Neunkirchen, 16th September 2020. After CDC and powder coating, perforated sheets in DC01 - DC06 grade steel from SCHÄFER Perforated Metal withstand over 1008 hours of extreme conditions in the salt spray test, in accordance with EN ISO 9227-0 and the ASTM D1654-2008 procedure A. To fulfil this high-quality standard, high-grade primer and powder coating alone isn’t sufficient. The main prerequisite is the first-class manufacturing standard of the perforation patterns. This requires the edges of the perforations to be rounded off in a separate process after initial perforation. This mechanical finishing is standard practice in perforated sheet production at SCHÄFER Perforated Metal.
The sheet perforation process involves metal stamps being mechanically pressed into the smooth surface of the sheets under great pressure, which then creates specific perforation patterns in the sheets. This process causes burrs to form on the underside of the sheets where the stamps puncture the metal. At SCHÄFER Perforated Metal, the sheets are therefore de-burred in a further process, using abrasives. In technical jargon, this finishing process is referred to as rounding and is essential for all subsequent anti-corrosion measures.
Only after rounding can chemical or electro-chemical processes provide the perforated sheets with permanent corrosion or oxidation protection. For this purpose, the sheets are given a solvent-free primer coat in a cathodic dip process (CDC), which makes them 90 % corrosion resistant. At this stage, the surface coating is not yet resistant to UV light. This can only be permanently achieved in the final powder coating process, which gives the sheets complete corrosion protection.
The main application fields for SCHÄFER perforated sheets are commercial vehicles, such as construction and agricultural machines, which are used in corrosive conditions under regular exposure to chemicals, moisture and dirt. The perforated sheets can be produced with a great variety of perforation patterns and in any standard RAL colours, according to customer wishes. The salt spray tests guarantee permanent corrosion resistance. The sheets were tested and approved in the test laboratories of the Sauerland company AkzoNobel in Arnsberg and the paint manufacturers Gross & Perthun GmbH & Co. KG in Mannheim.