Wood fibre

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Wood fibres (also spelled wood fibers, see spelling differences) are usually cellulosic elements that are extracted from trees and used to make materials including paper.

Contents

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. [1] Wood fibres can also be recycled from used paper materials. [2]

Paper

Wood fibres are treated by combining them with other additives which break down the fibres into a spongy mass called 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. [3]

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) is a polyurethane based glue which is used in fairly small quantities (3-4% by mass). This is essentially the same glue use 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. [4] However, more recent research suggests that wood fibre can have detrimental effects on "plant growth regulators". [5] [ non-primary source needed ]

Composites

Wood fibres can be combined with thermoplastics to create strong, waterproof products for outdoor use, such as deck boards or outdoor furniture. [6]

See also

Related Research Articles

<span class="mw-page-title-main">Plywood</span> Manufactured wood panel made from thin sheets of wood veneer

Plywood is a composite material manufactured from thin layers, or "plies", of wood veneer that have been stacked and glued together. It is an engineered wood from the family of manufactured boards, which include plywood, medium-density fibreboard (MDF), oriented strand board (OSB), and particle board.

<span class="mw-page-title-main">Pulp (paper)</span> Fibrous material used notably in papermaking

Pulp is a fibrous lignocellulosic material prepared by chemically, semi-chemically or mechanically producing cellulosic fibers from wood, fiber crops, waste paper, or rags. Mixed with water and other chemicals or plant-based additives, pulp is the major raw material used in papermaking and the industrial production of other paper products.

<span class="mw-page-title-main">Engineered wood</span> Range of derivative wood products engineered for uniform and predictable structural performance

Engineered wood, also called mass timber, composite wood, human-made wood, or manufactured board, includes a range of derivative wood products which are manufactured by binding or fixing the strands, particles, fibres, or veneers or boards of wood, together with adhesives, or other methods of fixation to form composite material. The panels vary in size but can range upwards of 64 by 8 feet and in the case of cross-laminated timber (CLT) can be of any thickness from a few inches to 16 inches (410 mm) or more. These products are engineered to precise design specifications, which are tested to meet national or international standards and provide uniformity and predictability in their structural performance. Engineered wood products are used in a variety of applications, from home construction to commercial buildings to industrial products. The products can be used for joists and beams that replace steel in many building projects. The term mass timber describes a group of building materials that can replace concrete assemblies.

<span class="mw-page-title-main">Medium-density fibreboard</span> Engineered wood product

Medium-density fibreboard (MDF) is an engineered wood product made by breaking down hardwood or softwood residuals into wood fibre, often in a defibrator, combining it with wax and a resin binder, and forming it into panels by applying high temperature and pressure. MDF is generally denser than plywood. It is made up of separated fibre but can be used as a building material similar in application to plywood. It is stronger and denser than particle board.

<span class="mw-page-title-main">Drywall</span> Panel made of gypsum, used in interior construction

Drywall is a panel made of calcium sulfate dihydrate (gypsum), with or without additives, typically extruded between thick sheets of facer and backer paper, used in the construction of interior walls and ceilings. The plaster is mixed with fiber ; plasticizer, foaming agent; and additives that can reduce mildew, flammability, and water absorption.

<span class="mw-page-title-main">Paperboard</span> Thick paper-based material

Paperboard is a thick paper-based material. While there is no rigid differentiation between paper and paperboard, paperboard is generally thicker than paper and has certain superior attributes such as foldability and rigidity. According to ISO standards, paperboard is a paper with a grammage above 250 g/m2, but there are exceptions. Paperboard can be single- or multi-ply.

<span class="mw-page-title-main">Pulpwood</span> Timber intended for processing into wood pulp for paper production

Pulpwood can be defined as timber that is ground and processed into a fibrous pulp. It is a versatile natural resource commonly used for paper-making but also made into low-grade wood and used for chips, energy, pellets, and engineered products.

<span class="mw-page-title-main">Paper machine</span> Industrial machine used in the pulp and paper industry

A paper machine is an industrial machine which is used in the pulp and paper industry to create paper in large quantities at high speed. Modern paper-making machines are based on the principles of the Fourdrinier Machine, which uses a moving woven mesh to create a continuous paper web by filtering out the fibres held in a paper stock and producing a continuously moving wet mat of fibre. This is dried in the machine to produce a strong paper web.

<span class="mw-page-title-main">Lamination</span> Technique of fusing layers of material

Lamination is the technique/process of manufacturing a material in multiple layers, so that the composite material achieves improved strength, stability, sound insulation, appearance, or other properties from the use of the differing materials, such as plastic. A laminate is a layered object or material assembled using heat, pressure, welding, or adhesives. Various coating machines, machine presses and calendering equipment are used.

