Photochemical Machining and Etching Processes

Usually, the first step towards photo-chemical machining process is the manufacturing of a photo-tool, this can be achieved by using a laser photo plotter to selectively expose a photographic film based on computer-aided design data. This process gives you the photo-tool.

After producing your photo-tool, the next step involves the selection and preparation of the metal for photochemical etching. During this stage of the photochemical machining process, keen attention is paid to the chemical composition of the material to be used. This is important because the result of the etching process depends largely on the chemical composition of the material. In order to ensure that the metal has good adhesion to the photoresist, the sheet metal has to be thoroughly cleaned with electrolytic alkaline, the cleaning process makes the metal free from dirt, grease, rust, and oil thus making it possible for it to be laminated with the photo-resist.

After undergoing lamination, the surface of the metal which has now been covered with photo artwork will then be exposed to a UV source. Note that, there is no defined time for the duration of the exposure but rather the amount of time that a metal spends under UV source depends solely on its thickness. After this process you will realize that the un-exposed negative working photo-resist will be washed away, leaving only the exposed photoresist on the surface to produce the required protective layer for the etching process.

Although there have been a lot of argument about how the metal stamping method does the same work as the photo-chemical etching especially as regards production of precision metal parts. But it’s however very important to note that, there are quite some distinguishing features that make photo-chemical machining process a more suitable option for projects than the stamping method. These features include the fact that, the photochemical is less expensive especially in the unit production of complex parts and also an iteration of designs. It also takes less time in the production of parts that are free of burrs, unlike the stamping method that takes a couple of weeks to produce parts that need further modification to eliminate the burrs on the product surface. Another interesting feature of the photo-chemical etching is the fact that, with the aid of the photo tool, designs can be easily modified and at a very low cost and time frame too.

Furthermore, the photo-chemical machining process has the capability to handle any thickness and texture of material that is thrown at it, while the stamping method, on the other hand, cannot process pre-hardened sheet metal.

Finally, most manufacturers prefer the photo-chemical machining method because of its amazing ability to still maintain the inherent physical-chemical properties of the sheet metal (especially magnetic materials) even after going through all the production process.


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