A large proportion of flexible polyurethane foam is made in blocks, either
discontinuously in simple boxes or in a continuous process known as slabstock foaming. In this process the raw
materials, polyol, di-isocyanate, water, auxiliary blowing agents, catalysts, surfactant and other additives are
metered continuously into an in-line mixer and the mixed reactants, still in liquid form, are poured into a
continuous paper and/or polyethylene mould on a moving conveyor. In the paper mould, the liquids foam and expand to
form a continuous block of foam. This block is cut into sections, stored for at least a day to cure and cool, and
then cut in a variety of ways into the shapes required. The main uses for this foam are mattresses, furniture,
automotive seating and textile laminating.