Burst Strength Research Articles

Preparation and Characterization of Whey Protein Isolate-based Coating Solutions and Coated Papers with Different Plasticizers

Whey protein isolates (WPIs) are a byproduct of cheese and milk processing. WPI-based films offer transparency and good gas barrier properties at a low relative humidity, along with numerous different functional groups. However, they are hydrophilic, which restricts their use, and feature poor mechanical properties like brittleness. In this study, we explored the properties of WPI based coating materials depending on the type and contents of plasticizers, to use as a barrier coating materials for paper. Coating materials of WPI/glycerol (GY) and WPI/sorbitol (SO) with different plasticizer contents were prepared by solution blending. These materials were then coated on the surface of paper. The morphological structure, burst strength, tensile index, elongation at break, air permeability, and surface properties of the WPI/GY and WPI/SO-coated papers were investigated and compared based on the type and content of plasticizer. Compared to the WPI/GY-coated papers, the cracking of coating layers on the WPI/SO-coated papers was mitigated with increasing SO content in the WPI matrix. The WPI/SO-coated papers exhibited a higher tensile index, elongation at break, and air barrier than the WPI/GO-coated papers. Surface property analysis revealed that the hydrophilicity of both coated papers increased with increasing plasticizer content. However, further research is needed to reduce the hydrophilicity in WPI-coated papers and improve the compatibility between WPI and the plasticizer to enable their application in packaging.

Effect of Enzyme-pretreated Cellulose Nanofiber on the Strength of Coloring Paper Used for the Production of Fruit Bags

In this study, we investigated the effect of enzyme-pretreated cellulose nanofiber (EN-CNF) on the strength of the coloring paper used for the production of fruit bags. A prototype of EN-CNF was made by Moorim P&P for a mill trial using bamboo bleached kraft pulp (Ba-BKP) and hardwood BKP (Hw-BKP) and its characteristics were analyzed. The handsheets were produced by adding EN-CNF into the Hw-BKP furnish and their physical properties were measured in a laboratory study to determine the optimum dosage of the EN-CNF in a mill trial. A mill trial was carried out to identify the effect of EN-CNF on the strength of coloring paper and white water qualities in the production process of the coloring paper. BRThe average particle size and fiber width of EN-CNF were measured to be 14.1 μm and 43.8 nm, respectively, and the strength of the handsheets linearly increased as the dosage of EN-CNF increased. In addition, the bulk and light-scattering coefficients of the handsheets decreased depending on the dosage of EN-CNF. As a result of the mill trial, the EN-CNF was effective for improving tensile strength by 23%, and burst strength by 22% when 0.75% of EN-CNF was added into the stock, and the white water quality did not change significantly according to EN-CNF addition. Therefore, it was concluded that EN-CNF could effectively improve coloring paper strength without causing major changes in the production process.

Art Paper for Large Wood Relief Block Printing – A Paper Development Study

Wood relief block printing was developed in China in the seventh century and is used today for many art printing applications. The presented research project describes the development of an art paper product applicable for large wood relief block printing from laboratory scale to large semi commercial production of art paper for printing image sizes of up to 44-inch (1118 mm) by 96-inch (2400 mm) at outdoor steam roller printing events or smaller indoor printing press applications.
 The improvement of the paper properties from laboratory development, small laboratory paper machine and semi commercial paper machine run for the production of the final art paper showed an improvement throughout the process development for the optical and mechanical paper properties and exceeded the set values set by the artist using the art paper.
 The produced art paper with a basis weight of 260 g/m² and a thickness of 171 µm is produced from a mixture of 70% northern bleached hardwood Kraft pulp and 30% northern bleached softwood Kraft pulp.
 The ISO brightness of the art paper off-white (egg-shell) colour was at 63.2% and the ISO color value for L, a, b. at 90.8, 1.1, and 12.6 respectively.
 The art papers surface roughness and porosity as a parameter for ink attachment and penetration is for the top side 2179 ml/min and for the bottom side (wire side) 2326 ml/min, whereas porosity was measured at 1668 ml/min.
 Bending stiffness in machine direction and cross machine direction was measured at 157mN and 70 mN respectively. Burst strength was measured at 2.24 kPA·m²/g.

