There are many factors that affect the quality of polyurethane spray foam. Next, we will focus on the seven main factors that affect its quality. If you understand the following main factors, you will be able to control the quality of polyurethane spray foam very well.
1. The influence of the surface layer and the surface layer of the wall base.
If there is dust, oil, moisture and unevenness on the surface of the external wall, it will seriously affect the adhesion, insulation and flatness of the polyurethane foam to the insulation layer. Therefore, it is necessary to ensure that the wall surface is clean and flat before spraying.
2. The influence of humidity on aerosol foaming.
As the foaming agent is prone to chemical reaction with water, the content of the product increases, which tends to increase the brittleness of polyurethane foam and will seriously affect the adhesion of rigid polyurethane foam to the surface of the wall. Therefore, the exterior walls of buildings are sprayed with rigid polyurethane foam before construction, and it is best to brush a layer of moisture-proof polyurethane primer (if the walls are completely dry in summer, a step can be saved).
3. The influence of wind.
Polyurethane foaming is done outdoors. When the wind speed exceeds 5m/s, the heat loss in the foaming process is too great, the raw material loss is too great, the cost increases, and the atomised droplets are easy to fly with the wind. The pollution of the environment can be solved by windproof curtains.
4. The influence of ambient temperature and wall temperature.
The suitable temperature range for spraying polyurethane foam should be 10°C-35°C, especially the temperature of the wall surface has a great influence on the construction. When the temperature is lower than 10, the foam is easy to take off the wall and bulge, and the foam density increases significantly and wastes raw materials; when the temperature is higher than 35°C, the loss of foaming agent is too large, which will also affect the foaming effect.