Popierius

Popierius is a sheet material composed of cellulose fibers that are pressed, dried, and bonded to form a continuous sheet. The majority of contemporary popierius is made from wood pulp, but it can also be produced from cotton or other plant fibers, or from recycled paper fibers. The properties of the final sheet depend on the fiber source, refining, and manufacturing steps.

Manufacturing typically begins with pulping raw material to separate cellulose fibers. The pulp is refined to achieve a desired fiber length and bonding ability, then formed into a sheet on a moving screen or wire. The sheet is pressed to remove water, dried, and often calendered to control thickness, smoothness, and gloss. Bleaching and chemical additives may be used to adjust color, brightness, strength, and ink receptivity. Sizing agents reduce ink spreading and improve water resistance.

Paper has a long history dating back to ancient China, with papermaking spreading through the Islamic world and into Europe by the medieval period. Modern papermaking developed with mechanized pulping and chemical processing from the 18th century onward, enabling large-scale production and a wide range of grades.

Popierius is produced in many grades and formats, including writing and printing papers, newsprint, packaging papers (such as corrugated board), tissue papers, and specialty papers for coatings, photography, and security applications. Grades are often described by grammage, brightness, whiteness, and finish (matte, coated, glossy).

Environmental considerations emphasize sustainable forestry, energy and water use, and end-of-life management. Recycled fibers can substitute for virgin pulp, reducing resource demand. Certification schemes like FSC and PEFC promote responsible sourcing, while recycling rates and chemical recovery affect overall environmental impact.