WITTMANN’s technology supports Swoboda CZ in Jihlava, Czech Republic in complex metal-plastic assemblies, which requires high degree of automation. With roughly 200 square meters of floor space, it is one of the largest and most complex production cells at this location. Millions of switchbox housing components are manufactured with this equipment every year.

The automated production cell is equipped with WITTMANN’s vertical injection molding machine, two-station rotary table, temperature controllers, and six-axis robot.

The large WITTMANN vertical injection molding machine with 270 tons clamping force stands at the center of the production cell, equipped with a two-station rotary table, plus temperature controllers also supplied by WITTMANN.

Efficient automation, consistent high quality, simplified maintenance

Bohuněk explained the convenience in many ways brought by the WITTMANN vertical injection molding machine.

Firstly, intuitive user interface of the WITTMANN machine control system enables even production staff with little experience to achieve a consistently high standard of parts quality, and to re-start the process efficiently after a standstill.

Secondly, a structural specialty of the vertical machines from WITTMANN include in the delivery as standard for all models with a two-station rotary table. This concerns the supply of the temperature control media. The connections are placed above, so that a central rotary distributor can be dispensed with. This ensures exceptionally easy accessibility to the molds, which simplifies both automation and manual work, such as maintenance servicing.

The two-station rotary table.

Sophisticated transfer system

The mold bottom halves are positioned on the rotary table to produce the switchbox housing components. The large six-axis robot removes the finished parts from the cavities and simultaneously refills them with new inserts.

“The challenge this part presents to us is the large number and diversity of the insert parts, which the automation system must handle safely,” said Václav Dostal, Managing Director of Swoboda.

Another robot assists the large six-axis robot. It is responsible for pre-positioning the insert parts in frames. The parts to be over-molded include several signal pins, power pins and sockets. Some inserts are presented to the robot in trays. Some of the pins are punched and bent in-line via reel-to-reel systems.

The impressive feature though is the transfer system inside the production cell. Via a rail system, the frames are transported to the clamping unit, where the multi-axis robot takes over the complete insert sets and places the pins and sockets into the mold cavities. They are then over-molded with white, fiberglass-reinforced plastic material.

The freshly injection-molded components are transported away from the clamping unit by the transfer system. They are passed to camera inspection and DMC marking, deposited in trays and then leave the production cell. All empty frames and transport carriages are returned automatically to their starting points at the end of the cycle.

Setting benchmarks for other locations worldwide

The entire automation has been developed and built on site.

Automation solutions from Jihlava are also in operation at other Swoboda locations around the world. The new production process for making switchbox housing components is exemplary.

The complete automation of all process steps and the excellent repeatability of the WITTMANN injection molding machine have successfully increased the efficiency and made it possible to reduce the unit costs. Moreover, they ensure high process stability and consistency of quality standards.