Environmental conditions for polyurethane spray foam
发布时间： 2018-08-24 16:29 Author: Polyurethane foam machine Source: http: //motokone.com
Published: 2018-08-24 16:29
The sprayed polyurethane rigid foam exterior wall exterior insulation technology uses on-site foaming technology. The construction site has higher requirements for the external environment such as temperature, humidity, wind, etc., and the main requirements are as follows:
1. Temperature factors: When spraying, the ambient temperature on site and the outer surface temperature of the substrate to be sprayed should be in the range of 15 ℃ ~ 35 ℃. If the temperature transition is too low, the adhesion between the polyurethane foam and the substrate will be reduced, and the density of the sprayed rigid foam product will increase significantly; if the temperature transition is too high, the foaming agent will be consumed too much, which is uneconomical.
2. The appearance of the base material: Polyurethane rigid foam is a polymer product produced by the mixed reaction of isocyanate and combined polyether. The isocyanate component can easily react with water to form urea. The foam will become brittle and the adhesion of the foam to the substrate will decrease. Therefore, the surface of the substrate to be sprayed is requested to be clean and boring, and no rust, dust, pollution, or moisture is requested. If there is dew or frost, it should be removed and dull.
3. Wind element: When spraying, the requested wind speed is below 5m / s. Because the wind speed exceeds 5m / s, the heat generated by the reaction will be lost, which will affect the rapid foaming reaction of the polyurethane foam and make the product appearance brittle. At the same time, because the spray foaming machine mixes the raw materials and sprays them in an atomized state, if the wind speed is too large, the atomized particles will be blown away, increasing the loss of raw materials and polluting the environment.
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