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Author(s):  
Emiru Yidnekew Melesse ◽  
Tesfaye Kassaw Bedru ◽  
Beteley Tekola Meshesha

The need for pulp and paper currently in the whole world has become shooting up massively. The generation of the pulp, as well as paper from woody materials, has a challenge due to deforestation, huge chemical and energy consumptions. Now, an alternative source for paper is lignocelluloses wastes, because of low cost, low energy, and chemical consumption. Among them, the banana pseudostem was best for the input of pulp and paper production. This investigation was on the production and characterization of pulp from Banana Pseudo Stem for Paper Making via Soda Anthraquinone pulping process. The amount of cellulose (41.45%), ash (12.4%), hemicellulose (23.37%), extractive (12.72%), and lignin (10.46%) contents were obtained at the initial compositional evaluation of the pseudostem. It has excellent fiber length (1.75mm), fiber diameter (22.15μm), an acceptable Runkle ratio (0.55), and flexibility coefficient (159.64). The effect of temperature (130,140 and 150 °C), cooking time (45, 60, and 75 minutes), the concentration of soda (10, 12.5, and 15%), were examined. The maximum pulp yield and kappa number was 36.7% and 22.8 respectively obtained at 10% of soda concentration, at 150 °C, and 63 minutes of cooking time from oven-dried raw material. The produced paper from the banana pseudostem has a tensile index, tearing index, smoothness, and porosity were 78.75 Nm/g, 19.1 mN.m2/g, 500-530μm, and 50 sec/100ml air respectively. This study indicates that high strength mechanical property and good surface properties paper can be produced from banana pseudostem pulp with a more environmentally friendly pulping process.


2021 ◽  
Vol 12 (1) ◽  
pp. 261
Author(s):  
Jacek Kucharski ◽  
Andrzej Fraczyk ◽  
Piotr Urbanek

Drying various materials constitutes an essential component of several industrial processes, e.g., paper production. Typically, rotating cylinders heated internally by water steam are used for drying tape-shaped material in paper-making machines. Such an approach remains very energy-consuming, while the whole process is expensive and in conflict with the global policy of reducing energy consumption in heavy industry. One promising alternative method of drying fibrous tapes is the induction heating of drying cylinders. In this paper, we propose a drying system based on a set of inductors (electromagnetic field sources) that generate energy in the mantle of the cylinder and dry the running tape. By enabling the movement of the inductors, the system provides a high level of flexibility in terms of reacting to the varying humidity of the tape. Additionally, imaging the temperature field on the cylinder surface provides a supplementary source of information, enabling the temperature profile to be controlled. Two types of humidity control systems, a one-loop feedback control and a cascade control, were designed and analyzed. Simulation analysis and experimental verification performed using a semi-industrial setup proves that using the proposed cascade control ensures more than 30% faster response of the whole dryness control system.


Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 32
Author(s):  
Yao Yao ◽  
Zhenbing Sun ◽  
Xiaobao Li ◽  
Zhengjie Tang ◽  
Xiaoping Li ◽  
...  

Sodium carboxymethyl cellulose (CMC) can be derived from a variety of cellulosic materials and is widely used in petroleum mining, construction, paper making, and packaging. CMCs can be derived from many sources with the final properties reflecting the characteristics of the original lignocellulosic matrix as well as the subsequent separation steps that affect the degree of carboxy methyl substitution on the cellulose hydroxyls. While a large percentage of CMCs is derived from wood pulp, many other plant sources may produce more attractive properties for specific applications. The effects of five plant sources on the resulting properties of CMC and CMC/sodium alginate/glycerol composite films were studied. The degree of substitution and resulting tensile strength in leaf-derived CMC was from 0.87 to 0.89 and from 15.81 to 16.35 MPa, respectively, while the degree of substitution and resulting tensile strength in wooden materials-derived CMC were from 1.08 to 1.17 and from 26.08 to 28.97 MPa, respectively. Thus, the degree of substitution and resulting tensile strength tended to be 20% lower in leaf-derived CMCs compared to those prepared from wood or bamboo. Microstructures of bamboo cellulose, bamboo CMC powder, and bamboo leaf CMC composites’ films all differed from pine-derived material, but plant source had no noticeable effect on the X-ray diffraction characteristics, Fourier transform infrared spectroscopy spectra, or pyrolysis properties of CMC or composites films. The results highlighted the potential for using plant source as a tool for varying CMC properties for specific applications.


