Glass production

Presence monitoring and identification of bottles

Laser scanners from Micro-Epsilon are used for high speed and fully automatic inspection of empty containers at bottlers and breweries. For this application, the Micro-Epsilon agent Tipteh has designed a test system based on laser line triangulation, which is used when the bottle crates are received. This inline system is equipped with five scanCONTROL 2900-50 laser line triangulation sensors from Micro-Epsilon. The crates are conveyed on a belt and scanned from above. Each scanner measures a row of bottles in the crates. Presence monitoring is carried out at conveyor speeds of up to 850 mm/s. The scanner uses the respective bottle height to determine whether the correct type of bottle is in the crate. The bottle height must not deviate more than 3 mm from the target height of the respective bottle type.

Compared with a solution based on conventional image processing systems, laser scanners from Micro-Epsilon not only monitor bottle presence but also bottle height. In addition, logged data for subsequent statistics, evaluations and process optimization can be acquired

Marking detection on cosmetics bottles

Before the printing process, a reference mark is embossed into the bottles. Due to the depression of the embossment, the color of the reference mark deviates slightly from the rest of the bottle surface. The colorSENSOR CFO100 detects this minimal color difference, which enables the exact determination of the printing position below the embossment. For a flawless print, accurate and reproducible positioning is crucial. If the marking is missing, the bottle is considered as faulty and will be rejected immediately. Therefore at the same time, a good / bad evaluation can be carried out as part of a quality control. A machine turns the cosmetics bottle while the colorSENSOR CFO100 constantly measures the surface of the bottle at a distance of less than 10 mm. The embossment is detected quickly and reliably. Next, the exact position for the bottle printing is determined and further process steps can be carried out. The colorSENSOR shows clear advantages over other measuring
methods. First, it masters the semi-transparent surface easily. Second, it is ideally suited to this kind of position measurement task due to its favorable price/performance ratio.

Temperature monitoring of X-ray tubes

Particularly in production processes of X-ray glass tubes, a predefined processing temperature must be maintained in order to achieve the required product stability. The production process includes the melting of different individual parts made from special glass into one.

For quality assurance purposes, the TIM G7 infrared camera detects the temperature of both glass parts during their melting process at a distance of 50 cm from the measurement object. The user can view the value measured on a PC in real time. And the TIMConnect software included enables the creation of videos of the melting process as RAVI files and to store these. The videos also enable measured values to be viewed at a later stage and to displace the measurement points/measurement windows. Data storage is particularly beneficial for warranty purposes, as these values can be used at any time as a basis for evaluation.

Measuring the curvature of lenses

In order to meet production tolerances, the contour of optical lenses such as eyeglass lenses or objectives, confocal chromatic sensors are used. Based on the distance values, statements about the surface properties can also be made. The sensors enable a large tilt angle which means they can also detect highly curved surfaces.

Measuring the center thickness of lenses

In order to meet production tolerances, the center thickness of optical lenses such as eyeglass lenses or objectives is measured using confocal chromatic sensors. The measurement is performed from one side and can also be carried out with very thin lenses.

Wall thickness measurement of container glass

With the wall thickness and roundness measurements in star wheel inspection machines, a fast measuring rate is required in order to support the ongoing process. Micro-Epsilon’s confocal chromatic measuring systems provide a high measuring rate and fast exposure time control. This also enables the measurement of thickness when the glass colors vary.

Temperature monitoring from the melting material to the cooling process

After the tin bath, flat glass has a temperature of approx. 600 °C. At the transition to the cooling zone and in the other subsequent cooling zones, thermoIMAGER infrared cameras are used for temperature inspection. Infrared cameras enable non-contact temperature monitoring of the cooling process from a safe distance to the glass. 

Thanks to the TIM Connect Software, the thermoIMAGER cameras can also be used as line scan cameras. The software enables the user to choose any line from the detector array and to position it.

Gap monitoring of safety glass

For quality control and process control during the production of safety glass, confocal chromatic displacement sensors with a multi-peak function are used. Confocal chromatic sensors from Micro-Epsilon enable thickness measurements to micron accuracy. confocalDT sensors detect up to 5 layers by evaluating 6 measurement values on the boundary areas.

