Structural Clay Products Industry Job Descriptions, Careers in the Structural Clay Products Industry, Salary, Employment
Definition and Nature of the Industry, Education and Training Requirements, Getting the Job
Many products are made from clay, which is a plentiful raw material in the United States. Among the most important clay products are those used in the construction industry. Common brick is the most widely used, along with bathroom tile, sewer tile, terra cotta, and firebrick. For many reasons, brick and tile are widely favored in the construction of homes, factories, stores, and public buildings. Brick and tile are strong and resistant to weather and fire, good insulators, relatively economical, and easy to maintain.
In 2004 the industry employed approximately 13,000 workers in about 200 facilities. While brick factories are found throughout the country, many are concentrated in the eastern and midwestern states.
The brick-making process is similar to that used to make other structural clay products. The first step is to extract clay from the earth. Clay is found on the surface of the earth or in mines in many areas of the country. Power shovel operators extract clay from huge open pits. Mine workers dig for clay in deep mines and load it on equipment that carries it up to the surface. Workers who operate washing and screening equipment drench the clay with streams of water to remove soil, sand, and pebbles. Operators use heavy rolling equipment to grind the material into fine particles and pass it through screens to remove lumps that the rollers could not break down.
Pug mill operators then continue the brick-making process. In the pug mill, revolving knives chop the screened clay and mix it with varying amounts of water, depending on the brick-making process that is to be used. The clay and water are mixed until the material holds together and can be readily molded into the desired form. The most common method of making bricks is the stiff-mud process, in which the clay mixture consists of about 18 percent water. Workers operate machines that force the clay under pressure into a shaping die (mold). The die gives the emerging stream of molded clay the shape that the finished bricks are to have. Using evenly spaced wires, brick-cutting machine operators chop the stream of clay into separate bricks. Some machines can produce more than 150,000 bricks during an 8-hour shift.
To make special kinds of bricks, including handmade ones, a soft-mud process is used, in which the water content may be about 24 percent and the clay has the consistency of paste. This clay mixture is poured into molds that give the bricks their shape. Hackers remove the formed bricks from the molds and place them on platforms to dry.
To produce bricks that are extra hard, workers use a drying process, in which the water content does not go above 12 percent. Operators of high-pressure hydraulic presses force the damp clay into molds where the pressure is maintained for some time. When the pressure is released, the operators remove the bricks by hand and prepare then for drying. Many of the bricks made in this way are used for outer walls, where they are exposed to all kinds of weather.
Depending on the amount of water remaining in the bricks after they have been cut or molded, the bricks need to dry for one to three days. Dry kiln operators handle the drying process. The bricks are moved to an outdoor location or placed in drying tunnels. The heat, humidity, and air flow are carefully controlled in the tunnels because the damp bricks are soft and can easily break or crumble.
The final stage is the firing or burning of the bricks. Kiln burners, who are among the most skilled workers in brick making, operate large ovens, or kilns, that are heated by coal, oil, or gas. After a kiln is loaded with bricks, the temperature is increased gradually until it reaches 1,800 to 2,800 degrees Fahrenheit. The temperature of the kiln depends on the kind of clay, its mineral content, and the kind of finished product desired. The intense heat causes the clay particles to melt partly and fuse together. As they cool, they become strong and hard.
Other structural clay products are made by methods similar to those used in brick making. Tile is glazed, or given a shiny, waterproof surface, by workers who add salt or some other chemical during the baking process. Tiles can be given nearly any color by the addition of dyes. To make sewer pipe, press operators use large presses to shape the clay mixture into pipes before baking it. Terra cotta is a high-quality clay that is usually reddish-brown in its natural state. It is used mostly for pottery, roof tiles, and many decorative purposes. Firebrick is made in refractories. Capable of withstanding high temperatures, it is used to line furnaces, ovens, and other equipment used to melt ore and to process metals and other materials. The manufacturing process of firebrick is similar to brick making, but various fire-resistant materials that melt only at a high temperature are added to the clay.
The structural clay products industry employs executives, supervisors, and administrators as well as sales, scientific, and technical personnel and clerical and maintenance workers. It employs many ceramic engineers who work to develop new processes or clay products and who oversee many operations.
Education and Training Requirements
Production workers in the structural clay products industry should be in good physical condition. There are no set education requirements, but a high school or trade school education is always an advantage. Courses in physics or chemistry are useful. Most jobs can be learned in a few weeks or months of training on the job.
Executives, engineers, and research workers need the same kind of training as in other industries. Engineers generally need a bachelor's degree in ceramic engineering. Some workers are hired as technicians after two years of training in a college or technical institute.
Getting the Job
To get started in a job in the structural clay products industry, you can apply directly to factories that make bricks and similar products. State employment offices, job banks on the Internet, and newspaper want ads can also provide job leads. If you attend a trade school or engineering college, your placement office may be able to help you find a job.
Advancement Possibilities and Employment Outlook
Production workers can advance to better-paying and more responsible jobs as they gain skills and experience. Some become supervisors.
The demand for workers depends on the amount of construction work being done in the area served by the plant. The job outlook also depends on the popularity of structural clay products over other building materials, such as wood, cast cement, or sheet metal. The increased use of automated machinery is expected to limit the total number of new workers needed. Some positions will become available as workers retire or leave their jobs for other reasons.
Making brick and other clay products requires working with heavy machinery and other equipment. High temperatures are involved in the kiln processing. Dust and moisture are present in the early stages of digging and treating the clay. However, most plants are well ventilated and safety precautions are followed. Because the kiln baking and drying processes must be continuous, most plants have three shifts. Filling large orders sometimes requires overtime work. Breakdowns or other emergencies may also put a plant on overtime. In general, however, the workweek is forty hours long. Most workers in the structural clay products industry belong to labor unions.
Earnings and Benefits
Earnings in the structural clay products industry are slightly lower than those in many other manufacturing fields. They often vary from one part of the country to another. Benefits usually include paid holidays and vacations, health insurance, and retirement plans.
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