Volume 10 Issue 4

Collagen extracted from leather waste was modified with maleic anhydride. Then, using ammonium persulfate as an initiator, by pre-modifying collagen reacted with styrene and ethyl acrylate monomers, a vinyl-grafted collagen sizing agent (VGCSA) for paper was prepared. Before the experiment, the performance of VGCSA was tested and VGCSA emulsion was applied to the surface sizing of the corrugated paper. Effects of the amount of VGCSA, the compound proportion of VGCSA, and starch and styrene-acrylic emulsion were studied relative to paper properties. The morphological changes of the paper before and after sizing were characterized by SEM. It was found that the collagen reacted with styrene and ethyl acrylate monomers. Through the grafting of vinyl and collagen, the crystallinity and thermal stability of VGCSA increased. The structure of VGCSA was spherical with a uniform size, and the average particle size was approximately 350 to 400 nm. After being sized, the surface fibers of paper became smooth and orderly. The optimal sizing of VGCSA was 8 g/m2. The optimal proportion of VGCSA with starch was 4:6, and the optimal proportion of VGCSA with SAE was 2:8. The research indicates that collagen extracted from leather waste could be used as a biomaterial, and environmental and economic benefits could be created as well.

Whole cells of Aspergillus oryzae 35 were used as a biocatalyst for the degradation of glycerol trioleate, which largely contributes to pitch deposits in papermaking. Different types of inducers in culture media showed various effects on both the biomass and lipase activity of whole-cell biocatalysts. The cells of A. oryzae 35 cultured with Tween 80 showed higher catalytic activity than the others. The effects of several key factors on A. oryzae 35-catalyzed treatment of a glycerol trioleate-containing whitewater model were investigated, and the optimal pH value, reaction temperature, substrate concentration, and shaking speed were determined to be 7.5, 45 °C, 50%, and 200 rpm, respectively. Results from a practical treatment of whitewater resin sediments with A. oryzae showed that the mean particle size of the original whitewater was sharply reduced from 534 nm to 356 nm after biocatalytic degradation. Aspergillus oryzae whole-cells are newly promising biocatalysts for whitewater treatment in papermaking industries because of their cost-effectiveness, simple preparation, and environmental friendliness.

Fines are an important factor in the papermaking industry with respect to their influence on the mechanical properties of paper. A procedure offering the possibility to produce handsheets with a constant amount of fines, as well as the determination of the fines content, is of great importance in evaluating the influences of different types of fines. In this work, a method based on a white water circulation system and fiber morphology characterization using a flow cell was evaluated. Three different wires for handsheet forming were studied (120-mesh, 325-mesh, and 500-mesh), and the 325-mesh wire was chosen for further trials. Using the 325-mesh wire, a constant amount of fines was achieved after discarding seven handsheets. This method allows reliable evaluation of the effects of primary as well as secondary fines and a cellulosic additive on handsheet properties.

Compression properties in three orthotropic directions for some important Turkish wood species, including Calabrian pine (Pinus brutia Ten.), Taurus cedar (Cedrus libani), Oriental beech (Fagus orientalis), and sessile oak (Quercus petraea), were studied using non-destructive and destructive techniques. The materials used in the study consisted of 720 small clear specimens of nominal dimensions of 20 x 20 x 60 mm. The influence of equilibrium moisture content (EMC) was studied over four batches of 15 specimens each, conditioned for six to eight weeks before testing at a temperature of 20 ± 2 °C and at four different relative humidity conditions (50%, 65%, 85%, and 95%). Time of flight values were measured with a commercial ultrasonic tester. Using the time results from the ultrasound device, the wave velocities (length/time) and Edyn values were calculated. Samples were also tested in uniaxial compression to determine the Young’s modulus and compression strength values in three orthotropic directions. The Edyn correlated well with the Young’s modulus and compression strength of the specimens; coefficients of determination ranged between 0.75 and 0.96. Moisture content seems to have more influence than density on sound velocities. Results showed that there is a weak and mostly negative correlation between the density of the specimens and the sound velocity values.

Wood has better load-bearing capacity following the formation of a char layer when exposed to fire. The charring rate is the most important property of wood with respect to its fire resistance and fire integrity. The objectives of this study were to determine the effects of factors, including density, gas permeability, ring width, grain orientation, and heat flux, on the charring rate. The charring rates of six Chinese woods were tested with a cone calorimeter with densities of 0.35 to 0.69 g/cm3 and moisture contents of approximately 12%. The results indicated that density, gas permeability, and heat flux, but not the grain orientation, significantly affected the charring rate. There was a positive, linear correlation between the heat flux and the charring rate. The density was nearly linearly related to the charring rate for either softwood or hardwood; the correlation was not found for all woods. The positive, linear correlation between the gas permeability and the charring rate was only found along the grain.

