The effects of heartwood and sapwood on kraft pulp properties of Pinus nigra J.F.Arnold. and Abies bornmuelleriana Mattf. were investigated. The differences in terms of chemical composition and fiber ...properties between the heartwood and sapwood of these species were also examined. Heartwood had more holocellulose and extractive compared to sapwood. Moreover, heartwood fiber length was shorter than that of sapwood. Kraft cookings of heartwood and sapwood each species were separately done under fixed cooking conditions. The results indicated that heartwood pulp had lower pulp viscosity and total pulp yield than sapwood did. The tear index of sapwood unbeaten and beaten kraft pulp was higher than that of heartwood. However, the burst and tensile indices of heartwood unbeaten and beaten kraft pulp were higher than those of sapwood.
Some trace elements were analyzed in Pleurotus Sajor-caju mushroom cultivated on chemithermomechanical pulp. In this experiment, phytohormones, such as 2.4-D and PS A6, were studied at concentrations ...of 10, 20 and 30 mg/100 ml, mixed into the pulp. Determination of mineral elements was done by flame atomic absorption spectrophotometry (Perkin Elmer model 1100 B). Sixteen mineral elements were determined in all samples. Cu, Mg, Pb, Na, Ag, Bi, Mn, Ni, Li, Co, Sb, Ca, Zn, Fe, Cr and Al contents of mushrooms, grown on treated pulp, were near control values. K was not present.
This study was carried out to determine the effects of adhesive ratio and pressure time on thickness swelling (TS), internal bond (IB), modulus of rupture (MOR), and modulus of elasticity (MOE) ...properties of oriented strand board (OSB). For this purpose, 80 mm long strands made of Scots pine (Pinus sylvestris L.) were bonded with phenol-formaldehyde resin at three different ratios (3, 4.5, and 6%) to produce three-layer cross-aligned OSBs. Strands used for the production of OSB panels were made up 40% of core layer and 60% of outer layers. The panels were pressed for three different press times, from 3, 5, to 7 minutes, under 0.4 MPa pressure, aiming for a target density of 0.70 g/cm3. TS, IB, MOR, and MOE properties of OSB panels were evaluated according to the standards (TSE EN 117-319-310). Results showed that MOR and MOE values were changed in the ranges 25.31 to 42.27 N/mm2, and 2848.90 to 6545.63 N/mm2, respectively. Also, the results showed that as adhesive ratio and pressure time increased, the TS, MOR, and MOE values increased too.
The coating of wood and wood panel surfaces basically serves for surface protection and its surface can be improved at various user areas. Different application methods are used for the coating of ...MDF surface. These are methods such as curtain coating, spraying, rolling, knife, etc. In this study, suitability of pigment coating method instead of the traditional surface coating methods used for coating MDF panels and the effects of fire retardants on surface properties of MDF coated by the best appropriate coating mixture was investigated. Calcite and clay were used as coating pigment and latex, urea formaldehyde, and melamine formaldehyde were used as adhesive. Coating/adhesive mixture obtained was applied to MDF panels with knives. Before the analysis, test samples were put to condition room and they were kept in there for 1 week. According to the results obtained, the best appropriate coating material was found as calcite. 22% concentrated melamine formaldehyde as adhesive and 0.25 mm as coating thickness was determined better than other combinations. Borax, boric acid and zinc borate as fire retardant were added to calcite/melamine formaldehyde with 22% mixture. So, the effects of fire retardant on surface characterization were determined. Surface properties of coated MDF panels tested were found lower than standard requirements except for abrasion resistance.
In this study, the effects of sodium borohydride (NaBH4) on properties of kraft pulp and paper obtained from European black pine (Pinus nigra Arn.) were investigated. Kraft−NaBH4 cookings were done ...under fixed cooking conditions by adding NaBH4 in the amounts of 0.5%, 1%, 1.5%, and 2% (oven-dried wood) to the cooking liquor. NaBH4-free kraft cooking was carried out as control. The results indicated that addition of NaBH4 to cooking liquor increased the pulp yield. However, the kappa number of pulp and beating time decreased. The brightness of kraft−NaBH4 papers was found to be higher than that of control papers. Addition of NaBH4 significantly decreased pulp viscosity and slightly decreased strength properties of papers.
European black pine (
Pinus nigra Arn.) chips were treated with the white-rot fungus
Ceriporiopsis subvermispora for periods ranging from 20 to 100 days. The effects of pretreatment on the chemical ...composition of wood and kraft pulping were investigated. The results showed that fungal pretreatment reduced the lignin and extractive content of wood chips. Also, weight losses occurred. Kappa number, viscosity, and reject ratio of biokraft pulps decreased. Biokraft pulps gave better response to beating, which led to significant energy saving during refining. The tear index, burst index, and tensile index of biokraft pulps were found to be lower than those of kraft pulps. However, the tensile index and burst index of 20-day biotreated and unbeaten pulp was higher than those of kraft pulp. Also, the tear index of 20-day biotreated and beaten pulp was higher than that of kraft pulp. The brightness of biokraft pulps decreased irregularly with increasing incubation time.
The coating of wood and wood panel surfaces basically serves for surface protection and its surface can be improved at various user areas. Different application methods are used for the coating of ...MDF surface. Th ese are methods such as curtain coating, spraying, rolling, knife, etc. In this study, suitability of pigment coating method instead of the traditional surface coating methods used for coating MDF panels and the effects of fi re retardants on surface properties of MDF coated by the best appropriate coating mixture was investigated. Calcite and clay were used as coating pigment and latex, urea formaldehyde, and melamine formaldehyde were used as adhesive. Coating/adhesive mixture obtained was applied to MDF panels with knives. Before the analysis, test samples were put to condition room and they were kept in there for 1 week. According to the results obtained, the best appropriate coating material was found as calcite. 22% concentrated melamine formaldehyde as adhesive and 0.25 mm as coating thickness was determined better than other combinations. Borax, boric acid and zinc borate as fi re retardant were added to calcite /melamine formaldehyde with 22% mixture. So, the effects of fi re retardant on surface characterization were determined. Surface properties of coated MDF panels tested were found lower than standard requirements except for abrasion resistance.
The effects of
Phanerochaete chrysosporium, a white rot fungus, on the chemical composition of
Abies bornmülleriana and
Fagus orientalis wood chips were investigated. After the chips were inoculated ...with the fungus, 20-, 40- and 60-day samples were analysed in order to determine the influence of fungal treatment on the chemical components of the cell walls, and the fibre properties of both species were measured. As a result of
P. chrysosporium growth, both types of wood had slight relative increases in percentage cellulose. Percentage holocellulose showed statistically significant decreases and solubility values increased considerably. The lignin ratio for
F. orientalis decreased significantly in relation to zero-time control samples.
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