H2Ofinish is a wet blasting technique that gives stainless steel and inox a low and reproducible SRI value below 0,010. This means minimal dirt attachment and optimal cleanability. H2Ofinish meets every requirement for sanitary and hygienic processing for the pharmaceutical industry as well as the food industry. Products treated with H2Ofinish are resistant to the daily cleaning and disinfecting done within the sectors of pharmaceutics, liquor and food. However, this technique can also be used within other industries such as automotive, architectonic objects, pools, and the medical industry. No harmful chemical substances are used in this process, the wet blasting technique has hardly any environmental impact.
SRI value: Amount of dirt on surface after cleaning.
It is common knowledge that stainless steel cannot be endlessly exposed to chemical or maritime environments without corrosion eventually occurring.
H2Ofinish is a technique that:
• Increased corrossion resistance
• Minimal dirt adhesion – SRI value below 0,010
• A smooth finish – Visual aspect: satin gloss
• Optimal cleanability – Protected against daily cleaning and disinfection
• Environmetal friendly – No use of chemicals
One of the reasons this surface treatment is very suitable for the pharmaceutical, and food & beverage industry is that the Soil Retention Index
(SRI) value after wet blasting appears to be the most preferable when compared to all other surface treatments and finishes. This concerns the value of the quantity of impurities that remain on a surface after a cleaning has taken place.
It is important that a surface is smooth, but also not too smooth; when the surface roughness is below Ra = 0,2µm, bacteriological contamination may arise because the adhesion forces between the surface and the bacteria have become larger. In other words, the rule “the smoother the surface, the higher the cleanability ” does not always seem to be true, when it concerns bacteria and micro-organisms. If the surface is too smooth, bacteria are difficult to remove due to negative pressure and adhesion.
WETBLASTING VS DRY BLASTING
Wet blasting is a much milder process than dry blasting. During dry blasting, with glass beads for example, the impact of the blasting agent actually breaks open the surface. The surface is then clean, but because the resulting surface has an open structure, it is susceptible to scratching, corrosion and adhesion of contaminants. This is the big difference with wet blasting: a finer blasting agent is used, and the impact is evenly distributed by the damping effect of the water, resulting in a much more even and closed finish. An animation of this can be seen in the three images below.
Glass bead blasting
• Metalfinish group •
H2Ofinish is an environmental friendly process which involves treating a surface with a pressurized mix of water and blasting agent. This results in an attractive satin gloss finish and also ensures a certain pressure build-up on the surface; also known as “peening”. The wet blasting gives a better surface structure and a lower SRI value than pearl blasting, because with the latter process the additive residue remains on the surface. This doesn’t occur with water jet blasting because it is prevented by the water flow. We work with the PureFinish process that focuses on reusing the water and abrasives after filtering it. The amount and ratio of additives can be adjusted at any time during the process for specific requirements.