Shopping on line can be easy, simple and save you lots of money. It can also take a lot of your time, frustrate you, and result in unwanted purchases. Now the same can be said for regular high street shopping, but with the vast opportunity presented by the Internet it will pay you to spend a few minutes reading this and understanding how to better optimize your Wood Pulp shopping experience:
1. Compare - without doubt the biggest advantage that the Wood Pulp offers shoppers today is the ability to compare thousands of Wood Pulp at a time. This is a great thing, but not necessarily all the time! Too much can be daunting at times so take advantage of the great comparison sites and where possible let them do the hard work for you.
2. Research - if it has been said it will be on the internet. Ignorance is no longer a justifiable reason for buying the wrong thing. Take the time to research in detail everything that you could possible want to know about
3. Testimonials - don't know anybody that has bought a Wood Pulp? Wrong! If the Wood Pulp is good the internet will let you know. Use the Internet as a friend and get testimonials before you buy.
4. Questions - Got a question about Wood Pulp then search the Forums, FAQ's, Blogs etc. Don't be afraid to ask .....
5. Reputation - Never heard of the company selling Wood Pulp? Don't worry, no reason why you should know every company in the world, but you know someone that does! Use the internet to find out what people are saying about Wood Pulp and build up a picture of their reputation for sales, returns, customer service, delivery etc.
6. Returns - still worried that even after all of the above your Wood Pulp wont be what you want? Check out the returns policy. There is so much competition now that someone, somewhere is bound to offer the terms that you are comfortable with.
7. Feedback - happy with your Wood Pulp then let people know, after all you are depending on others people input in your buying decision, so why not give a little back.
8. Security - check for the yellow padlock on the Wood Pulp site before you buy, and the s after http:/ /i.e. https:// = a secure site
9. Contact - got a question about Wood Pulp, or want to leave a comment then check out the sites contact page. Reputable companies have them and respond.
10. Payment - ready to pay for your Wood Pulp, then use your credit card or PayPal! Be aware of companies that don't accept them, there may be genuine reasons but given the huge amount of choice you have when buying online there is no reason at all not to buy via credit card or PayPal.
Wood pulp is a dry fiberous material prepared by chemically or mechanically separating the fibers which make up wood. Pulp can be either fluffy or formed into thick sheets. The latter form is used if the pulp must be transported from the pulp mill to a paper mill. Pulp which is shipped and sold as pulp (not processed into paper in the same facility) is referred to as
market pulp. When suspended in water the fibers disperse and become more pliable. This pulp suspension can be laid down on a screen to form a sheet of paper, and this is the primary use for wood pulp. Wood pulp is the most common material used to make paper. The timber resources used to make wood pulp are referred to as pulpwood. Wood pulp comes from softwood trees such as spruce, pine, fir, larch and
Tsuga, and hardwoods such as
eucalyptus,
aspen and
birch.
History
Using wood to make
paper is a fairly recent innovation. In the 1800s, fiber crops such as linen fibres were the primary material source, and paper was a relatively expensive commodity. The use of wood to make pulp for paper began with the delevopment of mechanical pulping in Germany by F.G. Keller in the 1840s. Chemical processes quickly followed, first with J. Roth's use of sulfurous acid to treat wood, followed by B. Tilghman's US patent on the use of calcium bisulfite, Ca(HSO3)2, to pulp wood in 1867. Almost a decade later the first commercial sulfite pulp mill was built in Sweden. It used magnesium as the counter ion and was based on work by C.D. Eckman. By 1900 sulfite pulping had become the dominant means of producing wood pulp, surpassing mechanical pulping methods. The competing chemical pulping process, the sulfate or
kraft process was developed by Carl Dahl in 1879 and the first kraft mill started (in Sweden) in 1890. The invention of the recovery boiler by G.H. Tomlinson in the early 1930s allowed kraft mills to recycle almost all of their pulping chemicals. This, along with the ability of the kraft process to accept a wider variety of types of wood and produce stronger fibers made the kraft process the dominant pulping process starting in the 1940s.
Global production of wood pulp in 2006 was 160 million tonnes (175 million tons). In the previous year, 57 million tonnes (63 million tons) of market pulp (not made into paper in the same facility) was sold, with
Canada being the largest source at 21% of the total, followed by the US at 16%. Chemical pulp made up 93% of market pulp.
