9 research outputs found

    Istraživanje utjecaja uporabe aktivnog mulja tretiranog octenom kiselinom na fizička svojstva i čvrstoću reciklirane celuloze

    Get PDF
    This study aimed to scrutinize chemical treatment of Mazandaran Wood and Paper mill activated sludge with 3 % acetic acid for the manufacture of environmentally eco-friendly bio composite. In this study, the paper pulp required was obtained from the waste newsprint paper. The activated sludge was treated in a beaker for 3 min in 3 % acetic acid and then in a water bath at 75 and 100 °C for 45 and 90 min. After that, the treated activated sludge was mixed and refi ned with waste newsprint paper pulp at ratios of 0, 5, 10, 15 and 20 %. The test specimens were prepared according to TAPPI standard and the physical properties (water absorption and porosity) and mechanical (tensile strength, tear strength, ring crush test, burst strength and folding strength) were measured. The results showed that the activated sludge treatment caused the increase in tear strength, ring crush test, burst strength and porosity as well as the decrease in water absorption, tensile strength and folding strength. FT-IR spectrum of the treated samples showed that the treatment with acetic acid strengthened and activated the functional groups on the surface of activated sludge fi bers. The activated sludge added at a level of 5 % at 100 °C for 90 min as well as at a level of 20 % at 75 °C for 45 min was more suitable than other treatments.Cilj ovog rada bio je proučiti kemijsku obradu aktivnog mulja proizvedenog u tvornici drva i papira Mazandaran izvedenu 3 %-tnom octenom kiselinom za proizvodnju ekološki prihvatljivog biokompozita. Celulozna kaša potrebna za istraživanje dobivena je od otpadnoga novinskog papira. Aktivni mulj obrađen je 3 %-tnom octenom kiselinom u čaši, i to u trajanju 3 minute, a zatim u vodenoj kupelji temperature 75 i 100 °C u trajanju od 45 i 90 min. Nakon toga taj je aktivni mulj pomiješan i rafiniran s celuloznom kašom od otpadnoga novinskog papira u omjerima od 0, 5, 10, 15 i 20 %. Ispitni su uzorci pripremljeni prema TAPPI normi, nakon čega su izmjerena njihova fizička svojstva (upijanje vode i poroznost) te mehanička svojstva (vlačna čvrstoća, čvrstoća na kidanje, tlačna čvrstoća prstena, čvrstoća na pucanje i preklopna čvrstoća). Rezultati su pokazali da je kemijska obrada aktivnog mulja pridonijela povećanju čvrstoće uzoraka na kidanje, otpornosti na tlačnu silu, čvrstoći na pucanje i poroznost te smanjenju upijanja vode, kao i vlačne i preklopne čvrstoće. FT-IR spektri tretiranih uzoraka pokazali su da obrada octenom kiselinom ojačava i aktivira funkcionalne skupine na površini vlakana aktivnog mulja. Aktivni mulj dodan u omjeru od 5 % pri 100 °C i u trajanju 90 minuta te u omjeru od 20 % pri 75 °C i tijekom 45 minuta bio je prikladniji od ostalih uzoraka

    Effect of initial planting density and tree features on growth, wood density, and anatomical properties from a Hevea brasiliensis trial plantation

    Get PDF
    The effect of initial planting density (500, 1,000, 1,500, and 2,000 trees per ha) on tree growth, wood density, and wood anatomical properties was studied in a 9-year-old Heave brasiliensis plantation in Malaysia. Results showed that effects of initial planting density on tree radial growth, wood density, fiber length, fiber wall thickness, and ray density were more visible in trees planted at 500 trees per ha compared with the other planting densities. Bole length was significantly increased with higher planting densities. However, vessel density showed an infinite pattern with increasing planting density. For vessel and ray areas, no significant effect of initial planting density was detected. A negative relationship was observed between wood density, fiber length, and fiber wall thickness with planting density, bole length, and height-to-diameter ratio. The ray density was significantly and positively correlated with stand/tree features with the exception of a negative correlation with radial growth increment. The regression models with various degrees of goodness of fit indicated that wood density followed by fiber wall thickness was successfully quantified due to selected stand/tree features. According to the results of this study, it is recommended that a low planting density of 500 trees per ha is ideal for rubberwood plantation development

    Variation in mechanical properties of two rubberwood clones in relation to planting density

