Wood Wool

in Wood

The term wood wool is used in the US to refer to finer grades of excelsior. The U. S. Forest Service has stated in 1948 and 1961 that, "In this country the product has no other general name, but in most other countries all grades of excelsior are known as wood wool. In the United States the name wood wool is reserved for only a small proportion of the output consisting of certain special grades of extra thin and narrow stock."

The US Standard Industrial Classification Index SIC is 2429 for the product "Wood wool (excelsior)". The same term is used by the United States for the external trade number under which wood wool is monitored: HTS Number: 4405.00.00 Description: Wood wool (excelsior); wood flour.

The number 4405.00 is applied to wood wool by the World Customs Organization in the Harmonized Commodity Description and Coding System (HS).

Grades and classifications

The 1973 US federal procurement specification PPP-E-911, cancelled in 1991, categorized "wood excelsior" products according to the following table of terms and dimensions:

TABLE I. Strand size for type I class A and B excelsior


Thickness of strand Width of strand

Grade Nomenclature Inch Inch


1 Superfine wood wool 0.006 0.020

2 Wood wool 0.012 0.020

3 Extra fine 0.015 0.031

4 Fine 0.018 0.031

5 Medium 0.021 0.041

6 Coarse or ribbon 0.015 0.167



Excelsior is used in packaging, cushioning, stuffing of stuffed animals, and for the cooling pads in home evaporative cooler systems known as "swamp coolers."

Excelsior, dyed green, makes an annual appearance as the "grass" in Easter baskets, or did in earlier decades before the prevalence of plastics.

Traditionally used in stuffing Teddy bears, it is still used in stuffing the muzzles of some collectible bears.

Excelsior has other applications, such as mats and blankets for erosion control, garden mulch, dog bedding, hutch bedding, and udder cleaning for dairy cattle. It is also used for the production of cement-bonded wood wool boards.

Excelsior is also used, banded into bale form, as archery backstops, comparable to how a straw bale would be used. If protected from the elements, it can last for many years. As locations wear, through repeated targeting, the bale can be soaked liberally. It expands and holds the water, just like a dry sponge would.


The fibers of wood wool can be compressed and when pressure is removed, they resume their initial volume. This is a useful property for minimizing the volume when shipping.

Due to high volume and large surface area, wood wool can be used for applications where water / moisture retention is necessary.

The width of these fibers varies from 1.5 to 20 mm, while their length is usually around 500 mm (depending on the production process).

In the UK there are specifications for dimensions, requirements on pH, moisture content and freedom from dust and small pieces, set by British Standard BS 2548 for wood wool for general packaging purposes. Originally this standard was issued in 1954 and subsequently re-issued in 1986.

When these fibers are bonded with cement or magnesite, bonded wood wool boards are produced. Slabs of bonded wood wool are considered environment friendly construction and insulation materials because they do not contain organic binders.


Excelsior is cut from "bolts" (round, halved, quartered, or otherwise split logs) of poplar (for example aspen), pine, spruce or eucalyptus. For evaporative cooler pads, the dominant source is the aspen.

Wood wool can be produced in either horizontal shredding machines or in vertical shredding machines.

A possible further processing option, is washing in order to remove dust.

Wood wool processing may involve drying, to achieve lower moisture in compliance with local requirements, as in the UK.

Finally, wood wool can be dyed, producing a variety of colored products.


A different product was once known as "wood wool," as well as "pine needle-wool," or "pine wood-wool." According to E. Littell, it was produced in Breslau of Silesia (today called Wrocaw in Poland) by Herr von Pannewich, mentioning that in 1842, five hundred counterpanes made of it were purchased for a hospital in Vienna. The process was chemical and made use of the leaves (needles) of Scots Pine.

In England, yet another product known as wood wool was produced by the chemical digestion of wood strips by sulphurous acid, with applications as absorbant material in surgical dressings and such. Another application of this product was that of sanitary towels, as shown in advertisements of 18851892 in Britain, called "wood wool diapers" or "sanitary wood wool sheets". The European "wood wool" was known in America in the last nineteenth century as distinctly different from excelsior.

The wood wool that is the topic of this article is that which has traditionally been known as excelsior in the US. Fifteen United States patents related to "slivering machines" for producing small wood shreds "known as excelsior" were listed in 1876. The earliest, a machine for "Manufacturing wood to be used as a substitute for curled hair in stuffing beds" was patented in the US in 1842; however, the product had no specific name when the process was first patented.

The 1868 patent "Improved capillary material for filling gas and air carburettors" is on a new use for "fibres torn from the wood by suitable machinery", that "is sold and used as filling for mattresses, its commercial name being 'excelsior'." This is the earliest description of the material by this name cited by the Oxford English Dictionary, though the term "excelsior mattress" had appeared in print as early as 1856.

In 1906, the now-common use of excelsior in the cooling pads of evaporative coolers appeared in a patent that stated, "I have found that excelsior makes a very cheap and good material for this purpose."

In the beginning of the 20th century wood wool was used as raw material for production of wood wool panels in Europe, especially in Austria. By 1930, the wood wool cement boards were being widely produced.