2021 ◽  
Vol 25 (12) ◽  
pp. 170-174
Author(s):  
Upendra Prasad Tripathy ◽  
Sunil Kumar Bishoyi

Pulp and paper making is the major old process industry in India which is water intensive and generates heavy water pollution. Pulp and paper industries are the fifth largest contributor to industrial water pollution. Waste water is generated from each and every section of paper making process and depends upon the type of pulping and bleaching process. Presently, primary and secondary (Biological) treatment systems based on activated sludge process are widely used by paper industry for effluent treatment. The process requires high energy and chemical inputs and involves high operational costs. One of the novel processes for treating effluent is its oxidation through ozonation which is a greener way of degrading pollutants. Ozonation of intermediate stage effluents having high colour load is more effective for industrial application and re-utilization.


2021 ◽  
Vol 1 (1) ◽  
pp. 15-21
Author(s):  
Siti Pratiwi Husain

The problem in this research is students still do not understand when writing scientific papers, in choosing a topic or problem, determining the title of a scientific paper, making an introduction, as well as references or data needed in writing scientific papers. The purpose of this service activity is to increase the knowledge of the participants about the importance of writing scientific papers and to improve the ability of the participants to determine the title and make an introduction properly and correctly according to the guidelines for writing scientific papers. The method used is the method of lectures, discussions and exercises. The results of the service activities show that 85% of participants who come from students who take part in this training activity can determine the title of the scientific work and prepare an introduction in the scientific work.


Author(s):  
Zhenxi Liu ◽  
Jiamin Chen ◽  
Wuhao Yang ◽  
Tianyi Zheng ◽  
Qifeng Jiao ◽  
...  

Abstract MEMS resonators have been widely used in the magneto-resistive (MR) sensor for modulating the magnetic flux to enhance the detection limit. However, the manufacturing tolerances in MEMS fabrication processes make it challenging to fabricate the identical resonators with the same vibration frequency, which greatly decreases the detection limit of the MR sensor. To synchronize the MEMS resonators and improve the performance of the MR sensor, the double end tuning fork (DETF) based comb-driven MEMS resonators is proposed in this paper, making the system operate at the out-of-phase mode to complete the synchronization. The dynamic behaviour of the resonators is investigated through theoretical analysis, numerical solution based on MATLAB code and Simulink, and experimental verification. The results show that the transverse capacitances in the comb will significantly affect the resonance frequency due to the second-order electrostatic spring constant. It is the first time to observe the phenomenon that the resonant frequency increases with the increase of the bias, and it can also decrease with increasing the bias through adjusting the initial space between the fixed finger and the moving mass, they are different from the model about spring softening and spring hardening. Besides, the proposed DETF-based comb-driven resonators can suppress the in-phase and out-of-phase mode through adjusting the driving and sensing ports, and sensing method, meanwhile make the magnetic flux modulation fully synchronized, and maximize the modulation efficiency, and minimize the detection limit. These characteristics are appropriate for the MR sensor, even other devices that need to adjust the resonance frequency and vibration amplitude. Furthermore, the model and the design can also be extended to characteristic the single end tuning fork (SETF) based MEMS resonator and other MEMS-based MR sensors.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Tesema Hailu Asrat ◽  
Rakesh Kumar Bachheti ◽  
Mesfin Getachew ◽  
Limenew Abate

Abstract The world demand for paper has been increased due to the increasing population Therefore, to cop up the limited wood fiber resources introducing raw material in pulp and paper industries is necessary. The aims of this study to evaluate the pulp and paper-making properties of Caesalpinia decapetela based on proximate chemical composition, fiber morphology, pulping, bleaching, and physical test of the final product. The results proximate chemical analysis showed that C. decapetela has holocellulose content of 78.14±0.1 % and lignin content 18.0±0.04 %. Fiber morphology revealed that the fibers were 0.708 mm long, 18.63 μm width, and have 5.1 μm cell wall thicknesses. Kraft pulping of C. decapetale, was performed at different active alkali (5 %, 10 %, 15 %, 20 % and 25 %) and temperature (150, 160 and 170 °C), keeping the sulphidity 25 % constant. The pulp maximum yield 44.1 % was obtained at active alkali content of 15 %, temperature 160 °C, and cooking time 90 minutes. The effect of pulping on fiber morphology was studied using scanning electron microscopy which showed the surface of fiber before pulping was tight, orderly arranged and the texture was relatively hard. After pulping, there was the removal of lignin, hemicellulose, and cellulose. Due to this fiber become soft loosened and contain micro-pores. Pulp produced was bleached, sheet preparation and testing were performed. The prepared paper sheets have a tensile index of 28.19 Nm/gm, burst index of 1.359 kPa m 2 / gm 1.359\hspace{0.1667em}\text{kPa}\hspace{0.1667em}{\text{m}^{2}}/\text{gm} , and tear indices of 4.2 mN m 2 / gm 4.2\hspace{0.1667em}\text{mN}\hspace{0.1667em}{\text{m}^{2}}/\text{gm} . This study concluded C. decapetale can be the new raw material for pulp and paper making industries. However, pilot plant studies are required to check this raw material for the full recommendation of the pulp and paper industries.


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