hardware stamping partsThe concept of precision sheet metal and green sheet metal introduced by the manufacturer keeps pace with the times. In the past, we learned sheet metal technology. We cut the seams of the metal plate with scissors, plan the lines with a scriber or a circle, and tap the folded edges with a wooden square ruler. Dimensional accuracy is not good. More than 1mm, the appearance does not see obvious hammer marks. Later there are hydraulic shearing machine and bending machine. The parts are processed with less labor, the surface quality is uniform after processing, and the appearance is very beautiful. Later appeared CNC shearing machine and CNC bending machine. The bending angle of the workpiece can be accurate to 0.1 °, and the size can be accurate to 0.1mm or even higher. Adjust the positioning multiple times, thus saving a lot of time and material (manual adjustment cannot avoid cutting waste or breaking a few sheets, even small pieces). Metal stamping parts manufacturers introduced so far, there has been an automatic silo, which can not only realize automatic feeding, but also automatically enter and exit the silo according to the thickness, material and size of the parts to be processed. In the modern processing process, punching, flanging, tapping, punching embossing, ventilation grille and other process operations can be completed on a CNC punching machine, and then connected to automatic bending, offline, Savanini bending machine The bending knife bending machine in the machine has also developed from manual mold change to automatic mold change. It was not until the 2017 Workers' Fair that the author saw that the express folding machine was more automated and the automatic mold function was more and more clever.

Metal stamping parts manufacturers introduced the current precision sheet metal processing uncoiling, leveling accuracy can reach 0.3~0.5mm. The bending accuracy of general sheet metal parts can reach 0.05mm to 0.1mm (CNC machine tools), and the positioning accuracy and repeated positioning accuracy of stamping processing are mostly not more than 0.1mm (of course large sheet metal products such as parts with a size greater than 1500mm, the accuracy is slightly larger), so the sheet metal parts cut by laser/digital punch/water jet and produced by CNC bending can usually meet the dimensional accuracy requirements.

Metal stamping parts manufacturers introduced us to both valuable assets, but also clear water and green mountains. Sheet metal raw processing requires the following processes to be qualified for production and discharge.

Passivation: When metal stamping parts manufacturers introduce electro-galvanized sheet metal parts, passivation treatment is required to obtain a denser oxidation protection layer. Stainless steel plate itself has a certain corrosion resistance, under normal circumstances can be directly processed, but in some cases need to be passivated. If the water heater tank adopts SUS304 or SUS316. The part still needs to be passivated to ensure that it will not corrode at high temperatures. The passivation solution contains 5% nitric acid, 2% potassium dichromate and 10% hydrofluoric acid in the pickling passivation two-in-one solution. The hexavalent chromium Cr6 + in potassium dichromate will seriously pollute the environment and cause serious harm to the human body (such as the reproductive system). Hydrofluoric acid is very corrosive, causing serious damage to teeth and bones, and also corroding glass. At present, China has successfully replaced Cr6 + with Cr3 +, which greatly reduces environmental pollution and replaces hydrofluoric acid with certain additives.

Spray paint and powder spraying: metal stamping parts manufacturers introduced in the paint and solvent (or add hardener) after spraying, with compressed air or electrostatic force to spray the paint atomized to the workpiece and attached to the surface of the workpiece, solvent volatilization (or mutual reaction) after curing to form a film. The disadvantage of this process is that the VOC (volatile organic gas) content is high, which is harmful to the human body; the utilization rate of paint is very low, only about 50%, which is a waste of resources. However, electrostatic powder spraying does not require large amounts of diluent. The powder does not contain harmful substances. After the additives are volatilized, the film is solidified and does not pollute the environment. The coating has good quality, high adhesion and mechanical strength, corrosion resistance, short curing time, no primer paint and high powder recovery rate. With the popularization and application of epoxy resin and polyester powder spraying, the aesthetics of sheet metal parts can be comparable to spray paint, and the corrosion resistance is also greatly improved.