Mastercut specialise in the precision cutting of thin materials, especially stainless steel. Photo Chemical Machining is an effective, relatively low cost method of producing intricate parts and shapes. Because we also cut material using the laser cutting process we are in a good position to advise on the most appropriate method for your part.
The process
Photo Chemical Machining (PCM), also known as Chemical Milling, Cutting or Etching, is a highly accurate manufacturing method which uses chemicals to remove layers of metal from sections of a sheet to leave text/graphics either proud of the surface or etched into the surface. A photographic process is used to define exactly where acid will be able to dissolve the metal and which parts will remain intact. The metal sheets can be half-etched or full-etched through, adding depth and dimension where required.
Once you send us the dimensions of your parts, we’ll help you select a material that is compatible with your application. After etching, forming achieves any final three-dimensional configuration you may need.
Small parts are often supplied still “tabbed” into the parent sheet to allow for “twisting” out by the customer. This reduces the risk of damage and is usually more convenient.
It starts with a Photo Tool
After we have the artwork in Vector format, or a .dxf/.dwg for parts, we can then make a photo tool. These are high resolution plots made on our in house image setter and look like the old "overhead transperancy"films. They are plotted onto a clear film, so everything that is black will be etched, and everything that is clear will be not etched.
Laminate, expose, develop
We then laminate the material (Stainless, brass or copper) with a light sensitive photographic laminate or "Resist". This is performed in a dark room. Once laminated, the photo tool is placed on top of the material and exposed to a high level UV light. The clear parts on the photo tool allow the UV light to pass through to the resist, and the laminate becomes soft in these areas. All the parts in the photo tool that are black and the UV light cannot pass remain hard resist. The whole panel is then put through a development process where the soft parts of the resist is dissolved, leaving all the hard parts behind. As seen in this image (Precision parts on the left image and plaque on the right).
Etch
Now it's time for etching. The panel will run through the etcher multiple times until we have either reached the desired depth (for half etched elements) or until the part is fully etch all the way through (for precision parts).
Strip resist
The plates are now etched and the resist is on. For projects that are either precision parts or projects that do not need paint filling, then now is the time to strip the resist off. This is done in a chemical bath and the job is completed after that. For paint filling projects, the resist is left on.
Finished product
Paint filled
For the small parts on the left hand picture, the project is complete. The parts are in "Sheet form" for the client to "twist out".
For the sign on the right hand picture, this has been 2 pack paint filled and the resist has been stripped off. This particular plate will now go and get laser cut around the perimeter to complete the job. This will be one of the longest lasting, hard wearing signs on the market.
Watch the movie
PCMI (Photo chemical machining industry) of which Mastercut are long time members, have made an interactive video explaining how the process works. Feel free to watch the movie and ask any questions you may have directly to us through the contact us page
Benefits
Intricate, high tolerance precision parts can be manufactured with shapes and detail unmatched by conventional methods, therefore PCM offers endless opportunities to designers and engineers. Prototype parts can be obtained in a short period of time, and tooling costs are significantly reduced. Even the most complex designs are possible with chemical etching without any affect to metal hardness, grain structure or ductility and materials remain free of surface burrs resulting in a superior finish and highly precise parts.
Size limitations
For stainless steel, copper and brass the sheet size is usually 300x300, 300x400 or 300x450. Larger sizes are also possible; please contact us to discuss your requirements.
What applications is it best for
We specialise in chemically etching precision parts, nameplates jewellery and more for these industries:
Aerospace
Automotive
Computer
Consumer
Decorative
Electronics
Mechanical
Medical
What can be cut?
Some common materials that can etched in thickness from 0.05 mm to 0.9mm include
Stainless Steel
Alloy 42
Beryllium Copper
Brass
Carbon Steel
Copper
Kovar
Magnetic Alloys
Nickel Silver
Phosphor Bronze
Spring Steel
Mastercut also offer - Laser Cutting - PCM Etching - Plating & Forming
Download Mastercut's Brochure from the resources page for an overview of all products and services
