Automated line solutions

By Ulrich Carlin Nielsen

A new Ishida packing line enables three to four operators to turn out sophisticated prepared salads, with all the trimmings, at up to 40 trays per minute. It also automates inspection and ensures an X-ray image is retrievable for every single pack.

Gastro Star AG produces 30 tonnes of fresh products every day, ranging from vegetables and salads to fruit, much of it grown under the company's direct supervision. A pioneer of convenience foods in Europe, it produces ready to use salad mixes under the Betty Bossi and Weight Watchers brands.

The company was an early adopter of automation in salad packing. The new line is part of a wider series of measures it has taken to rationalise and increase efficiency in the face of a steady demand for its products.

Gastro Star decided to increase capacity by optimising the operation of its three existing tray-packing lines and installing a fourth, more completely automated line with a new level of quality control. The first step was to concentrate all its tray-packing resources into one building, in order to maximise tray handling efficiency from initial delivery of trays to the factory to dispatch of the finished product.

The new line was designed by Ishida Integrated Solutions, who installed it in November 2009 in conjunction with Itech, Ishida's Agent in Italy and Switzerland. It produces 200g and 250g packs and includes tray denesting, multihead weighing, tray sealing, labelling, seal testing, vision system, X-ray inspection, checkweighing and packing into crates, yet is under 20m in length. Overall room height was restricted to just 4.08m. Despite this, the Ishida design enables crates of prepared leaves (cut to size and washed) to be run via an elevator to a point above the multihead weigher, where they tip the salad into an infeed system.

The tray sealer at the heart of the line is a state-of-the-art Ishida QX-1100. It handles four trays at a time, flushing them with an atmosphere of oxygen, nitrogen and carbon dioxide, and delivers a neat, economical seal with no protruding edges.

A new level of automation

The new line has something to offer at all the points where labour has been intensive in the past. The special stainless steel contact surfaces and sophisticated vibratory system of the 10-head Ishida RS-series weigher reduce the likelihood of clumping or sticking of leaves. The need to manually rectify potential product-in-seal problems is largely eliminated by a distribution system that delivers the leaves to the tray in a neat and discrete batch via a feeder tube and dipping funnel, then gently tamps them to below the tray edge. At the end of the line, the IPS (Ishida Packing System) pick-and-place system not only automates what used to be the most labour-intensive part of the line, but does it at high speed and with far greater flexibility by picking individual packs rather than pre-determined lots or layers.

While such a high-volume line would previously have needed six or seven operators, the new Ishida Gastro Star installation uses three, occasionally four.  The addition of a plastic cup containing product-specific additions, such as salad dressing, cheese or croutons, accounts for much of the small amount of labour involved.

"Such a high tech line is very simple to operate," says Project Manager Johann Meier. "All the operators have to do is place the cups in the trays by hand, monitor the salad leaves supply and replace film and labelling materials. The important parameters are preset, and a qualified, Ishida-trained supervisor is only needed to take care of product changeovers".

Making hygiene less labour-intensive

Given the importance of hygiene in the food industry, any quest for rapid, efficient operation should always extend to cleaning. One of the most time-consuming aspects of cleaning is accessing those difficult-to-reach areas of a fixed structure, where incomplete cleaning will lead to a build up of food waste. The new Ishida line has the weigher mounted on wheels, for easy movement around the floor, and both weigher and infeed system can be effortlessly raised and lowered for full cleaning access. Together with the general Ishida policy of designing contact parts to be removeable and replaceable without tools, this means that hygiene standards can be improved while man-hours spent cleaning are reduced.

Faster than the human eye

Automation has a key role to play in more rigorous yet much faster inspection of packs for defects or foreign bodies, providing extra protection for the end-consumer as well as for retailers and brand reputations.

The Ishida Seal Tester can detect a 0.75mm hole or gap in the seal at high speed. Mounted on it, and capable of using its rejection system, is an Ishida Vision System which verifies that each label is appropriate and positioned correctly, as well as relating the overprinted data to the company's information systems in order to check that dates, weights, prices and barcodes are correct.

Complete traceability: the ultimate security against groundless claims

Gastro Star may be the first packaged salads producer to install an X-ray inspection system linked to complete traceability of every pack. Not only can the monitoring system record the exact gas mixture received by each modified atmosphere pack, and the temperature at which sealing took place, it can also enable the company to bring up at any future time the X-ray image associated with the pack, in order to settle any dispute about its contents.

The chosen X-ray inspection system is an Ishida IX-GA 2475, which can not only detect unwanted metal, plastic, glass, stone, rubber and bone, but can also draw attention to underfilled or damaged packs. According to Johann Meier, "Metal detectors are not appropriate for our products, which incorporate not only salad leaves, but also, depending on the product, eggs, croûtons or a dressing in a cup with an aluminium closure. The X-ray machine is very easy to tune up and detects even the tiniest contaminant particles. The diameter of the smallest contaminant detected so far was only 0.6mm."

Attitudes to X-ray inspection have changed with the arrival of fully functional systems at moderate prices. Ueli Forster, Managing Director of Gastro Star says: "Using an X-ray machine has improved product safety. Some time ago, the technology was very expensive, but in the meantime, buying an X-ray machine has become a sensible investment".

It was an investment that also gave Gastro Star certified improvements in safety standards to communicate to its customers.

One-stop benefits

The 30-40 packs per minute achieved with the new line is double that of the former fastest line at Gastro Star. Giveaway is one to two percent, by comparison with 10 percent. Currently working no more than two shifts per day, Gastro Star calculates that it will pay for itself within five years.

With expert scheduling by Gastro Star, a typical product changeover takes under 10 minutes, while a traysealer tool change takes 30 minutes. "The whole project has been very well and very professionally managed," says Ueli Forster.  "We were surprised to encounter so few problems.

"Ishida is an expert in line solutions and made the best integrated proposal. The line's layout was convincing and service as well as guaranteed line availability were included. In addition, we were keen, as we lacked experience with such a line, to be able to rely on a one-stop-shop supplier"

Customer: Ishida Europe Ltd

Industry: Weighing & Packing Equipment Manufacturer

Challenge: Rationalise and increase efficiency, increase capacity, optimise automation with a new level of quality control.

Solution: Design and install a complete automated line capable of enabling three to four operators to produce prepared salads at up to 40 trays per minute, whilst automating inspection and making every pack traceable to a stored X-ray image.

Benefits: Reduction in give-away from 10 percent to one to two percent, unprecedented pack compliance and traceability. One-stop-shop supplier able to guarantee line availability and service whilst being an expert in integrated line solutions.

Biography

Ulrich Carlin Nielsen is Business Development Manager-Large Solutions for Ishida Europe Ltd and a member of the board. He has spent the last 25 years using his in-depth application knowledge to design food factories, including those for some of the world's largest food manufacturers, as well as developing new machines and registering several patents along the way.