Search results
Results From The WOW.Com Content Network
Old Photograph of the production process of paper with pulpwood. 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.
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 ...
The kraft process (also known as kraft pulping or sulfate process) is a process for conversion of wood into wood pulp, which consists of almost pure cellulose fibres, the main component of paper. The kraft process involves treatment of wood chips with a hot mixture of water, sodium hydroxide (NaOH), and sodium sulfide (Na 2 S), known as white ...
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]
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 ]
The production and use of paper has a number of adverse effects on the environment. Worldwide consumption of paper has risen by 400% in the past 40 years [clarification needed] leading to increase in deforestation, with 35% of harvested trees being used for paper manufacture. Most paper companies also plant trees to help regrow forests.
Many papers mills have recycled business papers by transforming the old business papers into beneficial letters and envelopes. The production process for recycled paper is more costly than the well-developed paper mills that create paper with the use of trees. This process in making recycled paper is also much more time-consuming.
The use of wood to make pulp for paper began with the development of mechanical pulping in the 1840s by Charles Fenerty in Nova Scotia [1] and by F. G. Keller [2] in Germany. Chemical processes quickly followed, first with Julius Roth 's use of sulfurous acid to treat wood in 1857, followed by Benjamin Chew Tilghman 's US patent on the use of ...