Wood wool

Wood wool, known primarily as excelsior in North America, is a product made of wood slivers cut from logs and is mainly used in packaging, for cooling pads in home evaporative cooling systems known as swamp coolers, for erosion control mats, and as a raw material for the production of other products such as bonded wood wool boards and used as stuffing for stuffed animals.

In the United States the term wood wool is reserved for finer grades of excelsior. The U.S. Forest Service 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 U.S. 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).

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

Excelsior has many applications, examples include:

Wood wool fibers can be compressed and when the pressure is removed they resume their initial volume. This is a useful property for minimizing their volume when shipping. Due to its high volume and large surface area, wood wool can be used for applications where water or moisture retention is necessary. The width of wood wool 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, pH, moisture content and freedom from dust and small pieces, set by British Standard BS 2548 for wood wool for general packaging purposes. This standard was originally 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 environmentally friendly construction and insulation materials because they do not contain organic binders.

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