Wood-free paper

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A sheet of wood-free paper Paper 450x450.jpg
A sheet of wood-free paper

Wood-free paper, tree-free paper, or fine paper is paper created from bleached, chemically-separated paper pulp, as to minimize lignin contents (the "wood" in question). [1] It is not as susceptible to yellowing as paper containing mechanical pulp. [2] [3] [4]

Contents

Overview

Lignin

Lignin is a natural complex polymer containing aromatic compounds that provide much of a plant's strength. In its natural form, it gives rigidity and resilience to the plant's structure, but its presence causes paper to weaken and turn yellow as it ages and eventually disintegrate. The reason for this is that as the paper ages, lignin releases acid which degrades the paper. [5] Lignocellulose from the xylem of shrubs and cambium from the inner bark of trees are made up of lignin, hemicellulose and cellulose, relevant to papermaking. [6]

Pulp

Paper pulp consists of cellulosic materials that have been broken down chemically and physically and filtered and mixed in water to reform into a web: creating pulp by breaking down the materials chemically is called chemical pulping, while creating pulp by breaking them down mechanically is called mechanical pulping. [6] [7]

In the chemical pulping of lignocellulose - plants with lignin content - chemicals separate the wood fibers. The chemicals lower the lignin content because chemical action solubilizes and degrades components of wood fibers, especially hemicelluloses and lignin. Chemical pulping yields single unbroken fibers that produce strong quality papers because the lignin that interferes with hydrogen bonding of wood fibers has been removed. Chemical pulps are used to create wood free paper that is of high quality and lasts long, such as is used in arts and archiving. [6] Chemical pulping processes take place at high pressures and temperatures under aqueous alkaline, neutral or acidic conditions, with the goal of totally removing the lignin and preserving the carbohydrates. Normally, about 90% of the lignin is removed. [7]

Mechanical pulping, in contrast, converts raw lignocellulose into pulp without separating the lignin from the cellulose. [7] No chemicals other than water or steam are used. The yield is about 90% to 98%. High yields result from the fact that lignin is retained. Mechanical pulps are characterized by low cost, high stiffness, high bulk, and high yield.  Mechanical pulp has low strength because the lignin interferes with hydrogen bonding between wood fibers. The lignin also makes the pulp turn yellow when exposed to light and air. Mechanical pulps are used in the production of non-permanent papers such as newsprint and magazine paper. Mechanical pulps made up 20% to 25% of the world production and this is increasing because of the high yield of the process and increasing competition for fiber resources. Advances in technology have also made mechanical pulp increasingly desirable.[ clarification needed ] [6]

Categories

Woodfree uncoated paper

Woodfree uncoated paper (WFU), uncoated woodfree paper (UWF) or uncoated fine papers is the paper industry technical term for base wood-free paper. [8] Both softwood and hardwood chemical pulps are used and a minor part of mechanical pulp might be added (often of aspen or poplar). These paper grades are calendered.[ citation needed ] The properties are good strength, high brightness and good archival characteristics. [9] They provide a non-glare surface suitable for reading and writing as there is no coating involved.[ how? ]

Offset paper

Offset paper is a type of woodfree uncoated paper with ISO brightness > 80% and a basis weight of 40–300 g/m2. Surface strength and low linting are the main parameters, but brightness and opacity are also important.

Lightweight offset paper, also called onionskin , has a basis weight of 25–40 g/m2 and are normally used for bibles (hence the colloquial name Bible paper) and dictionaries.

Composition

Wood-free paper is made from a variety of raw materials, including

Wood-free paper has a number of advantages over paper that contains mechanical pulp:

Wood-free paper is used in a variety of applications:

