Effects of Water on the Mechanical Properties of Paper and their Relationship to the Treatment of Paper

1992 ◽  
Vol 267 ◽  
Author(s):  
Timothy Vitale
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Tap Water ◽  
Water Immersion ◽  
Exchange Process ◽  
Elastic Behavior ◽  
Elastic Fibers ◽  
Plastic Behavior ◽  
Stress Strain ◽  
Strain Behavior

ABSTRACTThrough a series of experiments the mechanical properties of paper are explored. Hydrogen bonding is fundamental to the performance of paper and its disruption results in distinctive stress-strain behavior. Stress-strain curves were generated from which tensile strength, Young's modulus, percent stretch, and work (tensile energy absorption) were obtained.It was found that the contribution of the fiber to the mechanical properties of paper is primarily elastic. Fibers are many times stronger than paper. Only fibers which have been severely deteriorated show measurable changes in stress-strain behavior. Fiber deterioration results in characteristically different stress-strain behavior than that which results from disruption of interfiber bonding.Water immersion results in the disruption of interfiber bonds in paper, leaving only 2-3% of dry tensile strength. Interfiber bonds make a profound contribution to the mechanical properties of the paper. Aqueous treatment is shown to be a radical treatment, altering the original dried-in properties of the sheet. The release of structural bonds and dried-in strains during wetting and the subsequent reformation of interfiber bonds during drying are shown to be independent of water purity, be it ultrapure water, tap water, or water containing washing aids such as Ca(OH)2, NaOH, CaCO3 or Na2CO3.The effects of immersion in organic solvents was explored. Solvents have effects on mechanical properties which are approximately proportional to the degree of swelling caused by the solvent. Water, the liquid which caused the greatest swelling of the liquids evaluated, is shown to be the most disruptive liquid followed by methanol and acetone; toluene caused virtually no change.To explore the behavior of interfiber bonds paper was taken through a solvent exchange process. A sample was immersed in water and then taken through separate ethanol and acetone immersions to toluene, and dried. The result was a sheet with little bonding and decreases in all mechanical properties. To explore the surface tension and capillary action effects of water, the solvent-exchanged sheet was re-immersed in water. Upon drying, interfiber bonding was reintroduced which resulted in the regain of mechanical properties lost.A paradigm for the mechanical behavior of paper is developed. Fibers contribute elastic behavior and interfiber bonds are a principal source of plastic behavior.

scholarly journals Characterization of Fibers Produced from Blends of Polybutylene and Polypropylene

2007 ◽  
Vol 2 (3) ◽  
pp. 155892500700200 ◽  
Author(s):  
Robert L. Shambaugh ◽  
Diana L. Ortiz
Keyword(s):  
Mechanical Properties ◽  
Differential Scanning Calorimetry ◽  
Tensile Strength ◽  
Scanning Calorimetry ◽  
Stress Strain ◽  
Strain Behavior

Blends of polybutylene (PB-1) and polypropylene were used to produce fibers at spinning speeds of 800–2100 m/min. Concentrations ranged from 0% PP to 100% PP. The stress-strain behavior of the resultant fibers was examined, and the fibers were analyzed for crystallinity via DSC (differential scanning calorimetry). Fibers produced from blends of PB-1/PP show mechanical properties that are in between the properties of the pure polymers. The tensile strength of 50% PB-1 fibers is comparable to the tensile strength of pure PP fibers. Fibers produced from blend compositions of 25 and 75% have higher tensile strengths than pure PP fibers, although these blend compositions have lower tensile strengths than pure PB fibers.

scholarly journals Numerical Prediction of Equivalent Mechanical Properties of Corrugated Paperboard by 3D Finite Element Analysis

2020 ◽  
Vol 10 (22) ◽  
pp. 7973
Author(s):  
Jongmin Park ◽  
Sewon Chang ◽  
Hyun Mo Jung
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Reaction Force ◽  
Simplified Model ◽  
Plastic Behavior ◽  
Stress Strain ◽  
Element Analysis ◽  
Strain Behavior ◽  
Equivalent Properties

This study is to obtain the equivalent (effective) mechanical properties of corrugated paperboard specifically that is widely applied in Korea for packaging of agricultural products. To analyze the equivalent properties of corrugated paperboard, finite element modeling, measurement of the reaction force, and superposition theory for the unit cell were applied. The stress-strain behavior obtained by applying the calculated equivalent mechanical properties to the simplified model of the corrugated paperboard is compared with experimental results. Nine equivalent mechanical properties governing the orthotropic behavior of corrugated paperboard were analyzed through finite element analysis (FEA). The stress-strain behavior of the corrugated paperboard experimentally showed elastic-plastic behavior, although the equivalent mechanical properties applied to the simplified model were elastic properties based on the theoretical approach, so that the finite element analysis results showed linearity. Therefore, when applying the calculated equivalent mechanical properties through FEA, the characteristics of the section where the strain only increases without the increase in the load due to the flute should be taken into consideration.