Manufacture of wood pulp
Harvesting trees
Most pulp mills use good
forest management practices in harvesting trees to ensure that they have a sustainable source of raw materials. One of the major complaints about harvesting wood for pulp mills is that it reduces the biodiversity of the harvested forest. Trees raised specifically for pulp production account for 16% of world pulp production, old growth forests 9% and second- and third- and more generation forests account for the balance, . Reforestation is practiced in most areas, so trees are a renewable resource. The FSC (Forest Stewardship Council) certifies paper made from trees harvested according to guidelines meant to ensure good forestry practices.
The number of trees consumed depends whether mechanical processes or chemical processes are used. It has been estimated that based on a mixture of softwoods and hardwoods 12 meters (40 ft) tall and 15-20 centimeters (6-8 in) in diameter, it would take an average of 24 trees to produce 0.9 tonne (1 ton) of printing and writing paper, using the kraft process (chemical pulping). Mechanical pulping is about twice as efficient in using trees since almost all of the wood is used to make fiber therefore it takes about 12 trees to make 0.9 tonne (1 ton) of mechanical pulp or newsprint.
Preparation for pulping
Only the
Formation#Wood are useful for making pulp.
Bark contains relatively few useful fibers and is removed and used as fuel to provide steam for use in the pulp mill. Most pulping processes require that the wood be chipped and screened to provide uniform sized chips.
Pulping
There are a number of different processes which can be used to separate the wood fibers:
Mechanical pulp
Manufactured grindstones with embedded silicon carbide or
aluminum oxide can be used to grind small wood logs called "bolts" to make "stone groundwood" pulp (SGW). If the wood is steamed prior to grinding it is known as "pressure groundwood" (PGW) pulp. Most modern mills use chips rather than logs and ridged metal discs called refiner plates instead of grindstones. If the chips are just ground up with the plates, the pulp is called "refiner mechanical" pulp (RMP) and if the chips are steamed while being refined the pulp is called "thermomechanical" pulp (TMP). Steam treatment significantly reduces the total energy needed to make the pulp and decreases the damage (cutting) to fibers. Mechanical pulps are used for products that require less strength, such as
newsprint and
paperboards.
Chemithermomechanical pulp
Wood chips can be pretreated with
sodium carbonate, sodium hydroxide,
sodium sulfite and other chemical prior to refining with equipment similar to a mechanical mill. The conditions of the chemical treatment are much less vigorous (lower temperature, shorter time, less extreme pH) than in a chemical pulping process since the goal is to make the fibers easier to refine, not to remove lignin as in a fully chemical process. Pulps made using these hybrid processes are known as chemi-thermomechanical pulps (CTMP).
Chemical pulp
Chemical pulp is produced by combining wood chips and chemicals in large vessels known as digesters where heat and the chemicals break down the lignin, which binds the cellulose fibers together, without seriously degrading the cellulose fibres. Chemical pulp is used for materials that need to be stronger or combined with mechanical pulps to give a product different characteristics. The kraft process is the dominant chemical pulping method, with sulfite process being second.
Recycled pulp
Pulp can also be made out of waste paper and paperboard.
Recycled pulp is most often used to make paperboard, newsprint or sanitary paper.
Bleaching
The pulp produced up to this point in the process can be bleaching of wood pulp to produce a white paper product. The chemicals used to bleach pulp have been a source of environmental concern, and recently the pulp industry has been using alternatives to chlorine, such as
chlorine dioxide, oxygen,
ozone and
hydrogen peroxide.
Environmental concerns
The major environmental impacts of producing wood pulp come from its impact on forest sources and from its waste products.
Forest resources
The impact of logging to provide the raw material for wood pulp is an area of intense debate. Modern logging practices, using forest management seeks to provide a reliable, renewable source of raw materials for pulp mills. The practice of
clear cutting is a particularly sensitive issue since it is a very visible effect of logging.
Reforestation, the planting of tree seedlings on logged areas, has also been criticized for decreasing biodiversity because reforested areas are monocultures. Proponents of reforestation and
Plantations#Forestry argue that in this respect trees are no different from any other agricultural crop. Logging of
old growth forests accounts for less than 10% of wood pulp, but is one of the most controversial issues.
Effluents from pulp mills
Pulp mills are almost always located near large bodies of water because of they require substantial quantites of water for their processes. Delignification of chemical pulps releases considerable amounts of organic material into the environment, particularly into rivers or lakes. The wastewater effluent can also be a major source of pollution, containing lignins from the trees, high biochemical oxygen demand (BOD) and dissolved organic carbon (DOC), along with
alcohols, chlorates, heavy metals, and Chelation agents. Reducing the environmental impact of this effluent is accomplished by closing the loop and recycling the effluent (see black liquor) where possible, as well as employing less damaging agents in the pulping and bleaching processes.
