Binderless Lignocellulose Composite from Bagasse and Mechanism of Self-Bonding

Abstract

The self-bonding of air-dry bagasse and bagasse pith exhibited during hot-pressing in a closely fitting mold is studied under varying conditions. It is shown that the ability of the particles to pack up closely is most important to self-bonding. The pith fraction which causes great trouble in paper and fiberboaid making gives a highly densified, plastic-like product superior to t hose from whole or depithed bagasse. This is attributed to the high lumen to cell wall ratio which favours the formation of interparticle bonds. Bending strength up to 130 N/mm 1 and water absorption äs low äs 10% are obtained at 25.5 MPa molding pressure and 175 °C. Increasing the initial moisture content of pith from 7 to 14 percent results in deterioration of both strength and water resistance while the contrary applies to depithed bagasse. Eventually, the mechanism of self-bonding is discussed. Bindemittelfreier lignocellulosischer Preßstoffaus Bagasse und Mechanismus der EigenverklebungZusammenfassung Das Eigenbindevermögen von lufttrockener Bagasse und Bagassemark, das während der Hitze-Druckbehandlung in einer dicht schließenden Preßform sich entwickelt, wird unter variierten Bedingungen untersucht. Es zeigt sich, daß die Fähigkeit der Partikel, in engen Kontakt miteinander zu kommen, äußerst wichtig für die Eigenverklebung ist. Die Markfraktion, die große Schwierigkeiten bei der Papierund Faserplattenherstellung macht, ergibt ein hochverdichtetes, kunststoffähnliches Produkt, das denen aus nicht entmarkter und entmarkter Bagasse überlegen ist. Man kann dies auf das hohe Lumen: Zellwand-Verhältnis zurückfuhren, das die Bildung von Bindungen zwischen den Partikeln begünstigt. Biegefestigkeiten bis zu 130 N/mm 2 und eine Wasseraufnahme von nicht mehr als 10% werden bei 25,5 MPa Preßdruck und 175 °C erhalten. Erhöht man die Ausgangsfeuchte der Markfraktion von 7% auf 14%, so verschlechtern sich sowohl Festigkeit als auch Wasseraufnahme und Dickenquellung. Das genaue Gegenteil trifft für entmaikte Bagasse zu. Abschließend wird der Mechanismus der Eigenverklebung diskutiert.About thirty years ago, Runkel and Jost (1948) developed a process for making highly densified molded products

Potential Use of Phoenix canariensis Biomass in Binderless Particleboards at Low Temperature and Pressure

“…As Mobarak et al (1982) found in bagasse, this feature could increase the capacity of the particles to compress, resulting in a stronger bond and probably contributing to less TS in the leaf sheath and higher in the rachis particleboards. The energy dispersive X-ray spectroscopy analysis results are shown in Table 5.…”

New thermal insulation boards made from coconut husk and bagasse

“…These raw materials are expensive particularly for developing countries like Thailand where the supply of chemical products are limited. It is therefore considered that in the context of Thailand with a surplus of agricultural waste materials, the production of binderless board is the preferred option [17]. While efforts have been made to develop binderless boards by using a high-temperature hot pressing process, it appears that the process can only produce binderless board with high densities [14][15][16][17][18] whereas thermal insulation requires a low density.…”

“…This is because these raw materials are available within Thailand, and reducing the transportation component of embodied energy gives the potential for an improved environmental profile compared with those that are imported from overseas. In addition the production of insulation materials tends to require use of chemical binders such as formaldehyde or phenolic resins which are toxic to humans; coconut husk and bagasse can be used to manufacture thermal insulation without a binder, a benefit in terms of environmental and health impacts [14][15][16][17][18].…”

Understanding the Mechanism of Self-Bonding of Bamboo Binderless Boards: Investigating the Structural Changes of Lignin Macromolecule during the Molding Pressing Process

“…There has been systematic research on binderless fiberboards since the 1980s. Mobarak et al (1982) prepared binderless lignocellulose composite from bagasse and discussed the potential mechanism of selfbonding (Mobarak et al 1982). Shen (1986) produced binderless fiberboards with a feasible process (Shen 1986).…”