Painting production lines such as automobiles produce a large amount of VOC using solvent coatings, as well as heavy metal problems. European automotive coatings use coating technology instead of painting. Coatings use water-based and powder coatings as much as possible, far below European emission regulations. Some advanced automotive coating lines further propose the concept of zero VOC emissions.
The surface treatment has a multi-step process of phosphating and passivation, and a heavy metal chromium passivating agent is used. Cr6+ is a carcinogen and is harmful to humans. Foreign countries have made great progress in simplifying the phosphating process and streamlining the chromizing process. The waterborne alkyd coating has been successfully applied in combination with phosphating and passivation, which not only simplifies the process, but also removes the passivating agent containing Cr6+. Epoxy primers, VOC-free acrylic latexes, air-drying varnish coatings and phosphating passivation simultaneous processes have also been developed.
It is used for the surface treatment of aluminum alloy and stainless steel for aircraft. The traditional process is phosphate phosphating, washed with water, and then passivated with dissolved hexavalent chromium salt and chromic acid mixture. After washing, it is dried and dried. Priming. The use of modified alkoxysilanes and alkoxy precursors to prepare conversion coating films by sol-gel method has also made great progress in replacing phosphating and passivation processes.
Hss Drill Bits For Wood-Hss Brad Point Drill Bit
HSS Fully Ground Wood Brad Point Drll Bit for Wood Precision Diling
1.HSS material and diamond ground. leaving them sharper and with a longer dillinglife than other bits made
from high carbon steel;
2.Brad point tip provides accurate positioning for starting the hole;
3.Spur cutting edges reduce splintering and ensure a smooth, clean hole;
4.Wide, smooth flutes give quick ejecting of wood chips;
5.Round shank is designed for use in power drills, drill presses, and boring machines;
6.Bit is precision ground for use in furniture making, doweling, cabinetry, and other woodworking applications where an exact hole size is required.
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