Mechanical pulp is not a major cause for environmental concern since most of the organic material is retained in the pulp, and the chemicals used (hydrogen peroxide and
sodium dithionite) produce benign byproducts (water and
sodium sulfate (finally), respectively).
Bleaching with chlorine produces large amounts of
organochlorine compounds, including dioxins. Increased public awareness of enviromental issues, as evidenced by the formation of organizations like
Greenpeace, influenced the pulping industry and governments to address the release of these materials into the environment{{cite conference |first=David A. |last=Sonnenfeld |authorlink= |coauthors= |title=Social Movements and Ecological Modernization: The Transformation of Pulp and Paper Manufacturing, Paper: WP00-6-Sonnenfeld|booktitle= Berkeley Workshop on Environmental Politics |pages= |publisher=Institute of International Studies (University of California, Berkeley) |date=1999 |location=Berkeley,CA |url=http://repositories.cdlib.org/cgi/viewcontent.cgi?article=1005&context=iis |accessdate=2007-09-20 |id= -->
. The amount of dioxin has been reduced dramatically by replacing some of all of the chlorine with chlorine dioxide. The use of elemental chlorine has declined significantly and as of 2005 was used to bleach 19-20% of all kraft pulp. EFC (elemental chlorine-free) pulping using chlorine dioxide is now the dominant technology worldwide (with the exception of Finland and Sweden where TCF is very important), accounting for 75% of bleached kraft pulp globally
Chemical pulp mills, especially kraft mills, are energy self-sufficient and very nearly closed cycle with respect to inorganic chemicals.
Alternatives
Today, some people and groups advocate using
fiber crop or agricultural residues instead of wood fiber as being more sustainability. However, wood is also a renewable resource, with about 90% of pulp coming from plantations or reforested areas. Non-wood fiber sources account for about 5-10% of global pulp production, for a variety of reasons, including seasonal availability, problems with chemical recovery, brightness of the pulp etc.
Research is under way to develop
biological pulping, similar to chemical pulping but using certain species of fungus that are able to break down the unwanted lignin, but not the cellulose fibres. This could have major natural environmental benefits in reducing the pollution associated with chemical pulping.
References
See also
External link
Wood pulp is a dry fiberous material prepared by chemically or mechanically separating the fibers which make up
wood. Pulp can be either fluffy or formed into thick sheets. The latter form is used if the pulp must be transported from the
pulp mill to a
paper mill. Pulp which is shipped and sold as pulp (not processed into paper in the same facility) is referred to as
market pulp. When suspended in water the fibers disperse and become more pliable. This pulp suspension can be laid down on a screen to form a sheet of
paper, and this is the primary use for wood pulp. Wood pulp is the most common material used to make paper. The timber resources used to make wood pulp are referred to as pulpwood. Wood pulp comes from softwood trees such as
spruce, pine,
fir, larch and Tsuga, and hardwoods such as eucalyptus,
aspen and
birch.
History
Using wood to make paper is a fairly recent innovation. In the 1800s,
fiber crops such as linen fibres were the primary material source, and paper was a relatively expensive commodity. The use of wood to make pulp for paper began with the delevopment of mechanical pulping in Germany by F.G. Keller in the 1840s. Chemical processes quickly followed, first with J. Roth's use of sulfurous acid to treat wood, followed by B. Tilghman's US patent on the use of calcium bisulfite, Ca(HSO3)2, to pulp wood in 1867. Almost a decade later the first commercial sulfite pulp mill was built in Sweden. It used magnesium as the counter ion and was based on work by C.D. Eckman. By 1900 sulfite pulping had become the dominant means of producing wood pulp, surpassing mechanical pulping methods. The competing chemical pulping process, the sulfate or
kraft process was developed by Carl Dahl in 1879 and the first kraft mill started (in Sweden) in 1890. The invention of the
recovery boiler by G.H. Tomlinson in the early 1930s allowed kraft mills to recycle almost all of their pulping chemicals. This, along with the ability of the kraft process to accept a wider variety of types of wood and produce stronger fibers made the kraft process the dominant pulping process starting in the 1940s.
Global production of wood pulp in 2006 was 160 million tonnes (175 million tons). In the previous year, 57 million tonnes (63 million tons) of market pulp (not made into paper in the same facility) was sold, with
Canada being the largest source at 21% of the total, followed by the
US at 16%. Chemical pulp made up 93% of market pulp.
