"The material we use is thermoplastic, traditionally granules made from polycarbonate and increasingly also from ABS Wasserklar," explains Stefan Eckert, who points out that there are no differences in quality in the end product. "It's all about the effort involved in the processing procedure. Polycarbonate is processed at 280 to 310 degrees Celsius and requires a temperature of 100 degrees Celsius for the mold. ABS, on the other hand, can be processed at 220 to 240 degrees, and 60 degrees Celsius is already sufficient for the mold.
- The starting material is melted and injected into the mold produced by the mold shop on the basis of the model design data at a pressure of up to 2,000 bar - the so-called shot must perfectly fill the mold with its details.
- After injection, a robotic arm removes the molded part, because the window sections are sensitive and must not simply fall onto the conveyor belt.
- An employee first performs a 100-percent product inspection, then breaks off the sprue and
- finally, the windows are carefully packaged separately for transport to the assembly line.
And what can go wrong? "The mold is mirror-polished and must be handled with the utmost care during the production process - a fingerprint would show up on the molded part," explains injection molding expert Stefan Eckert.
"Furthermore, the machines must also be cleaned to a high degree of cleanliness. For example, there must be no deposits left from a previously sprayed material, because otherwise we have rejects due to contamination." For this reason, employees prepare the machine and molds for each series with a special cleaning granulate. "The granules also require the utmost care - if a single black bead gets lost in the starting material, up to 20 shots will produce black streaks."