A better understanding of saw-chain cutting mechanics is needed for more efficient chainsaw designs. The effects of varying key parameters such as workpiece moisture content, workpiece density, cutting velocity, and depth-of-cut, while established for other types of cutting, are largely unexplored and/or unpublished for saw chains. This study contributes to filling this gap through experimentation and analysis. Experiments were conducted using a custom-built saw-chain testing apparatus to measure relevant forces over a range of workpiece moisture contents, workpiece densities, cutting velocities, and depths-of-cut. Analysis consisted of fitting linear regression models to experimental data, identifying trends, and exploring optimum cutting conditions. Results showed that over the range of values included in the study, workpiece moisture content and density had effects that depended on the depth-of-cut. Cutting velocity had a small effect, and depth-of-cut had a large effect. All trends fit well with linear models; however, depth-of-cut required one linear fit for small-to-mid values and a second fit for mid-to-large values. Maximum efficiency was found to occur at a depth-of-cut equal to the transitional value between fits. These results provide basic relationships that can lead to the more effective and efficient use and design of chainsaws.

The synergistic effect of two fire retardants, a Si-Al compound and chlorinated paraffin, was tested on ultra-low density fiberboards (ULDFs). To further understand the mechanism of fire retardancy, morphologies of unburned and burned ULDFs were studied using a scanning electron microscope with energy dispersive spectroscopy. It was found that as the volume of the burned ULDFs shrank, some crevices appeared. In addition, less fly ash formed on the top of specimens, and more bottom ashes remained in the original framework, with a clear network of structure built by the fibers. Carbon was almost absent in the fly ash; however, the weight ratio of C in the bottom ashes reached the maximum (> 43%) of the composition. Oxygen, Al, and Si appeared to have varying weight ratios for different ashes. Oxygen content increased with increasing Si and Al contents. Furthermore, Cl sharply decreased to less than 1% after combustion. Therefore, upon combustion, it was found that almost all of the substances in ULDFs, except for the Si-Al compound, were pyrolyzed to volatile carbon oxides and Cl compounds, especially the fly ash and lightweight C compounds.

This study was conducted to evaluate the possibility of utilizing kenaf (KNF) in LLDPE/PVOH to develop a new thermoplastic composite. The effect of KNF loading on the processability and mechanical, thermal and water absorption properties of linear low-density polyethylene/poly (vinyl alcohol)/kenaf (LLDPE/PVOH/KNF) composites were investigated. Composites with different KNF loadings (0, 10, 20, 30, and 40 phr) were prepared using a Thermo Haake Polydrive internal mixer at a temperature of 150 °C and rotor speed of 50 rpm for 10 min. The results indicate that the stabilization torque, tensile modulus, water uptake, and thermal stability increased, while tensile strength and elongation at break decreased with increasing filler loading. The tensile fractured surfaces observed by scanning electron microscopy (SEM) supported the deterioration in tensile properties of the LLDPE/PVOH/KNF composites with increasing KNF loading.

The ultrafiltration membrane reactor, utilizing a membrane module with a suitable molecular weight alleyway, retains the larger cellulase components. Smaller molecules, such as the fermentable reducing sugars and water, pass through the membrane. The purpose of this work was to investigate the capability of recycling cellulase in the UF membrane. PS30 hollow fiber membrane, an ultrafiltration method using internal pressure, was found to be an ideal membrane separation device, allowing re-use of the enzyme. A Box-Behnken experimental design (BBD) established the following optimum pretreatment parameters: operation pressure at 1.73 bar, temperature at 36.38 °C, and a pH of 5.92. Under these conditions, the model predicted a membrane flux yield of 2.3174 L/(m2•h). The rejection rate of the UF membrane was over 95%.

Value added manufacturing activity in the wood sawmilling industry of Peninsular Malaysia is important for employment opportunities, particularly for low income citizens living in this rural area, to provide returns to the local economy while being environmentally sustainable. This paper is a review on the value added wood sawmill industry in Peninsular Malaysia, using the value of major import and exports of major timbers products and forested area in Peninsular Malaysia over the period 2003 to 2012. The productivity performance measures that are based on the concept of value added are emphasized in this paper. The value added in wood sawmill industry was found to increase from year 2003 to 2012. Consequently, Malaysia is moving on the right path to achieve the goal of National Timber Policy 2020, transforming the timber industry into high value addition industry. However, further analysis using the value added productivity measure found that the value addition rely on international timber price rather than skilled workers.