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The Manufacture of Brick
Milestones Vol 13 No 4 Winter 1988

Let us go into a brick factory, or as it is commonly known, a "BRICK YARD" back in the early 20's and learn how the "BRICK" is made. The brick has always been in demand for construction purposes and today it is the successful rival of its ancient enemy, wood, and for certain parts of the country, triumphant over that newer entrant into the field of building materials, cement. But even where wood, stucco and cement are presented to the public view it would be a safe guess that somewhere in those walls there is bricks. So let us enter the Brick Yard. Here we find those rounded structures familiar to everyone, known as kilns and we shall see their use later on in this story. We now apply at the office for admission to the plant and permission to look at it. An obliging gentleman consents to accompany me upon this journey. Now this gentleman is a splendid spokesman and I will allow him to tell the story. First stop is the storage rooms.

"Here we store about 8,000,000 bricks, this building is nearly 500 feet long and all under one roof. Here you will notice a little pile of bricks, these are samples of the type of brick which is manufactured here. Notice that there is very few of the old style red brick. It is only within recent years, however, that we have been manufacturing any great number of fancy bricks, but the popular demand today is for multi-colored brick. People are more particular about the outside appearance of their houses than they once were. You will notice that the brick varies in shade from a very light yellow to that having a dark iron appearance.

When we have satisfied ourselves with the appearance of the bricks we are taken to the clay mine which is maintained on the premises of this company. On our way we pass the automatic device for unloading coal. Here we are told, 50 tons of coal may be unloaded in about 45 minutes. The car is dumped and the coal taken to a tower where it is kept until a wagon load is needed. It is then automatically loaded into the wagon, thereby eliminating handling and also saving a great deal of time.

Upon reaching the entrance to the mine the guide again takes up the story. "Here," he says, "is the entrance to our clay mine. Back about 3,000 feet from this entrance is where the clay is taken out. It is drilled by electricity and then shot down with dynamite and hauled to the entrance. You will notice that where we now stand is some 50 feet above the shop room. There is a reason for this which I will explain in a moment. You see that here the clay is dumped into an enclosed trough. Now follow me." We go down a flight of stairs on the hillside and about half-way down we stop. "We have now reached the place where the first step of the conversion of clay into bricks takes place. If you will just step here you can see where the giant crushers take the pieces of clay, which have been conveyed by gravity through the trough into which you saw them dumped up above, and break them into smaller particles. Some of this clay is very hard and you notice how easily these rollers grind it."

"From here the clay is carried through a series of sieves and drying pans and finally emerges as a very fine powder. We use about 275 tons per day! We now retrace our steps to the shop where we see the powdered clay as it comes from the drying pans. It is then run into a mixing machine, where enough water is added to it to make the clay tenacious but not sticky. Then it is run into a tube, which is smaller at the end from which the shaped clay is expelled. This opening is just the size of a brick and a solid mass of clay is constantly being forced out. At this point one of two things is done. If rough surface or texture brick is desired, the clay is run through rollers covered with ordinary carpet on a piece of wire. This roughens the surface. If smooth surface brick is wanted the process is merely omitted. As the clay moves along on an endless belt it runs into the cutting machines. This cuts about 25 bricks at a time. It is then put on conveyers and is ready for the drying ovens. The purpose of drying ovens is, when the brick is cut it contains about a pound of water. It weighs about six pounds. The drying ovens evaporate outmost of the water and when they go into the kilns to be burned they weigh about as much as the finished brick. They also obtain the same color as the original clay, and the only difference is that they are a definite shape and are compact. There is absolutely no chemical change thus far. Now tot he kiln which is being filled. Inside we find men at work laying in the bricks. "You will notice first the construction of the kiln," our guide continues. "Around the outside at intervals of about 10 feet there are placed grates. While the burning is taking place a fireman is constantly watching the fires and regulating the heat of the kiln. What actually happens is this: The heat and fumes rise to the top of the kiln and then are drawn downward by the drafts which are placed in the floor. In this way every brick is burned. Passing under the floor they go up and out through the chimneys you see on the outside. Now the effect on the bricks amounts to this: the intense heat, about 2,200 degrees Fahrenheit burns out the remaining water and certain chemicals. Practically all of the clay contains iron and aluminum along with several other substances. These are fused together and cause the color of the brick to change. Near the end of the burning period, which lasts from 9 to 11 days the heat is increased slightly and then is accomplished what is known as "flashing." The process causes the peculiar marking and dark spots upon the bricks and also makes the very dark bricks. After the burning is stopped it takes a week forthe kiln to cool to remove the bricks. So from the time the kiln is filled tothe removal it takes about 20 days, they are then taken to the storage sheds.

The capacity of the kilns is from 90 to 100 thousand bricks. Now that I have taken you on the trip through the "Brick Yard" I am sorry I cannot do like the Heinz Co., and offer you a taste of our product. However, you may enjoy a Brick Cheese Sandwich after reading this.

Vivian McLaughlin, Director
Resource and Research Center, Carnegie Library, Beaver Falls, PA