Polyurethane foaming process

 Polyurethane foam process is divided into the following three:

一、The dimer method

Foam process is the dimer method (white) and pre polymers (black) material to make, and then add water in pre polymers, catalyst, surfactant and other additives in mixed under high-speed mixing foam, after curing under a certain temperature curing.

二、Half the dimer method

Half of the dimer method (foam process is part of polyether polyols (white) and diisocyanate (black) material to make pre polymers, and then the other part of the polyether or polyester multivariate alcohol and diisocyanate, water, catalyst, surfactant and other additives, such as foam under high speed stirring mixing.

三、Step in the foaming process

Polyether or polyester polyol (white) and isocyanate (black), water, catalyst, surface active agent, foaming agent and other additives raw materials such as step, after mixing foam under high speed stirring. 

Step in the foaming process is generally used.Another manual foaming method, that is the easiest way, accurate weighing, mix all ingredients in a container, then immediately put these raw materials mixing, injection mould or need filling the space of foam plastic.Note: when weighing must be isocyanate (black) material finally said. 

Polyurethane hard foam bubble is usually at room temperature, molding process is simpler.According to the construction can be divided into manual foaming mechanization degree and mechanical foaming;According to the stress of foam can be divided into high pressure foaming and low pressure foam;According to the forming method can be divided into casting foaming and spraying foam.