Crailsheim, Germany. It looks light and playful when one watches pieces of blue cheese being picked up, lifted through the air and placed back down. The robot arms are moving at such a speed that the eye can hardly follow. This versatile packaging and final packaging process has been choreographed under the direction of the Crailsheim specialists for complex turnkey packaging project, IPS.

But only what has been intensively and meticulously prepared and fine-tuned will eventually succeed and work perfectly in practice. Starting product of the project: Pre-packaged Arla blue cheese in the form of a triangular segment of a circle that comes in five different weights: 100g, 125g, 150g, 200g and 225g with identical bases and hence different product heights. On the IPS line, the pieces of cheese are first gapped, marked, checked and, if necessary, stored; then a plastic lids and different labels as well as barcode labels are applied to the plastic packs and finally they are packed in carton trays.

The variety of carton trays is just as large; there are trays in which the packaged cheese is placed in single rows of up to nine packs, but also so called fan-shaped trays, in which rows of semicircles, each consisting of three cheese triangles, are packed. And as if that wasn’t enough, there are further variants due to the carton lids, closing up to three singe-row trays side by side or two short fan-shaped trays one behind the other under one lid, or simply “capping” them with a long fan-shaped tray. So much for the standard program. But IPS even exceeded the standard by using a product buffer to bridge any interruptions in the packaging process, for instance due to changeover on upstream machines or on the labeling machines.

Perfect timing: Process organization saves time

Having been packaged in the upstream thermoforming machine, the cheese pieces arrive at the take-over position to the IPS line in two rows. The first task of a Schubert TLM-F2 robot is to turn rows of products, which have previously been oriented tip to tip, by 180° in order to obtain rows of uniformly oriented cheese triangles. Then the products are placed on a transport system on which they will pass the inkjet printer, where each plastic cup is marked with a batch code at a designated location for internal product tracking and tracing or data archiving. A metal detector and a checkweigher check the pieces of cheese which can, if necessary, be discharged via reject devices.

The product flow then follows the branch to the buffer where the products can be accumulated during a changeover on downstream packaging equipment. Then the products are aligned and, if necessary, turned in a space-saving manner by a Schubert TLM-F2 robot, in order to make use of the full loading capacity of the buffer boxes provided for this purpose. If at a later time the product flow from production is interrupted, for instance because of changeover or cleaning on the thermoforming machine, the IPS system will use this time by retransferring the products back out of the boxes in correct orientation by means of a TLM-F2 robot.

After that the cheese – coming either from the buffer or the direct product flow –, the plastic cup and the plastic lid are assembled and various labels are applied. The cup, which in this type of packaging is virtually upside down, is always labeled with a product label on the visible side and, in addition, a promotion label can be applied on the inside. The plastic lid, which is also called “breakfast board”, is sealed with a label and coded with a double-digit batch code. The label with its two overhanging tabs is applied with utmost precision and joins the lid to the cup. Nine labels at a time are dispensed onto vacuum conveyors by two Herma labeling units. A Schubert TLM-F2 robot then picks up nine lids at a time and places (i.e. sticks) them on the sealing labels.

In parallel, the pre-packaged pieces of cheese are indexed in via a TLM grouping chain. A TLM-F2 robot places the products on the lids taken from a magazine. Then the side tabs of the sealing label are evenly pressed onto the cup. And finally the finished pieces of cheese can be placed on the outfeed conveyor. These processes – from the placing of the cups on the lid to the application of the labels to the placing of the cheese on the outfeed conveyor – are all carried out by a single TLM-F robot with only one tool.

Versatile handling

The final station is the Schubert carton packaging unit. A TLM transfer unit presents flat blanks of the various tray types to a TLM-F2 robot. Using a folding box and a hot glue device, the robot erects the trays and, depending on the type of display, folds inclined product supports and then puts the trays on vacuum conveyors. In the meantime, the cheeses are positioned via grouping chains and then placed on a TLM grouping table by a TLM-F2 robot. Here, the products are arranged into formation according to the trays to be filled. After that, nine of the single-row trays or two of the fan-shaped trays in readiness are loaded at a time. After the loading of the tray, the vacuum conveyor indexes one step further, where a lid that is also erected from a flat blank is stuck onto the tray. An outfeed conveyor then transfers the finished tray to a pallet loading station that completes the entire packaging process.

The automated handling of this large variety of products with flexible Schubert robot systems is an achievement in itself. What’s more, as a thinking partner, IPS takes care of the organization and optimization of the work flows. No less impressive are the mere output numbers. With all formats, 200 cups/min are packaged and labeled. With trays and lids, the output ranges from 12 fan-shaped trays to 40 single-row trays. In operational practice the overall efficiency of the IPS line is above 90%.

Grand finale with high output and uptime

The line is exceedingly compact in proportion to its functionality and is operated by only one person. Format changeovers from one product weight to another are purely software-based and can be carried out in five minutes. If the packaging is also changed, mechanical changeover with mistake-proof quick-change features can be completed in about 20 minutes.

After having been ordered from IPS in December 2004, the line has been running in two-shift operation at Arla ever since its acceptance in October 2005.