Meaning
Superhard cutting implements made from sintered diamond particles perform secondary machining on abrasive, filled polymer components. Molders utilize these specialized tools for trimming, drilling, and pocket milling on plastics reinforced with glass fibers, carbon fibers, or mineral fillers that rapidly wear out standard carbide tooling. The extreme hardness of the cutting edges ensures long tool life and maintains precise part tolerances across extended production runs.
Wear Resistance
Sintered diamond crystals resist the highly abrasive actions of reinforcing fibers that can dull standard steel tools in a few cycles. When polycrystalline diamond tooling is employed, the cutter retains a sharp edge, which prevents fiber breakout and delamination in the molded plastic. This sharp geometry is critical for cutting clean holes and slots without generating high localized heat, which can melt or degrade the polymer matrix.
Consequently, machine uptime increases due to a reduction in the frequency of tool changes.
Surface Finish
Sharp cutting actions produce clean surfaces on complex molded parts, eliminating the need for post-machining deburring. When cutting glass-filled nylon, the tool cleanly shears through the reinforcing fibers rather than tearing them from the resin.
Cost Balance
Higher initial tool costs are offset by the dramatic increase in tool life and the reduction in scrap parts. A single diamond cutter can outlast tungsten carbide tools by a factor of fifty or more when machining highly filled resins. This longevity stabilizes the secondary machining process, allowing for automated, unattended production runs without the risk of dimensional drift due to tool wear.
