How to apply polyurethane foam for assuring the quality of the insulation?
26.01.2018
Before applying polyurethane foam it is recommended to identify the atmospheric conditions and the characteristics of the under layer, plus to manipulate the parameters in such a way so that they will correspond to the specifications provided by each producer in part.
Regarding the temperature and the recirculation degree of the material it is suggested to follow the specifications coming from the producer regarding the way in which the polyurethane foam is supposed to be applied. Some will recommend a simple recirculation of the polyol while others would recommend a warm recirculation.
Testing the quality of the polyurethane foam
Before applying the foam it is better to spray firstly a small amount of it in order to check the quality of the material. When generating the samples the protection norms are to be respected and the cooling time is to be respected. If the samples are pulverized into plastic bags, extra protection norms are to be taken into consideration, as there is a risk of spontaneous combustion.
The thickness of the polyurethane foam layer
The producers recommend respecting the thickness for each applied layer in part plus the time that is necessary for cooling the material before going on with the next layer. Applying a too thick layer without taking into account the time needed for cooling it could increase the fire risk through spontaneous combustion. Closed cell materials retain warm much better than open cell ones, needing therefore a longer time for cooling purposes.
It is relevant to note that the surface temperature is similar to the one of the ambient, while the interior will be warmer. Applying an extra layer before real cooling can only increase the temperature within the under layers till the point that the entire process can become dangerous. This will affect also the quality of the insulation. Therefore it is recommended to use a special thermometer for checking the temperature during application.
Extremely speaking, pulverizing a foam layer which is to thin, specially when using open cells material can generate insufficient warm affecting the quality of the overall work.
The thickness of the application is stipulated by each producer in part and by the norms into force. Monitoring it is to be permanently done for avoiding over coverage and lost of material.
The trimming
Trimming of the polyurethane foam insulations it mandatory specially when using open cells material. There are series of ways to do it, able to assure obtaining a constant layer of the surface. It is anyway recommended to apply the method suggested by each producer in part. Cleaning and eliminating the dust afterwards is absolutely necessary. For this reason it is better to use an industrial vacuum cleaner.
Reparation works
Usually, during trimming processes one can identify the areas to needs reparation works. These can be done while using extra amounts of polyurethane foam. All protection materials such as plastic follies, and ventilation equipment are to be kept into function during operation.
Coatings
For conformity, it is necessary to apply an extra protector cover, which is paint. Usually, the producer of polyurethane foam is making recommendations related to it and its way of application.
