Polyurethane foam is the most widely used flexible foam plastic.
Tolylene diisocyanate (TDI) and polyalcohols are the basic ingredients for the production of polyurethane foam. Blowing agents, such as methylene chloride and water, and various additives are also required.
Mixing of the raw materials
During production, the raw materials (TDI, polyalcohol, blowing agents and additives) are pumped from their own storage tank to a common mixing chamber. Adequate dispersion can be achieved by the stirring of high speed impeller installed in the mixer.
Foam forming and settling
The foam gradually solidifies when travelling up the settling chamber by the action of paper conveyor. It is then cut into 2.1 long blocks by an electric cutter after the foam is hardened.
Curing
The newly formed foam blocks are still very hot when transported to the storage area. Although the peripheral of the foam is cooled to room temperature, the centre of the block can still be hotter than 100℃. It must be cured at room temperature for at least 18 hours before further processing.
To assure the product quality, the laboratory performs routine tests on selected batches. Most of the tests, such as density measurement, tensile and compression strength tests are mechanical in nature.