Paper Processing Workers

The U.S. Department of Labor has cataloged nearly 250 distinct job titles for the skilled and semiskilled workers who operate pulp and paper processing machinery. These workers perform a wide variety of duties throughout the entire spectrum of the pulp and papermaking process.

Pulpmaking and papermaking are two separate processes. Some mills produce only pulp, some only paper, and still others—called integrated mills—produce both.

The pulping process truly begins at the barker. The barker operator controls the movement of cut logs into and out of machines that clean and strip the bark. Several types of machines may be used in this step of the papermaking process, but all operate on the same principle. The logs are fed into the barker on a conveyor belt. In the barker, they are tumbled against a revolving drum that strips off the bark, while a jet of water, controlled by the barker operator, washes off dirt and other impurities. If logs become jammed in a machine, the barker operator breaks up the jam with a pike pole and chain hoist. The cleaned and stripped logs are carried on a conveyor belt to the chipping machine.

The chipper operates a machine that cuts logs into one-inch-square chips in preparation for their conversion into pulp. He or she regulates the flow of the logs according to their size. The work of the pulp mill begins when the chips arrive at the mill.

Some mills use a thermomechanical process to make pulp. In this process, the chips are fed into machines that grind them into smaller fibers. After this, the fiber is placed into a large vat and mixed with water and other chemical products. During this process, the color of the pulp is lightened.

In another method of pulping known as chemical pulping, wood chips are cooked along with soda, ash, acid, or other chemicals in a high-pressure vat, or digester. The digester operator, a skilled worker who supervises one or more helpers, operates controls that regulate the temperature and pressure inside the digesters and the flow of steam into these machines. This worker tests samples of the digester liquid to determine when the pulp has been cooked to the proper degree. When the process is completed, the pulp, which has the consistency of wet cotton, is mechanically blown or dumped into a blow tank where it is washed to remove traces of chemicals and other impurities. Pulp to be used for white paper is then bleached in a chemical process.

The papermaking process begins where the pulping process ends. In its first step, the beater engineer controls the process that mixes the pulp with sizing, fillers, and dyes to produce a liquid pulp solution. The beater engineer starts the pumps of the beater engines and controls the flow of pulp into the vat by regulating the opening and closing of valves. After the liquid pulp solution has been mixed, the beater engineer draws samples of it for testing in the laboratory and uses sophisticated computer equipment to make sure the desired consistency and fiber size have been reached.

The paper-machine operator is largely responsible for the quality of the finished paper. As the liquid pulp enters one end (called the wet end) of the huge paper machine, it flows over a continuously moving belt of fine wire screen, which causes the fibers to adhere and form a thin sheet of paper as the liquid from the pulp drains out. The paper-machine operator regulates the flow of pulp and the speed and pitch of the machine's wire belt to produce paper of desired thickness, width, and strength. This operator uses a computerized process control system to monitor the quality of the paper being produced and also draws samples to be sent to the lab. In addition, the operator may supervise other workers on the machine crew.

Backtenders work at the opposite end (that is, the dry end) of the paper machine, usually under the supervision of the paper-machine operator. They operate the machinery that dries, calendars (smooths), and finishes the paper and winds it onto rolls. Backtenders control the temperature of the drying and calendaring rolls, adjust their tension level, and control the speed of the continuous sheet of paper through an automated control system. They inspect the paper for spots, holes, and wrinkles, and they mark defective sections for removal. The backtenders also operate the machinery that cuts the rolls of paper into smaller rolls for shipment.

Process engineers work in the mills to help establish schedules to ensure maximum use of equipment, employees, tools, and capacity. They coordinate production operations to meet delivery dates of finished product. Quality control engineers install and oversee product inspecting and testing procedures within the mills that are used to establish and maintain quality standards.

Pulp-and-paper lab testers use standard testing equipment and chemical analyses to monitor and control the quality of paper products. Testers determine the liquid content of cooked pulp and measure its acidity with a pH meter. Using a wire screen, a press, and a drying oven similar to those used in the days when all paper was made by hand, they make a single sheet of paper from the pulp. They then examine it under a microscope and use automated equipment to count the number of dirt specks in a unit area. They test the sample sheet for bursting, tearing, and folding strength on an apparatus specially developed for this purpose. They also perform these tests on samples of paper from the huge rolls produced by the paper machine. The pulp-and-paper tester also tests paper samples for brightness, using a reflectance meter, and for weight, thickness, and bulk, using scales and a micrometer. All test data are recorded and reported to the machine operators, with instructions to correct variations from the standard specifications. Some paper mills put their lab data on a computer database so the data can be used by both machine operators and customers.

Other paper processing occupations include pulp plant supervisors, who coordinate all the activities of workers who are responsible for the cooking, bleaching, and screening of pulp in preparation for use in making paper; cylinder-machine operators, who operate cylinder-type equipment for making paper, cardboard, insulation board, and other types of fiber sheets; and control inspectors, who inspect pulpwood boards (such as ceiling tiles, insulation panels, and siding) that are used in construction.