Introduction to basic knowledge of the hottest pul

Introduction to the basic knowledge of pulp

I. The concept and classification of pulp

pulp is a fibrous material made from plant fiber through different processing methods. It is the main raw material of the paper industry. The plant fiber in pulp mainly comes from wood, which provides 93% of the world's plant fiber. The main component of wood is cellulose, in addition to hemicellulose, lignin, resin, pigment, pectin, ash and other substances in varying degrees

pulp can be divided into wood pulp, non wood pulp and waste pulp according to the source of raw materials. Pulps made from wood by chemical, mechanical or a combination of the two methods are collectively referred to as wood pulp; Other pulps made of non wood fibers, such as bamboo and grass, are called non wood pulp. About 30% of the total amount of paper products can be recycled as secondary fibers, which are collectively referred to as waste pulp

pulp can be divided into chemical pulp, mechanical pulp and chemical mechanical pulp according to different manufacturing processes. Among them, chemical pulp uses chemical methods to separate fibers from lignin to obtain fibers, including caustic soda method, sulfate method, sulfite method, etc; Mechanical pulp includes stone mill wood pulp, disk mill mechanical pulp, thermal mill mechanical pulp, etc. According to the processing depth, it can be subdivided into bleached pulp, semi bleached pulp and unbleached pulp (natural color pulp). For a specific variety, it is often named by several different classification methods, such as bleached kraft softwood pulp, bleached kraft hardwood pulp, natural color sulfite reed pulp, poplar mill pulp, etc., so that users can generally understand the performance and use of pulp according to its name (the specific classification is shown in the figure)

wood is classified according to tree species. Generally, it can be divided into coniferous wood and broad-leaved wood. Therefore, wood pulp mainly includes coniferous pulp and broad-leaved pulp. Around the world, 35% of the forest storage is coniferous trees, so that the oil flows back to the oil tank from the main oil cylinder of the oil pump through the oil return valve. The design of auto parts adopts aluminum materials, and 65% of the storage is broad-leaved trees

coniferous leaves are mostly thin, so they are called conifers. Because of their soft texture, they are also called corks, such as larch, spruce, etc. Conifers are mostly grown in cold regions in middle and high latitudes, such as North America, northern Europe, Russia, Chile, New Zealand and other regions and countries. Conifers have the characteristics of long growth cycle (years), long fiber length, light color and low wood density. The pulp made of coniferous trees as fiber raw materials is called coniferous pulp

the leaves of broad-leaved trees are mostly broad-leaved, so they are called broad-leaved trees. Because of their hard texture, they are also called hardwoods, such as eucalyptus, birch, etc. Broad leaved trees mostly grow in tropical and subtropical regions, such as the United States, Brazil, Chile, Indonesia and other countries. Broad leaved trees have the characteristics of short growth cycle (years), short fiber length and high wood density. Pulp made from broad-leaved trees is called broad-leaved pulp

non wood pulp refers to the pulp made of grass, reed, bamboo, cotton and hemp. Straw pulp generally contains more hemicellulose. Bleached straw pulp can be used to make all kinds of medium and high-grade writing paper and typing paper. Bamboo pulp takes moso bamboo, Phyllostachys pubescens, Neosinocalamus affinis, etc. as raw materials, and the fiber shape and length are between wood and grass fibers. It is mostly used to make offset printing paper, typing paper and other high-level cultural paper. Natural color bamboo pulp can be used to make packaging paper, etc

waste paper pulp is made from waste paper or the edge of paper cut by the printing plant after mechanical mixing, bleaching and deinking. The fiber strength and performance of waste paper pulp are determined by the type of pulp used in waste paper. However, the fiber properties become worse than the original fiber because it is eroded by liquid medicine or damaged by mechanical force again. According to the quality of waste paper pulp, it can be used to make printing paper, writing paper, cardboard and low-grade paper. Waste pulp accounts for the largest proportion of domestic consumption, but its processing is directly processed from different types of waste paper into pulp and then enters the papermaking production line, not into the commodity circulation link

II. Common wood pulp brands

at present, the import brands of bleached kraft softwood pulp commonly used in China's pulp market are mainly from Canada, the United States, Chile, Russia and Finland. In 2017, the total import volume from the above five countries accounted for about 93% of the total import volume of bleached softwood pulp, of which Canada accounted for about 31.3% of the total import volume. Canadian bleached needle pulp brands mainly include Northwood, celgar, Cariboo, and harmac tensile test samples 1. Generally, the following samples (horse brand), catalyst Crofton, Howe Sound, etc; American bleached needle pulp brands include Alabama (Alabama), IP, etc; Russian bleached needle pulp brands include ust ilimsk (black needle) and Bratsk ilimsk (cloth needle); Finnish bleached needle pulp brands include UPM (Finland Europe) and so on; Chile's Bleached needle pulp brands include Arauco (Silver Star), Pacifico (Pacific), etc. The domestic brand of bleached needle pulp is mainly the "three needles" brand produced by Yunnan Yunjing Forest Paper Co., Ltd

the main importing countries of bleached kraft hardwood pulp in China's pulp market are Indonesia, Brazil, Chile and Russia. Among them, Indonesian bleached broad pulp brands mainly include Oki (tiger brand), TPL (Eagle brand), Riau (Acacia microphylla), etc; Brazilian bleached broadleaf pulp brands include Suzano (goldfish), Guaiba (bird), fibria (parrot), bull (Eldorado), etc; Chilean bleached pulp brands include Arauco (star), Santa Fe (Santa Fe), etc. Domestic bleached broad pulp brands mainly include the "leading" brand produced by Hainan Jinhai Pulp and Paper Co., Ltd; "Senbo" brand produced by Shandong Asia Pacific Senbo pulp and Paper Co., Ltd; "Chenming" brand produced by Zhanjiang Chenming pulp and Paper Co., Ltd

Table 2: list of some imported bleached needle pulp and bleached broad pulp brands