Anatomical and chemical characterization of Alstonia boonei for pulp and paper production

Alstonia boonei, an abundant lesser utilized species within the West African Subregion, was evaluated as an alternative raw material for pulp and paper production. The basic density (BD), fibre characteristics [fibre length (FL), fibre diameter (FD), lumen diameter (LD) and wall thickness (WT)], derived anatomical indices [Flexibility Ratio (FR), Slenderness Ratio (SR), Rigidity Coefficient (RC), Luce’s Shape Factor (LSF), Solids Factor (SF) and Runkel Ratio (RR)] and chemical composition (lignin, holocellulose, 1% NaOH solubility and ash contents) of A. boonei were studied to evaluate variation along the trunk (base, middle and top portions) and ascertain its suitability for pulp and paper production. Significant variations were observed in the density and fibre characteristics along the trunk of the tree. Although the FD was large, the observed adequate FL, thin-wall and large LD implied easy beating of fibres and manufacture of dense, smooth and strong papers. The favourable SF, RR, FR, RC, and LSF values obtained for the fibres would produce papers with suitable burst and tearing strengths and folding endurance. Chemically the lower lignin (< 30%), ash and 1% NaOH solubility and the high holocellulose contents of A. boonei, will generate a higher pulp yield. A. boonei although a low-density species, will be desirable for pulp and paper production.

Silk-based bilayered small diameter woven vascular conduits for improved mechanical and cellular characteristics

A major impediment to the development of small diameter vascular grafts is to achieve an optimal balance between its mechanical properties and cellular response. To address this, the technique of cylindrical weaving has been combined with electrospinning to fabricate a seamless bilayered conduit (∼3 mm) having an inner cell-friendly nanofibrous layer of poly(caprolactone)/collagen and an outer mechanically compliant woven silk layer. Mechanical characteristics such as burst strength, suture retention, compliance and leak resistance were found to be improved for this bilayered conduit when compared to the commercial standard. In-vitro studies revealed that the lumen of the conduit was non-hemolytic and could support adhesion and viability of endothelial cells. Overall, our studies suggest that the proposed bilayer construct could be a suitable candidate for small diameter vascular prosthesis.

State of the Art in Metal Matrix Composites Research: A Bibliometric Analysis

Metal matrix composites (MMC) are the materials of tomorrow. This paper presents an in-depth analysis of the MMC research articles published in Web of Science (WoS) during 2001–2020. The study firstly included year on year publications, publication types, sources, research directions as well as the most productive researchers, organizations and nations. Secondly, a detailed analysis of collaborations among various MMC researchers, organizations and countries has been presented. Thirdly, citations based linkages among the published articles, sources, researchers, institutions and places have been discussed relative to their respective collaborative link strengths. A co-occurrence analysis of MMC keywords was also conducted to highlight the most important keywords trending in this area. Finally, burst detection analyses of keywords and references were carried out to unearth sudden citation spikes of keywords and documents. Primary results indicate that research articles formed 80.54% of all MMC publications in WoS. The journal ‘Materials Science and Engineering A: Structural Materials, Properties, Microstructure and Processing’ published maximum MMC articles. Collaboration analysis results indicate that Zhang D, the Chinese Academy of Science and People’s Republic of China, attained topmost collaboration based total link strengths (TLS). Citations based analysis showed that Zhang D, the Shanghai Jiao Tong University (China), People’s Republic of China and the journal ‘Materials Science and Engineering A: Structural Materials, Properties, Microstructure and Processing’ received highest citation TLS values. Keyword ‘Graphene’ scored the highest citation burst strength (2018–2020). The future of MMC research lies in processing and characterization of novel nanocomposites with reinforcements such as graphene and boron carbide for various applications.

