Efficient gelling

PVC gel is applied onto a glass-fibre substrate web. This then passes under a heated chrome drum to ensure a smooth surface finish prior to clear aluminium oxide particles being deposited in the PVC surface to achieve slip-resistant properties. Polyflor used to find that the gel was sometimes still liquid, which led to it running off the web.

Heraeus conducted trials using a CIR emitter test module. These proved so successful that a 72kW CIR medium wave cassette was installed on the process line to heat the PVC in a gel drum. It is controlled by its own optical pyrometer to ensure that the gel attains a temperature of 60°C. This is achieved using only three of the six emitters in the cassette. The installation has prevented un-gelled PVC running off the edges of the substrate, saving product and eliminating process and maintenance problems.