Effect of using magnetic water on the mechanical properties of concrete exposed to elevated temperature

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wasim Barham ◽  
Ammar AL-Maabreh ◽  
Omar Latayfeh
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Elevated Temperature ◽  
Flexural Strength ◽  
Tap Water ◽  
Splitting Tensile Strength ◽  
Content Type ◽  
Normal Water ◽  
Magnetic Water

PurposeThe influence of using magnetic water instead of tap water in the mechanical properties of the concrete exposed to elevated temperatures was investigated. Two concrete mixes were used and cast with the same ingredients. Tap water was used in the first mix and magnetic water was used in the second mix. A total of 48 specimens were cast and divided as follows: 16 cylinders for the concrete compressive strength test (8 samples for each mix), 16 cylinders for the splitting tensile strength (8 specimens for each mix) and 16 beams to test the influences of magnetized water on the flexural strength of concrete (8 specimens for each mixture). Specimens were exposed to temperatures of (25 °C, 200 °C, 400 °C and 600 °C). The experimental results showed that magnetic water highly affected the mechanical properties of concrete. Specimens cast and curried out with magnetic water show higher compressive strength, splitting tensile strength and flexural strength compared to normal water specimens at all temperatures. The relative strength range between the two types of water used was 110–123% for compressive strength and 110–133% for splitting strength. For the center point loading test, the relative flexural strength range was 118–140%. The use of magnetic water in mixing concrete contribute to a more complete hydration process.Design/methodology/approachExperimental study was carried out on two concrete mixes to investigate the effect of magnetic water. Mix#1 used normal water as the mixing water, and Mix#2 used magnetic water instead of normal water. After 28 days, all the samples were taken out of the tank and left to dry for seven days, then they were divided into different groups. Each group was exposed to a different temperature where it was placed in a large oven for two hours. Three different tests were carried out on the samples, these tests were concrete compressive strength, flexural strength and splitting tensile strength.FindingsExposure of concrete to high temperatures had a significant influence on concrete mechanical properties. Specimens prepared using magnetic water showed higher compressive strength at all temperature levels. The use of magnetic water in casting and curing concrete can increase the compressive strength by 23%. Specimens prepared using magnetic water show higher splitting tensile strength at all temperatures up to 33%. The use of magnetic water in casting and curing can strengthen and increase concrete resistance to high temperatures, a significant enhancement in flexural strength at all temperatures was found with a value up to 40%.Originality/valuePrevious research proved the advantages of using magnetic water for improving the mechanical properties of concrete under normal conditions. The potential of using magnetic water in the concrete industry in the future requires conducting extensive research to study the behavior of magnetized concrete under severe conditions to which concrete structures may be subjected to. These days, there are attempts to obtain stronger concrete with high resistance to harsh environmental conditions without adding new costly ingredients to its main mixture. No research has been carried out to investigate the effect of magnetic water on the mechanical properties of concrete exposed to elevated temperature. The main objective of this study is to evaluate the effect of using magnetic water on the mechanical properties of hardened concrete subjected to elevated temperature.

scholarly journals Low-Pressure Membrane for Water Treatment Applications

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Huda AlFannakh ◽  
Heba Abdallah ◽  
S. S. Ibrahim ◽  
Basma Souayeh
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Drinking Water ◽  
Humic Acid ◽  
Tap Water ◽  
Permeate Flux ◽  
Membrane Performance ◽  
Polyethersulfone Membrane ◽  
Contaminated Drinking Water

Three ultrafiltration membranes were prepared using phase separation techniques. The membranes were characterized by scan electron microscope, porosity, pore size distribution measurement, and mechanical properties. The membrane performance was carried out using synthetic solutions from humic acid and tap water to express the contaminated drinking water. The polyvinylidene difluoride (M2) has the highest tensile strength 33.2 MPa with elongation of 52.3%, while polyacrylonitrile (M3) has the lowest mechanical properties, tensile strength 16.4 MPa with elongation of 42.7%. Polyethersulfone membrane (M1) provides the highest removal of humic acid, which was 99.5, 98.8, and 98.2% using feed concentrations 0.1, 0.3, and 0.5 g/l, respectively, while M3 provides the highest permeate flux which was 250, 234.4, and 201.4 l/m2 h using feed concentrations 0.1, 0.3, and 0.5 g/l, respectively. Analysis of water samples indicates that the prepared membranes can be used to treat the contaminated drinking water which produced the high quality of drinking water after treatment.

