Procjena mehaničkih i morfoloških svojstava kompozita proizvedenih od polilaktičke kiseline i drvnih vlakana s dodatkom nanografena

The present study analyzed the effect of nanographene (NG) application at three rates (0.75, 1.5, and 3 %) on the production of PLA85/F15 and PLA70/F30 composites. The incorporation of NG into the PLA/wood fi ber composites significantly improved the tensile and bending properties. The results indicated that composites made from PLA68.5/F30/NG1.5 had the highest tensile and bending properties. Furthermore, it was revealed that the addition of fi bers to PLA decreased the composite impact strength in comparison with pure PLA, whereas the addition of NG improved its impact strength, but not as much as pure PLA. The highest impact strength was observed in the composites containing 15 % fi bers and 1.5 % NG (PLA83.5/F15/NG1.5 composites). The composites made from 30 % wood fiber and 1.5 % (PLA68.5/F30/NG1.5 composites) NG had the best interfacial surface between the wood fiber and the matrix of composites.U radu je analiziran učinak nanografena (NG), dodanoga u različitim količinama (0,75, 1,5 i 3 %), na svojstva kompozita proizvedenih od polilaktične kiseline (PLA) i drvnih vlakana (F) (kompoziti PLA85/F15 i PLA70/F30). Ugradnjom NG-a u kompozite PLA/F znatno su poboljšana vlačna i savojna svojstva kompozita. Rezultati su pokazali da su kompoziti s dodatkom 1,5 % NG-a (PLA68.5/F30/NG1.5) imali najbolja vlačna i savojna svojstva. Nadalje, iz rezultata se može zaključiti da se dodavanjem drvnih vlakana u PLA smanjuje otpornost kompozita na udarce u usporedbi s čistim PLA, a dodavanjem NG-a poboljšava se otpornost kompozita na udarce. Međutim, ta je otpornost i dalje manja od otpornosti kompozita od čistog PLA. Najveća otpornost na udarce zabilježena je za kompozite koji sadržavaju 15 % drvnih vlakana i 1,5 % NG-a (kompoziti PLA83.5/F15/NG1.5). Kompoziti proizvedeni od 30 % drvnih vlakana i 1,5 % NG-a (kompoziti PLA68.5/F30/NG1.5) imali su najbolju površinu između drvnih vlakana i matrice kompozita

A study on physical properties of composites produced using recycled polymer filled with paper mill sludge composites

In this study, physical properties of composite produced using recycled polymer (polypropylene and polyethylene) filled with two types of paper mill sludge (sludge on the DAF and waste water sludge) were investigated. Three levels of paper sludge (15, 30 and 45 wt %) were used to produce composites. Haake machine was used to blend materials and to produce standard samples; injection molding system was utilized. Density, water absorption and thicknesses swelling of composites were measured. The increasing of both paper mill sludge (sludge on the DAF and wastewater sludge) to the recycled polyethylene and polypropylene increased the density of composites. But, comparing the data obtained from density measurement with literature showed that utilization of paper mill sludge produced relatively lower density and cost on the unit volume basis. Adding both paper mill sludge (sludge on the DAF and waste water sludge) increased water absorption and thicknesses swelling. The samples containing polypropylene and waste water sludge showed lower water absorption and thicknesses swelling compared with other composite

Investigation on newsprint paper production from wheat straw and its specification

In this study, production of bleached chemical- mechanical pulp from wheat straw for newsprint papermaking was investigated. Wheat straw for pulping was obtained from Lorestan province. Wheat straw CMP pulp was prepared at 120, 140, and 160 °C temperature, 45 minute time, 10, 12, and 14% chemicals charge and 10:1 cooking liquor and straw ratio. The yield after defibration treatment varied between 56.5% and 72.5%. Two optimum pulps bleached by TCF method applying 2% and 3% NaOH, 1.5% and 2% H2O2, and 60 and 120 minutes bleaching time. One way analysis variance method showed that bleaching time had the most significant effect on optical properties of handsheet. Applying 3% (based on oven dry weight of the unbleached pulp) NaOH, 2% H2O2, and 120 min. in bleaching improved the brightness and opacity to 52.9%, and 79.5% ISO, respectively. Optimum pulp strengths including tensile, burst and tear indices were measured 43.87 Nm/g, 2.18 kPa.m2/g, and 8.46 mN.m2/g, respectively. All the strengths were higher than newsprint paper strength produced by Mazandaran wood and paper and Korean companies

Effect of xylanase treatment on properties of alkaline peroxide mechanical pulp from poplar (Populus nigra) wood

The aim of present study was to investigate the effects of xylanase enzyme obtained from Trichoderma viride on APMP pulp from Populus nigra wood. Treatment temperature, time, enzyme dosage and pulp consistency were varied. The results demonstrated that treating by xylanase has considerable effects on pulp. Paper brightness improved in average 2.5% ISO and the highest gain was 4.5%. Also, using enzyme resulted in enhancement of tear and burst indices. Breaking length of paper from enzyme treated pulp was increased to 4098 meters. Further treatment by xylanase reduced the pulp yield by 2.78% as compared to sample without enzyme treatment. The impact of other treatment such as washing by distilled water and alkaline extraction revealed that these treatments did not have significantly effect on the results of enzyme treatment. The optimum temperature, time, enzyme dosage and pulp consistency were 40-50° C, 70 minutes, 10 U/g of oven dried pulp and 10% respectively

