Plastic Mold Making And Precision Machining

Modern Plastic mold maker and precision machining facilities rely heavily on wire EDM machining as part of their arsenal to compete in the global economy. These amazing machines have replaced many traditional methods of toolmaking, and have opened new avenues for production and profitability.

Most Plastic mold maker have several WEDM’s that run around the clock. In fact, it is difficult to imagine returning to the old days of very tedious manual surface grinding, jig-grinding and filing. The operations that previously took days for a highly skilled toolmaker can now be done better and faster, with little human intervention.

Years ago it was speculated that the wire would not have any application in plastic mold making because of the nature of the mold components used. A wire EDM requires a through the hole, as opposed to a blind hole, and molds, by nature are blind holes, so to speak.

My how things have changed! True enough, a great deal of core and cavity work cannot be done by the wire, but, on the other hand, many components are made every day on the wire. Some details are obvious candidates for WEDM, but designers have become very creative over the years and have developed new approaches that save a great deal of time and money, not to mention aggravation!

Take for instance, an insert with varying angles, radii and shapes. It is a simple process to make the insert and pocket fit to extremely tight tolerances, such as .0001 inch. This would be enough to drive a precision surface grinding expert mad, and would take much, much longer manually.

Applications for wire EDM machining

• Insert pockets
• Fitted inserts
• Core pins
• Slides
• Slide assemblies
• Contoured parting lines
• Angle blocks, or wedge blocks
• Jig-grinding operations
• Shut-off surfaces

The list could go on and on, from one industry to the next. Think of all the applications in aerospace precision machining! Imagine how many special cutters are made on the wire. Consider how many exotic materials, such as Inconel, that are extremely difficult to machine, are machined easily by a little brass wire and some electricity!

A competent programmer/operator can handle 3 or 4 machines at a time, thus further reducing expenses. With the chronic lack of qualified help available and the ageing workforce, it makes more sense than ever to rely on the WEDM for essential machining.