Jun 14 2009
Matching the cutting or etching process to the number of units is the key to lower product development costs when it comes to thin metal parts. Here, Jim Cove of Mastercut Technologies explains how photochemical milling (PCM) offers economies when laser cutting becomes prohibitive.
The transition from laser cutting to PCM and stamping
Laser cutting thin metal parts is often most cost-effective for the small volumes associated with prototyping and initial production but Mr Cove says the transition to greater production volumes generally demands a rethink.
"As the unit volumes increase, there may come a point where stamping becomes an option," Mr Cove says. "But when you crunch the numbers on tooling costs, having the right punch, handling and other issues, you may find yourself laser cutting for longer than you thought."
"A less well-known intermediate step, photochemical milling, provides very economical components reliably, accurately and consistently without limiting your ability to alter the design along the way."
PCM: photocopying for metal
The PCM process exposes the image of the required parts onto light-sensitive film laminated to the material of the parts. Once developed, only the exposed areas of film remain in place. After a series of passes through the acid etching machine, the areas unprotected by the film simply disappear, leaving only the wanted components. The parts are secured with carefully placed "tabs" that allow the part to snap out of the sheet easily, often without leaving any sharp edges.
"PCM is the closest thing to 'photocopying' of metal parts - and brings all its advantages," Mr Cove says. "The etching process takes no longer per sheet regardless of the intricacy or number of parts. Another major advantage is the ability to partially etch or to include fold lines, holes, slots, mesh, text and logos without significantly increasing the process time or cost."
The PCM process is well proven. Over 15 years, Mastercut Technologies' Gold Coast factory has perfected PCM for stainless steel, copper, brass, beryllium copper, nickel alloys and more in thicknesses as thin as 0.05mm. "Of course, Mastercut's YAG laser is the preferred option for very small runs but PCM has proven to be the process of choice as volumes increase," Mr Cove says.