ICI Polyurethanes' aim of taking MDI-based products into the last real bastion of TDI - flexible slabstock foam for furniture and bedding - has received a significant boost with the news that Sweden's Ikea furniture chain will be using ICI's Waterlily foam in a range of products from the start of next year.
Since its launch some two years ago, Waterlily water-blown MDI foam has attracted significant attention because of its environment friendly claims, and there are now six foam producers in Europe manufacturing the product under licence from ICI. These are currently located in Italy, Germany, France, the Netherlands and the Nordic countries. By next year ICI hopes to have added further foamers in Spain and Austria.
Ed Cassidy, international research and technology team leader for ICI Polyurethanes, based at Everslaan in Belgium, explains that over 40 furniture makers, notably in Italy, have products coming to the market in retail stores, and that ICI is working closely with these firms to create a brand awareness among consumers of the Waterlily name.
Adding Ikea - one of Europe's top furniture makers and retailers - to the ranks of Waterlily users will, he hopes, add a further seal of approval to the product in the customers' eyes. ICI started earlier this year to promote the Waterlily concept to both retailers and the consumers, stressing the comfort and 'green' credentials of the foam, which does not use a chemical blowing agent, contains no halogen- or phosphorus-containing ingredients, and can be recycled chemically.
Currently, 25 grades of Waterlily are being produced, with densities ranging from 30-80 kg/m3, at the higher end of conventional TDI slabstock foam range. ICI produces the three-component systems at its Rozenburg site, in the Netherlands, which is home to a commercial size slabstock line used for development work and customer trials.
To date ICI has chosen to market Waterlily solely in Europe, because of the issue of foam density and the fact that foams used in the US and Far East are generally of a lower density that Waterlily cannot, as yet, achieve. It can, however, replace TDI high resilience foams, which hold a 10-15% share of the European slabstock market.
The key to the Waterlily system is the control ICI keeps over the formulation of the two main components: a full prepolymer which contains polyether polyols reacted with MDI, and a high functionality polymeric MDI. When mixed with water, the foam is blown by the CO2 and steam produced, but as Cassidy stresses, there is no PU reaction at the foaming stage - as this takes place under controlled conditions at ICI during the preparation of the pre-polymer.
One result is a much lower exotherm and a fast and much more easily controlled reaction with no chance of scorch or fire. This removes the need to use antioxidants in the formulation, and eliminates the curing period required for TDI foams after blowing. Another is the elimination of the need to use a PU catalyst, removing a source of heavy metals in the finished product.
The density and hardness properties of the foam are controlled by varying the ratios of prepolymer to isocyanate and prepolymer to water in the foam formulation. Waterlily, explains Cassidy, can be produced on existing slabstock lines and gives converters the possibility either of replacing TDI HR foams or of introducing new products to their lineup. For a new line investment, says Cassidy, Waterlily would prove very cost effective, as it requires less curing and storage space.
The one country that has not taken up the Waterlily challenge is the UK, where leading foamers have been approached but as yet to no avail. The issue here is the UK's stringent flammability regulations which require combustion modified foams to be used. However, trials at Rozenburg with Waterlily and additions of melamine have proved successful in terms of flammability performance, although the foams are of a higher density than the market requires. There could be a niche to replace latex foams, though, believes Cassidy.