Detailed process of polyurethane on-site foaming

Sep 13,2023

Polyurethane foaming technology

1. Advantages of polyurethane on-site foaming technology:

The method of foaming, spraying (or instilling) polyurethane foam insulation layer on site, the surface of which is a whole, no joints, reduced cold loss, high surface and construction efficiency, easy to meet quality requirements, reduce construction procedures, and also omit the anti-corrosion coating on the surface of the pipe.

2. Polyurethane on-site foaming construction process principle

The principle of polyurethane foam foam plastic foaming spraying and infusion process is that the poly reaction of polyether isocyanate can generate amformate, that is, the required polyurethane ethyl ester, which is commonly known as polyurethane foam. In the reaction process, catalysts, cross-linking agents, foaming agents, foam stabilizers, etc. are added at the same time, and their role is to promote and perfect the chemical reaction.

These raw materials are divided into two groups, after full mixing, they are driven into the special spray gun by the metering pump in proportion, fully mixed and sprayed on the surface of the pipeline or equipment in the spray gun or in the filling mixer, reacting, foaming within 5-10S to form foam, and curing and molding.

3. Polyurethane on-site foaming construction method

1) Spraying method: according to this formula, the two groups of solutions are stored in two barrels, the materials are filtered to the metering pump, driven by the air motor, the material is input into the material pipe to the spray gun body, the compressed air control valve brings the materials into the mixing chamber, and after mixing, it is sprayed into the pipeline or equipment for foam molding through the nozzle nozzle.

2) Perfusion method: the prepared two groups of solutions are stored in the barrel to filter to the metering pump, driven by the air motor, the material is input into the material pipe to the filling mixer, and the compressed air is passed into the filling motor all the way, and the mixing shaft is driven to mix the two groups of materials, and then injected into the mold for foam molding.

4. Precautions for polyurethane on-site foaming construction

Stir the material at room temperature to make it mix the reaction, and then quickly pour it in the space that needs to be formed, and the foaming time of the reaction should be controlled during construction, so that the mixed material after mixing is liquidally poured into the void. During the foaming process, a large expansion force will be generated, and the perfusion interlayer or model should be properly reinforced.