Measuring of foils and sheet metal
also on difficult surfaces

M7 laser sensor  


M7 laser sensors are optimally suited for verifying surface quality of foils and thin films. Roughness, flatness, waviness, material thickness and other product attributes to be monitored during manufacturing process.

Foil lap joints at the surface - e. g. adhesive tapes - are identified reliably, even at high-speed conveyors.

Our M7 sensors are measuring equally fast and very accurate on black rubber or shining steel.
On very rough surfaces or at badly scratched spots the competitive products are almost failing totally. Even within these terms, our sensors are providing reliable measuring values.

Manufacturing of decor foil
 
While foil is fed through the press cylinders of the printing machine, the glued joints (carrier foil - decor foil) have to be identified reliably, otherwise facility damages will occur frequently. Undesired machine breakdowns happened.
The task of sensor technology is to secure correct splice detection. Because different kinds of foils are manufactured, the foil thickness is varying between 0,1 und 0,8 mm (0.004 and 0.03 in.). The carrier foil is thicker mostly. At the attachment point, two foils and an adhesive tape, varying in thickness, are lying upon each other. A fixed threshold adjustment for the detection of this attachment point is ineligible.
The transport velocity amounts up to 11 m/s (36 ft. per sec.).

Our M7 laser sensor with an operating range of 4 mm (0.16 in.) was applied. The foil is passing the sensors with a speed of 11 m/s (36 ft. per sec.). Minor rough spots are registered by the sensor. If the adjustable threshold will be reached, the measuring system is turning off the prime mover or an alarm signal is triggered - depending on programming of the control system. In addition to glued joints monitoring, the system is providing a control of foil thickness. For quality control, the data will be stored in a PC.

By use of M7 sensors, expensive machine downtimes and repair times could be prevented. In this way, costs will be saved and the productivity rises.
Detection of transparent stickers

On foil refinement, in certain distances transparent stickers will be affixed. During production it has to be ascertained, whether these stickers are there or not.
The difficulty on measuring is, that based on transparent stickers, a sight check is not possible.
With tactile sensors, a measuring at a sticker thickness of 50 µm (0.002 in.) and at a foil velocity of 28 m/s (91.9 ft./sec.) is not feasible.

For this task, the laser distance sensor M74 was applied. This sensor is especially adapted for transparent and / or highly reflective, mirroring surfaces.
With a measuring range of 2 mm (0.078 in.) and a resolution of 1 µm (0.039 mil), this sensor is ideally suited to surely record the height difference of 50 µm (0.002 in.). Due to the frequency limit of 10 kHz, the sensor has ample reserves to get along with the foil velocity of 28 m/s (91.9 ft./sec.).
The subsequent processing of data in the production system is enabled by evaluation electronics.

 

For over 20 years, MEL is the most innovative producer of intelligent sensors. Take advance from our experience.
We are delivering turnkey solutions, or soft- and hardware for integration into user specific projects.