Page 27 - Packaging News Magazine Mar-Apr 2021

March-April 2021 | www.packagingnews.com.au SUPPLIER SPOTLIGHT
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Sensor and sensibility: Control of continuous webs
In the consumer goods industry, especially in printing and packaging, the processing of continuous webs is a real challenge. PKN takes a look at solutions from SICK that assist with key process steps.
EXACT guidance of the material web, correct material tension in the machine and cutting the web at the right spot at the end are all essential for efficient and precise process results.
There are solutions from SICK to assist with every one of these pro- cess steps.
WEB CONTROL, WEB EDGE MONITORING AND
WIDTH MEASUREMENT
The web must be correctly guided from the drum to the processing area all the way to the further processing point. The AS30 array sensors offer assistance here. They work on a scan- ning principle and use a line of light to reliably detect the finest of edges based on grayscale differences.
The position of the web in a cross offset is detected with a repeatability of up to 30 μm. The position is issued via an analog output or IO-Link.
Operation with retro-reflectors in the background is possible with cer- tain device variants to enable the pro- cessing of transparent material webs as well. This allows for reliable detec- tion of the edges of transparent webs.
Users who would like to monitor both web edges or process many
different width formats with one device now have a flexible and ver- satile solution for web running con- trol and quality assurance with the MLG-2 WebChecker automation light grid.
Features such as the patented cross beam technology as well as light intensity measurement and individual evaluation of up to every 500 beams result in an accuracy of ± 0.3 mm and a resolution of 0.1 mm per web edge, thereby ensuring highly precise measurement of the web width.
The MLG-2 WebChecker generates position information for both web edges. If these move out of the speci- fied target positions, this is output to the machine controller via switching outputs of the light grid.
ABOVE:
The AS30 array sensors allows for reliable detection of the edges of transparent webs.
LEFT: For users who process many different width formats, the MLG-2 WebChecker automation light grid has you covered.
FAR LEFT:
The KTS Prime contrast sensor is perfectly suited for the detection of print marks.
CUTTING – WITH OR
WITHOUT PRINT MARKS
The KTS Prime contrast sensor is ide- ally suited to the detection of print marks. Even at very high speeds, it reliably detects grayscale variations between the mark and the back- ground on matte, shiny and transpar- ent surfaces.
The KTS Prime, with its modern design, high-precision RGB LED and VISTAL housing, impresses in print mark detection with TwinEye technology, colour mode, high switching frequency, excellent grayscale resolution, 7-segment dis- play and IO-Link. Thanks to various teach-in processes, integrated colour mode and variable sensor adjustment, commissioning is more flexible and the processes stable.
The response time of 10μs and a jitter of 5μs ensure accurate detection of contrast differences, even at high machine speeds. The PS30 pattern sensor enables precise cutting of endless webs without making any print marks, even at high process speeds of up to 10 m/s.
The sensor reads a pattern based only on the contrasts in the printed image and calculates the position sought from that pattern. This opens up a whole new world of design free- dom for more attractive labels. ■