Reflections of a Glass Maker

Alan Slavich

• Publisher: Page Publishing, Inc.
• Year: 2021
• ISBN:
  9781662429798
• Topic: Tecnologia e ingegneria
• Subtopic: Biografie in ambito scientifico e tecnologico

Reflections of a Glass Maker is a unique look into the history and transition of the flat glass industry in the United States as told by an insider. Flat glass is a vital part of our lives, as it provides protection from the elements and views of the world. The making of flat glass is an ancient process but has been a mystery to most of civilization since it was first invented. The evolution of flat glass processes is covered in this book. The latest evolution in flat glass production is a remarkable new invention called the float glass process that was invented in the 1950s by the Pilkington company in England. The amazing float glass process was introduced into the United States in 1963. This new process completely transformed the flat glass industry forever.

The invention of float glass allowed much higher production levels with increasingly higher quality of the finished product. The author began his career in the float glass industry in 1963 and retired after fifty-five years in the industry. He entered the industry at such a unique time and was able to watch as the very old flat glass processes were replaced by the new revolutionary float glass process. He relates experiences with three different companies that utilize the float glass process. He shares some technical data and history of the flat glass industry as well as some humorous instances that occurred along the way. The book gives the reader a comprehensive look at an industry about which most people simply know very little.

Ford Nashville

So now the first float process for Ford was beginning to operate in Nashville, and Dorian Gray and I were transferred to Nashville and assigned to the production manager. Our assignment was to provide technical support to the new process and be a liaison to the research office in Lincoln Park, Michigan about the operations in the plant. Up until then, the analytic and technical evaluations on the production processes were done by the quality control department in the plant. It was somewhat awkward to say the least when Dorian and I were assigned to the plant and were supposed to interact with the QC folks.

Fortunately, we had more experience with float glass so the transition really went pretty smoothly and we did create an efficient group to solve production problems.

* * *

When I went to Nashville, I was still single and I lived in an apartment. I was able to enjoy single life and did some dating along with many other activities that single people enjoy. Then another important thing in my life occurred on April 27, 1968. I got married to Beverly Joy Staggs. Her nickname was Gidget, and she was a girl that grew up in Hohenwald, Tennessee. Her father had been killed in a car accident when she was very young, so she never knew him. Her mother was a beauty shop operator and raised Gidget with her sister, Faye, in Hohenwald, Tennessee.

Beverly was working at Hayes Garment Company in Nashville when I met her, and after a few months, we got engaged and then married in the house of a friend. We bought a three-bedroom trilevel house on a one-half-acre lot for $19,900. That was about the average cost for that type of house then. We ended up with three children: John, born in 1971; Steve, born in 1972; and Paula, born in 1980. Sadly Gidget smoked and passed away from lung cancer on March 16, 2008.

I also spent time during this period working on the vertical draw process that was in operation at the plant. The vertical draw was shut down after all the other three operations—the Colburn process and another plate glass line—were converted to float. The vertical draw process at Nashville was a Pennvernon design, as I explained before. There was not a lot of technology available, and the operation involved a lot of old manufacturing techniques that were learned by experience. One thing for sure, on the vertical draw line where the glass was pulled forty feet vertically out of the pot up to the cutting floor, you always heard “what goes up must come down,” and it often did.

The Nashville vertical draw had four machines at the drawing end of the furnace—two on the sides and two at the end of the refiner. About the longest any of the machines would run would be about thirty days before the ribbon was lost. When the process was started, the bait pulled the glass up into the rollers and then water-cooled knurls on each side of the machine would grab the ribbon to help pull the glass out of the machine. As the process continued to run, the water-cooled knurls would cool the area underneath the head and start to devitrify the glass there. This caused the pool to shrink where the glass was being pulled, and the knurls would have to be moved in to stay on the glass.

