scholarly journals Effect of uniaxial stress on bursting energy absorption of paper

BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 7249-7262
Author(s):  
Konrad Olejnik ◽  
Anna Stanisławska ◽  
Jean-Francis Bloch

The overall usefulness of the bursting energy absorption (BEA) was studied for a better analysis of paper strength properties. Additionally, the changes of the BEA during more complex deformations of paper products, e.g., preliminary or simultaneous tensile and burst, were determined. For the purpose of the research, an experimental setup was designed. The results showed that the correlation between BEA and bursting strength was linear, but the proportionality strongly depended on paper grade. Thus, a more accurate method to characterize the bursting resistance (BR) of paper was proposed. The BR parameter is described by the three following parameters: average bursting strength, average bursting energy absorption, and the slope of the fitted linear regression curve (relationship between the bursting energy absorption and the bursting strength). This method revealed new mechanical behaviors of papers related to their preloading.

2015 ◽  
Vol 5 (01) ◽  
Author(s):  
Sonny Kurnia Wirawan ◽  
Nina Elyani ◽  
Ike Rostika

The use of recycled fibers derived from old corrugated cardboard (OCC) potential for enhanced strength properties through the addition of carboxy methylcellulose (CMC). Research carried out on local OCC with variation of time reaction, temperture, and the dosage of of CMC and CaCl2. Handsheet laboratory was made, and then analyzed the strength properties include tensile index, tensile energy absorption (TEA) index , bursting index and folding endurance, as well as coarseness and kink. The results show the optimum condition is achieved on the conditions of the reaction time of 20 minutes, the reaction suhue 25°C, the concentration of CMC 0,75% and concentration CaCl2 0,5% . Strength properties improvement was achieved at 3,07% tensile index, folding endurance 43,75% and bursting strength 36,81% .Keywords: CMC, OCC, strength properties   ABSTRAKSifat kekuatan serat daur ulang yang berasal dari kotak karton gelombang (KKG) bekas berpotensi untuk ditingkatkan melalui penambahan karboksi metil selulosa (CMC). Penelitian dilakukan terhadap KKG bekas lokal dengan variasi waktu, suhu, dan dosis penambahan CMC dan CaCl2. Lembaran kertas dibuat secara laboratorium , kemudian dianalisis sifat kekuatan meliputi indek tarik, indek tensile energy absorption (TEA), indek retak, dan ketahanan lipat, serta analisis coarseness dan kink. Hasil penelitian menunjukan kondisi optimum dicapai pada waktu reaksi 20 menit, suhu reaksi 25°C, konsentrasi CMC 0,75% dan konsentrasi CaCl2 0,5%. Peningkatan kekuatan yang dihasilkan adalah indeks tarik 3,07%, ketahanan lipat 43,75% dan indeks retak 36,81%.Kata kunci: CMC, KKG bekas, sifat kekuatan


TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 653-664
Author(s):  
IGNACIO DE SAN PIO ◽  
KLAS G. JOHANSSON ◽  
PAUL KROCHAK

Different strategies aimed at reducing the negative impact of fillers on paper strength have been the objective of many studies during the past few decades. Some new strategies have even been patented or commercialized, yet a complete study on the behavior of the filler flocs and their effect on retention, drainage, and formation has not been found in literature. This type of research on fillers is often limited by difficulties in simulating high levels of shear at laboratory scale similar to those at mill scale. To address this challenge, a combination of techniques was used to compare preflocculation (i.e., filler is flocculated before addition to the pulp) with coflocculation strategies (i.e., filler is mixed with a binder and flocculated before addition to the pulp). The effect on filler and fiber flocs size was studied in a pilot flow loop using focal beam reflectance measurement (FBRM) and image analysis. Flocs obtained with cationic polyacrylamide (CPAM) and bentonite were shown to have similar shear resistance with both strategies, whereas cationic starch (CS) was clearly more advantageous when coflocculation strategy was used. The effect of flocculation strategy on drainage rate, STFI formation, ash retention, and standard strength properties was measured. Coflocculation of filler with CPAM plus bentonite or CS showed promising results and produced sheets with high strength but had a negative impact on wire dewatering, opening a door for further optimization.


2017 ◽  
Vol 12 (1) ◽  
pp. 155892501701200
Author(s):  
Züleyha Değirmenci ◽  
Ebru Çoruh

This paper reports the effect of loop length and raw material on the air permeability and the bursting strength of plain knitted fabrics. In this study, a series of plain knitted fabrics were produced on a circular knitting machine with cotton, polyester, acrylic and viscose by Ne 30/1 yarns. Each fabric type was produced with four different stitch lengths. All the fabrics were knitted at the same machine setting in order to determine the effect of their structure on the fabric properties. Their geometrical and physical properties were experimentally investigated. The influences of the loop length and the raw material on the number of the courses per cm, number of the wales per cm, loop shape factor, thickness, fabric unit weight, tightness factor, air permeability and bursting strength are analyzed. Statistical analysis indicates that raw material and loop length significantly parameters affect the air permeability and the bursting strength properties of the fabrics.