Manufacture of wood pulp
Harvesting trees
Most pulp mills use good forest management practices in harvesting trees to ensure that they have a sustainable source of raw materials. One of the major complaints about harvesting wood for pulp mills is that it reduces the
biodiversity of the harvested forest. Trees raised specifically for pulp production account for 16% of world pulp production, old growth forests 9% and second- and third- and more generation forests account for the balance, .
Reforestation is practiced in most areas, so trees are a renewable resource. The FSC (Forest Stewardship Council) certifies paper made from trees harvested according to guidelines meant to ensure good forestry practices.
The number of trees consumed depends whether mechanical processes or chemical processes are used. It has been estimated that based on a mixture of softwoods and hardwoods 12 meters (40 ft) tall and 15-20 centimeters (6-8 in) in diameter, it would take an average of 24 trees to produce 0.9 tonne (1 ton) of printing and writing paper, using the kraft process (chemical pulping). Mechanical pulping is about twice as efficient in using trees since almost all of the wood is used to make fiber therefore it takes about 12 trees to make 0.9 tonne (1 ton) of mechanical pulp or newsprint.
Preparation for pulping
Only the Formation#Wood are useful for making pulp. Bark contains relatively few useful fibers and is removed and used as fuel to provide steam for use in the pulp mill. Most pulping processes require that the wood be chipped and screened to provide uniform sized chips.
Pulping
There are a number of different processes which can be used to separate the wood fibers:
Mechanical pulp
Manufactured grindstones with embedded
silicon carbide or aluminum oxide can be used to grind small wood logs called "bolts" to make "stone groundwood" pulp (SGW). If the wood is steamed prior to grinding it is known as "pressure groundwood" (PGW) pulp. Most modern mills use chips rather than logs and ridged metal discs called refiner plates instead of grindstones. If the chips are just ground up with the plates, the pulp is called "refiner mechanical" pulp (RMP) and if the chips are steamed while being refined the pulp is called "thermomechanical" pulp (TMP). Steam treatment significantly reduces the total energy needed to make the pulp and decreases the damage (cutting) to fibers. Mechanical pulps are used for products that require less strength, such as
newsprint and
paperboards.
Chemithermomechanical pulp
Wood chips can be pretreated with sodium carbonate, sodium hydroxide, sodium sulfite and other chemical prior to refining with equipment similar to a mechanical mill. The conditions of the chemical treatment are much less vigorous (lower temperature, shorter time, less extreme pH) than in a chemical pulping process since the goal is to make the fibers easier to refine, not to remove lignin as in a fully chemical process. Pulps made using these hybrid processes are known as chemi-thermomechanical pulps (CTMP).
Chemical pulp
Chemical pulp is produced by combining wood chips and chemicals in large vessels known as digesters where heat and the chemicals break down the lignin, which binds the cellulose fibers together, without seriously degrading the cellulose fibres. Chemical pulp is used for materials that need to be stronger or combined with mechanical pulps to give a product different characteristics. The kraft process is the dominant chemical pulping method, with sulfite process being second.
Recycled pulp
Pulp can also be made out of waste paper and paperboard.
Recycled pulp is most often used to make paperboard, newsprint or sanitary paper.
Bleaching
The pulp produced up to this point in the process can be
bleaching of wood pulp to produce a white paper product. The chemicals used to bleach pulp have been a source of environmental concern, and recently the pulp industry has been using alternatives to
chlorine, such as
chlorine dioxide,
oxygen, ozone and hydrogen peroxide.
Environmental concerns
The major environmental impacts of producing wood pulp come from its impact on forest sources and from its waste products.
Forest resources
The impact of logging to provide the raw material for wood pulp is an area of intense debate. Modern
logging practices, using forest management seeks to provide a reliable, renewable source of raw materials for pulp mills. The practice of
clear cutting is a particularly sensitive issue since it is a very visible effect of logging.
Reforestation, the planting of tree seedlings on logged areas, has also been criticized for decreasing biodiversity because reforested areas are monocultures. Proponents of reforestation and
Plantations#Forestry argue that in this respect trees are no different from any other agricultural crop. Logging of
old growth forests accounts for less than 10% of wood pulp, but is one of the most controversial issues.
