A compact, self-contained micromolding system with a unique injection and clamping mechanism is now available in an even smaller version. The M3 mini machine is a new companion to the original M3, introduced at K 2013 by MHS Mold Hotrunner Solutions, Georgetown, Ont. (see Oct. ’13 Close Up). Both machines are designed for direct gating of small to micro-sized parts without any cold runner. They are fully enclosed and cleanroom ready. Operation is by electric servomotors and pneumatics. Overall dimensions are 150 cm long x 60 wide x 150 cm tall. The original M3, which molds up to 32 parts with a 4-ton clamp, has about 50% greater footprint and height.
The M3 mini can mold from one to 12 runnerless parts per cycle using small, low-cost cavity inserts. The standard 17.5 x 12 cm (7 x 5.75 in.) cavity insert plate substitutes for a conventional injection mold and can be installed in less than a minute. Each insert typically contains six individual cavities and runs a typical cycle of 5 sec. The 2.2-ton clamp uses electromagnets to hold it shut.
Melt is extruded by a stationary screw, which feeds several micro-plungers. Each plunger injects directly into an MHS hot-runner valve-gate nozzle for direct gating into the cavity. This approach minimizes material residence time and degradation. Part sizes can range from 1 to 400 mg. The M3 mini costs less than the M3 and can mold a wider range of part sizes, including larger parts. Optional auxiliaries include a vision system and integrated dryer and parts removal.