2019 ◽  
Vol 25 (3) ◽  
pp. 316-321
Author(s):  
Florentina SEDERAVIČIŪTĖ ◽  
Jurgita DOMSKIENĖ ◽  
Ilze BALTINA

The article presents an experimental study of mechanical properties of cellulose biofilm produced by bacterial fermentation process. Naturally derived biomaterial has great current and potential applications therefore the conditions of material preparation as well as control and prediction of mechanical properties is still a relevant issue. Bacterial cellulose was obtained as a secondary product from Kombucha drink. Presented technique for material preparation and drying is particularly simple and easy to access. The influence of drying temperature (25 °C, 50 °C and 75 °C) on the sample size (thickness and planar dimensions) and mechanical properties (tensile and bursting strength) of cellulose biofilm has been evaluated. It was estimated that during drying biofilm specimens lost up to 92 % of weight and up to 87 % of thickness therefore planar specimen dimensions varied insignificantly. The study showed that the drying temperature is important for optimum strength properties of bacterial cellulose biofilm. The maximum tensile strength (27.91 MPa) was recorded for the samples dried at temperature of 25 °C, when the moisture from the biomaterial is removed gradually and good deformation properties are ensured (respectively tensile extension 18.8 %). Under higher drying temperature biomaterial shows lower values of tensile strength and higher values of bursting strength. The maximum bursting strength (57.2 MPa) was recorded for samples dried at 75 °C when punch displacement changes were insignificant for all tested samples (from 17.8 mm to 21.7 mm). DOI: http://dx.doi.org/10.5755/j01.ms.25.3.20764


2019 ◽  
Vol 265 ◽  
pp. 01008 ◽  
Author(s):  
Marta Kosior-Kazberuk ◽  
Julita Krassowska

The analysis of fracture mechanics parameters of concrete with new types of fibers is essential for the dissemination of their application and development of new methods of structural design.Fracture mechanics parameters are widely used to analyze the material behaviour and also in the design process of selected structures. The paper reports the results of an experimental programme focused on the effect of non-metallic (basalt) fibers on the fracture properties of concrete investigated in Mode I conditions. The changes in concrete properties were analysed on the basis of the critical stress intensity factor KIc, the critical value of crack tip opening displacement (CTODc) and the fracture energy GF. The addition of the basalt fibers had a slight effect on the strength properties of concrete but, at the same time, it had a significant influence on the fracture parameters by the modification of pre-cracking and particularly post-cracking behaviour of the concrete. Results of measuring the toughness and energy-absorption characteristics showed that the specimens reinforced with basalt fibers acquired a great ductile behaviour and energy absorption capacity, compared to ordinary concrete specimens.


2018 ◽  
Vol 33 (2) ◽  
pp. 327-335 ◽  
Author(s):  
Mohamed El-Sakhawy ◽  
EL-Shahat H. A. Nashy ◽  
Ahmed El-Gendy ◽  
Samir Kamel

Abstract The utilization of the solid tannery wastes as a promoting agent to improve paper sheet properties was investigated. Solid tannery wastes from pickled hide shavings are treated to remove acid and salts, and hydrolyzed at pH 10 by using potassium carbonate. The produced hydrolysable collagen (gelatin) was used as coating for paper sheets. The gelatin concentrations from 0.5–2.5 % were used as coating solution and its effect on thermal aging and mechanical properties was studied. A direct proportion between gelatin concentration and improvements of paper mechanical properties was observed. A kinetic study based on paper strength properties confirmed the stabilizating effect of gelatin on paper sheets. Paper sheets coated with 2.5 % gelatin solution were thermally aged at temperatures range between 100–200 °C for different time intervals from 1–6 h, and after that it was subjected to natural aging for two years. Gelatin coating improves the paper sheets mechanical properties and thermal stability.


2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Hua Chen ◽  
Jian Lou ◽  
Fei Yang ◽  
Jia-nan Zhou ◽  
Yan Zhang ◽  
...  

In this study, pulping conditions for kraft pulping of bamboo residues were investigated, predominantly focusing on cooking temperature and time during pulping. Oxalic acid and cationic starch were used for the modification of natural stellerite, and the use of modified stellerite for preparing filter paper for PM2.5 filtration was investigated. The optimal pulping technology of bamboo residues was established based on the following experimental parameters: liquor ratio of 1 : 5.5, cooking temperature of 160°C, and a holding time of 2 h. Modification by oxalic acid resulted in the promotion of pore formation at the stellerite surfaces and induced the microscopic changes. Nevertheless, paper strength remained practically unchanged after the addition of fillers, indicating that the cationic starch preblend method is a promising technique for papermaking because it enhances the strength properties of paper. With the variation in the addition of modified stellerite from 3 to 15%, while simultaneously maintaining the basis weight constant at 60 gm−2, the filtration efficiency of paper sheets first increased and then decreased later; thus the optimum stellerite content was found to be 9%. Filtration efficiency was suggested to be affected by gas flowing velocity.


2015 ◽  
Vol 819 ◽  
pp. 246-250 ◽  
Author(s):  
A.A. Sinar ◽  
Zainuddin Firuz ◽  
M.A. Nur Azni ◽  
A.Z. Nur Hidayah ◽  
Md Akil Hazizan ◽  
...  

This paper describes the effect of multi walled carbon nanotubes (MWCNTs) on the properties, especially the strength properties of rigid polyurethane (PU) foams produced from palm oil based polyol (POP) and methylene diphenyl diisocyanate (MDI). The foam composites in the ratio of 1:1.1 (wt. %) mixed at speed 2000 rpm. The addition of MWCNTs into PU foam are varies from 0 wt. % to 3 wt. %. The properties evaluated were compressive strength, density and energy absorption. Compressive strength of PU foam composites with 0.5% of MWCNTs showed the highest value 1.162 MPa of compressive strength compared to other foam composites. It was proved by modeling displacement nodal magnitude using NX Software (version 8.5). The density was increased 15.69 % with addition of 0.5 % MWCNTs into the PU foam. Increasing the amount of MWCNTs in PU foam was found to improve the energy absorption from 22.89 J for pure PU to 24.53 J for foam composites with 3 % MWCNTs.


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