Project Description

Sulphur Compounds in Thermoplast

Thermoplast spacers are crucial for the long term sealing of the gas-filled double-layer glass in VELUX A/S thermo-windows. The LINX team at Aarhus University studied the effect of sulphur compounds on thermoplast spacers used in thermo-windows.

Water and other problematic molecules can seep into many materials. The process may be slow, but given years, it all adds up and can eventually cause problems in products. Thermoplast, a mouldable and easily applied type of plastic, is no exception.

Thermoplast spacers used in double-layer thermo-windows pose a significant materials challenge since they are exposed to constant wear and tear from UV-Light, heat, humidity, etc. In certain thermoplast spacers, sulphur-containing compounds are of particular concern. Previous investigations have shown that the thermoplast spacers have a relatively low permeability towards sulphur-containing compounds, which was suspected to be a result of the desiccant in the thermoplast reacting with the sulphur-containing compounds. This could potentially deplete the desiccant and thereby lower the moisture impermeability of the material, which would pose a problem for the long term sealing of the thermos-windows.

In collaboration with VELUX A/S, the LINX team at Aarhus University used X-ray diffraction to examine if and how sulphur-containing molecules penetrate the thermoplast spacer material. More specifically, it was investigated whether the sulphur-containing molecules react with components of the thermoplast, which could deteriorate the performance of the material.

Techniques and Methods

In this LINX project, the LINX team at Aarhus University (AU) used position resolved X-ray diffraction to investigate how sulphur-containing compounds penetrate thermoplastic spacers, and whether this process is correlated to the moisture permeability in the material.

In the previous LINX project “Water and Humidity in Thermoplast” between VELUX A/S, Aarhus University and Technical University of Denmark, the ingress of moisture in thermoplastic spacers was examined. The methods already developed in that project were applied in the present project. This allowed us to efficiently quantify the relative ratios of different crystalline components through the thermoplastic spacers, and determine whether the sulphur-containing compounds had reacted with the desiccant.

Project Information

Participants: VELUX, Aarhus University.
Start date, end date:
 November 2017 – June 2018.
Permeation of sulfur compounds and moisture in thermoplast spacers (FP06.003, Sorption of liquids and humidity).