By David Reed, UT EditorLeverkusen, Germany-A bathtub designed by FA Porsche Design seems like the most ludicrously self-indulgent idea I have heard of in quite a while. I mean, who would see you in it? Which is surely the only reason for buying a Porsche anything!?But the item in question is, of course, stylish, and it does use two sorts of polyurethane materials and a new process technology developed by specialists with Bayer MaterialScience GmbH. Also, since a prize was recently given to a toilet seat using Bayer polyurethane materials, it suggests that a new market segment is developing.In fact the bathtub is part of a new premium bathroom range by German manufacturer, Keramag AG, a leading maker of such equipment, based in Ratingen, Germany, dubbed 'F1.' This comprises a series of washbasins and WCs as well as cupboards and the free-standing, deep bathtub, which measures 1m x 2m and, thanks to the new technology, is self-supporting.The tub's shape is produced by thermoforming a thermoplastic film - in this case acrylic - and then reinforcing the reverse side using Bayer's new Multitec short-fibre spray polyurethane system. This typically consists of an isocyanate, two polyols - one fast-reacting the other slow - and an optional foam additive. This system, containing cut glass fibres just 12mm long, is sprayed onto the reverse side of the acrylic film at room temperature in several layers. It only takes three to five minutes for the sprayed-on reinforcement to cure, Bayer says."This method saves a lot of time compared with the conventional method, which involves reinforcing the reverse side using a time- and labour-intensive hand lay-up process with unsaturated polyesters and cut glass fibres, explained Marc Schütze, a polyurethane expert at Bayer MaterialScience. It also avoids the use of the styrene solvent and co-reactant of conventional process, he added.After curing, the tub can support considerable loads, Bayer claims. The material can be painted using several methods and its high-quality surface satisfies all the aesthetic requirements of modern bathroom design, the statement adds.The tub sits on a base which is also made of polyurethane, this time Bayer's Baydur 60 rigid polyurethane integral skin foam, which is supplied by the polyurethane system house, Büfa Polyurethane GmbH & Co. The base is made in one shot in a closed aluminium mould and has a moulded-in tongue and groove system for joining to the upper part of the tub to give a perfect fit, the Bayer statement concluded."