The causes of paint loss during the processing of steel space frame structure

The space frame steel structure is sanded and painted according to the requirements of anti-corrosion. The amount of paint is largely related to the thickness of the dry film, as well as the construction method and coating system.

Paint loss caused by the surface roughness of the workpiece.

When painting the spray-treated surface, the film thickness at the peak of the steel plate should be less than the waves film thickness. In order to meet the anti-corrosion thickness requirements at the peak (to avoid pitting corrosion), the paint "hidden" in the pits of the waves is equivalent to being wasted, which is the "steel plate roughness consumption loss". The following table shows the paint loss caused by different spraying methods (expressed in dry film thickness):

Paint loss caused by uneven film thickness distribution

After the film thickness reaches or exceeds the specified film thickness during the acceptance of the paint film after construction, the technical service representative, the supervisor or the owner will sign as normal, but the part that does not meet the specified film thickness will be required to recoat, so it will inevitably cause "excessive thickness" loss. The specific factors leading to uneven distribution of paint film thickness mainly include: worker proficiency, construction environment, simple or complex construction work piece (flat work piece), and construction method (no air spraying, air spraying, brushing, rolling).

Processing and construction waste

Space frame steel structure processing and construction waste refers to the waste of paint that is lost to the surrounding environment or the ground without reaching the surface of the construction workpiece. If there is no air spraying, the loss of paint is about 10-20%, if there is air spraying, the loss of paint is more than 50%, and the loss of rolling is about 5%. When the brush is well controlled, it is relatively less. Bridge spraying in high wind environment can cause more than 100% waste.

Waste of paint remaining in the container. After the paint is applied, the average loss of the paint remaining on the inner wall of the paint bucket and the rubber tube is about 5%.

In summary, the paint loss coefficient during construction is mainly caused by the loss of surface roughness of the workpiece, the loss of uneven paint film thickness, the waste of construction, and the waste of residual paint in the container.