scholarly journals Investigation of the Mechanical Properties of St. Lawrence River Ice

1971 ◽  
Vol 8 (2) ◽  
pp. 163-169 ◽  
Author(s):  
L. W. Gold ◽  
A. S. Krausz
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Yield Stress ◽  
Power Law ◽  
River Ice ◽  
Stress Strain ◽  
Strain Behavior ◽  
Brittle Transition ◽  
Ductile To Brittle Transition ◽  
St Lawrence River

Observations are reported on the stress–strain behavior at −9.5 ± 0.5 °C of four types of ice obtained from the St. Lawrence River. The ice was subject to nominal rates of strain covering the range 2.1 × 10−5 min−1 to 5.8 × 10−2 min−1. A ductile-to-brittle transition was observed for strain rate of about 10−2 min−1. In the ductile range the four types had an upper yield stress that increased with strain rate according to a power law.

Stress-Strain Equations for Some Near-Eutectic Tin-Lead Solders

1991 ◽  
Vol 113 (4) ◽  
pp. 475-484 ◽  
Author(s):  
K. P. Jen ◽  
J. N. Majerus
Keyword(s):  
Strain Rate ◽  
Printed Circuit Boards ◽  
Volume Fraction ◽  
Total Error ◽  
Tensile Tests ◽  
Elastic Behavior ◽  
Plastic Behavior ◽  
Strain Rates ◽  
Stress Strain ◽  
Engineering Strain

This paper presents the evaluation of the stress-strain behavior, as a function of strain-rate, for three tin-lead solders at room temperature. This behavior is critically needed for reliability analysis of printed circuit boards (PCB) since handbooks list minimal mechanical properties for the eutectic solder used in PCBs. Furthermore, most handbook data are for stable eutectic microstructure whereas PCB solder has a metastable microstructure. All three materials were purchased as “eutectics.” However, chemical analysis, volume fraction determination, and microhardness tests show some major variations between the three materials. Two of the materials have a eutectic composition, and one does not. The true stress-strain equations of one eutectic and the one noneutectic material are determined from compressive tests at engineering strain-rates between 0.0002/s and 0.2/s. The second eutectic material is evaluated using tensile tests with strain-rates between 0.00017/s and 0.042/s. The materials appear to exhibit linear elastic behavior only at extremely small strains, i.e., less than 0.0005. However, this “elastic” behavior showed considerable variation, and depended upon the strain rate. In both tension and compression the eutectic alloy exhibits nonlinear plastic behavior, i.e., strain-softening followed by strain-hardening, which depends upon the strain rate. A quadratic equation σy = σy(ε˚/ε˚0) + A(ε˚/ε˚0)ε + B(ε˚/ε˚0)ε2 fit to the data gives correlation coefficients R2 > 0.91. The coefficients σy(ε˚/ε˚0), A(ε˚/ε˚0), B(ε˚/ε˚0) are fitted functions of the normalized engineering strain rate ε˚/ε˚0. Replicated experiments are used at each strain-rate so that a measure of the statistical variation could be estimated. Measures of error associated with the regression analysis are also obtained so that an estimate of the total error in the stress-strain relations can be made.

scholarly journals A More Realistic Study on the Mechanical Properties of CFRC Composite Grouting Material under a Long-Term Water Immersion Process

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Yao Xiao ◽  
Huafeng Deng ◽  
Jianlin Li ◽  
Eleyas Assefa
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Carbon Fiber ◽  
Water Immersion ◽  
Fiber Content ◽  
Grouting Material ◽  
Bonding Properties ◽  
Grouting Materials ◽  
Dam Foundations