<span class="mw-page-title-main">Wood–plastic composite</span> Composite materials made of wood fiber and thermoplastics

Wood–plastic composites (WPCs) are composite materials made of wood fiber/wood flour and thermoplastic(s) such as polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), or polylactic acid (PLA).

<span class="mw-page-title-main">Hardboard</span> Type of fiberboard (engineered wood product)

Hardboard, also called high-density fiberboard (HDF), is a type of fiberboard, which is a pressed wood or engineered wood product. It is used in furniture and in the construction industry.

<span class="mw-page-title-main">Nonwoven fabric</span> Sheet of fibers

Nonwoven fabric or non-woven fabric is a fabric-like material made from staple fibre (short) and long fibres, bonded together by chemical, mechanical, heat or solvent treatment. The term is used in the textile manufacturing industry to denote fabrics, such as felt, which are neither woven nor knitted. Some non-woven materials lack sufficient strength unless densified or reinforced by a backing. In recent years, non-wovens have become an alternative to polyurethane foam.

<span class="mw-page-title-main">Wood drying</span> Also known as seasoning, which is the reduction of the moisture content of wood prior to its use

Wood drying reduces the moisture content of wood before its use. When the drying is done in a kiln, the product is known as kiln-dried timber or lumber, whereas air drying is the more traditional method.

<span class="mw-page-title-main">Building insulation material</span> Insulation material

Building insulation materials are the building materials that form the thermal envelope of a building or otherwise reduce heat transfer.

<span class="mw-page-title-main">Paper</span> Material for writing, printing, etc.

Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses, or other vegetable sources in water, draining the water through a fine mesh leaving the fibre evenly distributed on the surface, followed by pressing and drying. Although paper was originally made in single sheets by hand, almost all is now made on large machines—some making reels 10 metres wide, running at 2,000 metres per minute and up to 600,000 tonnes a year. It is a versatile material with many uses, including printing, painting, graphics, signage, design, packaging, decorating, writing, and cleaning. It may also be used as filter paper, wallpaper, book endpaper, conservation paper, laminated worktops, toilet tissue, currency, and security paper, or in a number of industrial and construction processes.

<span class="mw-page-title-main">Vulcanized fibre</span>

Vulcanized fibre also known as red fibre is a laminated plastic composed of only cellulose. This material is a tough, resilient, hornlike material that is lighter than aluminium, tougher than leather, and stiffer than most thermoplastics. The newer wood-laminating grade of vulcanized fibre is used to strengthen wood laminations used in skis, skateboards, support beams and as a sub-laminate under thin wood veneers.

<span class="mw-page-title-main">Electrical insulation paper</span> Paper used as electrical insulation

Electrical insulation papers are paper types that are used as electrical insulation in many applications due to pure cellulose having outstanding electrical properties. Cellulose is a good insulator and is also polar, having a dielectric constant significantly greater than one. Electrical paper products are classified by their thickness, with tissue considered papers less than 1.5 mils (0.0381 mm) thickness, and board considered more than 20 mils (0.508 mm) thickness.

<span class="mw-page-title-main">Types of concrete</span> Building material consisting of aggregates cemented by a binder

Concrete is produced in a variety of compositions, finishes and performance characteristics to meet a wide range of needs.

The wet strength of paper and paperboard is a measure of how well the web of fibers holding the paper together can resist a force of rupture when the paper is wet. Wet strength is routinely expressed as the ratio of wet to dry tensile force at break.

<span class="mw-page-title-main">Paper chemicals</span> Chemicals used in paper manufacturing

Paper chemicals designate a group of chemicals that are used for paper manufacturing, or modify the properties of paper. These chemicals can be used to alter the paper in many ways, including changing its color and brightness, or by increasing its strength and resistance to water. The chemicals can be defined on basis of their usage in the process.

References

  1. Philip Joseph Burton (2003). Towards Sustainable Management of the Boreal Forest. NRC Research Press. pp. 759–. ISBN   978-0-660-18762-4.
  2. Pratima Bajpai (21 November 2013). Recycling and Deinking of Recovered Paper. Elsevier Science. pp. 8–. ISBN   978-0-12-417169-5.
  3. "Wet process vs Dry process wood fibre insulation". 17 March 2019. Retrieved 1 October 2024.
  4. Gericke, William F. (1940). The Complete Guide to Soilless Gardening (1st ed.). London: Putnam. pp.  38& 84. ISBN   9781163140499.
  5. Wallheimer, Brian (October 25, 2010). "Rice hulls a sustainable drainage option for greenhouse growers". Purdue University. Retrieved August 30, 2012.
  6. Caroline Baillie (8 March 2005). Green Composites: Polymer Composites and the Environment. CRC Press. pp. 94–. ISBN   978-0-8493-2576-2.

Further reading