Liffey Mills adopts robot technology

Liffey Mills is involved in the production, storage and processing of grain and feedstuffs for animal use. The company’s main area of operation is the manufacture of cattle feed and meal, fertilisers, agricultural chemicals and grass seeds. It has 100 employees and has been in business for some 15 years. At their mill in Roscrea, Tipperary in Ireland, Liffey Mills had a unique problem at the end of their new manufacturing process for cattle feed. There was a need to palletise 25 kg bags of their “Milk Master” and “Beef Nuts” feed at a very high speed. They turned to Webster Griffin in Turnbridge Wells, UK for a tailor-made solution.

Liffey Mills were confronted by some particular problems, which were best solved by a robot palletiser. There was limited space available so a conventional palletiser was simply too large. Since the company need to palletise at speeds of up to 1,200 bags/hour, a simple low cost ‘pick ‘n’ place’ palletiser could not be considered. When operating at 1,200 bags/hour the robot is picking up, palletising and returning to the pick-up position in three seconds and changeover of the loaded pallet with the next empty pallet must be completed in under five seconds. Liffey also needed to palletise onto a large 4’ x 5’ (1,200 mm x 1,500 mm) agricultural pallet, therefore an articulated robot with extensive reach was essential. They chose the Okura robot.

Okura robot
The Okura robot is designed and developed for palletising; hence it has distinct advantages above other industrial robots, which can be adapted to stack bags onto pallets. The new system includes bag in-feed conveyors with flattener to squeeze the bags flat and prepare them for palletising. The Okura A1600 palletising robot has empty pallet magazine, extensive pallet handling conveyors, high-speed pallet stretch wrapper and integrated control. The Okura control software is self-optimising – ensuring speed and accuracy is maintained. It is able to handle different bag or pallet sizes – new palletising programmes can be prepared, evaluated and downloaded to the robot from a laptop PC. It provides ‘precision palletising’ resulting in neat, square palletised loads, it has fewer moving parts and is less expensive to maintain than a conventional palletiser.

Flexibility
Since the robot is not dedicated to palletising one type of unit load, in the future Liffey Mills can use their Okura to palletise pails, bins, boxes or even cattle licking blocks. So that bagged product can be packed and despatched immediately to the farm or merchant, the robot was combined with an automatic pallet wrapping line. To ensure stability during transit, loaded pallets are stretch wrapped by the Unitech 300, which can also receive random pallets from other packing lines as well as the robot palletiser. On arrival the pallet height is checked and an appropriate wrapping programme is selected. This is Liffey Mills’ first robot and the first Okura palletising robot in Ireland. It is supplied by Webster Griffin.

Mark Wilson, managing director of Webster Griffin was very pleased with Liffey Mills’ choice. “Our new robot is a low cost alternative to conventional palletisers that provides the flexibility and durability to cope with anything an industrial environment can throw at it. With the application of our expertise an Okura robot is an attractive proposition for most animal feed and pet food producers,” he said.