A Novel Alaska Pollock Gelatin Sealant Shows Higher Bonding Strength and Nerve Regeneration Comparable to That of Fibrin Sealant in a Cadaveric Model and a Rat Model

A novel biocompatible sealant composed of Alaska pollock-derived gelatin (ApGltn) has recently shown good burst strength and biocompatibility in a porcine aorta. The purpose of this study was to investigate the bonding strength and biocompatibility of the ApGltn sealant in transected digital nerves of fresh frozen cadavers and in the sciatic nerves of a rat model. Eighty human digital nerves of fresh frozen cadavers were transected for biomechanical traction testing. They were treated with four surgical interventions: (1) suture plus ApGltn sealant; (2) suture; (3) ApGltn sealant; and (4) fibrin sealant. Forty-three sciatic nerves of male Wistar rats were used for functional and histopathologic evaluation. They were treated with six surgical interventions: (1) suture plus ApGltn sealant; (2) suture; (3) ApGltn sealant; (4) fibrin sealant; (5) resection with a 5-mm gap (10 rats per group); and (6) sham operation (three rats). Macroscopic confirmation, muscle weight measurement, and histopathologic findings including G-ratio were examined 8 weeks after the procedure. The maximum failure load of the ApGltn sealant was significantly higher than that of a fibrin sealant (0.22 ± 0.05 N versus 0.06 ± 0.04 N). The maximum failure load of the ApGltn sealant was significantly lower that of suture plus ApGltn sealant (1.37 N) and suture (1.27 N). Functional evaluation and histologic examination showed that sciatic nerves repaired with ApGltn sealant showed similar nerve recovery compared to repair with the suture and fibrin sealant. The ApGltn sealant showed higher bonding strength and equal effect of nerve regeneration when compared with the fibrin sealant.

Hydrophobization of Cationic Cellulose Nanofiber Using Rosin Sizing Agent

This study was conducted to explore a new method for imparting hydrophobicity to cellulose nanofiber (CNF) using a rosin sizing agent. Anionic CNF was made from hardwood bleached kraft pulp by micro-grinding; this anionic CNF was then used to prepare cationic CNF through quaternization. The hydrophobization of CNFs was performed by adding the rosin sizing agent to the anionic and cationic CNFs. The zeta-potentials of the CNFs were measured to identify the adsorption rate of rosin sizing agent in the CNFs. CNF films were made from anionic and cationic CNFs containing rosin-sizing agent. The contact angle, FT-IR spectra and burst strength of CNF films were analyzed after heat treatment was conducted to cure the rosin sizing agent.<BR>The zeta-potential of the cationic CNF decreased with the addition of the rosin sizing agent, however there was no significant change in the anionic CNF. After heat treatment of the films, the contact angle of the cationic CNF film was 95°, which was higher than that of anionic CNF film. These results indicated that the anionic rosin sizing agent adsorbed more on cationic CNF than on anionic CNF, and the FT-IR spectra showed the same trend. The burst strength of the CNF film showed the highest value at 3% of rosin sizing agent dosage. Therefore, it was concluded that the rosin sizing agent was effective for the hydrophobization of the cationic CNF and that the dosage should be less than 3% to simultaneously maintain the high contact angle and burst strength of the CNF film.

Burst strength assessment of X100 to X120 ultra-high strength corroded pipes

This paper addresses analytically and numerically the burst strength of ultra-high strength steel pipelines with corrosion defects based on their elastic-plastic collapse behaviour. First, a model that properly accounts for the strain hardening behaviour of this category of pipelines is derived. An appropriate theoretical model with strain hardening based on the von Mises yield criterion is chosen and verified by finite element analyses and burst test data for intact ultra-high-grade steel pipelines. An extensive series of finite element analyses are then conducted to derive a scheme for assessing the effect of corrosion defects on the burst strength of such pipelines. Three sets of new burst strength models are proposed for ultra-high strength corroded pipes based on a parametric study of finite element analyses and intact pipe failure criteria. Subsequently, the proposed models’ validity and versatility are discussed by comparing with various other relevant models and burst test data specific to this class of steel pipes. The results indicate that the proposed models are adequate for burst strength prediction of ultra-high strength pipes with corrosion defects.

