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The physical properties of any material are determined by its chemical structure. Wood contains an abundance of chemical groups called free hydroxyls. Free hydroxyl groups readily absorb and release water according to changes in the climatic conditions to which they are exposed. This is the main reason why wood's dimensional stability is ...
The term creosote has a broad range of definitions depending on the origin of the coal tar oil and end-use of the material. With respect to wood preservatives, the United States Environmental Protection Agency (EPA) considers the term creosote to mean a pesticide for use as a wood preservative meeting the American Wood Protection Association (AWPA) Standards P1/P13 and P2. [6]
Wood degradation is a complex process influenced by various biological, chemical, and environmental factors. It significantly impacts the durability and longevity of wood products and structures, necessitating effective preservation and protection strategies.
The chromium acts as a chemical fixing agent and has little or no preserving properties; it helps the other chemicals to fix in the timber, binding them through chemical complexes to the wood's cellulose and lignin. The copper acts primarily to protect the wood against decay, fungi, and bacteria, while the arsenic is the main insecticidal ...
Acetylated wood is a type of modified wood that is produced through a chemical modification process and does not contain any toxic substances. [1] It produced from a chemical reaction (named as acetylation), involving acetic anhydride and a modification process to make wood highly resistant to biological attacks by fungi and wood-boring insects and durable to environmental conditions.
A forest product is any material derived from forestry for direct consumption or commercial use, such as lumber, paper, or fodder for livestock. Wood, by far the dominant product of forests, is used for many purposes, such as wood fuel (e.g. in form of firewood or charcoal) or the finished structural materials used for the construction of buildings, or as a raw material, in the form of wood ...
Chemicals, referred to as 'cooking liquor' help break down wood chips into a mass of fibres. [9] The chemicals used are: 1) sulfite salts with an excess of sulfur dioxide and 2) caustic soda and sodium sulfide (kraft process). The lignin of the wood is made soluble, resulting in fibre separation into whole fibres.
More than 90% of the fluff pulps are fully bleached chemical softwood pulps, of which more than 90% are kraft pulps. The most common raw material source for fluff pulps are southern bleached softwood kraft from loblolly pine. SBSK from other species and NBSK are also used to make fluff pulp. [4] Thicker fibres are preferred to improve the bulk.