OptiGlas is a control system for error analysis in drinking glasses and similar products made of glass or ceramics capable of modular configuration. The system has been designed especially for the drinking glass industry, taking into due consideration the hard usage conditions the product sometimes meets. Moreover, particular care has been given to a simple operating surface and quick implementation of innovative elements. Another factor enhancing reliability is the dust-free computer system and optical measurement structure.
The system contains several modules allowing the controlling of various error categories. Users can choose their individual sets of modules for solving their control tasks. For all modules, we can supply all necessary optical supplements as unit construction systems which can be easily adapted to the user's technical equipment.
The optical solution and thus control sensitiveness can be adapted according to the user's requirements. Error detection tolerance ranges between the measurements of 0.05 and 0.5 mm. Our software typically allows 30 glasses to pass per minute, but this can be speeded up on demand to more than 60 glasses per minute. The user can initiate reconfiguration of the software for new products in about 10 minutes. Depending on the requirements, control systems can be placed either during hot-shaping or after cool-bathing, or else for post-processing as final control mechanism. Thus, the high reliability and precision of our control systems provides for optimum quality control.
Interference tolerance for the individual error types can be set independent from each other. Besides complementary sorting (good vs. bad), several quality classes can be determined. In connection with an automatic handling system, this is an important step towards total process automation. On top of reducing personnel, this mechanism provides for higher product quality, since automatic control enables error-free sorting around the clock.
Our systems also integrate statistical process control. All relevant statistical data can be retrieved through transparent screen menus. Alternatively, a glass follow-up can be integrated, for example for assigning an error in the hot-shaping to the individual processing stations. For the SPC functions, a station-oriented evaluation is also possible.
Besides hardware and software, we can design and develop entire control machines for individual users.

Possible error types

Geometrical errors inside the goblet Bottom plate Mouthpiece
· Glass height · Shakes · Degree of melting
· Uneven glass · Rough bottoms · Roughness
· Elliptic goblet · Waves of low temperature · Cuts
· Poorly blown goblet · Breaks
· Uneven goblet walls · Evenness
· Straightness

Geometric error in Stem Surface error Production
· Scalene stems · Scratch · Drop weight measurement
· Sucker · Contamination · Kölbel length measurement
· Broken stem · Water fleck
· Striae

Between goblet and stem Error in glass Veredelung
· Bad pressed · Waves of low temperature · Gold border check
· Over-pressed · Striae · Calibration marker check
· Compressed · Knot · Impression check
· Shaping ring
· Stones
· Bubbles

Control units in glass construction:

The illustration shows the central unit of an analyzer consisting of user PC 19" and additional image analysis and control computers. In addition to the actual image analysis, the system also control CNC axes for automatic adjustment of cameras in case of product shifts. The system is built into a water-cooled, dust-free 19" cupboard.


Examples in praxis:

Mouthpiece construction errors

These images show mouthpiece construction errors. Pictures have been taken with the line camera of the rotating glass, representing a 360-degree total of the mouthpiece.

In the first image, you can see both an embrasure and an uneven melting degree. The second image shows a harsh mouthpiece.


Over-pressure between goblet and stem Sucker
Image Image

The image on the left shows a drinking-glass with an over-pressure between goblet and stem. Pictures have been taken on the rotator to analyze the glasses in nine different positions in order to detect even the smallest errors. Error detection is provided by comparing the outside contour Fourier specters. This detection mechanism is highly insensitive towards height and position variations, as well as towards glasses standing at an angle. A reliable control even under harsh environmental conditions and production sways in the glass geometry is thereby enabled. The image on the right illustrates the detection of a stem sucking by symmetrical analysis of outward contours.

Example: Error in goblet Example: Shaping ring
Image Image Image

The rotating goblet is photographed before light and dark background illumination, as well as in front of a line pattern. Thus, all possible goblet errors can be detected. On the right-side image, you can see a shaping ring on the faulty pattern.