The main components of brochure printing paper

The main components of brochure printing paper

Paper is mainly composed of fibers, fillers, adhesives, and pigments

(1) Fiber.

There are many types of fiber materials, and plant fibers are mainly used in papermaking. In the gaps where plant fibers interweave and bond with each other, extremely small mineral materials need to be added to change the adaptability of paper, which is convenient for printing and writing. Plant fibers used in papermaking are divided into various types such as wood, stem, seed wool, leaf fiber, and phloem fiber. In China, stem fibers are the main materials for paper production.

The length, width, and shape of fibers from different raw materials vary, but their general structure is similar, both being hollow semi transparent tubes with gradually tapered seals at both ends. The different lengths of plant fibers have a significant impact on the properties of paper. Under the same conditions, the strength of paper made from fine and short fibers is lower than that made from coarse and long fibers. Therefore, more advanced paper mostly uses bast or seed wool as the main raw material, or adds some short fibers.

(2) Packing material.

There are many gaps between the interwoven fibers, and fillers must be added. Fillers can fill the gaps in fibers, making the paper smooth and increasing its flexibility. At the same time, they can improve the opacity and whiteness of the paper, reduce its elasticity, and meet the requirements for use.

Common fillers include talc powder, barium sulfate, calcium carbonate, gypsum powder, kaolin, etc. Generally, talc powder is used for printing paper, while kaolin and barium sulfate are used for advanced printing paper. The amount of filler used is generally around 20%. Excessive filler can affect the performance of the paper, such as reduced tensile strength and toughness, and decreased absorption capacity of fibers for ink.

(3) Rubber material.

Adding adhesive can fill the gaps on the surface of the paper, reduce the capillary action in the paper, improve the water resistance of the paper, and improve the gloss, strength, and prevention of paper fuzzing after adhesive application. This enables the paper to resist fluid penetration and diffusion on the paper surface.

Commonly used adhesives include rosin, polyvinyl alcohol, alum, water glass, starch, etc. According to the different requirements for paper use, there are different methods of applying glue, including in paper glue, surface glue, heavy glue, and light glue. The amount of glue applied to different types of paper varies greatly, accounting for 0.25% -9% of the pulp quality. Excessive glue application can also affect the paper's ink absorption capacity.

(4) Colorants.

Plant fibers have a certain color, but after bleaching, they are still not pure white, but slightly light yellow or light green, which cannot meet the requirements of making white paper. Therefore, colorants need to be added for color matching and whitening treatment. At the same time, the addition of colorants can change the color of the paper. The pigments commonly used for making white paper are ultramarine and indigo, while for making high-quality paper, a certain amount of fluorescent whitening agent needs to be added. Inorganic pigments and organic dyes are mostly used in the production of colored paper.

The main components of brochure printing paper