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While in theory any tree can be used for pulp-making, coniferous trees are preferred because the cellulose fibers in the pulp of these species are longer, and therefore make stronger paper. [18] Some of the most commonly used trees for paper making include softwoods such as spruce , pine , fir , larch and hemlock , and hardwoods such as ...
Handmade paper is also prepared in laboratories to study papermaking and in paper mills to check the quality of the production process. The "handsheets" made according to TAPPI Standard T 205 [20] are circular sheets 15.9 cm (6.25 in) in diameter and are tested for paper characteristics such as brightness, strength and degree of sizing. [21 ...
Paper production is the most common and main use for pulpwood. Paper can be produced from both hardwood and softwood trees, and each species for both types of trees have specific and unique properties that make the type of paper and other products produced differ.
Paper made from chemical pulps are also known as wood-free papers (not to be confused with tree-free paper); this is because they do not contain lignin, which deteriorates over time. The pulp can also be bleached to produce white paper, but this consumes 5% of the fibres.
Kraft pulp is darker than other wood pulps, but it can be bleached to make very white pulp. Fully bleached kraft pulp is used to make high-quality paper where strength, whiteness, and resistance to yellowing are important. The kraft process can use a wider range of fiber sources than most other pulping processes.
In North America, virgin (non-recycled) wood fibre is primarily extracted from hardwood (deciduous) trees and softwood (coniferous) trees. The wood fibre can be extracted as a primary product, or collected during the milling of lumber. [1] Wood fibres can also be recycled from used paper materials. [2]
Relating tons of paper recycled to the number of trees not cut is meaningless, since tree size varies tremendously and is the major factor in how much paper can be made from how many trees. [10] In addition, trees raised specifically for pulp production account for 16% of world pulp production, old growth forests 9% and second- and third- and ...
The lignin causes the paper to become brittle and yellow when exposed to air or sunlight. Traditionally, newsprint was made from fibers extracted from various softwood species of trees (most commonly, spruce, fir, balsam fir or pine). However, an increasing percentage of the world's newsprint is made with recycled fibers.