Continuous foam production is by far the most popular and efficient method for the manufacture of FPSF and is practiced in one of its many forms by all the world's major polyurethane companies.

Although the degree of sophistication built into these types of machines can vary from simple manually controlled to highly computerized and automated, the basic principles outlined below apply to all continuous machines. The raw materials are stored in suitably sized tanks or containers and are conditioned to the required temperature to achieve optimum control over the process. Accurate metering pumps are used to deliver the ingredients from their storage tanks to a mixing chamber. Depending on local conditions, some of the ingredients can be mixed together in blending tanks before they are metered to the mixing head, although many foamers prefer to meter each component separately, so as to minimize handling. The pumps must be capable of precision metering to an accuracy of 0.5%.

On emerging from the mixing head, the liquid mixture is poured continuously on to moving paper or plastic film mould, which is supported on a moving conveyer.  As the expanding mixture moves down the conveyor, it is changing from liquid to solid elastomer, this part of the process is usually complete within the first 2 to 3 minutes,  (7 to 10 metres from the point of pouring).

The continuous foam block, which can be up to 2.2 metres wide and a little over 1 metre high, is transported a further 50 metres. This ensures proper foam curing before cutting with a specially designed band knife.  Block lengths can vary according to their ultimate use requirements from about 1 metre, to as much as 60 metres. Continuous foam machines have undergone a number of changes and improvements over the years in order to improve block shape, processing control and efficiency.