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MDF is typically made up of 82% wood fibre, 9% urea-formaldehyde resin glue, 8% water, and 1% paraffin wax. [4] The density is typically between 500 and 1,000 kg/m 3 (31 and 62 lb/cu ft). [ 5 ] The range of density and classification as light-, standard-, or high-density board is a misnomer and confusing.
This is a list of insulation materials used around the world. Typical R-values are given for various materials and structures as approximations based on the average of available figures and are sorted by lowest value. R-value at 1 m gives R-values normalised to a 1 metre (3 ft 3 in) thickness and sorts by median value of the range.
The R-value is the building industry term [3] for thermal resistance "per unit area." [4] It is sometimes denoted RSI-value if the SI units are used. [5] An R-value can be given for a material (e.g., for polyethylene foam), or for an assembly of materials (e.g., a wall or a window). In the case of materials, it is often expressed in terms of R ...
Fiberboard (American English) or fibreboard (British English) is a type of engineered wood product that is made out of wood fibers. Types of fiberboard (in order of increasing density) include particle board or low-density fiberboard (LDF), medium-density fiberboard (MDF), and hardboard or high-density fiberboard (HDF).
Closed-cell foams are superior insulators. While open-cell foams typically have R-values of 3 to 4 per inch (RSI-0.53 to RSI-0.70 per inch), closed-cell foams can attain R-values of 5 to 8 per inch (RSI-0.88 to RSI-1.41 per inch). This is important if space is limited, because it allows a thinner layer of insulation to be used.
The chemical composition of common natural fibers are shown below; [6] these vary depending on whether the fiber is a bast fiber (obtained from the bark), a core fiber (obtained from the wood), or a leaf fiber (obtained from the leaves).
Chemical pulping involves dissolving lignin in order to extract the cellulose from the wood fiber. The different processes of chemical pulping include the Kraft process, which uses caustic soda and sodium sulfide and is the most common; alternatively, the use of sulfurous acid is known as the sulfite process, the neutral sulfite semichemical is treated as a third process separate from sulfite ...
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]