Volume 9 Issue 3

The aim of the paper was to examine the application of regenerated cellulose fibers as a reinforcement material in particleboard production. Single-layer, 10 mm thick panels, with the density of 800 kg/m3 were produced with addition of regenerated cellulose fibers in the range of 0 do 15% by mass during panels’ production. The mechanical and physical parameters of the produced panels were tested, as well as work of fracture. The results showed that addition of regenerated cellulose fibers to the structure of wood-based composite did not improve their modulus of rupture, modulus of elasticity, or internal bond. The physical parameters of the produced panels (water absorptivity, swelling in thickness when soaking) also were reduced. The work of fracture of the tested panels increased with increasing content of regenerated cellulose fibers. A strong linear regression between work of fracture and regenerated cellulose fibers content was observed.

Several properties of wood including the cutting power requirements can be correlated to wood density. Therefore, according to the literature, the cutting power requirements (and/or cutting forces) could be computed as a function of the wood specific gravity. This research shows that such an approach, based solely on specific gravity, may be considered a rather rough and imperfect estimate of cutting power. Samples of Scots pine (Pinus sylvestris L.) wood from different provinces in Poland with varying densities were machined on a sash gang saw. The average cutting force versus average wood density (estimated with the standard gravimetric method) was calculated, and the local cutting forces correlated to the local wood density. The average values of the cutting forces measured at selected points along the sample’s length were calculated by linear regression to the X-ray absorbance (density) estimated by means of X-ray radiography.

This study was conducted to evaluate the effects of bio-oil incorporation on properties of bio-oil-phenol formaldehyde (BPF) resol resins along with the optimization of petro-phenol substitution level. Crude bio-oil prepared from endocarp shells of Ziziphus mauritiana by direct solvolytic liquefaction (ethanol-water 1:1 wt./wt. at 300 °C) was used to partially substitute the petro-phenol (30% to 75% wt./wt.) in the resin synthesis. The modified resins were subjected to measurement of various properties, including molecular weight, pH, viscosity, density, gel/cure time, non-volatile solid content, and limiting oxygen index. Bonding performance of the BPF resins was evaluated by measuring the mechanical and hygroscopic properties of the particle boards developed using such resins. With the incorporation of bio-oil, the viscosity and molecular weight of the BPF resins increased, while the values of pH, density, non-volatile solid content, and limiting oxygen index decreased. The gel, cure, and bonding tests revealed that with the addition of more than 45% bio-oil, the gel/cure times of the BPF resins increased, while the bonding performance decreased. Petro-phenol could therefore be substituted by crude bio-oil up to 45% wt./wt. safely.

Financial, environmental, and supply chain analyses of empty fruit bunch (EFB) biomass are needed for the development of a sustainable green chemicals industry in Malaysia. Herein, holistic analysis of the supply system and EFB life cycle cradle-to-gate are analyzed in an effort to make recommendations for the commercial-scale collection and delivery of EFB from crude palm oil (CPO) extraction facilities to biorefineries in Malaysia. Supply chain modeling tracked inputs and outputs for financial analysis. The openLCA software was used for life cycle assessment (LCA). Allocation scenarios were used to explore the impact of accounting methodologies on the competitiveness of EFB compared to other feedstocks. Sensitivity analysis on the effect of transportation distance, emission flows, and allocation methods on resulting environmental impacts were conducted. The No Burden, Economic, and Mass allocation scenarios resulted in 17, -2.3, and -265 kg CO2-eq. BD tonne-1 EFB global warming impacts (GW), respectively. Delivered cost for EFB was calculated to be approximately 45 US$ BD tonne-1. Environmental burdens were sensitive to allocation scenario, covered area, and land use change. Delivered cost was sensitive to transport distance, covered area, and yield. It was shown that there is sufficient Malaysia EFB available for between 9 and 28 biorefineries, depending upon the scale of production.

The torrefaction of red oak (Quercus rubra) was performed in a pilot rotary kiln reactor, and the apparent kinetic results were compared with the results of torrefaction performed in a bench-scale fluidized reactor. Mass loss, gross calorific analyses, ultimate analyses, and proximate analyses were applied to the final torrefied material. The experimental torrefaction temperatures were 250, 275, 300, and 325 °C, and the experimental total torrefaction times were 20, 35, 50, and 80 min. A significant variation of the energy content occurred in the range of temperature between 275 and 300 °C, with the energy yield changing from 97.5% to 83.6%, respectively. The molar ratios H:C:O for the torrefied red oak presented a behavior independent of the experimental equipment when the temperature ranged between 250 and 325 °C. For the torrefaction process of red oak in the pilot rotary kiln reactor, a first-order reaction and one-step kinetic model were fitted with a maximum error of about 7.5% at 325 °C. The observed reaction rate constant (k) for the rotary reactor was 0.072 min^-1 at 300 °C, which was 71% lower than the reaction rate constant for torrefied red oak in a bench-scale fluidized reactor. Arrhenius analysis determined an activation energy of 20.4 kJ/mol and a frequency factor of 5.22 min^-1. The results suggest significant external heat and mass-transfer resistances in the rotary system.

