Pulp is one of the main inputs for papermaking. It is a polysaccharide-type carbohydrate common in nature. Main structural cell mass of plants, cellulose was discovered in 1838 by the French chemist Anselme Payen, who determined its chemical formula (C6H10O5)n.
Cellulose consists of up to 50% of the wood composition. Because it is a structure found in abundance in species such as eucalyptus and pine, it is widely used as a raw material in everyday products, mainly paper.
Chemically, it is formed by glucose monomers, between 15 and 15,000, joined by glycosidic bonds. Thus, it is considered a glucose polymer. Cellulose is differentiated because it is an insoluble carbohydrate and resistant to various chemical reactions. In addition, it is the main component of the cell wall of the plant cell, which gives rigidity to plants.
Industrially, cellulose is processed to produce paper and fibers. Due to the quality of the fibers present in the wood, the main plant species used for the extraction of cellulose are:
- Eucalyptus (short fiber, used mainly for the manufacture of tissue paper);
- Pine (long fiber, used mainly for the manufacture of packaging paper).
For species to be exploited for this purpose, there are many forests planted to serve as raw material in the production of paper, an activity of great economic relevance in North America. In addition to paper, it can be used in the manufacture of personal care products, such as disposable and absorbent diapers, among a wide range of items.
TYPES OF PULP
- Short fiber pulp: produced from eucalyptus wood, is the ideal solution for the tissue segment, manufacturing toilet paper, facial tissues, napkins, etc. In addition, it can be used in the production of printing and writing papers, cardboard, packaging and special papers, as it guarantees resistance to traction and bursting, softness, resistance to air passage, opacity and printability. It is the most used in countries like Brazil with good fiber formation and distribution.
- Long fiber pulp: most used in North America, it is made from pine, especially for the production of special packaging and papers, such as filters and fiber cement products. It can also be used in the tissue segment, producing toilet paper, towels and napkins. Its main characteristics are: resistance, absorption, specific volume and porosity.
- Fluff cellulose: manufactured from long pine fiber, it can be used in personal care products, such as female and incontinence absorbent, infant and adult diaper, daily protector, wet wipe, among others. Its characteristics are: low defibration energy, high capacity and absorption speed, liquid retention and uniformity.
PULP PRODUCTION PROCESS
To be used by the industry, cellulose goes through a series of processes, divided into the following stages: forestry, wood preparation, obtaining cellulose, drying and finishing.
The process takes place as follows: the extracted wood is peeled and chopped to be then boiled in water and chemical agents, resulting in a pulp.
Then, this pulp goes through a washing process, in which impurities are extracted. After resting for a while, the bleaching stage begins, in which cellulose becomes purer.
At that moment, the obtained pulp is distributed on a table and becomes a large sheet, ready for drying and pressing. Finally, the material can be cut, packaged and transported.
- French chemist Anselme Payen discovered and isolated cellulose in 1838, also determining its chemical formula.
- In 1870, Hyatt Manufacturing Company using cellulose produced celluloid, the first thermoplastic polymer.
- Since then, cellulose was used to produce rayon (cellulosic fiber fabric) in the 1890s and cellophane in 1912.
- Hermann Staudinger determined the chemical structure of cellulose in 1920.
- In 1992, Kobayashi and Shoda synthesized cellulose without using biological enzymes.