Effluents from pulp mills
Pulp mills are almost always located near large bodies of water because of they require substantial quantites of water for their processes. Delignification of chemical pulps releases considerable amounts of organic material into the environment, particularly into rivers or lakes. The wastewater effluent can also be a major source of pollution, containing lignins from the trees, high
biochemical oxygen demand (BOD) and dissolved organic carbon (DOC), along with alcohols,
chlorates, heavy metals, and
Chelation agents. Reducing the environmental impact of this effluent is accomplished by closing the loop and recycling the effluent (see black liquor) where possible, as well as employing less damaging agents in the pulping and bleaching processes.
Mechanical pulp is not a major cause for environmental concern since most of the organic material is retained in the pulp, and the chemicals used (
hydrogen peroxide and
sodium dithionite) produce benign byproducts (water and
sodium sulfate (finally), respectively).
Bleaching with chlorine produces large amounts of
organochlorine compounds, including
dioxins. Increased public awareness of enviromental issues, as evidenced by the formation of organizations like
Greenpeace, influenced the pulping industry and governments to address the release of these materials into the environment{{cite conference |first=David A. |last=Sonnenfeld |authorlink= |coauthors= |title=Social Movements and Ecological Modernization: The Transformation of Pulp and Paper Manufacturing, Paper: WP00-6-Sonnenfeld|booktitle= Berkeley Workshop on Environmental Politics |pages= |publisher=Institute of International Studies (University of California, Berkeley) |date=1999 |location=Berkeley,CA |url=http://repositories.cdlib.org/cgi/viewcontent.cgi?article=1005&context=iis |accessdate=2007-09-20 |id= -->
. The amount of dioxin has been reduced dramatically by replacing some of all of the chlorine with chlorine dioxide. The use of elemental chlorine has declined significantly and as of 2005 was used to bleach 19-20% of all kraft pulp. EFC (elemental chlorine-free) pulping using chlorine dioxide is now the dominant technology worldwide (with the exception of Finland and
Sweden where TCF is very important), accounting for 75% of bleached kraft pulp globally
Chemical pulp mills, especially kraft mills, are energy self-sufficient and very nearly closed cycle with respect to inorganic chemicals.
Alternatives
Today, some people and groups advocate using
fiber crop or agricultural residues instead of wood fiber as being more sustainability. However, wood is also a renewable resource, with about 90% of pulp coming from plantations or reforested areas. Non-wood fiber sources account for about 5-10% of global pulp production, for a variety of reasons, including seasonal availability, problems with chemical recovery, brightness of the pulp etc.
Research is under way to develop
biological pulping, similar to chemical pulping but using certain species of fungus that are able to break down the unwanted lignin, but not the cellulose fibres. This could have major natural environmental benefits in reducing the pollution associated with chemical pulping.
References
See also
External link
Wood pulp - Wikipedia, the free encyclopedia
Wood pulp is a dry fibrous material prepared by chemically or mechanically separating the fibers which make up wood. Pulp can be either fluffy or formed into thick sheets.
Wood-pulp paper - Wikipedia, the free encyclopedia
Wood-pulp paper is paper made from wood pulp, which is produced from trees by a variety of mechanical and chemical processes. Paper made from wood pulp ranges from toilet paper ...
wood pulp definition of wood pulp in the Free Online Encyclopedia.
wood pulp: see paper paper, thin, flat sheet or tissue made usually from plant fiber but also from rags and other fibrous materials. It is used principally for printing and writing ...
Wood-pulp definition of Wood-pulp in the Free Online Encyclopedia.
wood pulp: see paper paper, thin, flat sheet or tissue made usually from plant fiber but also from rags and other fibrous materials. It is used principally for printing and writing ...
Tasmania wood pulp mill approved - Telegraph
Telegraph Earth is your source for environmental and green news and environmental and green issues, with information on climate change, global warming, pollution, green living and ...
Eden Carter Wood - Pulp.Net
Eden Carter Wood was born in New Zealand and currently lives in the UK. She is working on a novel.
wood pulp
Wood that has been processed into a pulpy mass of fibres ... Tiscali Quicklinks. Please visit our Accessibility Page for a list of the Access Keys you can use to find your way ...
wood pulp - Hutchinson encyclopedia article about wood pulp
Wood that has been processed into a pulpy mass of fibres. Its main use is for making paper, but it is also used in making rayon and other cellulose fibres and plastics.
Wood-pulp - Hutchinson encyclopedia article about Wood-pulp
Wood that has been processed into a pulpy mass of fibres. Its main use is for making paper, but it is also used in making rayon and other cellulose fibres and plastics.
D2W Treating wood-pulp
D2W Treating wood-pulp &c D2W _____ This heading comprises the following subject matter: ...
