| abstract |
A process for continuous manufacturing of moisture-curable polyurethane formulations used as sealants and adhesives. The process is characterized by the fact that the reactive components are introduced independently, and without the need for a prepolymer, to a mixer. Solid or liquid raw materials can be either pre-blended or fed directly to the mixer, a twin-screw extruder, which provides the requisite energy to homogenously mix the raw materials and drive the chemical reaction. The process is designed so that the extruder barrel and screw allow variable feed addition and heat exchange down the length of the machine. This allows various operations to be performed at different points in the extruder, including reaction, dispersive mixing, distributive mixing and devolitization. |