Zahoransky, a supplier for (tooth)brush production, packaging machines, and mold construction, recently integrated a monitored size changeover system, known as ERCO (Ergonomic Rapid Changeover), into the packaging lines for all types of blister packaging. For this application, it chose electronic position indicators for monitored size changeover from SIKO.
The packaging machines with the ERCO system are in the Z.PACK series.
“We aimed to design the Z.PACK in such a way that the process would be reliable enough to eliminate operating errors and therefore waste and damage to the machines. We also wanted to reduce the refitting times significantly and save money for our customers,” said Jörg Philip Zimmermann, Head of Product Sales Packaging.
The packaging division and the brush machine business unit both recognized that the electronic position indicator from SIKO was already working well in the monitored size changeover in a brush machine. The aim was to integrate this system into the Z.PACK packaging machines also.
Bus-compatible position indicator with status LEDs
The individual stations on the packaging line are moved in a straight line on two guide rails and must be repositioned precisely for each changeover. To ensure process reliability, Zahoransky chose AP10S electronic position indicators from SIKO with a linear magnetic sensor connected to them. This position indicator allows precise linear measurement of the manual slide adjustment on the guide rails. The bus interface is what sets the electronic AP10S indicator apart from mechanical variants. The PLC sends target values to the position indicator and reads the actual values measured. The target values are set up in a recipe management system within the machine controller; there is a recipe with all of the relevant target values, such as the station positions, for each of the products to be made. The machine controller does not enable the entire system until feedback confirms that all the positions set manually are correct.
The position status is displayed with LEDs: green for “Position correct” and red for “Position not correct.” The external magnetic sensor for determining the correct position measures with an absolute accuracy of up to +/- 35 µm. Only when all of the LEDs turn green following adjustment can the packaging machine be put back into operation.
The Z.PACK standard machine with a chain length of four meters includes the following stations, each of which can be equipped with the AP10S position indicator: the material infeed, into which the blister film is fed via a chain system, and the heating and deep drawing systems, into which the SIKO position indicators can be integrated. Here, the film is preheated and deep-drawn with a blister mold that matches the mold stamp — as a positive or negative mold. The product is then inserted, either by hand or automatically, with a pick-and-place unit. Then the cover material, such as cardboard, Tyvek, aluminum, PET or PVC film, is fed in and the whole thing is sealed, either by heat sealing or ultrasound sealing.
Finally, partial or complete cutting is carried out. Depending on the needs of the customer, additional stations can also be integrated which can also be equipped with position indicators for size changeover. Insertion of leaflets, laser or inkjet printing, blind imprinting on the packaging edge, perforation of cardboard and film, folding of the filled blisters, camera-aided monitoring, and scanning of barcodes are all possible. All stations must be adjusted to the new film width on every product change. Cutting contours for the blister packs must be exact for a perfect product, as must the seal surfaces.