SHOTBLASTING AND PRIMING FACILITY
Applied Primers : Jotun, Akzo Nobel, Hempel, International, Nippon Ceramo, Sigmaweld Or any other primers as per customer wish
HEATING SECTION
While applying heat to the profile, the humidity is to be removed and the steel must be pre-heated at appropriate temperature. In order to acquire appropriate drying, before applying the primer onto the surface of the steel, the recommended steel temperature should be between 30 °C and 40 ° C depending on the primer type and thickness.
SHOTBLAST SECTION
The shoot blasting section ensures a clean and smooth steel surface (ISO 8501-1: 1988 Sa 2½ - very intense blasting cleaning). There should be a cleaning unit as well as the blasting unit. This unit is required for cleaning the dust and the erosive particles (grit, shot) sprayed on the surface of the material.
STEEL CLEANLINESS
So as to achieve a good protection against corrosion after shopprimer, it is necessary that the material to be painted is applied Sa 2½ - very intense blasting cleaning. During the preparations for Sa 2½, there shall be no oil, grease and dirt on the surface of the material; additionally, there shall be no remnants of rust and paint and any other foreign matters.
SMOOTHNESS OF STEEL SURFACE
The application of the grit shot will create the rough surface quality as per standard Sa 2½. This roughness shall depend on the quality and dimension of the particles such as grit, shot, etc. and on the grit shot speed of the spraying. This roughness shall create a good adhesive area for the primer and therefore, the adhesiveness of the primer on the steel profile shall be enhanced.
By examining the surface profile with a magnifying glass, irregular surface gorges and peaks can be observed. The ideal surface profile Ry level (the spaciousness between the gorges and peaks) for the primer application should be between 40 and 75 μm.
APPLICATION OF PRIMER
After passing through the shot blast section the steel now proceeds to the priming centre where the required prefabricated primer is applied through a vertical moving head consisting of nozzles spraying the primer on both sides of the steel profile.
DRYING SECTION
The final part of the surface treatment process is for the steel to pass through the heated after dryer.
It is advised to do this process in a closed environment for air pollution protection.
