Flat-glass making thrives in Toledo

Jan. 1, 2015

In Ohio’s north-west region, the city of Toledo area for more than a century has been associated with the automotive industry. After all, Detroit, the automotive capital of the world, is only 45 miles away.

In Ohio’s north-west region, the city of Toledo area for more than a century has been associated with the automotive industry. After all, Detroit, the automotive capital of the world, is only 45 miles away.

But even if cars and trucks are the epitome of a discrete-manufactured product, process industries make many of the things that go into them.

To support the auto industry and for other reasons, companies are found in the Toledo area that have extensive material expertise "in ferrous and non-ferrous metals, plastics, glass, fiberglass and composite materials," says John Gibney, a vice president with Toledo’s Regional Growth Partnership, a private economic-development organization.

For glass in particular, based on regional industrial development starting the second half of the 19th century, the Toledo area seems to have an affinity. There are said to be about 4,000 direct jobs in glass and glass-parts production in the four-county region immediately surrounding the city.

For example, using a production line more than one quarter-mile in length, one Toledo-area company produces more than one-million square feet of flat glass per day. The batch ingredients in glass are melted at about 2800 F, formed into sheets and cooled — all while floating, and being conveyed, on a bed of molten tin. Glass has been made at the Pilkington North America Rossford site since at least 1898.

Some background

Most of the flat glass is produced for the auto industry. In addition, modern architecture is practically defined by glass use. And glass-related materials advances are leading to many exotic applications in consumer electronics and energy conservation.

Pilkington North America is part of The NSG Group, a Tokyo-headquartered conglomerate with annual revenues of about $7 billion, operating in more than 30 countries. The NSG Group is among the top glass makers in the world. Others include Guardian Industries, Saint-Gobain S.A., Corning Inc., Schott AG and Asahi Glass Co. (AGC).

PIlkington’s Rossford, Ohio plant has two of the immense flat-glass production lines referenced above. The lines run 24 hours a day, 365 days a year. In fact, unless something would happen, the machines only completely shut down once every 15 to 18 years.

"At which point they’re completely rebuilt," says Stephen Weidner, Regional Director of Sales and Marketing for the Architectural Glass SBU. In the United States today, it’s said, there are 30 such glass-making lines. China has more than 200 and a serious over-capacity problem.

The U.S. glass industry has been weakened in recent decades by overseas competition. Commonsense, however, dictates that given a level playing field, the high cost of shipping fragile glass should make local production more economic.

Innovators & entrepreneurs

Toledo is recognized as the glass capital of the world since three sizable and separate companies, all manufacturing glass products, were headquartered in Toledo, Ohio. This unique situation — and the similarities in the company names — is due principally to the inventiveness of three men: Edward Drummond Libbey, Michael Joseph Owens and Edward Ford.

The glass industry in Toledo can be traced to 1888 when Edward Drummond Libbey moved his Libbey Glass Co. there from New England. In 1898, Edward Ford formed the Edward Ford Plate Glass Co. in Rossford, Ohio, and built the largest plate-glass plant in America.

Later, in 1916, the Libbey-Owens Sheet Glass Co. was formed and, in 1930, the Edward Ford Plate Glass Co. and the Libbey-Owens Sheet Glass Co. merged to form the Libbey Owens-Ford Co. (LOF).

Through the years, three major international glass companies would become entwined: LOF, Pilkington and Nippon Sheet Glass, now called NSG Group. In 1981, Pilkington plc acquired 30 percent of LOF. In 1986, Pilkington swapped its ownership in LOF for the ownership of the entire glass division and the Libbey Owens-Ford name. In 1990, NSG Group became a 20 percent shareholder in LOF. In 2000, NSG swapped its stake in LOF for holding in Pilkington plc. The same year LOF changes its name to Pilkington North America, Inc., its name today.

The British Pilkington Group originated in 1826. Between 1953 and 1957, Alastair Pilkington invented the flat-glass production method still used today under license by numerous glass makers around the world. It was revolutionary because it avoids the costly need to polish and grind plate glass to make it clear.

Remarkable yet repeatable

Today about 400 people are employed at the Rossford site. Formerly, it took several thousand workers deployed across the 2.5-million square feet facility to produce 15-million square feet of glass per year. Today, less than 200 personnel are involved in flat-glass production, operating on about one-million square feet of the site and producing more than one-million square feet of mostly green glass each and every day, says Weidner.

Pilkington North America has additional float glass lines: two in Laurinburg, North Carolina, and one in Ottawa, Illinois. The float-glass method gives glass sheets uniform thicknesses and flat surfaces.

Glass is made primarily from sand, soda ash, dolomite and lime stone, plus lesser amounts of gypsum, sodium nitrate and rouge, as well as relatively minor amounts of cobalt and nickel. In the float-glass method here briefly described, the fine-grained ingredients are mixed and melted in a regenerative furnace to 2800 F.

Glass from the melter flows gently, or is squeezed, over a refractory spout and onto the mirror-like surface of molten tin. Tin is used because it has a high specific gravity, is cohesive, and immiscible with molten glass. A positive-pressure protective atmosphere, typically of nitrogen or hydrogen, prevents oxidation of the tin bath.

After it is formed, to relieve the stresses of cooling, the "ribbon" of glass undergoes annealing heat-treatment in a long furnace known as a lehr. Diamond wheels trim off "selvedge" or stressed edges. Inspection data drives "intelligent" cutters.

Once cooled, the glass is lifted off the tin and onto rollers.

Some of the plant’s most recent productivity gains are process-control and information-technology related, says Weidner, especially given eased data access. The control room at the Rossford plant hums with activity, but there is very little paperwork involved any more.

"We take out overhead costs through automation and IT," says Weidner, "in many small projects over the course of the year. We have about 20 projects a year related to energy savings. Over the last ten years we’ve saved a month of energy costs — switching to variable speed drives, looking at belts on motors and checking the lighting — and that’s significant."

Final words

The city of Toledo today has a population of something less than 300,000 people, with the greater metropolitan area comprising more than 600,000 souls.

Toledo has been known as the Glass City because of its long history of innovation in the industry. Besides the heritage and current involvement outlined above, Owens-Illinois, Owens Corning and numerous industry offshoots and spin-offs have played an important role in the local economy.

In the not-so-distant wake of the Great Recession, Toledo has an appealing grittiness that sometimes makes it look like a town that could use a break. But it has a skilled, educated workforce, sound infrastructure, reasonable living costs and inexpensive natural gas. One is impressed by the obvious satisfaction the locals take in getting things done right. As a result, Toledo is finding a high-tech and process-industry place for itself in the current era of globalization.

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