It’s interesting that simple day-to-day products often have the most complex molds. One example is toothbrushes.
The 16-fold injection mold has two injection stations and one loading and removal station located outside the tool. Two different materials in the same color are processed in the
No time-consuming color changes (two hours on average) are necessary,
“What has been produced during the day can now be in the supermarkets’ storerooms by the evening,” according to a press release from Zahoransky.
The technical challenge was interesting because seven injection units had to be connected to the mold in a tight space. The availability of several material feeds, the different processing temperatures of the various materials and the close spacing between the different nozzles at the same cavity were also factors. Injection molding was done on a six-component machine from Engel. The seventh injection unit from Boy was integrated in the production process.
Mold-Masters supplied a special two-part soldered runner which is unique for Mold-Masters. Instead of having only straight channels, these runners have as many as three melt levels with gentle curves and turns. This allows design freedom because of natural balancing, a uniform thermal profile and a comparatively low construction height. This technology allows two or more melt flow-ways to be integrated into a single runner. The design also allows six (and more) materials and colors in a single runner.