Introduction
Paper is one of the most versatile materials in the world. It's quite literally everywhere and we tend to take it for granted. But how is paper made? Here are some of the steps involved in converting raw wood into paper:
1. Logs are harvested from the trees and brought to a pulp mill.
Logs are harvested from the trees and brought to a pulp mill. At this stage, they’re chipped into small pieces, which are then stripped of their bark. The logs are cooked in pulping solutions that separate the wood fibers from other organic material. The resulting fiber can be bleached or left unbleached (and therefore brown).
2. The bark is stripped off, and the logs are chipped into small pieces.
The logs are cut into small pieces called chips. The chips are cooked in a pulping solution made of water, chemicals and heat. The chemicals separate the fibers from the lignin, which is a woody substance that holds all of the fibers together. The pulping solution also adds color to make paper white or colored, depending on what kind you want to make.
3. These chips are cooked in pulping solutions to separate the fibers from the lignin that holds them together.
The wood chips are cooked in pulping solutions to separate the fibers from the lignin that holds them together. This process is called cooking and it happens in a pulp mill, which is a large facility where wood chips are cooked in water to make paper pulp.
The cooking process involves several steps: First, the wood chips are soaked and then treated with chemicals that break down the lignin bonds between cellulose fibers. Next, heated water is added to dissolve sugars present within wood and form a slurry containing dissolved organic compounds such as hemicellulose sugars and other organic acids. This mixture of dissolved plant materials is called black liquor where it flows into digesters at temperatures up to 140°C (284°F) for about 30 minutes before being treated with alkaline chemicals (cations) such as sodium hydroxide or sodium sulfide which helps remove additional water from black liquor so only about 10% remains when finished cooking process ends up producing papergrade pulp powder product with varying porosity depending on end use application needs
4. The fiber can be bleached, or left unbleached if it will be used in brown or newsprint paper.
You can immediately see the difference. The paper on the right has been bleached to remove any brown or yellow tints. This is done most often to make white paper, but it can also be used to make brighter shades of colored paper.
The difference between chlorine and chemical bleaching is that chlorine is used in much higher concentrations than chemicals, so more steps are involved in producing chlorine bleached paper.
5. Some chemicals (fillers) may be added to change the composition of the pulp for a specific use.
Paper is made from cellulose, a natural material that's found in plants. Some chemicals (fillers) may be added to change the composition of the pulp for a specific use. Fillers can include anything from ground up recycled paper to clay or calcium carbonate. For example, clay is often added to increase opacity and make paper more rigid, while calcium carbonate is added for smoother writing surfaces and greater transparency - making it more suitable for printing newspapers and magazines on high-quality papers with relatively low costs compared with other printing processes like offset lithography which requires special presses at higher costs per page printed.
6. Next, mixers add water and wetting agents to create a slurry of pulp.
Once the fibers have been separated, they are combined with water and wetting agents. Wetting agents help prevent the fibers from sticking together. They do this by lowering the surface tension of the water, which means that it becomes thinner and spreads out more easily. The result is an easier time separating individual fibers from lignin during processing.
7. The slurry is moved through a screen that is built out of wires resembling window screens but with much smaller holes, usually .0635 mm or less in diameter.
The slurry is moved through a screen that is built out of wires resembling window screens but with much smaller holes, usually .0635 mm or less in diameter. This allows the water to pass through while allowing the fibers to stay behind. The process is repeated until there are no longer any pieces of wood left in the slurry.
The resulting papermaking fibers are collected on a belt and pressed into a roll called a sheet which looks similar to cardboard and can be used as such or further processed into different types of paper products such as copy paper and toilet tissue.
8. Presses remove much of the remaining water through a process called pressing.
Presses remove much of the remaining water through a process called pressing.
Presses are also used to make paperboard for cereal boxes, pizza boxes, etc.
Presses are also used to make corrugated cardboard for milk cartons and juice boxes.
Paper towels and toilet paper are made through a similar press process that leaves them with very low moisture content (less than 10%).
9. Drying involves using high-speed air and steam to evaporate more water from the sheet.
Drying involves using high-speed air and steam to evaporate more water from the sheet.
Dryers are used to dry paper after it has been through the machine. They can be heated by either steam or hot air, depending on how much energy is required for a particular batch of sheets. The drying process is usually done in two steps: first, the wet sheet is dried by blowing hot air over it; then, once it's dry enough, another set of fans blows across the sheet at nearly hurricane speed to get rid of any remaining moisture.
10. Paper has many steps involving trees, cooking and printing before you ever see it at a store.
The journey from tree to paper begins with harvesting trees. To make pulp, wood chips are cut into small pieces and cooked in a beehive-shaped structure called a digester. The softened wood chips are then pressed through a wire mesh and spread out on large metal tables, where they're allowed to dry during the winter months.
After drying, the soft material is ready for pressing into sheets of paper at high pressure to remove any remaining water content. This final product is then cut into standard sizes such as legal size or letter size sheets before being packaged for sale at stores like Staples or Walmart (or online).
Conclusion
Paper is an amazing invention that has been around for thousands of years. It is made from trees, which are renewable resources that can be used over and over again. The process of making paper is complicated and requires many steps before you ever see it at a store. Paper manufacturers take great care in trying to make sure they use as many recycled materials as possible, so they can reduce the impact on our environment while providing us with products like notebooks or greeting cards that we enjoy using every day!
Comments
Post a Comment