Eventually—and this was about thirty days—the rollers could no longer be extended further into the machine and grasp the sheet and the glass ribbon would then fall back into the machine. So about every thirty days at the longest, we would hear buckle on number one, two, three, or four, and the ribbon would come crashing down. Then the pot had to be reheated and restarted, which took several hours. Occasionally the drawbar or the elI blocks in the forming areas of the machine had to be replaced as well, which took extra time, as these blocks had to be changed while hot.

I spent a lot of memorable moments working with Carl Sheppard and Don Roach during this time in analyzing what was going on in the vertical draw process. It was a learning experience for sure, and annealing causes and effects became apparent when trying to anneal a ribbon of glass in a chimney. Old supervisors like Bill Maynard and Al Snater had their ways of dealing with issues. They had learned through the years about solving a problem by remembering what happened last time. There wasn’t a lot of actual data to help with the operation, but as was often said, it was a process that was more of an art operation than a production operation.

* * *

Changing out the drawbar and ell blocks on a machine was very archaic. These clay pieces had to be heated in a kiln and installed hot. Obviously, it was quite an operation to pull any of the clay pieces out of the hot kiln and replace it into the hot machine area without breaking it.

There were kilns on the floor that were used to heat up the clay pieces. Most of the time, the kilns were cold since the clay pieces were not changed that often. One guy figured out that it was cool inside the kiln when it was not firing and that he could open the door and could crawl inside and sleep while his crew was on the midnight shift. One night, the production guys saw him go into the kiln, and after he had enough time to go to sleep, they closed the door and started yelling to fire it up. You never heard anyone yell so loud and long, and they sure broke him of that little issue.

* * *

One of the parameters on the vertical draw machines was the speed that the rolls were turning. That speed determined the speed that the ribbon of glass would obtain as it passed up the chimney, which was the annealing section of the machine. Since the total pull on the furnace was less than 200 tons per day, that meant each machine was pulling less than 50 tons per day. Consequently, a small change in speed could have a big impact on speed that the ribbon passed through the annealing zone. Therefore it was prudent to control the speed carefully and watch very closely when the speed was changed.

Annealing was never very good on the vertical draw because the currents inside the chimney were never controlled very well. You would often hear “Buckle on number four,” which meant the ribbon was not going up like it should. Or you might have a cross break on number four–balcony, again a result of poor annealing.

The production manager at Nashville at the time who started the vertical draw process for the first time was Ed Sczesny. He told the guys on the process that when it was running, it would be like dollar bills going up. Of course after the process got started, one of the guys was on a machine when it started breaking in the lehr. He yelled down to Ed, “Mr. Sczesny, there may be dollar bills going up, but there are nickels and dimes coming down!”

* * *

Again, there was competition among the supervisors to have the best production, so there was one general foreman (the head supervisor on the shift as they were called), who found a way to always adjust the speed of the machines as he left so that about an hour after the next shift started, annealing problems would crop up. This always made the shift after his look worse. It is hard to imagine the satisfaction he got out of this, but I guess when the only job security one thought was his knowledge of the process and then the production on his shift versus the other shifts, it made him feel he was showing to management that he was important.

* * *

One of the funny things I remember about the vertical draw operation happened on the cut off floor. Like I described, the ribbon was pulled out of the pot and went up forty feet to the cut off floor. The glass ribbon, after going up the forty feet, came through a slot in the floor and was scored and snapped to the length of the long direction of the size they were making, and this bracket was laid down on a conveyor. The conveyor then carried the ribbon under a set of cutting wheels that added the short dimension of the size they were making. Then the conveyor turned ninety degrees, and the scores were snapped by pressure rolls, and the brackets were separated and came to the end of the line, where the unloaders packed the glass into the containers.

If a new employee only went to the cut off floor, he wouldn’t know what was underneath the floor on which he was standing. Most of the time, new employees were hired who had never been in the glass factory before, so they really had no idea what was going on. Usually the first job they performed as a new employee was to be an unloader.

This new employee was taken directly to the cut off floor and was shown the glass coming to the packing station. He had no idea where the glass was coming from. He just was doing what he was told, and that was to take the glass as it came to him and put it into the container. So he was busy packing for a couple hours, and he yelled for the supervisor. So the supervisor went over and asked him what he wanted. He said, “Boss, do you think we will get this thing unloaded by quitting time?”