See also

References

  1. ↑ He, Zhibin; Hui, Lanfeng; Liu, Zhong; Ni, Yonghao; Zhou, Yajun (2010-04-01). "Impact of High-Yield Pulp Substitution on the Brightness Stability of Uncoated Wood-Free Paper". TAPPI Journal. 9 (3): 15–20. doi: 10.32964/tj9.3.15 . ISSN   0734-1415.
  2. ↑ Bajpai, Pratima (2015), "The Control of Microbiological Problems∗∗Some excerpts taken from Bajpai P (2012). Biotechnology for Pulp and Paper Processing with kind permission from Springer Science1Business Media.", Pulp and Paper Industry, Elsevier: 103–195, doi: 10.1016/b978-0-12-803409-5.00008-2 , ISBN   9780128034095, PMC   7158184 , S2CID   89782614
  3. ↑ "Print lingo explained: Woodfree paper". Warners Midlands Plc. 2016-05-10. Archived from the original on 2022-12-10. Retrieved 2022-12-10.
  4. ↑ Papers, Peters (2020-03-12). "Know your paper terms: Wood-free paper". Peters Papers. Retrieved 2022-12-10.
  5. ↑ "The Coniferous - Leading Paper Trading Company". theconiferous.com. Retrieved 2023-10-19.
  6. 1 2 3 4 Biermann, C. J. (1996). Handbook of pulping and papermaking. Elsevier.
  7. 1 2 3 J.C. Roberts, The Chemistry of Paper, 1st edn., Cambridge, 1996
  8. ↑ The paper made without using mechanical pulp
  9. ↑ Paulapuro, Hannu (2000). "1". Paper and Board grades. Papermaking Science and Technology. Vol. 18. Finland: Fapet Oy. pp. 35–37. ISBN   952-5216-18-7.
  10. 1 2 3 4 Manninen, Marjo; Kajanto, Isko; Happonen, Juha; Paltakari, Jouni (2011-08-01). "The effect of microfibrillated cellulose addition on drying shrinkage and dimensional stability of wood-free paper" . Nordic Pulp & Paper Research Journal. 26 (3): 297–305. doi:10.3183/npprj-2011-26-03-p297-305. ISSN   2000-0669. S2CID   137540823.
  11. ↑ Kemppainen, K.; Siika-aho, M.; Pattathil, S.; Giovando, S.; Kruus, K. (January 2014). "Spruce bark as an industrial source of condensed tannins and non-cellulosic sugars" . Industrial Crops and Products. 52: 158–168. doi:10.1016/j.indcrop.2013.10.009. ISSN   0926-6690.
  12. ↑ Kumar, Varun; Pathak, Puneet; Bhardwaj, Nishi Kant (February 2020). "Waste paper: An underutilized but promising source for nanocellulose mining" . Waste Management. 102: 281–303. Bibcode:2020WaMan.102..281K. doi:10.1016/j.wasman.2019.10.041. ISSN   0956-053X. PMID   31704510. S2CID   207965485.
  13. ↑ Bajpai, P. (1999-04-05). "Application of Enzymes in the Pulp and Paper Industry" . Biotechnology Progress. 15 (2): 147–157. doi:10.1021/bp990013k. ISSN   8756-7938. PMID   10194388. S2CID   26080240.
  14. ↑ Wong, C.H.; Nicholas, J.; Holt, G.D. (2003-04-01). "Using multivariate techniques for developing contractor classification models" . Engineering, Construction and Architectural Management. 10 (2): 99–116. doi:10.1108/09699980310466587. ISSN   0969-9988.
  15. ↑ American Institute of Timber Construction (2012-07-16). Timber Construction Manual. Wiley. doi:10.1002/9781118279687. ISBN   978-0-470-54509-6.
  16. 1 2 3 Windrich, E. (1998-01-01). "Book Reviews : Adebayo Adedeji (ed.), South Africa and Africa: Within or Apart'? (London: Zed Books and Cape town: SADRI Books, 1996), xiii, 258 pp. Cloth $55.00, paper $19.95" . Journal of Asian and African Studies. 33 (3): 278–279. doi:10.1177/002190969803300306. ISSN   0021-9096. S2CID   220925623.
  17. 1 2 3 Bajpai, Pratima (2015), "The Control of Microbiological Problems∗∗Some excerpts taken from Bajpai P (2012). Biotechnology for Pulp and Paper Processing with kind permission from Springer Science1Business Media.", Pulp and Paper Industry, Elsevier: 103–195, doi: 10.1016/b978-0-12-803409-5.00008-2 , ISBN   978-0-12-803409-5, PMC   7158184 , S2CID   89782614
  18. 1 2 "BASF sells Intertech & Pira to the Smithers group" . Focus on Pigments. 2010 (12): 6–7. December 2010. doi:10.1016/s0969-6210(10)70272-1. ISSN   0969-6210.
  19. ↑ Hakkila, Pentti (1989), "Utilization of Residual Forest Biomass", Springer Series in Wood Science, Berlin, Heidelberg: Springer Berlin Heidelberg, pp. 352–477, doi:10.1007/978-3-642-74072-5_8, ISBN   978-3-642-74074-9 , retrieved 2023-10-12{{citation}}: Missing or empty |title= (help)
  20. ↑ Coppola, Floriana; Fiorillo, Flavia; Modelli, Alberto; Montanari, Matteo; Vandini, Mariangela (April 2018). "Effects of γ-ray treatment on paper" . Polymer Degradation and Stability. 150: 25–30. doi:10.1016/j.polymdegradstab.2018.02.004. ISSN   0141-3910.
  21. ↑ Wu, Zonghua; Tanaka, Hiroo (April 1998). "Permanence of wood-free paper I: Paper-making additives in naturally degraded wood-free papers". Journal of Wood Science. 44 (2): 111–115. Bibcode:1998JWSci..44..111W. doi: 10.1007/bf00526255 . ISSN   1435-0211. S2CID   95493027.
  22. ↑ BUKOVSKÝ, VLADIMÍR (1997). "Yellowing of Newspaper after Deacidification with Methyl Magnesium Carbonate" . Restaurator. 18 (1). doi:10.1515/rest.1997.18.1.25. ISSN   0034-5806. S2CID   96841775.
  23. 1 2 Tillmann, Otmar (2006-01-20). "Paper and Board Grades and Their Properties". Handbook of Paper and Board. pp. 446–466. doi:10.1002/3527608257.ch11. ISBN   9783527309979.
  24. ↑ Velebil, J.; Malaťák, J.; Bradna, J. (2016-12-31). "Mass yield of biochar from hydrothermal carbonization of sucrose". Research in Agricultural Engineering. 62 (4): 179–184. doi: 10.17221/73/2015-rae . ISSN   1212-9151.
  25. ↑ Hsieh, Yung-Cheng (1997). An investigation of the factors affecting dot gain on sheet-fed offset lithography presses (Thesis). Iowa State University. doi: 10.31274/rtd-180813-10494 .
  26. ↑ Hoekstra, Arjen Y. (2015), "The water footprint of industry" , Assessing and Measuring Environmental Impact and Sustainability, Elsevier, pp. 221–254, doi:10.1016/b978-0-12-799968-5.00007-5, ISBN   9780127999685 , retrieved 2023-10-12
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