The long-term effect of water immersion on the mechanical properties of CFRC composite grouting materials was studied by using five different carbon fiber contents (0, 0.25%, 0.50%, 0.75%, and 1.00%). The direct shear and long-term immersion tests were performed based on the specified and optimum values of carbon fiber content, respectively. The results showed the following: (1) the application of carbon fiber significantly improved the shear resistance of CRFC composite grouting material by using “reinforcing” and “anchoring” actions. The shear strength of the specimen was increasing by 5.66%∼43.41% when the carbon fiber content increased from 0.25% to 1.00%. After a comprehensive analysis, the optimum carbon fiber content was found to be 0.75%. (2) The degradation in the compressive and tensile strength of CRFC composite specimens exhibited a consistent trend (i.e., a steep gradient was gradually followed by a gentle slope) under a long-term water immersion process. About 90% of the total degradation in the compressive and tensile strength has occurred in 90 immersion days (i.e., 16.05% and 18.45%, respectively). In comparison, the degradation in the tensile strength (20.05%) was slightly higher than the compressive strength (18.16%). (3) Under the long-term water immersion process: the properties of the specimens were gradually deteriorating, the carbon fibers were gradually reaching a fatigue stage, and the bonding properties of carbon fiber was decreasing, which resulted in a reduction in the compressive and tensile strength. The uniaxial compression failure mode changed from brittle to ductile, and the development of local failure was very noticeable. Based on the findings of this paper, groundwater has a significant impact on the mechanical properties of grouted rock mass such as dam foundations and abutments. Therefore, the degradation in the grouting materials has to be considered in practical cases.

Computer Simulation of Nanoparticle Aggregate Fracture

2007 ◽  
Vol 1056 ◽  
Author(s):  
Takumi Hawa ◽  
Brian Henz ◽  
Michael Zachariah
Keyword(s):  
Mechanical Properties ◽  
Molecular Dynamics ◽  
Computer Simulation ◽  
Tensile Strength ◽  
Direct Relationship ◽  
Brittle Materials ◽  
Ductile Failure ◽  
Strain Behavior ◽  
Nanoparticle Aggregate ◽  
Nanoparticle Aggregates

ABSTRACTNanoparticle aggregates have been found to possess unique mechanical properties. Aggregates of metal nanoparticles can be strained up to 100% before failure, and even typically brittle materials are observed to have a ductile failure mode. In this effort two materials; namely silver and silicon, were chosen to represent ductile and brittle materials, respectively. Aggregates with 2 to 6 particles were simulated using the molecular dynamics (MD) algorithm to determine the stress-strain behavior of the aggregate. Many interesting observations are made including the negligible affect of strain rate on ultimate tensile strength, and the direct relationship between Young's modulus and nanoparticle size.

scholarly journals Stress-Strain Behavior of Perfluorosulfonic Acid Membranes at Various Temperatures and Humidities: Experiments and Phenomenological Modeling

2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Ahmet Kusoglu ◽  
Yaliang Tang ◽  
Michael H. Santare ◽  
Anette M. Karlsson ◽  
Simon Cleghorn ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Flow Behavior ◽  
True Strain ◽  
Plastic Behavior ◽  
Stress Strain ◽  
True Strain Rate ◽  
Material Constants ◽  
Strain Behavior ◽  
Constitutive Response ◽  
Perfluorinated Sulfonic Acid

The constitutive response of perfluorinated sulfonic acid (PFSA) membranes based on tensile testing is investigated, and a phenomenological constitutive model for the elastoplastic flow behavior as a function of temperature and humidity is proposed. To this end, the G’Sell–Jonas (1979, “Determination of the Plastic Behavior of Solid Polymers at Constant True Strain Rate,” J. Mater. Sci., 14, pp. 583–591) constitutive model for semicrystalline polymers is extended by incorporating, in addition to temperature, relationships between the material constants of this model and the measured relative humidity. By matching the proposed constitutive model to the experimental stress-strain data, useful material constants are found. Furthermore, correlations between these material constants and Young’s modulus and proportional limit stress are investigated. The influence of material orientation, inherited from processing conditions, on the stress-strain behavior is also studied. The proposed model can be used to approximate the mechanical behavior of PFSA membranes in numerical simulations of a fuel cell operation.

Stress-strain behavior of individual electrospun polymer fibers using combination AFM and SEM

2009 ◽  
Vol 1185 ◽  
Author(s):  
Fei Hang ◽  
Dun Lu ◽  
Shuang Wu Li ◽  
Asa H Barber
Keyword(s):  
Tensile Strength ◽  
Deformation Process ◽  
Tensile Deformation ◽  
Polymer Fibers ◽  
Electrospun Fibers ◽  
Stress Strain ◽  
Strain Behavior ◽  
Atomic Force ◽  
Resultant Stress ◽  
Scanning Electron

AbstractTensile deformation of individual electrospun polyvinyl alcohol (PVA) nanofibres was performed using a novel combination atomic force microscope (AFM)- scanning electron microscope (SEM) technique. The AFM was used to provide manipulation and mechanical testing of individual PVA nanofibers while the SEM was used to observe the deformation process. Resultant stress-strain curves show how the elastic modulus shows comparable, or even slightly increased, values to isotropic films. In addition, the electrospun fibers were tested to failure to measure their tensile strength.

Sign in / Sign up

Export Citation Format

Share Document