It was an innocent question, but everyone got a big laugh out of it.

* * *

During all my time in Nashville, asbestos gloves were standard for hot work around the furnace and bath. We never knew anything about the asbestos fibers and the potential for cancer if the fibers were inhaled. We also had asbestos coats, and the glass shields for looking into the furnace were covered with asbestos. On the vertical draw process, the conveyor rolls were made from asbestos, and these rolls were constructed by the hourly folks on a lathe. They didn’t necessarily always wear any mask or other protection from the asbestos when they were machining the asbestos discs into rolls. No one knew the dangers at that time.

Later on, asbestos was removed from the hot areas of the plants, but we even had asbestos gloves when I went to the Jerry Run plant with AFG. As it turned out, I knew a couple of the old guys who had worked on making the rolls who died from cancer, but at that time, we didn’t suspect that the asbestos was the cause. I will say that asbestos was the best material for protecting the body from the heat. I think, in reality, the gloves never really released any fibers, so using asbestos gloves probably was not a big danger. Since asbestos was removed from use around the hot areas of the processes, there have been many replacement materials used for protection from the heat, but none of them have been as good at that task as the asbestos material.

* * *

Recently, the float glass processes have begun using stainless steel conveyor rolls to replace the asbestos rolls that were standard initially. When the changeover was being done, there were strict procedures for the removal of the asbestos rolls and protection procedures as the rolls were removed. This was a costly procedure, as the areas had to be isolated and everyone working in the area had to wear protective clothing and masks and the asbestos had to be covered so as to not release any fibers into the atmosphere. This change was the result of new technology which was not learned in the early years of making continuous ribbons of float glass. The float glass processes today are safer without the asbestos usage, but us old-timers enjoyed the asbestos gloves and clothing when working in the heat. Again, the materials today are good but not as good as asbestos.

Eventually, as the conversion of the Colburn and the other two plate lines in Nashville were converted to the float glass process, it was apparent that more technical support was necessary. Wayne Basler soon became production manager in Nashville, and Wayne brought Bob Thompson to the plant and created the glass technical group. At that time, I was assigned to the group as well as Dorian Gray. The group included a large number of former QC people in the plant as well as other tech people from the old pilot plant group. Some of the people in the tech group were Floyd Austin, Bobby Caplinger, Bob Smith, Bill Nollner, John Atkinson, Paul Eggers, and Ray Watson, to name a few.

The conversion of the Colburn process to Nashville number one float took place in 1966. The Dearborn plate glass furnace was converted to float in 1967. Nashville number two was converted from a plate glass process to float in 1968 and finally Nashville number three was converted from a plate glass process to the float process in 1970. In Nashville, all three processes had a different furnace, bath, and annealing lehr configurations, and there was also the issue that Nashville number one and Nashville number three were producing clear glass and Nashville number two was producing green-tinted glass for the cars.

As Nashville number one was started as a float process, there were many new operating parameters of the process that we needed to understand and determine what the process was doing or telling us. Obviously one of the most important differences was that the Colburn and the plate lines formed the glass ribbon directly as the glass exited from the furnace. As described earlier, the Colburn process lifted the glass about two feet from a pool of glass at the furnace exit and bent the ribbon over a roller. The roller speed was adjusted to increase or decrease pull on the formed sheet so as to adjust the thickness of the sheet when the ribbon bent over the roll. Faster roll speed produced a thinner glass sheet and slower roll speed produced a thicker sheet. Then the glass was propelled horizontally on rollers through the lehr to be annealed. This aspect of the Colburn process was a big improvement in annealing since the sheet was annealed horizontally versus annealing the ribbon in a chimney with the extreme air currents present in the vertical draw machines.

The plate lines had a standard width canal, which brought this width of glass to the furnace exit where the glass was squeezed through a set of water-c...