Many manufacturers of plastic components use inflexible linear gantries restricted to Cartesian motions for loading and unloading plastic parts on injection molding machines. According to Marco Plewe, key technology manager for plastics at Kuka Roboter GmbH, a German robotics firm, these cumbersome telescopes can also conflict with crane tracks located on the ceiling of a production facility.
Kuka, however, has a new way of getting around these issues. Integrated into Kuka's function packages on the third robotic axis is the latest Festo valve terminal technology of type CPX/MPA with vacuum — a very economical application. Plastic injection molding machines can now be lightly and easily equipped and unloaded.
The slim Kuka shelf-mounted robots mean no more space limitations due to ceiling height or floor space. Depending on the model, the shelf-mounted robots can hoist weights from 6 to 210 kg. The shelfmounted robots load film and inserts into the injection molding machines for back injection and foaming. They also remove small parts; ensure precise lasering, flame-machining, deburring, and installation; and mount parts on transport frames or painting skids.
The entire spectrum of injection molding products can be efficiently handled with these robots: pipettes for medical applications, mobile phone covers, vacuum cleaner housings, or automotive instrument panels. Up until now, Kuka supplied only the robot and typical optional robot add-ons — the front-end and the power supply required for it were put together by the project engineers themselves.
Economical and compact
"We now want to offer our customers an economical function package designed for the Kuka robot," explains Plewe. The company is concentrating its efforts on continuous further development of their robots together with the function packages. "So the development of the new Festo CPX/MPA valve terminal is just what we were looking for," says Plewe.
The CPX/MPA valve terminal is practically custom-made for installation on the mobile A3 axis robot arm. It is particularly flat and can be housed in very small spaces. In spite of its low construction volume, the terminal offers high performance. Mechanically significant parts and manifold blocks are made from metal, making the modular valves thoroughly sturdy and reliable.
The media/power supply enables flexible connection of pneumatic and electrical control chains to form an individualised automation application. Flexible expansion stages (up to a total of four user valves and four vacuum circuits) are possible. Savings in power consumption and in maintenance are achieved by means of vacuum generators with air economy circuits.
VADMI vacuum generators offer great advantages compared to solutions based on vacuum pumps, which are situated much further away from the vacuum suction points. The long lines necessary result in high pressure losses.
"Pumps, which cannot be switched off and on, do indeed give rise to higher power costs than vacuum generators. Plus, the plant investment and maintenance costs for this type of vacuum generation are markedly higher than those for vacuum generators," according to Plewe. The latter do not incur any maintenance costs at all.
The first to benefit from the Kuka robot function package are companies processing plastics. "But it's not going to end there," confides Plewe. "Every other industry that uses Kuka robots will be able to rely on this automation solution."