View source for Wood fibre

{{short description|Part of a plant}}
{{Use British English|date=August 2016}}
'''Wood fibres''' (also spelled '''wood fibers''', see [[spelling differences]]) are usually [[cellulose|cellulosic]] elements that are extracted from trees and used to make materials including [[paper]].

The end paper product (paper, paperboard, tissue, cardboard, etc.) dictates the species, or species blend, that is best suited to provide the desirable sheet characteristics, and also dictates the required fibre processing (chemical treatment, heat treatment, mechanical "brushing" or refining, etc.).

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.<ref name="Burton2003">{{cite book|author=Philip Joseph Burton|title=Towards Sustainable Management of the Boreal Forest|url=https://books.google.com/books?id=r9rgVWO1MUkC&pg=PA759|year=2003|publisher=NRC Research Press|isbn=978-0-660-18762-4|pages=759–}}</ref>  Wood fibres can also be [[recycled]] from used paper materials.<ref name="Bajpai2013">{{cite book|author=Pratima Bajpai|title=Recycling and Deinking of Recovered Paper|url=https://books.google.com/books?id=DZ3TAAAAQBAJ&pg=PA8|date=21 November 2013|publisher=Elsevier Science|isbn=978-0-12-417169-5|pages=8–}}</ref>

==Paper==
Wood fibres are treated by combining them with other additives which break down the fibres into a spongy mass called [[Pulp (paper)|pulp]].  The pulp is then processed, and the network of tiny fibres is pressed flat, becoming paper.

==Construction material==
Wood fibres can be pressed into various types of flat boards, used as insulation, renderboard and sarking. Densities vary from 60Kg/m3 insulation boards to 180Kg/m3 render boards. Some types of woodfibre are flexible, others very rigid. Flexible insulation is designed to be friction-installed between timbers or fitted on top of somewhat irregular surfaces

There are manufacturers in Poland (Beltermo, Steico), Germany (Gutex, Steico HQ), France (Pavatex) and Norway (Hunton)..

There are two different manufacturing processes: wet and dry.<ref>{{cite web|access-date=1 October 2024 |title=Wet process vs Dry process wood fibre insulation |date=17 March 2019 |url=https://www.backtoearth.co.uk/news/wet-process-vs-dry-process-wood-fibre-insulation/}}</ref>

In the wet-process, chipped, waste timber is ground up into small pieces then boiled up with water and a few other chemicals designed to break down the timber into the fibres. During this process, many of the sugars which are of interest to fungus and mould are removed. This slurry is then poured on to a belt sieve and compressed to remove as much water as possible and heated with steam to bond the fibres together. The steaming process softens the natural lignin around the fibres which holds the fibres together in the board, which is typically manufactured to around 20mm thickness. These boards are then laminated up with a water based glue into thicker layers to produce boards up to around 120mm thick.

In the dry-process waste timber is dried and ground up into fibres, then mixed with a synthetic glue called  PMDI (polymeric methylene diphenyl diisocyanate). PMDI is a polyurethane based glue which is used in fairly small quantities (3-4% by mass). This is essentially the same glue used in OSB and MDF. The mixture is then laid on a conveyor belt and compressed to the correct thickness and density, then steam is applied to cure the boards. These boards are made to the desired thickness and are not usually laminated.

Wet-process boards are typically denser and have much stronger capilliary action to move water around. The dry process consumes less energy.

==Hydroculture==
Wood fibres can be used as a substrate in [[hydroponics]]. [[Wood wool]] (i.e. wood slivers) have been a substrate of choice since the earliest days of the hydroponics research.<ref>{{cite book|last1=Gericke|first1=William F.|title=The Complete Guide to Soilless Gardening|date=1940|publisher=Putnam|location=London|isbn=9781163140499|pages=[https://archive.org/details/soillessgardenin031829mbp/page/n301 38]& 84|edition=1st|url=https://archive.org/details/soillessgardenin031829mbp}}</ref> However, more recent research suggests that wood fibre can have detrimental effects on "plant growth regulators".<ref name="woodfibre pgr">{{cite web | url=http://www.purdue.edu/newsroom/research/2010/101025LopezHulls.html | title=Rice hulls a sustainable drainage option for greenhouse growers | publisher=Purdue University | date=October 25, 2010 | access-date=August 30, 2012 | author=Wallheimer, Brian}}</ref>{{Primary source inline|reason=This citation is vague in its description of its findings and is in contradiction of more established science suggesting wood fibre is a perfectly adequate media choice. Need more citations to back this claim up.|date=March 2016}}

==Composites==
Wood fibres can be combined with thermoplastics to create strong, waterproof products for outdoor use, such as deck boards or outdoor furniture.<ref name="Baillie2005">{{cite book|author=Caroline Baillie|title=Green Composites: Polymer Composites and the Environment|url=https://books.google.com/books?id=DkcivQH1WkQC&pg=PA94|date=8 March 2005|publisher=CRC Press|isbn=978-0-8493-2576-2|pages=94–}}</ref>

==See also==
* [[Hemp paper]]
* [[Pulp (paper)]]
* [[Woodfibre, British Columbia]]
* [[Wood flour]], a form of wood fibre

==References==
{{Reflist}}

==Further reading==
* [https://news.gov.bc.ca/releases/2019FLNR0269-002168 Over $27 million to help more wood fibre use]
* [https://www.terrassendielen-lager.de Terrassendielen] (in German)
* [https://open.alberta.ca/dataset/4f922c4b-79ac-4825-a803-17e8ccdcb961/resource/0e5829f9-5fb8-4302-b875-d50fa086bed6/download/lands-drivablewoodfibresurfaces-2008a.pdf Drivable wood fibre surfaces]

{{Fibers}}{{Paper}}
{{Wood products}}

[[Category:Cellulose]]
[[Category:Insulation fibers]]