Editing Paperboard (section)

===Raw materials===
The above-mentioned fibrous material can either come from fresh (virgin) sources (e.g. wood) or from [[Paper recycling|recycled waste paper]]. Around 90% of virgin paper is made from [[timber|wood]] pulp.<ref name="ind">{{Citation 
|last=Datamonitor
|title=Global Paper and Paperboard - Industry Profile
|date=June 2008
|ref=0199-2406
}}</ref>
Today paperboard packaging in general, and especially products from [[ecolabel|certified]] [[sustainability|sustainable]] sources, are receiving new attention, as manufacturers dealing with environmental, health, and regulatory issues look to [[renewable resources]] to meet increasing demand. It is now mandatory in many countries for paper-based packaging to be manufactured wholly or partially from [[recycling|recycled]] material.
 
Raw materials include:

* '''[[Hardwood]]:''' C. {{convert|0.05|in|mm}} in length e.g. [[Birch]] which has short fibres. It is generally more difficult to work with; however, it does provide higher tensile strength, but lower tear and other strength properties. Although its fibres are not as long and strong as those in softwood, they make for a stiffer product defined by some stiffness tests. Hardwood fibres fill the sheet better and therefore make a smoother paper that is more opaque and better for printing. Hardwood makes an excellent corrugating medium.
*'''[[Softwood]]:''' C. {{convert|0.13|in|mm}} in length e.g. [[Pine]] and [[spruce]] which have typically long fibres and make superior paperboard in services where strength is important. Softwood makes excellent linerboard.
* '''[[Deinked pulp|Recycled]]:''' Used paper is collected and sorted and usually mixed with virgin fibres in order to make new material. This is necessary as the recycled fibre often loses strength when reused; the added virgin fibres enhance strength. Mixed waste paper is not usually [[Deinking|deinked]] (skipping the deinking stage) for paperboard manufacture and hence the [[pulping|pulp]] may contain traces of inks, adhesives, and other residues which together give it a grey colour. Products made of recycled board usually have a less predictable composition and poorer functional properties than virgin fibre-based boards.<ref name="igg">{{Cite journal
|last=Iggesund Paperboard AB
|title=Paperboard the Iggesund Way
|year=2008
|page=10
}}</ref> Health risks have been associated with using recycled material in direct food contact. Swiss studies have shown that recycled material can contain significant portions of mineral oil, which may migrate into packed foods.<ref>{{cite web
  |author=Federal Institute for Risk Assessment (Germany)
  |title=Migration of mineral oil from packaging materials to foodstuffs (BfR Opinion No. 008/2010 of 2009-12-09)
  |access-date=2010-04-21
  |url=http://www.bfr.bund.de/cm/230/migration_of_mineral_oil_from_packaging_materials_to_foodstuffs.pdf}}</ref> Mineral oil levels of up to 19.4&nbsp;mg/kg were found in rice packed in recycled board.<ref>{{cite web
  |author=Bundesinstitut für Risikobewertung
  |title=Übergänge von Mineralöl aus Verpackungsmaterialien auf Lebensmittel
  |access-date=2010-04-21
  |url=http://www.bfr.bund.de/cm/216/uebergaenge_von_mineraloel_aus_verpackungsmaterialien_auf_lebensmittel.pdf}}</ref>

* '''[[Tree-free paper|Others]]''': It is also possible to use the fibres of [[Bagasse|Sugarcane Bagasse]], [[Straw]], [[Hemp]], [[Cotton]], [[Flax]], [[Kenaf]], [[Abaca]] and other plant products