    Get PDF
    Variation in mechanical properties of two rubberwood clones in relation to planting density. Hevea brasiliensis as a fast-growing species with rotation age of about 25 years is usually managed under intensive silviculture techniques. Normally, it has a high amount of lower quality juvenile wood that needs to be characterised for proper usage. Samples from four planting densities (500, 1000, 1500 and 2000 trees ha-1) of two new rubberwood clones [RRIM 2020 (A) and RRIM 2025 (B)] were subjected to selected mechanical tests. Significant differences in modulus of rupture (MOR) and modulus of elasticity (MOE) between planting densities were found except for MOE from clone B. The significant difference in clone B for compression parallel to grain was between the lowest planting density and the rest. In clone A, the significant difference for hardness was between densities of 1000 and 2000 trees ha-1 and in clone B between 500 and 1000 trees ha-1. Planting density was responsible for significant differences in shear parallel to grain between the lowest and highest planting densities in clone A and between 500 and 1500 trees ha-1 in clone B. Wood density moderately correlated with mechanical properties, so the regression equations were established directly with the planting densities. Properties including compression and hardness from clone A and MOE and compression from clone B were not successfully quantified in relation to planting density using a regression approach. Consequently, the mechanical properties in young trees were not highly affected by planting density. There were more visible differences between low and extreme planting densities than with moderate densities. Low planting density emerged as the optimum density

    Physical behavior of hydro-thermally treated oil palm wood in different buffered pH media

    Get PDF
    This study investigated changes in the physical properties of oil palm (Elaeis guineensis) wood (OPW) using various buffered media for the hydrothermal treatment process. The buffered media were prepared separately for three different treatment conditions: pH of 8, pH of 5, and tap water. These treatments were compared with unbuffered, control samples. The OPW samples were taken from the outer part of the trees. The OPW samples were treated with the buffered media at a temperature of 140 °C for 120 min. The parameters evaluated were wood density (ρ), equilibrium moisture content (EMC), mass loss (ML), water absorption (WA), volumetric swelling (SV), anti-swelling efficiency (ASE), and water repellent efficiency (WRE), for both treated and untreated samples. The buffered media significantly affected the EMC (%), ρ (g/cm3), ML (%), and WA (%), with no significant effects on the ASE (%) and WRE (%). It was concluded that the hydrothermal treatment in the buffered medium with a pH of 8 had the most significant effect on the physical properties of OPW

    Effects of altitude on density and biometric properties of hornbeam wood (Carpinus betulus)

    Get PDF
    Aim of the study: This study aimed to investigate the effect of altitude difference on the wood dry density, fiber dimensions, and morphological properties of hornbeam wood (Carpinus betulus L.).Area of study: The study area was located in the province of Mazandaran, north of Iran.Material and method: 18 mature trees were randomly selected and harvested at six altitude levels (300, 500, 700, 900, 1100, and 1300 m) in the north of Iran. The clear test samples‎ were prepared‎ at diameter at breast height (DBH) to measure the wood dry density, fiber length, fiber diameter, cell wall thickness, Runkel coefficients, flexibility coefficients, and slenderness coefficients. Further ‎analyses included the relationships between the wood properties and site conditions (temperature, ‎precipitation, crown canopy, ‎and understory herb layer) as well as tree’s main dimensions ‎(tree height and the DBH).Main results: The results indicated significant effects of altitude variations on the studied ‎properties. The pattern variations of wood properties were very regular at different levels of height. The average fiber length and fiber diameter decreased while the wood dry density and cell wall thickness increased with increasing the altitude levels. The average values of wood dry density, fiber length, fiber diameter, cell wall thickness, slenderness coefficients, flexibility coefficients, and Runkel coefficients of hornbeam wood were 698 kg/m3, 1.42mm, 25.58 µm, 5.72µm, 55.55, 54.04%, and 0.93, respectively, in the above six altitudes. Pearson matrix correlation showed that there were significant relationships between temperature, crown canopy, tree height and DBH ‎with the studied wood properties (except the slenderness coefficients)‎.Research highlights: The hornbeams grown at altitudes above 900-1300 m were not suitable for pulp and ‎paper production‎ due to relatively higher Runkel coefficients, the lower flexibility coefficients, as well as smaller fiber length than other altitude levels.Additional Keywords: Carpinus betulus; altitude variation; density; fiber dimensions; morphological properties.Abbreviations used: WDD (wood dry density); FL (fiber length); FD (fiber diameter), CWT (cell wall thickness); FC (flexibility coefficient); RC (Runkel coefficients); SC (slenderness coefficient)

    Optimization and empirical modelling of physical ‎properties of hydrothermally treated ‎oil ‎palm wood in ‎different ‎buffered media using ‎response ‎surface ‎methodology