Soybean flour (SF)-based adhesives were prepared with either γ-amino, γ-glycidyl, or γ-methacryloyloxy-propyltrimethoxysilane (KH550, KH560, and KH570) silane coupling agents (SCAs) as an enhancer to explore the effect of SCA on the enhancement and mechanisms of the adhesive. Then, the shear adhesion, viscosity, solid content, and morphological properties of the modified SF adhesives were characterized in detail. The cross sections of the cured adhesives were evaluated with a scanning electron microscope (SEM). The results showed that KH560 was the most efficient SCA for improving the water-resistant bonding strength of the modified SF adhesive. With the addition of 3 wt% KH560, the water-resistant bonding strength of the sample was maximized at 0.98 MPa, meeting the requirements for interior plywood. The SEM revealed few holes and cracks, as well as a smooth surface, on the cross section of the cured KH560-modified SF adhesive, indicating that KH560 is a crosslinking agent that could enhance the water-resistant bonding strength of the resulting plywood. In the hot press process, the effects of hot press time and temperature on the water-resistant bonding strength of the adhesives were not significant.

A green wood composite material was developed from the two environmentally friendly substrates natural rubber (cis-1,4-polyisoprene) and rubber wood (Hevea brasiliensis). Natural rubber (NR) was introduced into rubber wood by pressurization of NR latex, followed by the removal of the aqueous phase to allow only dry NR to remain inside the wood structure. Scanning electron microscopy images and the weight increase of the dry impregnated samples revealed the retention of dry NR within the rubber wood. The natural rubber enhanced the water resistance and compressive strength of the treated rubber wood.

The study of viscoelastic and mechano-sorptive creep on bamboo laminated veneer lumber (BLVL) and bamboo/poplar plywood (BPP) is described in this paper. Bending creep tests parallel to the grain were carried out on two bamboo-based composites for a length of 90 days. The specimens measured 500 mm × 20 mm × 12 mm. Based on the experimental data, the creep curves of two boards were evaluated. The results are summarized as follows: (1) the anti-creep property of BLVL was better than that of BPP; (2) ; and (3) compared with the creep curve in a constant environment, the creep deformation changed more dramatically under varying environment.

Eucalyptus plantation area has been increasing in Brazil, with 29% of the total plantation area being located in Minas Gerais state, which currently is being utilized primarily for charcoal production. However, diseases often increase the production costs of Eucalyptus. The objective of this study was to evaluate the effect of the fungus Ceratocystis fimbriata Ellis & Halsted on Eucalyptus wood for charcoal production. The basic density, volume, extractives, lignin, and holocellulose content of the wood were determined, as well as the gravimetric yield, volatile matter, fixed carbon, ash, and gross calorific values of charcoal. The introduction of the fungus C. fimbriata to Eucalyptus decreased the wood production and holocellulose content, but it also increased the wood’s lignin and extractives content. The chemical changes in the wood did not affect the charcoal produced. Volume of wood losses due to C. fimbriata can result in a loss of up to 3478.43 US$/ha.

This research was conducted to study changes in mechanical properties due to mixing of old corrugated container (OCC) pulp with virgin neutral sulfite semi-chemical (NSSC) pulp. The OCC pulp was collected after removal of printing, glued parts, and unwanted additives. To prevent cutting of fibers, dedicated containers were broken down by hand before pulping. Handsheets with a base weight of 127 g/m2 were made by mixing the NSSC and OCC pulps at proportions of 60, 70, and 80 wt% of NSSC. Mechanical properties, including tensile strength, burst strength, tearing strength, corrugated medium test, and ring crush test, were evaluated using TAPPI standards. Addition of up to 30% OCC improved the tensile strength, tear strength, and burst strength of the handsheets significantly in comparison with the control sample (21, 25, and 59%, respectively). However, the corrugated medium test and ring crush test decreased by about 13 and 9%, respectively. The results of this study revealed that mixing 30 wt% OCC with NSSC yielded a higher quality paper.