How to Make Newsprint

Southland Paper Mill

Although the Internet has begun to provide readers with an abundance of news online, there are still a great deal of people who prefer to read their news the old fashioned way: printed upon newsprint. Making newsprint at home is practically impossible; sophisticated machinery is needed to complete the process.
Paper of all types is gathered from around---including old newspapers, magazines, take out wrappers, flyers, notebook paper---anything that is clean and contaminant- free. Plastic bags, paper with food debris, yellow pages and cardboard are unusable for printing newspapers.
The paper is generally collected in recycling bins from various places and then held for pickup or transported to a paper mill where the recycling process can begin. Once the paper arrives at the paper mill, it is sorted for quality. Not all paper will pass the test, and that will be put aside for other uses. The paper that is of high enough quality to continue on in the process will be put into huge silos---large enough to hold 10,000 tonnes of paper. Approximately 8,000 tonnes will be used each day, so recycling for newsprint is big business.

Instructions

The Newsprint Process

1. The paper is constantly being machine shoveled onto conveyor belts that will carry it to the pulper. At the pulper, the paper is mixed with 50 degrees C water and sodium silicate. These pulpers are like gigantic washing machines, swirling the paper together and allowing unsatisfactory items to rise to the top to be discarded. This pulping station is the first that will take the paper through fourteen stages of cleaning, each stage in a separate pulper.

   Once through all of the pulpers, the "stock," as the paper is now called, is moved into the fiber preparation plant, where the temperature is considerably warmer. The first stop for the stock is the centrifugal cleaners, where it is spun to reduce water content and remove sticky notes, staples, sand and small pebbles that may contaminate the paper.

2. Next, the stock is pumped into large de-inking tanks. Fatty acid soap is mixed with the stock and air is pumped into the water. The ink sticks to the bubbles, which rise to the top of the tank. Combined with the calcium in the water, the bubbles form a scum on the surface that is mechanically removed.

3. In the next step, the water content of the stock is reduced further, to 30 percent fiber, utilizing two presses. Hydrogen peroxide is added to the stock to whiten the fibers and the temperature is raised to 85 degrees C. The increase in temperature helps remove an adhesives or glue that may still be in the stock.

   After raising the temperature, the stock is transferred to a bleaching tower for fifteen minutes and diluted to a 1 percent fiber to water ratio. It is then passed through several cleaners and washers until it arrives at a set of wire presses, ready to be made into new paper.

4. At this point, the stock consists of 0.77 percent fiber and 99.3 percent water. It is sprayed onto a set of rollers, which carry it to the top of the paper machine. At the top, the stock is trapped between two fabric conveyor belts, which squeeze the water out evenly from both sides, allowing the stock fibers to bind together to form a wet sheet of paper. Moving through the paper machine, the stock is dried in a variety of ways, and leaves the "wet end" of the process with a ratio of 50 percent water to fiber.

5. Continuing on to the "dry end" of the process, the paper passes over 31 rotating dryer cylinders to remove most of the remaining moisture. At the end of the process, the paper will contain only 9 percent moisture. The result is a giant roll of white paper, measuring 9.4 metres wide and weighing between 30 and 40 tonnes. The roll is then cut into smaller widths, dictated by the customer, by a large set of rotary blades. Once cut into the smaller widths, the rolls are ready to be printed again and are stored until called for by the customer.

References

• Aylesford Newsprint