In the twenty-first century, excelsior appears in numerous patents directed to erosion control and sediment control methods and devices; for example, the 2006 "Sediment control device and system;" a few late twentieth-century patents on these uses refer to "excelsior/wood wool."


^ US commodity code: Wood wool (excelsior)

^ Nelson Courtlandt Brown (1919). Forest Products, Their Manufacture and Use. J. Wiley. p. 425. http://books.google.com/books?id=HrJCAAAAIAAJ&pg=RA1-PA425&dq=wood-wool+excelsior+europe+called&lr=&as_brr=0&as_pt=ALLTYPES&ei=OxhkSa62A4S6lATTsqAD. 

^ W. F Gericke (2007). Soilless Gardening. p. 38. ISBN 9781406770643. http://books.google.com/books?id=CoZdpTtYXrgC&pg=RA1-PA38&dq=excelsior+grade+wood-wool+date:1990-2009&lr=&as_brr=0&as_pt=ALLTYPES. 

^ a b Forest Products Laboratory (1948). Excelsior manufacture Original report dated May 1948 Reveiwed and reaffirmed 1961. US Dept of Agriculture, Forest Service. http://ir.library.oregonstate.edu/dspace/bitstream/1957/1758/1/FPL_1711ocr.pdf. 

^ US Standard Industrial Classification Index SIC 2429 for "Wood wool (excelsior)"

^ HTS Number for Wood wool (excelsior)

^ Harmonized Commodity Description and Coding System (HS), page 2, 4405.00 wood wool

^ "Federal Specification: Excelsior, Wood, Fabricated Pads and Bulk Form". September 28, 1973. http://www.everyspec.com/FED+SPECS/download.php?spec=PPP-E-911D.010605.pdf. 

^ E. F. Lindsley (July 1984). "Solar air conditioners the hotter it gets, the better they work". Popular Science (Times Mirror Magazines): 6466. ISSN 0161-7370. http://books.google.com/books?id=AQROL_5mY5cC&pg=PA66&dq=evaporative+cooler+swamp+excelsior&lr=&as_brr=1&as_pt=ALLTYPES&ei=9SpkSZS_GYLkkwT904XuAg. 

^ David Daniel (2005). The Marble Kite. Macmillan. p. 35. ISBN 9780312323516. http://books.google.com/books?id=neMHrtKF_DsC&pg=PA35&dq=excelsior+grass+easter-basket&lr=&as_brr=3&as_pt=ALLTYPES&ei=MS1kSYaZB4_AlQSKlJndCQ#PPA36,M1. 

^ "The Tradition of the excelsior stuffing". HERMANN-Spielwaren GmbH. http://www.hermann.de/fertigung/fer_st3e.htm. Retrieved 24 July 2006. 

^ Market Analysis of Erosion control Mats United States Department of Agriculture

^ Wood wool applications

^ Udderwoodwool

^ Wood wool Cement Boards, Production and use, page 284 in "The Ecology of Building Materials", Bjrn Berge, Filip Henley, Howard Liddell, Architectural Press, 2001, ISBN 0750654503, 9780750654500

^ Jim L. Bowyer, Rubin Shmulsky, John G. Haygreen (2007). Forest Products and Wood Science. Blackwell Publishing. p. 412. ISBN 9780813820361. http://books.google.com/books?id=bmNLXwtkpD8C&pg=PA412&dq=cement+wood-wool-board+excelsior&as_brr=3&ei=7OCDSdiCM4K0kAT3j62kBg. 

^ Larry Wise (1992). Bow and Arrow: The Comprehensive Guide to Equipment, Technique, and Competition. Stackpole Books. p. 912. ISBN 9780811724111. http://books.google.com/books?id=Bz6xU2VdV8MC&pg=PA128&dq=excelsior+bales+archery&as_brr=3&ei=DzBkSa7TDorIlQSlkYiMCA. 

^ BS 2548 Specification for wood wool for general packaging purposes (British Standard)

^ a b BS 2548 BSI British Standards

^ Wood Based Panels International, Friday, March 1 1996

^ European Commission Research - Industrial Technologies, 15/09/2005

^ The Black Poplar

^ Roger E. Simmons (1912). Wood-using Industries of New Hampshire. I. C. Evans co. p. 53. http://books.google.com/books?id=O4ZOAAAAMAAJ&pg=PA54-IA1&dq=excelsior+wood-wool+aspen&as_brr=3&ei=IJ9jSem-FImINI7QrLIN. 

^ The suitability of Eucalyptus grandis and two provenances of Pinus kesiya for wood wool-cement slab manufacture by A J Hawkes; A P Robinson; Publisher: London : Tropical Products Institute, 1978. ISBN 0859540863 9780859540865

^ Gert Jan Bom et al. (1999). Evaporative Air-conditioning: Applications for Environmentally Friendly Cooling. World Bank Publications. p. 25. http://books.google.com/books?id=jJBS4FKl7kUC&pg=PA25&dq=wood-wool+intitle:%22Applications+for+Environmentally+Friendly+Cooling%22&lr=&as_brr=0&as_pt=ALLTYPES&ei=SviHSbSXPJTUlQS1iOj-BQ. 

