Forum Glastechnik im VDMA e.V.

VDMA: New diamond cutting head reduces micro-cracks in thin glass

A glimpse of the error scanner from dr. Schwab Inspection Technology GmbH.

Frankfurt/Main, 5 August 2014 - A diamond cutting head that reduces micro-cracks to a minimum, new systems to measure – among other things – the tension of thin glass, and a machine concept for tempering of bottles. According to the German Engineering Federation (VDMA), those are just some of the highlights with which Germany’s glass machine manufacturers will be showing their innovative strength at the industry’s leading trade show glasstec in Düsseldorf from 21 to 24 October.

Every penny counts when a company makes bottles, particularly for the beverage industry. The thinner the bottle, the less material is used, and the lower the expenses. Moreover, the breaking resistance needs to be the same or – preferably – higher. The German company JSJ Jodeit, which supplies glass melting furnaces and special glass machinery, has now developed a concept for a thermal tempering unit that can be integrated into existing bottle production lines. Its main attraction is that it will be installed directly after the IS-machine, at a point where the bottles are still hot, as they have only just left the machine. This means that, to reach the temperature required for tempering purposes, much of the heating process can be omitted. This does of course save energy while also being more eco-friendly.

The hot bottles are fed from the IS-machine into a unit where they are first heated up to the needed temperature for thermal tempering. At this stage they are also homogenised. The second step in the process involves the sudden and abrupt cooling of the bottles. The tempered bottles are then transported to the existing annealing lehr where they undergo further cooling. According to the owner of JSJ Jodeit, Harald Jodeit, Ph.D., there are plans to realise the concept as a pilot plant in close collaboration with an IS- machine and container glass manufacturer.

Constant pressure at all times
Another highlight will be offered by the German glass machine manufacturer Grenzebach. This company has developed a new cutting head, designed specially for thin glass and minimising the number of micro-cracks that may occur during the cutting process. The benefit is achieved through special controls which keep the pressure of the cutting tool on the glass at a constant level at all times. “More features in less space,” says Roland Jennings, Head of Development at Grenzebach. This is apparently all that needs to be said. However, he adds that the new cutting head will be compatible with the current tools, so that it can be retrofitted into existing machinery.

But Grenzebach also has a lot to offer in matters of measurement engineering. Since the integration of dr. Schwab Inspection Technology GmbH, a company specialising in image processing and surface inspections, Grenzebach has been marketing a range of measuring machines for surface tension, glass thickness and defect analysis. Franz Krommer, Sales Manager at Dr. Schwab, says: “We have, among other things, a system that permits reliable and usable tension measurement for sheet glass”, an innovation which he describes as “hitherto unparalleled”. Several units are already in use, and the response has apparently been consistently positive. They will be presented at glasstec.

A globally unique selling point
Another company worth visiting will be Bystronic Glass. Its new product, called speed’line, can produce triple glazing within the same amount of time taken by conventional lines for double glazing. Bystronic Glass will also be presenting a new technique that allows filling both spaces between panes with inert gas at the same time. “This,” says Product Manager Tobias Neff, “gives us a globally unique selling point in the industry.”