Fire resistant bagasse paper as packaging material using 1,3-di-p-toluidine-2,2,2,4,4,4-hexachlorocyclodiphosph(V)azane with hydroxyethyl cellulose

This manuscript aimed to enhance the mechanical, thermal, and ignition properties of bagasse paper when coated with different coatings synthesized from hydroxyethyl cellulose, 1,3-di-p-toluidine-2,2,2,4,4,4-hexachlorocyclodiphosph(V)azane, Talc powder, NaHCO3, cellulose nanocrystal. The effect of these coatings on the mechanical properties was studied by measuring elongation, tensile strength, and burst strength. The stages of degradation and ash residue of the measuring specimens were determined using thermal gravimetric analysis (TGA), behind that, the ignition properties as the flame chamber (UL/94), and limiting oxygen index (LOI) was measured according to standards. These tests proved that 1,3-di-p-toluidine-2,2,2,4,4,4-hexachlorocyclodiphosph(V)azane has a direct effect on improving the mechanical characteristics and enhancing the ignition properties of the coated specimens compared to uncoated. In this study the physical, mechanical, thermal, and ignition properties of the bagasse paper sheets were enhanced by easy and low-cost method via synthesis of new coatings based on commercially available chemicals in a reasonable cost.

Locust bean gum adsorption onto softwood kraft pulp fibres: isotherms, kinetics and paper strength

The adsorption of locust bean gum (LBG) onto Northern Bleached Softwood Kraft (NBSK) pulp improved paper tensile and burst strength and lowered refining energy by strengthening inter-fibre bonding. Adsorption kinetics and isotherms were investigated to develop a fundamental understanding of the adsorption mechanism. The adsorption rate followed pseudo-second-order kinetics and the activation energy was 99.34 kJ·mol−1, suggesting chemisorption. The adsorption rate constant increased rapidly with temperature from 25 to 45 °C (k = 1.93 to 24.03 g·mg−1·min−1), but the amount adsorbed at equilibrium decreased (qe = 1.91 to 0.48 mg·g−1 o.d. fibre). LBG adsorption to NBSK at 25 °C was consistent with the Langmuir adsorption model for LBG < 2.1 wt% of o.d. fibre, suggesting reversible, homogenous adsorption to a finite number of sites on the fibre surface. Refining to 3000 rev increased the heterogeneity of the NBSK pulp surface leading to multi-layer Freundlich adsorption with adsorption constant n = 5.00, and the equilibrium constant Kf = 2.57 mg·g−1·(mg·L−1)−1/n at 25 °C. Favorable adsorption conditions for negatively charged LBG were identified: 25 °C for 10 min, low dosage level (< 2 wt%), lightly refined (< 3000 rev) NBSK pulp at low fibre consistency (< 0.5 wt%), high agitation rate (> 150 r.p.m.), acidic or neutral conditions (pH 2–7) without salt addition.Graphic abstract

Fish Gelatin-Based Absorbable Dural Sealant with Anti-inflammatory Properties.

Cerebrospinal fluid (CSF) leakage from the dura mater during craniotomy is a common complication, which is associated with infection, meningitis, pneumocephalus, and delayed wound healing. In the present study, we developed an absorbable fish gelatin-based anti-inflammatory sealant for dura mater sealing to prevent CSF leakage. Gelatin derived from Alaska pollock (ApGltn) was modified with α-linolenic acid (ALA), an omega-3 fatty acid that exhibits anti-inflammatory properties, and cross-linked with a poly(ethylene glycol)-based cross-linker to develop ALA-ApGltn sealant (ALA-Seal). ALA-Seal demonstrated a higher storage modulus and tangent delta (tan δ) compared with those of the original ApGltn sealant (Org-Seal). The swelling ratio of ALA-Seal was markedly lower than that of DuraSeal, a commercially available dural sealant. Ex vivo burst strength measurements using porcine dura mater indicated that there was no significant difference between DuraSeal and ALA-Seal, despite ALA-Seal having an order of magnitude lower storage modulus. The anti-inflammatory properties of ALA-Seal, evaluated using brain microglial cells, were considerably higher than those of DuraSeal and Org-Seal, with a minimal adverse effect on cell viability. Therefore, compared to DuraSeal, ALA-Seal is a potential dural sealant with a lower swelling ratio, similar burst strength, and higher anti-inflammatory properties, which may prevent CSF leakage.

