Construction National

Iko’s compound quality hits the roof

Over the past two years Clay Cross-based Iko, a major UK supplier of roofing membranes in the UK, has worked closely with its compounder, Chinley-based Vinyl Compounds (VC), to develop PVC materials compliant with the standards relevant to the roofing industry.

The standards include ATG, British Board of Agrément (BBA), the European Union (CE), FM Approvals, Komo and SGS Intron.

In 2009 Iko invested in a new roofing line consisting of three twin-screw extruders. Iko now processes around 3500 tonnes of PVC compounds per annum for its Amourplan membranes. These are offered in variants for mechanical fixing, gluing and detailing. The PVC formulations for these are respectively reinforced with polyester, reinforced with glass fibre and backed with polyester, and unreinforced.

Iko initially found the compounds difficult to process on its extruders, with serious pressure fluctuations at the die heads resulting in large amounts of material being rejected. Using its laboratory facilities, VC traced the problem to product variation between bulk bags. Processing aids were not being dosed accurately enough at the compounding stage to ensure a consistent product composition.

VC now monitors the torque and pressure characteristics of the compounds to check for unacceptable variations between bags. Test results are forwarded to Iko before deliveries are accepted.

With the problem fixed, Iko’s site manager Andrew Salmon tells PRW: “Vinyl Compounds is now supplying consistent, colour-checked materials which produce little or no deviation from the production setpoints of our extrusion dies.”

VC has also helped Iko to investigate the use of alternative fire retardant materials, and is currently assisting with ageing tests.

In a move to undertake some of its material testing in house, Iko has replicated some of VC’s laboratory facilities, purchasing the same lab-scale extruder, colorimeter and spectrometer. The company is currently engaged in a £2.5m investment programme to bring all compounding in house, with a view to improving competitiveness in its markets.

Salmon concludes by commending VC’s flexibility in meeting Iko’s varying supply requirements. “We buy a range of compounds to achieve the different performance characteristics of our roofing membranes. By supplying this variety of materials on a ‘just in time’ basis, Vinyl Compounds enables us to minimise our materials inventory on site."