Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Effect of Mannanase and Lipase on the properties of colloidal wood extractives and their interaction with mechanical pulp fines
2002 (English)In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 9, no 2, 127-137 p.Article in journal (Refereed) Published
Abstract [en]

The effects of enzymatic treatments of dissolved and colloidal substances (DCS) released from thermomechanical pulp (TMP) have been investigated. A model dispersion of DCS was made by leaching several portions of TMP in distilled water and separating the fibrous material. Some samples were enriched in colloidal particles by removing dissolved substances using ultra-filtration. The DCS, which had been subjected to different enzymatic treatments, were added in a fixed quantity to TMP fines that had been made cationic, and were subsequently used to form handsheets. All DCS additions increased the content of lipophilic extractives in the sheets. Lipase gave a complete hydrolysation of triglycerides into free fatty acids. The untreated DCS gave no significant decrease in tensile strength, because of the relatively small addition. A treatment of the DCS with Lipase gave a higher extractives content and a tensile strength on the same level as the reference. A Mannanase treatment gave a decrease in strength compared with the reference at the same amount of extractives in the sheet. A combined treatment with Mannanase and Lipase gave a more pronounced decrease in tensile strength. Two possible reasons for the differences in strength at a given amount of extractives were suggested: (i) the destabilisation of the colloidal wood extractives due to the Mannanase could affect the distribution of the colloid in the sheet, making it more detrimental to sheet strength compared with the stable colloid. This would account for the observation that Lipase did not affect sheet strength as such, but the combination with Mannanase gave the lowest tensile strength; (ii) the decomposition of galactoglucomannans in aqueous solution would diminish their positive effect on tensile strength and/or affect the adsorption of the colloid. A reflectometry technique was used to quantify the adsorption of the differently treated DCS onto a model surface of the cationic fines. Colloidal wood extractives were identified on the surfaces after adsorption using staining and light microscopy. No variations in adsorbed amounts were found that could explain the differences in sheet strength, which indirectly suggests that the distribution of the colloid over the surface was affecting the ability of a strong bonded joint to be formed between two such surfaces.

Place, publisher, year, edition, pages
2002. Vol. 9, no 2, 127-137 p.
Keyword [en]
adsorption, dissolved and colloidal substances, enzymes, mechanical pulps, reflectometry, retention, tensile strength, wood resin, adsorption, reflectometry, quality
Identifiers
URN: urn:nbn:se:kth:diva-21886ISI: 000177946900004OAI: oai:DiVA.org:kth-21886DiVA: diva2:340584
Note
QC 20100525Available from: 2010-08-10 Created: 2010-08-10 Last updated: 2017-12-12Bibliographically approved

Open Access in DiVA

No full text

Authority records BETA

Wågberg, Lars

Search in DiVA

By author/editor
Wågberg, Lars
In the same journal
Cellulose (London)

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 33 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf