Mukki design
8/13/2007
Source: Technews Publishing (Pty) Ltd. August 2007
http://www.instrumentation.co.za/article.aspx?pklArticleId=4640&pklCategoryId=67

Mukki manufactures a variety of dairy products, including fresh, ultra-high-temperature (UHT) processed milk, fresh and UHT cream and mascarpone. The complete cycle of production, from the removal of the milk from the tanks through to packaging, recording processing times, treatment parameters and quantity ratings is carefully monitored.

The main production stages include processing the milk and packaging dairy products, batching cartons in multiple transit units (for the most part made up of returnable plastic crates) and, finally, palletising and shipping products to customers.

Logic plays a vital role in optimising times and runs, completing orders quickly and without mistakes, maintaining the cold chain and transferring data to the control system. To help with this, Mukki turned to Vicenza-based system integrator Mariani. This company set up a data collection network that connects to all the machines, and it developed monitoring and management software that communicates with both the host and the programmable logic controllers on each machine. The robot management program links sales, warehousing and production, so that palletising works in response to orders received.

Even the labelling phase of the packaged product is computerised, with the system gleaning information from each individual pallet via an identification label. The label bears the bar code and data relating to the product's sell-by date, as well as all the information needed for correctly carrying out picking operations.

In this kind of organisation, robots are assigned an important part to play, marrying the performance of ABB hardware and Mariani intelligence. Their job is to translate the end-of-line work instructions into actions.

In Florence, IRB 640 robots have been used for both palletising and depalletising.

Four IRB 640 robots handle the palletising of crates of dairy products received from the four packaging lines.

In the latter case the robots remove empty crates from the pallets that are returned from the points of sale. The robots have a gripper designed to pick up a layer of eight crates, which they can unload onto two different conveyor belts. There are six layers of crates per pallet.

In palletising, the robots are equipped with a gripper capable of picking up and depositing crates without making contact with the product. They handle 600 containers per hour, picking up two crates per cycle and making up a maximum of seven layers per pallet, each with eight crates. The maximum palletised height is 1650 mm.

The software and machinery developed by Mariani handle a complex flow of operations.

Milk is packed into laminated cardboard containers with resealable tops. After filling, four robots working at 40 000 items per hour insert the individual packs into suitable crates, using a special device that controls the smoothness of the operation.

For complete packaging operations, Mukki approved four wraparound cartoners working at 7000 items per hour, a continuous shrink-wrapper and two robots for conveying secondary packaging to palletising.

A battery of four robots carries out palletising of the crates arriving from the four packaging lines. An automatic shuttle system feeds the empty pallets and conveys the full ones to the cold-storage rooms. All the pallets of finished product are marked with labels bearing the logistical information needed for efficient and prompt distribution.

Packaged fresh milk has a brief stay in a cold-storage room at 4°C, where preliminary operations are carried out prior to loading onto the vehicles that transport it to points of sale. UHT milk is placed in an automated warehouse with space for 2500 pallets, allowing for optimal handling of batches while at the same time minimising lead times and maximising the efficiency and safety of operations.