Raw material of paper:virgin pulp and recycled pulp
Paper is composed of fibers, auxiliary materials and moisture. The main raw material of paper is plant fiber. Of course, there are also a small amount of special paper made of mineral fiber (glass fiber, asbestos fiber, etc.), animal fiber (silk fiber, wool fiber) or synthetic fiber (aramid fiber, polyester fiber, etc.). into. In order to endow paper with different properties to meet different purposes, or to improve the papermaking process, some auxiliary materials are added in the papermaking process, including fillers, sizing materials, dyes and various chemical additives, etc. The proportion of auxiliary materials is related to that of paper. Types and uses. Almost any paper and board that feels very dry contains a certain amount of moisture (5%~6%). In paper, plant fibers account for the largest proportion. The main sources of plant fibers are: wood raw materials, non-wood raw materials and waste paper.Usually virgin pulp paper is made from wood raw material and non-wood raw materials.At the same time,recycled pulp is made from waste paper.
1. Wood raw material
Wood fiber raw material is the main raw material for papermaking. There are two types of wood, coniferous and hardwood. Longer fibers of coniferous wood are suitable for producing high-quality pulp and high-grade paper. The fiber of broad-leaved wood is shorter than that of soft-leaved wood, which is suitable for making paper with better evenness and moderate strength. The most obvious advantage of broad-leaved wood is that it grows fast and distributes widely. It is a good raw material for making mechanical pulp. There are about 20 kinds of paper-making wood commonly used in my country. Among them, the coniferous materials mainly include masson pine, Korean pine, fish scale pine and larch Fir, Yunnan pine, etc., broad-leaved wood mainly includes poplar, birch, common wood, chestnut, etc.
2. Non-wood raw materials
Non-wood fiber papermaking raw materials mainly include stalk fiber, leaf fiber, bast fiber and seed fiber of gramineous plants. The common ones are reed, bamboo, sugarcane bagasse, rice straw, sorghum stalk, corn stalk, awn stalk, asparagus, kenaf, bark, cotton, rags,banana tree stem etc.
3. Waste paper
With the rapid development of my country's paper industry, wood and non-wood raw materials are difficult to meet the needs of the paper industry. In order to understand the shortage of raw materials for papermaking, waste paper has been widely used in papermaking and has become an important raw material for papermaking. According to statistics, in 2013, the total national pulp consumption was 91.47 million tons, wood pulp was 23.78 million tons, accounting for 26% of the total pulp consumption, non-wood pulp was 8.29 million tons, accounting for 9% of the total pulp consumption, and waste paper pulp was 59.4 million tons. t, accounting for 65% of the total pulp consumption. Recycling waste paper for papermaking not only solves the problem of insufficient raw materials for papermaking, but also reduces energy consumption and environmental pollution.
It is a favorable move to implement the national policy of sustainable development and promote circular economy.
