View source for Medium density fiberboard (MDF)

[[File:MDF Sample.jpg|thumb|medium-density fiberboard (MDF)]]
== Description ==

A type of [[fiberboard]]. common name for an engineered wood product made from mixture of fine wood fibers and resin bonded together then compressed into panels with smooth, flat surfaces at high temperature and pressure. Medium density fiberboard (MDF) panels are constructed from 82% wood fiber, 9% urea-formaldehyde resin and 1% paraffin wax.  The density of the board, typically between 500-1000 kg/m3, is dependent on the type of fiber (softwood or hardwood) that is used. MDF boards are available in large sheets (4' x 8') in a variety of thicknesses, such as 3/8", 1/2", 5/8", 3/4" and 1".  In recent years, manufacturers have started using greener materials, such as non-toxic binders, and non-wood fibers (straw and bamboo).  Variations, lightweight (L-MDF) and ultralightweight (U-MDF), use less quantities of resin, resulting in lower weights, but also less strength.

== Synonyms and Related Terms ==

Medium-density fiberboard; MDF

Brand names: Medex®; Medite®; Medite II® 

== Applications ==

*Exhibit - case construction, mountmaking

== Personal Risks ==

Health risks associated with elevated concentration of volatile organic compounds (VOCs): respiratory irritation, irritability, inability to concentrate, and sleepiness. Health risks associated with exposure to formaldehyde gas: eye and respiratory irritation, respiratory difficulty .  

Dust and chemicals released when worked.

== Collection Risks ==

Any wood product may release VOCs (volatile organic compounds) such as aldehydes, terpenes, and acids (Baumann et al. 2000). The types and quantities of VOCs released depends on wood species, as well as the presence of coatings. Generally, the most VOCs are released when the product is new. Barrier layers (i.e. coatings) can be applied to limit the release of VOCs.

'''Links to Oddy Test results posted on AIC Wiki Materials Database Pages for individual materials below'''

° [http://www.conservation-wiki.com/wiki/Oddy_Test_Results:_Case_Construction_Materials Newmarket MDF] Tested in 2006 with and without  polyurethane coating
== Environmental Risks ==

== Physical and Chemical Properties ==
{| class="wikitable"
|Property|| Standard MDF||Lightweight MDF||Ultralightweight MDF
|-
| Weight<Br>3/4" x 4' x 8' sheet||90 lbs||76 lbs||64 lbs
|-
| Face screw-holding<Br>strength||337 lbs||247 lbs||180 lbs
|-
|}

== Working Properties ==

Dust and chemicals released when worked. MDF has lower tear out (smoother edge when sawed) than particle board. MDF boards are uniform, dense smooth and free from knots or grain patterns.  They are also consistent in strength and size.  When machined with high quality tools (carbide, ceramic or diamond), they rarely chip-out or fuzz.  They may be glued, doweled, painted or laminated and are dimensionally stable.  Low-grade MDF may swell and break when saturated with water.  Unsealed MDF may warp or expand in humid environments.

== Forms and Sizes == 

The standard size for fiberboards is 4 x 8 feet.

== Resources and Citations ==
* Exhibit Guidelines Technical Notes: [https://www.conservation-wiki.com/wiki/Using_Composite_Panels_for_Exhibit_Case_Construction Using Composite Panels in Exhibit Case Construction]
* Melissa G.D. Baumann, Linda F. Lorenz, Stuart A. Batterman, and Guo-Zheng Zhang, “Aldehyde Emissions from Particleboard and Medium Density Fiberboard Products,” ''Forest Products Journal'' 50 (9): 75–82, 2000. 
* Charles Goodwin, contributed information
* Illinois Department of Public Health, “Formaldehyde,” Environmental Health Fact Sheet, http://www.idph.state.il.us/envhealth/factsheets/formaldehyde.htm (Accessed 25 Sep. 2020).
* Kevin Ann Reinhart, “What Is the Difference Between Particle Board and Medium Density Fiberboard?” SFGate, https://homeguides.sfgate.com/difference-between-particle-board-medium-density-fiberboard-99189.html, (accessed 25 Sep. 2020), 2018.
* Megan Salas, contributed information, MWG group, 2020.
* Wikipedia: https://en.wikipedia.org/wiki/Medium-density_fibreboard
* Wood Magazine: https://www.woodmagazine.com/materials-guide/lumber/medium-density-fiberboard

[[Category:Materials database]][[Category:MWG]][[Category: Particleboard/Pressedwood]][[Category: Board/Panel, Composite]]