Photochemical machining also known as photochemical engraving is an ideal manufacturing process for producing precise fabric components. Chemical etching is obtained with a photo-resist stencil which is removal procedure in selected areas.
The photochemical machining procedure starts with the fabrication of a photo tool. There are several methods for producing photo tools. The most widespread method is to manufacture a photo tool of the precise and correct size with a laser photo conniver to selectively display the photographic film with regards to the design data of the computer.
The following step is to prepare and choose the metal for photochemical engraving. The ease engraving a material largely depends on its chemical symphony, as water is controlled by chemical corrosion. Before it’s lamination using the photo-resist, the sheet is cleaned using electrolytic alkalis to eliminate all rust, dust, oils and grease. The pre-treatment guarantees good adhesion to the photo-resist.
The coated metal substrate, enclosed with photographic artwork, is uncovered under a UV source. The time of exposure depends on the metal thickness. The concealed negative working photo resistor will be washed and the uncovered photo-resist will stay on the substrate forming the etching protective layer.
The chemical machining procedure is comparable to metal stamping, as both methods can be used in producing accurate parts of sheet metal. The precise stamping of metal has a low cost of production, but comes with a high tooling cost, particularly for complicated parts. Photochemical machining takes less production time usually taking 2 or 3 days for samples production.
Chemical etching is the ultimate method for making openings for optical applications. In optics or the opening aperture determines the tapered angle of a beam of light. The beam of light is then focused on the image plane. The aperture determines how parallel the rays of light accessed are which is significant for the image plane appearance. For instance, if the opening is narrow, highly collimated rays will be accepted resulting in a prickly focus.
Since the aperture opening is supposed to be so precise, chemical engraving is a finer production method. The process makes components made of photo resist sheet metal and etchants to corrode unwanted areas. These engraved parts can be used to exact and very accurate specifications. Since the procedure does not exert physical pressure on the metal, the parts will be produced without holes, which can affect the shape and size of the opening. In comparison, processes like metal stamping need additional abrasion treatments to remove burrs.