Time-variant burst strength of pipe with corrosion defects considering mechano-electrochemical interaction

This study aims at assessing the time-variant burst strength of pipe with corrosion defects under high internal pressure. A new numerical model was developed, where the mechano-electrochemical interaction was considered in a simplified manner. The damage evolution of corrosion, which was governed by a stress corrosion model, was realized by a user defined UMESHMOTION subroutine. The time-variant corrosion morphology and burst strength can be obtained using the numerical model. The proposed method avoids the disadvantages of the conventional method, where the damage form and size at a given moment are presumed and history-independent. Based on this simplified method, the effect of a single and two adjacent local corrosion defects on the burst strength of the pipe was investigated. Moreover, a new method was proposed that can consider the time-variant reliability of the pipe along with the randomness of the corrosion rate, geometry, and material strength. The predicted value of the deterministic method was also compared with that obtained by the stochastic method. Furthermore, systematic parametric studies were also conducted.

Effect of uniaxial stress on bursting energy absorption of paper

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.

Electrospun polyacrylonitrile nanofibrous membranes supported with montmorillonite for efficient PM2.5 filtration and adsorption of Cu (II) ions

AbstractIn this study, we have fabricated polyacrylonitrile/montmorillonite (PAN/Mt) nanofibrous nanocomposites with variation in concentration of Mt from 0.25% to 1.00%. The electrospinning process developed PAN/Mt nanofibrous nanocomposites having reduced fiber diameters and high surface roughness as observed in Field emission scanning electron microscopy. The nanocomposite nanofibers were characterized by X‐ray diffraction (XRD) and thermogravimetric analyzer for intercalation and thermal stability respectively. PAN/Mt nanofibrous nanocomposites were tested for their water vapor transmission rate, air permeability, burst strength, and tensile strength. The filtration efficiency of 0.75% PAN/Mt nanofibrous nanocomposite was found to be 98.7% for PM2.5 particles present in air with a pressure drop of 46.8 Pa. The adsorption of copper (II) (Cu (II)) ions using 0.75% PAN/Mt nanofibrous nanocomposites has also been studied. The effect of contact time and initial concentration of adsorbent on the adsorption of Cu (II) ions have been analyzed. It was found that the PAN/Mt nanofibrous membranes follows pseudo‐second‐order kinetic model and Langmuir adsorption isotherm for the adsorption of Cu (II) ions from aqueous solutions. This study suggests the potential implication of PAN/Mt nanofibrous nanocomposites for filtration of PM2.5 and adsorption of metal ions.

Experimental study of hoop stress of crescent shaped and eccentric worn casing

The decrease of collapse and burst strength of wear casing increases the risk of wellbore failure, and limits the selection of testing and completion operation parameter. For determining the residual strength of wear casing. 95/8“x 11.99mm-P110 casing is processed into the crescent and eccentric wear casing specimens with wear depth as 4 mm and 6 mm respectively. The experiments of wear casing loaded with radial centralized forces are carried out, and the finite element method is used to verify the experimental results. The circular stresses of outer surface at worn and unworn position of casing increase with the load exerted by the compression tester, and reach the yield strength of material of casing finally. The circular stress of the external surface of the worn position of casing is greater than the ones of unworn casing. The differences between the results which come from the analysis of the finite element method and the experimental data are less than 10%. So the results which are obtained by the experiment of the crescent-shaped and eccentric wear casing loaded with radial centralized forces are reliable. The circular stress of the external surface of the worn position of crescent-shaped wear casing is greater than the one of eccentric wear casing. The differences between them are less than 10%.