Roundness of bottles

With the roundness measurement of container glass, a fast measuring rate is required in order to support the ongoing process. Confocal chromatic sensors from Micro-Epsilon are used for thickness measurements in the star wheel while providing high measuring rates and accuracy in order to ensure reliable operation.

Plunger stroke in IS machines

For 24-hour operation in the glass production involving more than 5 million measuring cycles pear year, Micro-Epsilon has developed an inductive EDS displacement sensor. This sensor determines the exact plunger position in IS machines and allows for the production to be carried out according to predefined specifications. In order to increase resistance to lubricants and shock loads, the entire sensor and electronics are now welded into a tight stainless steel housing.

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Color measurements of glass shades

The color is the crucial and visually distinctive feature of glass products. This is particularly true with natural and recycled raw materials based on varying compositions, where continuous and objective control of the color effect is an essential prerequisite for consistent quality. The ACS3 transmission sensor from Micro-Epsilon is used to inspect the glass colors and shades continuously.

Planarity and thickness of display and flat glass

For the production of display glass, glass sheets with consistent thickness are required. The production process is regulated based on the measured results. Confocal chromatic sensors from Micro-Epsilon are used to detect the thickness from one side. Due to their high measuring rate, the sensors are also applied in high speed processes. When the sensors operate in a traversing manner or in several tracks, the planarity of complete sheets can be documented.

Thickness of glass coatings

Glasses are often reinforced with safety and security films which provide increased splinter protection. In order to measure the film layer and to determine the thickness of the applied adhesive, confocal chromatic sensors from Micro-Epsilon are used. These measure the thickness of the finest of layers from one side. With one measurement, the thickness of the glass, film and the applied adhesive can be determined.

Edge measurement of glass

In many handling processes, precise positioning of glass sheets is required. The position of the sheets is determined via the detection of the glass edges. Laser profile sensors from Micro-Epsilon measure the edge position at several points and transmit this information to the control system.

Bottom thickness measurement of container glass

With the wall thickness and roundness measurements in star wheel inspection machines, a fast measuring rate is required in order to support the ongoing process. Micro-Epsilon’s confocal chromatic measuring systems provide a high measuring rate and fast exposure time control. This also enables the measurement of thickness when the glass colors vary.

Non-contact temperature measurement when shaping container glass

In container glass production, the process relevant temperature must be inspected at different points. Non-contact temperature sensors are used during the shaping process that involves temperatures in excess of 500 °C. As the shaping process lasts for just a few seconds, the sensor response time is critical. During both the forming process of the parison and the final shaping process, the heat treatment of the glass can be influenced either by directly measuring the glass surface or by indirectly measuring the surface of the forming tool. At the end of the production process, the glass is tempered again to reduce the stress in the container. Therefore, the glass is heated again and then cooled for a period of up to 30 minutes in a cooling tunnel. When the containers leave the heating zone, the cooling process is monitored using non-contact temperature sensors.

Distance measurement onto anti-reflective coated glass

Anti-reflective coated glass is inspected during the coating process using laser-optical displacement sensors from Micro-Epsilon in order to determine undulations and torsion. The planarity of the coated glass surface is measured in several tracks. Based on the patented Blue Laser Technology, optoNCDT 2300-2DR sensors provide high measurement accuracies on coated glass surfaces.

Distance control of print heads for glass printing

When printing on materials such as glass and ceramics, very fine detailed structures are applied on the carrier material, which requires precise positioning of the print head. For distance measurements, optoNCDT 1420 laser triangulation sensors from Micro-Epsilon are used. With a measuring range of 10mm, these determine at various points in the print head the respective distance from the surface to be printed. The data obtained enables the determination of the edges and the surface tilt and therefore the exact positioning of the print head.

Surface inspection of display glass

Fully-automatic defect detection on shiny surfaces is based on deflectometry systems. Extremely small inclusions or defects are detected reliably.

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Automated inspection of shiny surfaces

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