Six-axis robots – the key to operational flexibility for Rosti

Citation

(2001), "Six-axis robots – the key to operational flexibility for Rosti", Industrial Robot, Vol. 28 No. 6. https://doi.org/10.1108/ir.2001.04928faf.006

Six-axis robots – the key to operational flexibility for Rosti

Six-axis robots – the key to operational flexibility for Rosti

Keywords: Plastics, Robots, Injection moulding

Rosti (Scotland) has installed 17 IRB 2400 robots at its state-of-the-art plastic injection moulding facility at Hamilton International Technology Park, near Glasgow (see Plate 6).

Plate 6 Flexibility, efficiency and potential downstream added value were key reasons for Rosti installing ABB six-axis robots

Six-axis robots were chosen because of the operational flexibility they offered, and, through the economies of scale achieved because of large volume production, they were competitively priced against carbon fibre, beam-type units.

Mr Knight, with considerable experience in the procurement of automated products, had traditionally opted for simple beam-type units on past installations, perceiving six-axis robots to be more expensive in terms of capital expenditure and maintenance.

This was set against knowledge that the acquisition costs of six-axis robots were falling, they were at least as effective as beam-type units in terms of speed and accuracy, and infinitely more flexible in operation.

Rosti supplies plastic parts to a wide range of markets within the teletronics, domestic appliance, medical, automotive, and packaging industries; therefore the flexibility to adapt quickly to product change was another crucial factor.

A cost exercise was carried out in-house, with a beam robot against a six-axis robot, with all-necessary guarding and ancillary production equipment in place. Rosti's engineers were surprised to find that the costs for each system were "very close".

With maintainability also surprisingly close between the two – considering the relative complexity of the six-axis robot against the simplicity of the beam-type unit – and with six-axis flexibility now a viable option cost-wise, David Knight decided that "six-axis" was the way forward.

Having decided to take the six-axis route, four major brands of robot were shortlisted. ABB robots were eventually chosen from the four. As well as fitting the robots, RTS incorporated Vincent palletisation equipment into the process.

David Knight says "The use of ABB six-axis robots coupled to RTS Vincent palletisation equipment has given us what could be almost classed as a 24-hour "lights-out" production facility, with the line requiring very minimal operator intervention throughout a shift. Re-programming for amended or completely new operations is also very easy".

Commissioned last summer, the IRB 2400 robots are employed on production lines that currently manufacture mouldings for the Ericsson T20 pocket phone.

Each of the 11 mouldings which make-up the phone has its own dedicated "just-in-time" production line comprising plastic-injection moulding equipment, IRB 2400 robot, RTS Vincent palletising equipment and connecting conveyor.

The robots, with their 10kg handling capacity, make light work of removing newly formed plastic parts from moulds and transferring them to pallet trays. Using customised grippers manufactured in an in-house toolroom, upward of 300,000 mouldings a day are transferred in this way.

The IRB 2400 uses QuickMove self-optimising motion control, which provides fast acceleration and constant high speed when complex path following. Control and operation are through the $4 robot controller, with windows-style user interface, function keys and pull-down menus.

With the mould cycle taking ten seconds and the robot in "waiting mode" for approximately six seconds of that time, there is plenty of scope for downstream added value and it is planned to bring small assembly operations within cycle in the near future.

On top of flexibility, efficiency and potential downstream added value, David Knight sees another dimension to the ABB equation: "They just look so good", he says. "Impressions count in this industry and our willingness to invest in state-of-the-art equipment throughout our plant, conveys a compelling message to our customers about our commitment to quality, efficiency and performance."

For further information please contact David Marshall, ABB Automation, Auriga House, Precedent Drive, Rooksley, Milton Keynes MK13 8PQ, UK. Tel. +44 (0)1908 350300; Fax. +44 (0)1908 350301; E-mail: david.marshall@gb.abb.com