Lignin-containing micro/nanofibrillated cellulose to strengthen recycled fibers for lightweight sustainable packaging solutions

As e-commerce drives the packaging growth, consumers are pushing for more sustainable packaging solutions. Considering the current societal needs, we have been able to engineer a new pathway for sustainable packaging solutions by developing lignin-containing micro- and nano-fibrillated cellulosic (LMNFCs) materials to strengthen the recycled fibers. LMNFCs from unbleached softwood pulp containing 14.4% lignin at high and low fibrillation levels were produced. Packaging papers from recycled old-corrugated containers were strengthened with LMNFCs with varying addition levels of 1 wt% to 3 wt% at two basis weights. The results show 2 wt% addition of LMNFC can enhance strength at low levels of fibrillation, and that basis weight can be reduced by 16.7%, from 150 gsm to 125 gsm, while maintaining a burst strength of 49-53 lbf. Reduction in basis weight and high lignin content of LMNFC also enhanced dewatering during sheet formation with the lowest increase in drainage time, 9%, relative to the 150 gsm with no LMNFC. The techno-economic analysis supports the feasibility of using LMNFC to produce lightweight and sustainable packaging materials at industrial scale with an 8% reduction in fiber cost.

Properties of Kevlar fabric composites reinforced by STF composed of monodisperse polystyrene microspheres

Shear thickening fluid (STF) composed of monodisperse polystyrene microspheres (m-PS-m) was prepared, and soft armor composites was constructed with Kevlar fabric reinforced by this STF in this work. Both the knife and the spike stab resistance performance of this soft composite are investigated and discovered to improve significantly over the neat Kevlar fabric (NKF), and the puncture resistance of the spike is dramatically superior to the cut resistance of the knife. 8 layers of STF-impregnated Kevlar fabric (STKF) will not be punctured under the highest impact energy while 10 sheets of NKF is impaled easily even under the lowest striking energy in experiments. The tensile strength of this soft composite is increased by more than 55% compared to NKF. The highest pull-out force for single yarn in STKF is nearly 6 times that of NKF. The highest pull-out force of single yarn and tensile strength for STKF are greatly improved to make it meet more requirements of different situations. More importantly, the excellent stab resistant and burst strength performance of STKF indicate that it has broad application prospects in the field of soft body armor.

Improving cellulose viscosity protection and delignification in ozone bleaching of low-consistency pulp with water-soluble chitosan

The effect of water-soluble chitosan (WSC) with molecular weights (Mw) from 1.0×104 to 1.0×106 on cellulose viscosity protection was explored during the treatment of low-consistency pulp with the ozone bleaching process (OBP). Through determination of the change in crystallinity, carboxyl content, and physical strength of ozone-bleached refined dissolving pulp, WSC was shown to effectively protect cellulose viscosity by scavenging free radicals and forming a protective film deposited on the fiber surface to prevent the destruction of cellulose by oxidants. During the OBP of sulfate hardwood pulp (SHP), application of a 0.5 % dose of WSC with a Mw of 1.0×105 increased not only the cellulose viscosity but also the selectivity of ozone delignification. The brightness, viscosity, and delignification selectivity of the bleached SHP were enhanced by 3.88±0.05 %, 13.0±0.10 %, and 76.6±0.50 %, respectively. Accordingly, the indexes of tensile strength, burst strength and tear strength of the resulting SHP hand sheet were increased by 38.6±1.0 %, 74.8±1.5 %, and 117.3±2.5 %, respectively. WSC had the best performance among the reported additives of equal weights for protection of cellulose viscosity in improving the pulp qualities after the OBP.

A study of residual burst strength of composite over wrapped pressure vessel due to low velocity impact

The aim of this research was to study the residual burst strength, dynamic structural response, and failure mechanism of composite overwrapped pressure vessel (COPV) subjected to low velocity impact by numerically and experimentally. A three-dimensional composite pressure vessel model was developed using Wound composite module (WCM) plugin of Abaqus. The impact response of composite pressure vessels was calculated based on the Hashin progressive damage criteria. The residual burst strength was predicted using maximum strain failure criteria. The COPV was impact tested and the residual burst strength was calculated. The predicted and testing results were compared, and a good correlation was found.