one. Pulp can be divided into wood pulp, waste pulp and non-wood pulp (bamboo, grass) according to the source of raw materials. Among them, wood pulp is mostly used to produce cultural paper, household paper and special paper, waste pulp is used to produce packaging paper, and the proportion of non-wood pulp is small, participating in the production of some household paper
1. Raw wood pulp
The upstream of the pulp is the forest, with tropical, subtropical and temperate broadleaf forest as the raw material of the product called broadleaf pulp (hardwood pulp), with temperate and cold coniferous forest as the raw material of the product called coniferous pulp (softwood pulp), because it involves bleaching, so sometimes also called drift width, drift needle.
Conifer leaves are pointed, also called softwood, such as deciduous, spruce, masson pine, red pine. Conifers are mostly found in middle and high latitudes, such as Europe, Russia, Siberia, and the United States. Conifer has a long growth cycle (15-25 years), its fiber is long and fine, pure and less impurities, the production of paper toughness, high folding resistance, good printability.
Broad-leaved trees have a hard texture, called hardwood, such as eucalyptus, birch, poplar, basswood, maple. It is mostly grown in middle and low latitudes, such as Brazil and Chile, and has a short growth cycle (3-6 years). Broad-leaved forests grow faster, so the fibers are shorter and the lignin content is lower
Several major forest production areas in the world, one is South America and North America. Brazil in South America and the United States and Canada in North America are all paper and pulp giants. The second is Northern Europe. Such as Finland and Sweden are also very developed paper industry, giant companies. Third, Southeast Asia. Mainly broad-leaved forest. Indonesia's Golden is a giant. Vietnam and Laos also have very good forest resources. The sun takes its place over Laos. Fourth, Africa. Africa's forest resources are mainly broad-leaved forests, which are rich and mouth-watering. The fifth is Russia. Forest resources accounted for more than one fifth of the time, coniferous forest in the majority, broadleaf forest is also very good. Only Africa and Russia do not produce paper giants in the five regions, and Africa has failed to live up to its resources because of political instability. Russia because the resources are mainly in Siberia and the Far East, the vast area is sparsely populated.
The difference between broadleaf pulp and coniferous pulp can be likened to cotton and chemical fiber, in addition to comfort, toughness, durability, smoothness are the advantages of coniferous pulp. Unlike cotton, which is more expensive than chemical fiber, broadleaf pulp has the advantage of being cheaper than coniferous pulp. Therefore, in practical applications, broadleaf pulp is often "blended" with coniferous pulp. Such as coated paper (books), white cardstock (invitations, greeting cards) such as the quality of cultural paper, the content of coniferous pulp will be relatively high, such as toilet paper, the content of coniferous pulp will be much lower, more play the role of "skeleton support", not to scratch a ground.
At present, the main commercial pulp traded in the world is needle and broadleaf bleached sulfate pulp, and China mainly imports such pulp. We usually divide bleached kraft pulp into five categories, namely, northern bleached softwood pulp, hardwood kraft pulp, southern bleached softwood pulp, hardwood kraft pulp and bleached eucalyptus kraft pulp. Our country imports from Canada, the United States, Russia, Finland, Sweden, Indonesia, Brazil and other countries, pulp is different, the nature is not the same.
2. Waste pulp
Waste paper is divided into national waste and foreign waste. There are some differences in quality between domestic waste paper and imported waste paper. Developed countries such as Europe, America and Japan have relatively complete waste paper recycling classification system, and the recovered waste paper is of high quality after treatment, and large-scale recycling effectively reduces production costs. In contrast, the recycling classification of domestic waste paper is relatively backward, the recycling system is scattered, and the overall quality of waste paper is low.
Compared with domestic waste paper, the biggest advantage of waste paper in the United States is its high fiber quality and can replace wood pulp.
At present, there are two main types of waste pulp imported into China, one is pulp board (including wet pulp, loose pulp, etc.), such products are mainly from Taiwan, Southeast Asian countries, products with high water content and short transportation distance, mainly by Liwen, Rongcheng, Sun, Nine Dragons and other large factories in foreign countries directly or jointly produced, imported after their own use.
The other is the roll pulp, mainly from North America, Southeast Asia, South Asia and other countries, such products are similar to finished paper (often called garbled paper, junk paper, etc.), can be used as paper, can also be used as pulp, long transportation distance, low water content. However, this part of the product is often the object of customs inspection because of the paper, and customs duties are often levied on finished paper when entering the customs.
email:1583694102@qq.com
wang@kongjiangauto.com