PAPER PRODUCTION CIRCUIT: STAGES AND CHARACTERISTICS - DUDAS - 2024

The paper production circuit refers to the chain of processes and procedures involved that pursue a simple objective: to convert wood into paper, creating this material that is used to a great extent in different companies and tasks, and even to write down everything that is not you want to forget.

Whether the paper is produced in a factory or by manual methods, it will always be made of interlaced fibers. These fibers can come from various sources, such as cloth rags, cellulose fibers from plants and, mainly, trees.

Corrugated Paper Manufacturing. Source: Ganesh Dhamodkar

High-quality paper can be produced with the use of fabric in the process. Nowadays, by using a good amount of cotton and linen fibers in the mix, many papers are created for special uses, from the paper for greeting cards to the special paper for drawing with a pen.

Although current papermaking techniques are eloquently more complicated than older forms, they are simply development improvements rather than entirely new methods.

Stages in the paper production circuit

A fairly simple methodology is required to make paper. It consists of mixing different fibers and heating them in water until they soften. The water should also contain chemicals to help soften the fibers as they heat up.

Mixing and smoothing the fibers forms an interlocking pattern within the paper. Then something similar to a screen is passed through the entire mixture, allowing the water to drip and / or evaporate. Then the remaining water is squeezed out, leaving a layer of paper.

The paper is made from wood fibers, but some papers also use rags, flax, and bagasse, which is the residue of sugar cane. You can also recycle used paper, which after being purified is mixed with virgin fibers to form paper again.

- Primary stage

Extract wood

The trees to extract the wood must be cultivated in forests specially destined for the production of paper, that are totally legitimate and sustainable.

Generally this wood is called soft wood, coming from trees such as fir, spruce or pine. In the same way, you can also find another kind of wood, such as hard wood that comes from eucalyptus.

Timber transport

The wood that is extracted from the trees is loaded into trucks to be transferred to a pulp mill, also known as a pulp mill or pulp mill.

This is where the wood is stored to be later transformed into paper. These factories occupy large fiefdoms, their objective being to obtain cellulose and paper pulp.

- Secondary stage

The procedure that is carried out in these plants consumes an enormous amount of energy and water.

Currently, there is a tireless fight to prevent the use of chemical materials from affecting the places where these pulp mills are located.

Cutting and extraction

This phase of the process is already carried out in the pulp mill, where the wood is cut into pieces. Additionally, the skin is removed as well as the bark.

Shredded

In this process, the wood, which is solid, begins to be transformed, taking it to a different material such as pasta.

A wood chipping machine is used to chop the wood into very small pieces or chips.

The accumulated wood chips from this process are stored in large piles in order to be able to use them later in the production circuit.

Cooking

This stage begins with the chips that are immersed in water and other chemicals at very high temperatures, which exceed 150 degrees Celsius.

This process helps to clean and separate the wood fibers to obtain what will be the cellulose pulp.

Pasta bleaching

The cellulose pulp needs to be bleached with the supply of other chemical products, which will gradually lighten it until it becomes a white paste. For this, it is deposited in other drums. These products are mainly caustic soda, peroxide, oxygen, and chlorine dioxide.

Depending on the amount of chemical products supplied in this phase, different types of paper will be obtained.

Drying

The objective of this process is to dry the cellulose after bleaching. This is obtained by means of a conveyor belt with hot rollers, which provide enough heat to be able to dry the pasta.

Packaging

After it has dried, the cellulose is stored in packages for later transport to the paper mills.

Manufacturing

In this phase, the white and dry pulp is transported to a paper factory, where its processing will continue.

In the factory, the cellulose pulp is dumped on a mobile canvas containing fibers, with the purpose of interlacing the fibers while the pulp passes, forming the sheet of paper.

At this point, the sheet of paper begins to lose its excess water. It is also when the compression phase happens.

The paper production is carried out by a paper machine, which is made up of an endless canvas that is driven by a group of mechanical rollers rotating at high speed.

The mixture of fibers falls on this canvas, forming a blanket that passes through the rollers, which absorb it and dry it, thus giving shape to the paper. This is rewound and stored later.

Second drying

Then comes a second drying when a large cylinder by means of a crushing is in charge of giving heat to the already existing sheets of paper obtained in the production circuit.

Through this drying, the sheet of paper is transformed into a smooth and quite white material, depending on the type of sheet.

Final touches

Starch is sprayed on the sheet, in order to ensure its quality by sealing the surface of the paper sheet.

The paper passes through steel rollers again, seeking to homogenize the smoothness and thickness of the sheets.

This process culminates when the paper is rolled up to arrange it in reels, leaving it ready for cutting to the required measurements.

- Tertiary stage

Distribution and commercialization

Paper has many uses, and can therefore be distributed to many different destinations. For example, part of the paper produced may be destined to commercialize toilet paper, just as it could be destined for other end products and industries.

References

1. Productive Circuit (2018). Paper Productive Circuit: Preparation and Manufacturing Step by Step. Taken from: circuitproductive.com.
2. Icarito (2019). Production process of the paper. Taken from: icarito.cl.
3. How Products Are Made (2019). Paper. Taken from: madehow.com.
4. Pulp and Paper Technology (2019). Manufacturing Process in the paper industry. Taken from: pulpandpaper-technology.com.
5. Fefco (2019). Description of product system. Taken from: fefco.org.