensation in window panes and discoloration, as well as delamination. The stability of the element as a whole is jeopardized. Its functionality is limited. 

Huge responsibility

A lack of material compatibility between the edge composite material, the LSG film and the glazing blocks used may cause the window sash to malfunction and become damaged. Customers are likely to seek redress from the window or door manufacturer if this issue occurs – as they are entitled to do so. After all, legislators also share the opinion that every window manufacturer is responsible for testing the compatibility of all the materials used in the window: 

This is why you need to be proactive and  prevent liability-related risks!

Clear requirement 

Glazing blocks, the edge composite material and the LSG film of a window system must not negatively impact each other when they come into contact. Technical Guideline (TR) No. 3 of the Glazier Trade sets this out clearly: “Materials are compatible with each other if no harmful interaction occurs between them.” Even air humidity or temperature fluctuations must not alter the synthetic material from which a block or the edge composite is made.

As a fabricator, you are required to observe your products and their behaviour under real conditions. A correctly performed material compatibility test provides a kind of preview of how the products will develop over the entire lifetime of a window. It simulates how the blocks interact with the edge composite or the LSG film over a prolonged period. This makes it possible to rule out potential damage that might only become apparent after installation and after a few years have passed, had a test not been performed.