Lignin-Laccase-Mediator-Systems (LLMS) for the Production of Binderless Medium Density Fiberboards (MDF)

Abstract

<p class="1Body">Medium density fiberboards (MDF) are produced mainly by urea-formaldehyde resins (UF) as binding agent, which are synthesized from finite fossil resources. Those boards may emit critical amounts of formaldehyde, which can influence the health of humans and animals. In recent times the wood panel board industry is looking for alternative glues which contain less or no formaldehyde. In order to avoid potential formaldehyde emissions altogether it would be preferable not to use binders which are formaldehyde based at all. One possibility is to use natural binders or to activate the wood fibers’ own binding forces by applying Laccase-Mediator-Systems (LMS). As a support of the LMS interactions with wood fibers technical lignin can be added. In this study it was found out that the addition of technical lignin intensified the fiber to fiber bindings. Two Lignin-Laccase-Mediator-Systems (LLMS) were analysed by Gel-Permeation-Chromatography and Cyclic voltammetry. Later the LLMSs were tested in the pilot scale production of MDF. The determination of the physical technological properties revealed that the LLMS treated MDF have higher dimension stabilities than only LMS treated MDF and approximately the same thickness swelling after 24 h. The results indicate that the application of LLMSs have a high potential for natural bonded MDF.</p>

Green Binder Based on Enzymatically Polymerized Eucalypt Kraft Lignin for Fiberboard Manufacturing: A Preliminary Study

“…Also, the thickness and density of the MDF were very different in both studies, and this may have an important impact on the final MDF properties [40]. In a more recent work [36], Euring et al were able to achieve MDF with good mechanical properties with an IB and modulus of rupture (MOR) of 0.42 and 20 Mpa respectively, yet, a TS of 50% was still an issue. To improve the dimensional stability of the fiberboards, the authors tested a laccase-mediator-system.…”

Effect of spent sulfite liquor on urea–formaldehyde resin performance

“…Every year, the global paper industry produces about 50 million tons of technical lignin, present in the spent liquors, as a byproduct [15 million tons of lignosulfonates (LS) and 35 million tons of kraft lignin] . Portugal is the third biggest pulp producer in Europe and disposes of a high content of technical lignin as a byproduct .…”

“…Portugal is the third biggest pulp producer in Europe and disposes of a high content of technical lignin as a byproduct . Despite the high amounts of produced technical lignin, the majority is burnt for energy production and regeneration of the pulping chemicals and only 2% is used in industrial processes …”

Effects of Density, Cellulose Nanofibrils Addition Ratio, Pressing Method, and Particle Size on the Bending Properties of Wet-formed Particleboard

“…Materials with a high content of lignin, starch, and sugar were deemed favorable to produce binderless boards (Boon et al 2013). Only a few researchers have investigated the production of binderless boards (Baskaran et al 2012;Hashim et al 2012;Boon et al 2013;Euring et al 2016;Tajvidi et al 2016), however, only through the dry-form process. Little research has been conducted using the wetforming process (Arévalo and Peijs 2016).…”