    No full text
    Physical properties are one of the ‎drawbacks of oil palm wood ‎‎(OPW) and they need to ‎be ‎improved via an appropriate method. The ‎response surface methodology (RSM) based on central composite ‎design (CCD) was used to evaluate and optimize the parameters of a hydrothermal treatment ‎and to create an ‎empirical model of the mass loss (ML, %), equilibrium moisture ‎content ‎‎(EMC, %), and anti-swelling efficiency (ASE24h, %)‎‏ ‏responses‎. This ‎study focused on the ‎effect of ‎hydrothermal treatment (HTT) ‎in ‎buffer solutions to control the ‎destructive effects of ‎released ‎acids ‎caused by the degradation of ‎hemicellulose acetyl groups‏.‏‎ A CCD, as ‎the most common RSM design, was applied with three treatment factors including the ‎buffer solutions ‎‎(acidic, neutral, ‎and alkaline with pH of 5 to 8), temperature (80 to 140 ‎‎°С), ‎time (40 to ‎‎‎120 ‎min), and a total of 20 ‎experiments‎.‎‏ ‏‎The results ‎showed that the ‎effect of the treatment temperature ‎was more notable ‎than time. The medium acidity (pH) variations in HTT can lead ‎to ‎the removal of ‎extractives and starch, hemicelluloses ‎hydrolysis‎, ‎the ‎destruction of the parenchymal cells wall, and ‎weight loss. Based on the variance analysis, the ‎quadratic and linear models proved to be highly significant with ‎minimal probability values (< 0.0001). The optimum conditions ‎predicted for the HTT were a pH of 7.3, a temperature of ‎112.7 ‎°С, and ‎a‏ ‏time of ‎109.6 ‎min

    MECHANICAL BEHAVIOR OF HYDROTHERMALLY TREATED OIL PALM WOOD IN DIFFERENT BUFFERED PH MEDIA

    Get PDF
    This study was carried out to determine mechanical properties of oil palm (Elaeis Guineensis) wood (OPW) in different buffered pH media; alkaline (pH 8), acidic (pH 5) and water at a temperature of 140 ºC for 120 min. The OPW samples were taken from outer part of trees. The modulus of rupture (MOR), modulus of elasticity (MOE), the compression strength parallel to grain (PCII) and hardness strength (HB) were measured on treated and untreated samples. The different buffer media significantly affect the mechanical properties of OPW. The results of MOE, MOR, PCII and HB of treated specimens showed a significant decrease compared to untreated specimens. The PCII and HB properties were significantly different between treated samples in water and pH 5 with the treated samples in pH 8 and also untreated samples. It was concluded that the hydrothermal treatment in the buffered medium decreased significantly the mechanical properties of treated specimens of OPW that could be related to the degradation of hemicelluloses. This highly affects bending and tensile strengths of the OPW

    Evaluation of bending strength of hydrothermally treated oil palm wood in various buffered media using response surface methodology

    No full text
    This study was focused on the effect of hydrothermal treatment in buffer solutions to improve mechanical properties of oil palm wood (OPW). To control the destructive effects of the released acids caused by the degradation of acetyl groups of the hemicelluloses, the hydrothermal treatment in buffered media was conducted using surface methodology (RSM). Central composite design (CCD) is a useful empirical design in RSM. The CCD and RSM were also applied to optimise the hydrothermal treatment variables (buffer solutions, temperature and time) as effective actual variables with 20 experiments. The results showed that the samples treated in neutral media and low temperatures displayed higher modulus of rupture (MOR) (MPa) and modulus of elasticity (MOE) (MPa) due to control of the medium acidity with low degradation of hemicelluloses. Furthermore, the treatment in buffered media significantly affected on mechanical properties of hydrothermally treated OPW. The effect of the temperature on bending strength were more notable than buffer solutions and time. The actual response according to predicted treatment conditions (pH = 7.12, temperature = 110 °C and time = 120 min) explained closest agreement with the predicted value with residual standard error (RSE) of less than 5%

    Physical Behavior of Hydro-thermally Treated Oil Palm Wood in Different Buffered pH Media

    No full text
    This study investigated changes in the physical properties of oil palm (Elaeis guineensis) wood (OPW) using various buffered media for the hydrothermal treatment process. The buffered media were prepared separately for three different treatment conditions: pH of 8, pH of 5, and tap water. These treatments were compared with unbuffered, control samples. The OPW samples were taken from the outer part of the trees. The OPW samples were treated with the buffered media at a temperature of 140 °C for 120 min. The parameters evaluated were wood density (ρ), equilibrium moisture content (EMC), mass loss (ML), water absorption (WA), volumetric swelling (SV), anti-swelling efficiency (ASE), and water repellent efficiency (WRE), for both treated and untreated samples. The buffered media significantly affected the EMC (%), ρ (g/cm3), ML (%), and WA (%), with no significant effects on the ASE (%) and WRE (%). It was concluded that the hydrothermal treatment in the buffered medium with a pH of 8 had the most significant effect on the physical properties of OPW
    corecore