Dosing components with precision and accuracy is a key factor for any chemical reaction. Polyurethanes make no exception. That’s why the dosing system of polyurethane foaming machines is designed to match the properties and the process parameters of the chemicals.
Chemicals are metered by pumps (which can be gear or axial pistons, depending on the pressure required for mixing) or by dosing pistons, which are widely used for chemicals with solid fillers, as they wear much less than pumps.
Making polyurethane parts is not just a matter of dosing polyol and isocyanate: additives, such as colors and blowing agents, can be dosed together with the two main components.