Photochemical machining is also referred to as photo etching or photochemical milling. The process involves formulating or manufacturing materials with the help of an etchant as well as photo resist in order to machine the area of interest. This process has an advantage over others such as punching as it can be used for mass production of complex parts accurately which is still cost effective. PCM is useful and allows alterations even in mass production.
There are various materials which can be used in photo etching including metals, plastics, wood, glass and acrylics. Broad categories of materials that can be used in photochemical machining include:
Metals are known to be hardy materials depending on where they appear on the periodic table. Some of the metals that can be engraved include:
- Beryllium copper
- Stainless steel
- Mild steel
- Nickel alloys
Plastics are widely used in every aspect of today’s life. Whether it is for kitchen utensils, tools, garden equipment, parts of a vehicle and electronics among others, the uses of plastics cannot be underestimated. Can plastic withstand photo etching process? That is a question to ponder upon because we all know that plastics cannot endure heat. However, manufacturers decided to become innovative and have come up with plastics that can withstand laser beams. These plastics known as micro laminates, laser engravable or micro surfaced plastics have thinner cap sheets to allow proper engraving and cutting properties.
Wood types are usually sourced from different tree species and therefore definitely have different properties. While some are soft others are hard thus meaning their engraving capabilities differ too. Most woods are laser friendly- soft wood requires less laser power while hard wood requires high laser power to be engraved. Hard woods are such as walnut, cherry and alder. The desirable feature in woods is the fact that the engraved part discolors and becomes distinct from the etched parts where etching was not done.
Ever seen glassware, medals, monuments, windows or glass doors with beautiful and creative patterns? That is what etched glass looks like. The reason glass is the most sought material in etching is the fact that the finish look is not only classy but it is also sophisticated. Laser exposed to glass fractures the surface producing a frosty look. Glass is delicate and hence requires to be protected from chipping or flaking during the etching process.
This is another famous material used in photochemical machining. It is suitable for both engraving and cutting. The best thing about acrylic is that it comes in many shapes and sizes and it is easy to engrave. Acrylic can be used as either cast or extruded. Cast like glass produces a frosty white contrast against its background after etching which is unlike extruded that remains clear even after the procedure. During photochemical milling, the material is engraved on the back to give a look though effect at the front.
Other products of the material may require coloring of one side for the pattern to be visible. This does not require hard tools just as the laser one and can be used for various materials.