Pilkington Glass

To conclude our tour of construction materials facilities, we visited the Pilkington Glass Factory in Ottawa, Illinois. Our hosts today were Mike Johnson, a Sales Manager with the company, as well as Andy Durban, one of Pilkington’s Quality Ambassadors. The company’s roots trace back to the Libbey Owens Ford (LOF) Glass Company formed in Toledo, Ohio roughly 100 years ago. Twenty years ago, after being purchased, the factory became Pilkington Libbey Owens Ford, and eventually just Pilkington. Five years ago Pilkington Glass joined the Japan-based NSG Group, now one of the two largest glass companies in the world. All Pilkington products, however, continue to carry the Pilkington name, including their American operations.

Our visit to the factory began with a presentation from Mr. Johnson, first detailing some of the company’s history and then discussing some of Pilkington’s products. Pilkington specializes in both automotive and architectural glass, tracing back to the glass company created for production of glass for aircrafts during World War II. With regards to architectural glass, Pilkington and the NSG Group, as a whole, offer a wide variety of products utilizing hard coatings. Mr. Johnson described and provided samples of a few of Pilkington’s products, including both clear and tinted glass. Another product discussed was the optiwhite low iron glass, which provides the clearest view possible of all of their products. He also showed us some of the uses of their anti-reflective glass, as well as the Pilkington Activ self-cleaning glass.

The next point discussed by Mr. Johnson was the position of glass in today’s construction industry. The glass products that are used by general contractors are the result of two independent paths. First, there are the designs and requirements set forth by the owner/developer as well as the architect. Also, there is the actual product’s path, from the manufacturer, to the fabricator, to the glazing contractor, and then finally to the general contractor. Keeping this process in mind is particularly important for this factory, as they now exclusively manufacture architectural glass. The greatest challenge with architectural glass is finding the proper balance between appearance and performance. This requires all involved properties to consider whether the glass is clear, tinted, reflective, or matched to current materials, as well as HVAC performance, comfort level, and glare. One of the largest changes Mr. Johnson and Mr. Durban have noticed within the last few years is a shift from aesthetics as the most important factor to things such as HVAC performance.

The key to the manufacturing operations of Pilkington is the float glass process, originally developed by Sir Alistair Pilkington in 1952. This original LOF plant began manufacturing plate glass by melting sand, drawing it from the furnace, and rolling it flat. This glass would then need grinding and polishing. The factory has now switched over to the float glass process. This is a continuous process which allows for year round production resulting in products being directly stored in inventory until requested by vendors. The various NSG Plants will have specific market segments but will also coordinate with each another in order to satisfy market demands when necessary. The float glass process utilizes a float line, usually around ¼ miles long, to manufacture silica sand, soda ash, lime, and dolomite into glass. First, the raw materials are inspected for purity before being melted through a careful procedure. After being heated in 20 minute cycles, the glass is spread over a molten tin bath, which naturally remains flat. The glass can be made thicker or thinner by movement speed of the cycles while the tin bath prevents oxidation. At this stage, tints can be added. After cooling, the glass is cut and passed along to automatic handling for packaging.

The float glass process has allowed the construction industry to achieve a level of clarity, comfort, and beauty not before seen with glass. As technology has changed, however, so has Pilkington’s place in the market, as the company now offers touch screens for electronics as well as glass for solar panels. The factory would see a crew of about 4000 employees back in the 1950’s, but now averages a crew size of roughly 160 due to robotics. This has allowed for additional quality and safety. All of the employees of the factory are members of the union, and the company utilizes a MAD swing shift. Under this scheme, a worker will have 7 midnight shifts followed by 2 days off, 7 afternoon shifts followed by 1 day off, then 7 morning shifts, followed by 4 days off.

After learning more about Pilkington as a company, we were given a tour of the factory. Not only were we able to see the float glass process in action, but we were able to see some of the other components of the factory that make this process work. First, we saw the shipping and inventory center which utilize the former grinding and polishing areas of the factory for storage. Next, we saw where raw materials are brought into the factory and stored at the beginning of the process. Also at this location was the cooling tower, which uses 600 gallons/minute to regulate the float glass process. The feeding process features two feeds to regulate the flow of materials, as well as a wide variety of controls to manage the process. We then traveled along the channel that the molten glass flows down, eventually reaching the molten tin bath. Cameras along the path allow workers to monitor the glass along its journey. Following refining, the glass is slowly cooled down from 1000 degrees Fahrenheit and washed with a liquid solvent. This washing process removes the Sodium Dioxide originally applied to the glass to prevent the stainless steel rollers from harming the glass on its way from the tin bath. Finally, the glass is scored and broken to the required dimensions. From there, we saw where Quality Control takes place, as well as the robots that bring the glass back for packaging. The tour did a great job of illustrating all we had learned about the float glass process and was an excellent way to end another great GLCM trip.