Robots take their pick in plastic moulding application

A Mitsubishi Electric robot/PLC/HMI combination has provided PCE Automation with a solution for its latest take-out system for plastic injection stretch blow moulding (ISBM) machinery.

The MK5 which also supports integrated leak testing of plastic containers is based on a Q-series PLC, a MELFA six-axis articulated arm robot and a GOT Series touch-screen HMI. 

The resulting machine not only reduces transfer and testing times but also provides greater flexibility to adapt for different production runs.

PCE Automation developed the MK5 robot cell to improve productivity for manufacturers of blow-moulded plastic containers. Having seen an opportunity for making improvements over existing ISBM take-out technology.

“Existing take-out solutions tend to use three-axis robotic arms to carry out a simple pick-and-place function. As a result, users often need to redesign a part of the machine each time a new project or type of plastic container needs to be processed,” explained Julian Tarratt, Sales Manager at PCE Automation.

“With increased personalisation and shorter runs of products becoming popular we wanted to develop a more versatile, efficient and reliable solution. Our preferred automation partner, Mitsubishi Electric, suggested a MELFA RV-F-Q series robot with a full range of movement through six-axis articulation. Using the more dextrous robot we were able to remove traditional limitations and provide a more adaptable solution.”

Integrated automation solutions for optimal performance

The resulting MK5 is a compact system, fully compatible with existing machinery, where the MELFA six-axis robot picks the newly made plastic containers from ISBM machines and holds them firmly as airflow leak tests are performed. 

Once the testing is complete, the robotic arm sets the containers down onto a conveyor for onward packing processes.

“Many products do not have a solid base and therefore cannot stand-up on conveyor belts transporting them to testing or packing stations. Integrating an articulated arm robot to pick them up and move them to and from the test station provides a simple solution to this problem and reduces processing and testing times significantly,”

Adapting to different container shapes is another benefit that was realised with the new solution. Ian Davison, Sales Development Manager at Mitsubishi Electric, explains: “The MELFA robot is built around flexible control via Mitsubishi Electric’s MELSEC Q-series PLC, which ensures very accurate high-speed operation.

“Once connected to a GOT 2000, GT25 model HMI, operating parameters and settings can easily be modified by the touch of an intuitive user interface.

“As a result, operators can select, add or modify new instructions from the HMI without any need to re-program the robot controller.”

Julian adds: “The beauty of Mitsubishi Electric’s robot package is the straightforward integration of the six-axis robot with the PLC and HMI. This not only results in a flexible system, but also allows the MK5 to have a very compact design. In the new format it is even possible to move the unit around the factory floor.”

PCE Automation’s solution is also a valuable tool for maintaining a controlled environment thanks to the robot reducing the potential for contamination.

In sensitive applications, for example when producing containers for the medical or food and beverage industry, the MK5 machine can be equipped with HEPA filters or fitted-out for use in cleanrooms.

Moulding the future of plastic container manufacturing

Several variations of the MK5 have already been designed for PCE Automation customers in different industries. 

“The creation of such a cutting-edge machine for ISBM take-out and testing would not have been possible without Mitsubishi Electric and its industry leading automation solutions,” concluded Julian Tarratt. “We first worked with the team there 20 years ago, when we specified one of their PLCs and we haven’t looked back since.

“We look forward to continuing to work together on developing innovative solutions for the ISBM manufacturing industry and beyond.”