MOLD TOOL PRODUCTION
At RJC , we make great tools for low-volume manufacturing. When making your mold tool we use pre-hardened tool steels such as P20 and NAK-80, and fully-hardened S136 tool steel. The material used will depend on your specifications, the type of resin and the number of parts you want to produce. Such as PP , PP+GF(20%/30%),ABS , PC/ABS , PC，PA66 ,POM，PA66+GF( 20%/30%/40%),PPA, PPS，TPE , TPU , TPV etc……
• Quick removal of large amounts of metal material
• Highly accurate and repeatable
• Suitable for many different kinds of substrates
• Low investment in tooling or preparation costs
• Fast turnaround
• What is EDM?
• EDM stands for electrical discharge machining, the applications best suited for this metal removal process are those characterized by extremely exacting tolerances and situations that would be extremely difficult or impossible to handle with any other method of machining.
• An Overview Of EDM
• The origin of electrical discharge machining goes back to 1770, when English scientist Joseph Priestly discovered the erosive effect of electrical discharges. In 1943, Soviet scientists B. Lazarenko and N. Lazarenko had the idea of exploiting the destructive effect of an electrical discharge and developing a controlled process for machining materials that are conductors of electricity.
• With that idea, the EDM process was born. The Lazarenkos perfected the electrical discharge process, which consisted of a succession of discharges made to take place between two conductors separated from each other by a film of non-conducting liquid, called a dielectric. The Lazarenkos achieved a form of immortality with this circuit, which today bears their name. Today, many EDMs use an advanced version of the Lazarenko circuit.
• How It Works
• During the EDM process, a series of non-stationary, timed electrical pulses remove material from a workpiece. The electrode and the workpiece are held by the machine tool, which also contains the dielectric. A power supply controls the timing and intensity of the electrical charges and the movement of the electrode in relation to the workpiece.
• At the spot where the electric field is strongest, a discharge is initiated. Under the effect of this field, electrons and positive free ions are accelerated to high velocities and rapidly form an ionized channel that conducts electricity. At this stage current can flow and the spark forms between the electrode and workpiece, causing a great number of collisions between the particles. During this process a bubble of gas develops and its pressure rises very steadily until a plasma zone is formed. The plasma zone quickly reaches very high temperatures, in the region of 8,000 to 12,000′ Centigrade, due to the effect of the ever-increasing number of collisions. This causes instantaneous local melting of a certain amount of the material at the surface of the two conductors. When the current is cut off, the sudden reduction in temperature causes the bubble to implode, which projects the melted material away from the workpiece, leaving a tiny crater. The eroded material then resolidifies in the dielectric in the form of small spheres and is removed by the dielectric. All this without the electrode ever touching the workpiece! Making EDM a no-contact machining process allowing you to achieve tighter tolerances and better finishes in a wide range of materials that are otherwise difficult or impossible to machine with traditional processes.