Glass Fabrication Conference Attendees Walk Through Glass Manufacturing Process in Cincinnati
April 7, 2009

The Glass Fabrication and Glazing Educational Conference opened in earnest this morning at 8 a.m. at the Hilton Netherland Plaza in Cincinnati. On the fabrication side of the dual education program, attendees began their day learning about the float glass manufacturing process. John Hughes, manager of technical services for AGC Flat Glass, walked his listeners through the process, beginning with the look at the market.

Hughes showed a chart from 2007 indicating the percentage of float glass installed in North America with the most significant share provided by, in order, PPG Industries, Guardian Glass Group, AGC Flat Glass and Pilkington NSG. "Obviously these numbers have changed quite a bit over the past couple of years with the economy and will continue to change," Hughes added, mentioning consolidations and mothballed plants.

He next helped the audience appreciate the tremendous costs of manufacturing, including the need to rebuild a line about every 15 years. Once that line is running, he said, "Energy is the greatest portion of our total cost, at 28 percent." The cost of raw materials followed the price of energy, with transportation closely following that.

He acknowledged the rapid changes the construction market has faced over the last year and noted that while the market will change very quickly the installed capacity of glass doesn't change quickly.

"To be efficient we like to produce one product for along period of time," he told his audience. Transitions among products can take up to 3 to 5 days. "During that process all we're doing is crushing glass … [spending] over $100,000 a day to crush glass."

Next Hughes "walked" his listeners down the float line, explaining the science behind each step.

A listener in the audience noted that a number of float lines have been closed in the last year due to those changes in demand, and asked what preparation needs to be done to get those closed lines ready to come back online.

"When we start the furnace back up it's really the amount of time it takes to get the quality glass back up," Hughes replied. He pointed out that there are two types of "shutdowns." "If you mothball a furnace it's shut down completely so you have to completely rebuild the refractory … and that can take some time,' he said. For a hot [shutdown?], he added, the plant may be down only 30-90 days "depending on the reason or repairs being done so there's not a lot of work being done to start the work back up."

Finally, Hughes summarized that "The float glass process hasn't changed a sign amount since the 1950s" when Pilkington first created the process. Now several factors are driving changes to the process to some degree:

• The cost of energy of the types of energy that are used to melt the glass. "In North America most of the float lines are run off natural gas," Hughes noted;
• Higher emissions standards;
• Changing supply and demand. "The solar glass market is growing very quickly," Hughes said, adding that most float glass manufacturers are adapting their supply to suit that particular demand for low-iron glass; and
• Changes in products and specifications. Hughes said that as standards increase or tighten up, tighter and tighter quality is demanded of the products available.

GlassFab continues through tomorrow. Stay tuned to USGNN.com™ for further updates.

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