Case Study: Bespoke High Temperature Cable Colour Coding Case Study
Cable Core Colour Identification at Extreme Temperatures
Customer requested a high temperature thermocouple cable, with each core easily identifiable at temperatures in excess of 600°C.
Thermocouple cable core colours burn away at approximately 300°C and identification of single cores becomes impossible, maintenance is time consuming, expensive and cables are replaced earlier than would normally be the case.
High temperature fibreglass was chosen as the insulation material, natural colour (white) and suitable to be impregnated with pigments to provide each core cable with a tracer mark/colour for identification purposes. Simply think of an electrical a plug blue, brown and green, yellow.
Traditional pigments are suitable for temperatures up to 300°C. At higher temperatures colour begins to fade and disappears completely meaning all cores within the cable return to their pre-pigmented natural colour – white.
Research identified a range of pigments used in the manufacture of high temperature industrial ovens and stoves. After discussions with the industrial oven manufacturer a method was identified to modify the pigment formulae. The resulting dye/liquid was applied to the fibreglass yarn using dip coating and yarn drying equipment where the curing/drying process was controlled by a series of ovens (four) all operating at different temperatures. This ensured the high temperature pigmented yarn was cured under very specific process conditions.
The result was a high temperature fibreglass thermocouple cable able to withstand temperatures of 700°C whilst retaining pigment/colour identification of all cores. This enhancement resulted in less maintenance down time and significant cost savings.