^ ISO 9567:1989 Woodworking machines Horizontal shredding machines for wood wool production, quadruple effect Nomenclature

^ ISO 9615:1989 Woodworking machines Vertical shredding machines for wood wool production, with hydraulic clamping Nomenclature

^ "Our wood wool is washed and cleaned to remove as much dust as possible"

^ Kiln dried wood wool

^ Colored Excelsior

^ Peter Lund Simmonds (1858). The Dictionary of Trade Products, Manufacturing, and Technical Terms: With a Definition of the Moneys, Weights, and Measures of All Countries. G. Routledge. p. 288. http://books.google.gr/books?id=ZcoEAAAAYAAJ&pg=PA288&dq=%22wood+wool%22+pine+date:1854-1865&lr=&as_brr=0&as_pt=ALLTYPES&hl=en. 

^ E. Littell (1852). Living Age. Boston: Littell & Co. http://books.google.gr/books?id=R4MfAAAAYAAJ&pg=PA430&dq=%22wood+wool%22&hl=en#PPA430,M1. 

^ Bertram Blount, Arthur George Bloxam (1905). Chemistry for Engineers and Manufacturers. C. Griffin and Company, Limited. p. 281. http://books.google.com/books?id=4WlBAAAAIAAJ&pg=PA281&dq=%22wood+wool%22+date:1860-1905&lr=&as_brr=0&as_pt=ALLTYPES&ei=LleFSbvNHpLElQTWu93EBg. 

^ Wood wool diapers, 1885-1895 advertisements

^ Advertisement for "sanitary wood wool sheets", 1895

^ H. A. Hare and Edward Martin (editors) (1897). Therapeutic Gazette Series III Volume XIII. Detroit: William M. Warren. p. 242. http://books.google.com/books?id=BbQCAAAAYAAJ&pg=PA242&dq=%22wood+wool%22+excelsior+date:1860-1905&lr=&as_brr=0&as_pt=ALLTYPES&ei=u1yFSfqbOKOMkQTRqe2pBg. 

^ Edward Henry Knight (1876). Knight's American Mechanical Dictionary: A Description of Tools, Instruments, Machines, Processes, and Engineering; History of Inventions; General Technological Vocabulary; and Digest of Mechanical Appliances in Science and the Arts. 3. Hurd and Houghton. p. 2214. http://books.google.com/books?id=mEYOAAAAYAAJ&pg=PA2214&dq=excelsior+fibers++date:0-1876&lr=&as_brr=3&as_pt=ALLTYPES&ei=T6NjSe7wDKWsNZzQ5YwN. 

^ Wm. Baker (1842). "Machine for manufacturing wood so as to be used as a substitute for curled hair in stuffing beds". U.S. patent 2654. http://www.google.com/patents?id=NiBBAAAAEBAJ&printsec=abstract&zoom=4&dq=fibers++wood+mattress&as_drrb_is=b&as_minm_is=1&as_miny_is=1776&as_maxm_is=1&as_maxy_is=1870#PPA1,M1. 

^ John A. Bassett (1868). "Improved capillary material for filling gas and air carburettors". U.S. patent 60670. http://www.google.com/patents?id=0WwAAAAAEBAJ&printsec=abstract&zoom=4&dq=60670. 

^ Michigan State Agricultural Society (1856). Transactions of the State Agricultural Society of Michigan: With Reports of County Agricultural Societies, for the Year 1849-59, vol. 7 (1855). p. 139. http://books.google.com/books?id=RKoSAAAAYAAJ&pg=PA139&dq=excelsior+mattress+date:0-1860&lr=&as_brr=1&as_pt=ALLTYPES&ei=Bgl-SdaUBqWQkAS92NDsBg#PPA139,M1. 

^ John Zellweger (1906). "Air filter and cooler". U.S. patent 838602. http://www.google.com/patents?id=04pHAAAAEBAJ&printsec=abstract&zoom=4&dq=cooling+excelsior&as_drrb_is=b&as_minm_is=1&as_miny_is=1799&as_maxm_is=1&as_maxy_is=1910&num=30#PPA2,M1. 

^ New strands to the wood wool story Botting, Mike in Wood Based Panels International, June 1, 1997

^ Peter S. Sanguinetti (2006). "Sediment control device and system". U.S. patent 7021869. http://www.google.com/patents?id=hot3AAAAEBAJ&printsec=abstract&zoom=4&dq=excelsior+erosion-control+sediment-control&as_drrb_ap=b&as_minm_ap=1&as_miny_ap=2000&as_maxm_ap=1&as_maxy_ap=2009&as_drrb_is=b&as_minm_is=1&as_miny_is=2000&as_maxm_is=1&as_maxy_is=2009#PPA1,M1. 

^ Erosion control blanket and method of, US Patent 5786281, Jul 28, 1998

Categories: Biodegradable materials | Fibers
Author Box
gaga has 1 articles online

I am China Manufacturers writer, reports some information about pram covers , baby pram strollers.

Add New Comment

Wood Wool

Log in or Create Account to post a comment.
Security Code: Captcha Image Change Image
This article was published on 2010/12/14