Non-hazardous “ultra-green” PU cleaner from Bio8

Envii EN705 is based upon naturally derived solvents, and has evolved from other applications in different industry sectors. “We came across the application in the PU industry by accident and did not realise the safety issues currently faced when cleaning equipment,” stated Andrew Hiron, Director, Bio8 Ltd.

The product EN705 has already undergone successful trials and is now being used by major PU processing customers in the UK and Europe, including leading flexible and rigid foamers, system houses, and spray foamers.

The product can be used to clean mixing heads, injectors heads, ball valves, fittings, rotor mixers, spray guns and other parts as well as moulds used for all types of polyurethane material including cured PU-elastomers, cured isocyanate, PU adhesives and spray foam insulation. It is even being used by a leading sports equipment supplier to clean golf ball moulds. While the product can be easily and safely handled, it is powerful enough to even clean polyurea spray equipment where there has been a build-up of several layers formed during coating procedures.

EN705 follows the same industry practice of soaking equipment and parts. EN705 ruptures the bonds in many polymeric compounds, softening it and allowing it to be removed easily with a cloth, stiff brush, paint scraper or compressed air. Recommended cleaning times are generally overnight although equipment used for polyurea coatings typically require 48 hours. EN705 also has the advantage of being used cold, unlike NMP which in some cases is heated to 120 – 150 °C. The photos illustrate the dramatic results

The product is also available as a coatable gel or a liquid, for use in dip tanks. It is “ultragreen”, non-hazardous and suitable for safe handling and disposal. The cleaner is readily biodegradable overcoming many disposal issues. Spent cleaner should be disposed of as industrial effluent because of the PU content, but users have reported a GBP 200 – 300 saving per 200 l drum, compared to the disposal costs of typical solvents used for cleaning. The product is available in 20 l and 200 l drums as well as in 1,000 l IBCs.

“EN705 is naturally more expensive than NMP and methylene chloride but when the reduction in waste disposal costs and benefits of safety and environmental issues are taken into account, we estimate that the product is cost neutral or at most has a small cost premium,” suggested Hiron. The material costs around GBP 200 per 20 l drum but can be used many times over.

Bio8 has also developed another cleaning product that will replace acetone that is used for cleaning off phenolic resin foam liquids.