Evaluation of thermal energy and activated carbon production from bagasse pith

The purpose of this study is the evaluation of bagasse pith for heating energy and activated carbon production. To assess the energy production of the pith, bulk density, melting point, and heating value were measured. Furthermore, percentage of moisture, ash, volatile compounds, fixed carbon, lignin, and elements contents were determined. Ash and volatile content average were measured at 30.23% and 67.14%, respectively. The bulk density average of the pith powder with 80 meshes was determined at 0.15 g/cm3. Lignin content and melting point of pith is measured 23.1%, and 1050 °C, respectively. Sulfur content is important in terms of environmental pollution and it was determined 0.3%. Gross heating value was measured directly by calorimeter bomb to 10.30 MJ/kg that is lower than bagasse and wood. The activated carbon produced from pyrolysis of bagasse pith was chemically activated with zinc chloride. The chemically activated carbons were characterized by measuring iodine of 504 mg/g, specific surface (BET) of 478 m2/g, and pore diameter of 7.45 nanometer. It is suitable for liquid absorption according to the pore size

Effect of ink and paper characteristics on print quality in board-packaging industries based on print density index.

Paper and ink characteristics effect on print density were investigated.  For this purpose three types of papers and four types of printing inks at 2 viscosities levels (25-30, 50-55) were used. Then characteristics of paper & ink were measured. Inks on sampled papers Printed and then printing density was measured. Statistical analysis was conducted based on a complete randomized design in factorial experimental model and means were analyzed and grouped by Duncan multiple range test (DMRT) using SPSS software. Result indicated that Solid content, pH and particles diameter of inks have significant effect on print density. While roughness and water absorption of papers do not have on significantly influences print density. There was not any significant different between two viscosity level and print densit

The Study of Fiber Fines and Its Effects On Optical and Physical Propertie of Newsprint Paper from CMP Pulp

The present study deals with effects of CMP  fines on optical and physical properties of newsprint papers, for which, different batches for CMP fines (0%, 10%. 20%. 30%) of totally 80% pulp  is taken, Where the remaining 20% of imported long fiber pulp was taken as fixed amount . The study focused on surving the effects of CMP fines on optical and physical properties of newsprint paper ,after mixing the pulps and making the handsheets . Generally, the results show the increase in CMP fine amount lead to increase ,Air Resistance and Opacity and decrease Caliper and Roughness, Also that changes in CMP fines has no effect on Brightness

The Effects of Some Production Variables on Physical and Mechanical Properties of Particleboard Made of Alnus subcordata by UF and MUF resin

An experiment was conducted to study polymerization conditions and important production factors, the amount of resin and press temperature, on physical and mechanical properties of produced boards by urea formaldehyde (UF) and melamine urea formaldehyde (MUF) were compared. Purify UF resin (control treatment) and its mixture with MUF at 25, 50 and 75% proportions in 170 and 180˚C temperature were used to make homogen particle boards. The proportion of resin to particles was 10 percent by dry weight. Other production factors were assumed as fix factors. Eight experimental groups (treatment) with three replications per each were studied. Produced particles were derived from species Alnus subcordata. Physical and mechanical properties measurement prepared samples were based on European EN standard. Examined Physical characteristics were water absorption and thickness swelling and mechanical characteristics were modulus of rupture, modulus of elasticity and so internal bond. The data were analyzed in completely randomized design with factorial arrangement (4*2). Statistical significances among treatment means were determined by multiple range test of Duncan. The results of this study showed that physical and mechanical properties of boards were improved by increasing the level of MUF resin and temperature. Eventually, with consideration all results and so quality and economical aspects of produced particleboard by MUF resin and its comparison with control group we have concluded that 50 percent of MUF resin and 180 degree centigrade of press temperature are optimal levels

Investigation of the antomical, biometry and chemical characteristics of juvenile and mature poplar (Populus alba) wood

Samples were prepared from the native poplar species (Populus alba) grown in Mehnan, a region in Bojnourd at the ages 5 and 25 and the anatomical, biometrical and chemical characteristics of the samples sections in three directions (cross section, radial and tangential) of the tree were measured.  Dioxan and Klason lignin were measured. Structural similarities in vascular cavities or impacted vessels in the form of binary, tripple or tetraploidy groups in juvenile and mature wood was observed primarily in radial direction. Fiber length and cell wall thickness variation in the juvenile and mature wood was significantly different and as the age of the tree increases, such difference is more significant.  This point need to be considered by cellulose industries. As the age of the tree increase and the wood matures, significant change in vessel size in samples from 5 or 25 years old trees was not detected. The result showed that the older wood contains lower content of extractive and lignin and higher content of cellulos

Effects of fungal treatments on chemi-mechanical pulp and paper properties from hornbeam wood

The strength properties of paper produced from pulp obtained after 1, 2 and 4 weeks treatment of hornbeam chips with the Phanerochaete chrysosporium BKM - 1767 fungus was evaluated and compared with control samples. After preparing fungal specimens, hornbeam chips were exposed to this fungus for one of the three periods of 1, 2 and 4 weeks at 39oC temperature and 65% relative humidity. Then CMP pulp was prepared using treated chips, chemical treatment temperature of 165oC, for either 80 or 90 minutes and sodium sulfite charge of 14, 18 and 22% (based on oven dry weight of the wood).  The liquor to chips was constant at 7 to 1. The results showed that the CMP pulping yield from treated chips was lower than control sample and the reduction after treatments for 1, 2 and 4 weeks was  almost 1.64, 2.84, 6.20 percent respectively. Also the strength indices of paper such as tensile strength, burst strength, tear strength and folding endurance paper prepared from treated chips were lower than control chip