Kwazulu-Natal company Insulite manufactures calcium silicate, marketed and sold under the brand name Insulite, which can replace most applications where asbestos insulation was always used, such as firedoors, boiler, piping and vessel insulation.

The use of many asbestos products has been banned world-wide due to the detrimental health effects asbestos fibres can have. There are also strict laws governing the removal and disposal of products containing asbestos.

MD Tony Barry says the company’s product is completely environment-friendly, and no polluting substances are used in the manufacture of the product. The main ingredients used in production are lime, silica and cellulose fibre. “Any waste or off-cuts can be disposed on to any dumpsite, and nothing can leach out. “In fact, a calcium silicate producer in the UK gives its waste product to farmers to plough back into their fields as a gentle liming agent. “It also assists in retaining moisture in the soil,” Barry says.

He adds that the product also offers an alternative to polyurethane, polystyrene, magnesium oxy-chloride and any other materials used in fire-resistant applications. Marketing agent for the product Graham Wheeler says the range of ready-made products the company manufactures include high-temperature insulation boards; pipe, tank and vessel insulation; and fire-resistant substrates for doors, walling, ceilings and enclosures. The company also manufactures blocks of calcium silicate in various densities – with dimensions of 3 000 mm by 1 200 mm by 200 mm – for different applications. The blocks are cut to customer requirements in shape, size and thickness. “We offer density variations from 220 kg/m3 up to 400 kg/m3. “The lower densities have better insulating properties than the higher densities.

“However, the higher densities do not only have excellent thermal and fire-resistant properties, but also feature greater compressive strength. “The choice of material depends on the application requirement,” Wheeler says.

According to Barry, the use of calcium silicate in fire doors was pioneered by Insulite, which has become an internationally acceptable option to traditional materials used in the fire-door core. “Calcium silicate insulation has also been respecified in the petrochemical industry in South Africa. “In addition, calcium silicate has been accepted as non-combustible high-temperature insulation among clients of international insurance companies. “Many fire departments in South Africa recommend the material for its stability, integrity and insulation properties under fire conditions,” Barry adds.

The product is recommended for the refractory, power plant, petrochemical, construction and building industries. According to Barry, the product has been supplied as noncombustible insulation, fire-rated cladding and substrates to the petrochemical and power plant industries, both locally and internationally; the construction industry as a cladding for structural steel; the pharmaceutical industry as a substrate in cleanroom enclosures and the automotive industry as environmental walls with cleanroom quality. Wheeler adds that Insulite composites offer an alternative to polyurethane, polystyrene, and any other insulating materials where fire- resistance is a requirement, such as cold-storage rooms. The concept behind the product originated in Europe.

However, the process and product was adapted and developed by Insulite in South Africa since 1995. Built on a five-hectare site, the company’s manufacturing facility, with 10 000 m2 of factory under cover, is situated at Cato Ridge, Kwazulu-Natal, 50 km from the Durban harbour.

Barry says in the past two years, Insulite has invested about R20-million, which was spent on plant upgrades to improve quality, a new boiler to improve cost-efficiency, computerised profile-cutting equipment to service the growing requirements in the pipe insulation industry, increased capacity, computerised monitoring of the process plant, acquisition of new technologies, sales and marketing, and research and development on existing products. He explains that the production process involves fine-grained lime and silica synthesised under controlled hydrothermal conditions to produce blocks of calcium silicate. “The blocks are formed from evenly distributed intermeshed needle-like crystals of Xonotlite that result in exceptional mechanical strength and extremely low hydration. “After removing the blocks from the moulds, they are dried and cut to customer requirements,” Barry says.

The company currently manufactures 10 000 m3 of Insulite a year. Barry adds that with small capital expenditure, production can be doubled as most of the equipment is already installed. The company currently exports between 70% and 80% of its production. The company is ISO 9002 accredited and exports its product worldwide, including to countries such as Australia, France, the Netherlands, Thailand, the UK, the US, and other countries in Africa.

According to Barry, the company’s biggest challenge is to change this ratio to supply 40% of its production to local markets and to export the remaining 60%.

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