Published On: Sat, Apr 9th, 2016

Automation slashes production costs in plastics sector

Investment in robotic automation can help plastics product producers improve their competitiveness by slashing costs and improving production processes. That is the verdict of Mike Wilson, general industry sales and marketing manager for ABB’s UK robotics business.

Wilson believes automation can produce energy savings, improve productivity and increase manufacturing flexibility.

Injection Moulding Machine

Automation slashes production costs in plastics sector

He cites the example of Swedish company AD Plast, a fourth tier automotive supplier, which installed 15 ABB robots on site and four robotised moulding machines to produce a three-part cooling system hose connector that can be found in a wide range of vehicles, including Mercedes-Benz cars.

Each robot sits at the centre of a production cell complete with quality-control systems. Raw plastic material for use in the moulds is contained in a separate area of the factory, where it is first conditioned and then fed by vacuum hose directly to the respective automated moulding machine. In the case of the three-part cooling system hose connector, both male and female parts are manufactured and then checked prior to assembly by a robot vision system.

Using a series of cameras, measurements are taken of each part to check that the cast pieces are within accepted tolerances – if there is an error, the robot system will reject the part. They are then assembled with an O-ring and subjected to an automated pressure test.

Once this has been passed, there is a final inspection by the vision system before the parts are packed and dispatched.

Using the robot manufacturing technique allows the company to run 24-hour production in three daily shifts. Wilson says: “Robotisation of AD Plast has allowed the company to remain competitive in the face of strong competition from overseas. In particular, the company can achieve consistent quality levels throughout its production cycle while maintaining competitive pricing.”

Robotics suppliers are not just urging the plastics sector to invest in their products but also to update these to improve productivity.

Nigel Richardson, managing director of Kent-based Geku, says the plastics industry has been historically slow in making investment in six-axis robots due to a misconception as to the cost and complexity of using multi-axis robots.

“Although six-axis may not always be the best solution when compared to the more traditional Cartesian ones, they are increasingly more likely to offer a low-cost and more flexible answer and moulders would be wise to give articulated robots serious consideration when contemplating new automation projects,” he explains.

Geku is embarking on a new project with injection moulding machinery supplier Arburg where a UK customer has older Cartesian robot systems already in operation. The existing robots currently demould the part before clipping a brass terminal block into the moulding. They then palletise the assembly before placing slip sheets in between each completed layer. The newly designed cell, while performing exactly the same operations, utilises just one six-axis ABB robot which undertakes all the required tasks including a simplified terminal assembly. The floor space requirement is also reduced considerably which is another obvious advantage.

Richardson says: “It’s not just about flexibility, it’s also about reliability – the ABB robot is designed to operate with up to 80,000 hours’ meantime between failure so you can be certain of improved output over the lifetime of the installation.”

Injection Moulding Machine

Automation slashes production costs in plastics sector

He also believes more small to medium-sized moulders will invest in robotics following the introduction of ‘collaborative robots’, which are intended to physically interact with humans in a shared workplace, because they are cheaper, flexible, easy-to-programme and can be moved easily from one process to another.

The Universal Robot range of collaborative robots offered by Geku have payloads ranging from 3kg up to 10kg, and Richardson says “subject to suitable risk assessment can potentially operate without guarding and in some instances, payback period has been as low as 165 days”.

ABB has also introduced a new collaborative robot into its range. The “Yumi” is a twin armed robot designed for lightweight demoulding and post mould operations. It is available with standard gripper options and integral vision if required.

Meanwhile, French robotics supplier Sepro has launched a complete package including robot, peripheral equipment, automation system design and services for plastic injection moulding companies. ‘Solution by Sepro’ encompasses three-axis, five-axis and six-axis robots. Jean-Michel Renaudeau, chief executive of Sepro Group, says: “For years we have been saying that robots should be expected to do much more than simply replacing a machine operator for part removal. And, recently, more and more of our customers are discovering that they can improve productivity and make added-value parts by harnessing the power of automation. That is why we have launched this new initiative.”

Injection moulding machinery supplier Wittmann Battenfeld (WB) UK has reported strong growth in its robotics and automation business. Barry Hill, managing director of WB UK, says: “Many of our customers are planning ever more complex factory layouts and automation systems to match. Our ‘one-stop shop’ approach – including moulding machines, robots, material handling and other ancillaries – is able to help them.”

Hill adds at the higher end of technical moulding the Wittmann pro robot and the new sprue picker are making inroads.

Meanwhile, Nigel Flowers, managing director of Sumitomo Demag, attributes the increase in the number of injection moulding machines sold equipped with robots from 18% in 2010 to almost 32% in 2015 to the fact they have become easier to programme and simpler to integrate. He says: “You no longer need to call in an absolute expert to carry out reprogramming.”