Bcm transtech robot controlled storage and lifting simplifies removal and replacement of heavy dies at SCA, Tampere, Finland
Today more than ever, corrugated board converters need trouble-free storage and rapid, reliable access to the right tools to ensure low cost production. A PC based management system and safe, easily accessed storage locations make it possible to acquire and maintain a good overview of the often bewilderingly large number of dies, whether they or not they are used frequently.
Another arguement in favour of a clearly arranged storage system and lifting and handling facilities is occupational health and safety.
The awkwardly shaped flat-bed or rotary dies that have to be collected in preparation for the next shift’s jobs represent a substantial weight. In many factories considerable muscle power is needed to haul them – once found – out of multi-storey racks and transport them to their place of use. Often it is only later that these substantial physical stresses over long periods make their painful effects felt.
In many corrugated board processing operations, a look at the die storage area reveals that equipment here is surprisingly basic compared with the rest of the plant. It is amazing that the absence of lifting and handling equipment has not yet resulted in any serious accidents. Many firms are aware of the risk of damaging dies or losing one’s balance when lifting and extracting bulky and heavy dies from poorly accessible storage locations, and – in the absence of reliable lifting equipment – they often seek to minimize these risks by designing questionable facilities of their own.
SCA Packaging Oy (formerly Neopac Oy) in Tampere, Finland, decided to totally restructure the storage facilities for its many hundreds of flat-bed dies. What it was looking for was an affordable, practicable solution.
Bcm transtech was consulted by Finnish industrial agency MMM Pakkausexpertit, headed by Mauri Mannila.
Production space is expensive and therefore scarce, so there was no plan to enlarge the factory building to accommodate a completely new storage system. So the company investigated the unused space above the corrugated production line.
A strong metal structure was installed to form an intermediate storey as the basis for a flat-bed die cassette store accessible from both sides. It provides storage space on two levels for metal cassettes designed to hold 1,700 tools. The bcm system has a robot controlled lift and is linked to SCA Tampere’s central computer, which is also used for central control of tool management and all production operations.
Alongside the ink department, the job documents are prepared for each die cutter and for each shift (normally two, but three at peak times). All dies, printing plates and inks needed for the next shift are collected on a driverless transfer trolley. For easier handling, the selected dies – in their cassettes – are stored in a metal ‘cage’ and transported within the building as a complete unit. This metal cage provides storage space for three cassettes.
The storage facility is over 100m long and around 3m high. All locations are addressed by the laser controlled robot lift in response to PC instructions. While the rail mounted system is moving to the next storage location, the scissor-type robot lift is raised or lowered and can swivel about its own axis. By the time it arrives at the designated cassette storage location, the lift has reached the correct height and the right removal/insertion position.
The lift selects all the cassettes required and places them in the metal cage which forms the ‘interface’ between die store and production department. Cassettes are identified by bar codes. When removing them from the store, the robot registers the codes of the three cassettes per cage so that it can subsequently call on its memory to replace the tools in the correct locations after use.
At a single stroke, says bcm, the only source of human error that could have resulted in confusion of the dies was effectively eliminated. In a final automation stage, a special computer program establishes the part number and its storage location.