The Influence of the Test-Specimen on the Results Obtained In Tensile Tests of Soft Vulcanized Rubber Mixtures

1953 ◽  
Vol 26 (2) ◽  
pp. 465-480
Author(s):  
R. Herzog ◽  
R. H. Burton
Keyword(s):  
Natural Rubber ◽  
Tensile Properties ◽  
Test Specimen ◽  
Tensile Tests ◽  
Stress Strain ◽  
Vulcanized Rubber ◽  
Different Types ◽  
Small Test ◽  
Soft Rubber

Abstract The small test-specimen of the VSM-1 type should not be used for measuring the tensile properties of pure-gum vulcanizates; instead, the VSM-1a type of test-specimen should be used for such vulcanizates. Results obtained with the different types of test-specimen differ greatly; hence, in reporting the results of any tests of this kind, the type of test-specimen used should be stated, and only results obtained with one particular type of test-specimen should be compared. For example, substitution of the VSM-2 type of test-specimen by the KTA-II type of test-specimen, which is of approxmately the same size, unfortunately does not result in any better agreement. Based on these differences, which in the case of natural rubber have been found to vary from one type of vulcanizate to another, it is natural to expect corresponding unpredictable differences with various synthetic elastomers. The determination of stress-strain properties of soft rubber vulcanizates is, therefore, fundamentally a problem of agreement on methods of testing, i.e., of standardization.

Impact Machine for Rubber Testing. Determining the Stress-Strain Diagram at High Speed

1937 ◽  
Vol 10 (2) ◽  
pp. 317-328 ◽  
Author(s):  
Geo J. Albertoni
Keyword(s):  
Tensile Properties ◽  
High Speed ◽  
Standard Procedure ◽  
Tensile Tests ◽  
Strain Diagram ◽  
Stress Strain ◽  
Impact Machine ◽  
Actual Performance ◽  
Stress Strain Relation

Abstract IN CONTRAST to the ordinary standard procedure at low speed, various methods have been devised to carry out tensile tests of rubber under rapid application of load, with the purpose of securing more definite indications, at a speed in agreement with actual performance. The application of those methods to the study of the tensile properties of rubber stocks goes as far back as 1910, when Beadle and Stevens (1) made use of the pendulum to investigate these properties. Their work applied to rubber compounds of different compositions and different loadings. More recently, Van Rossem and Beverdam (2) presented a set of results tending to prove an optimum in the tensile properties, coinciding with the best cure as determined by practical observation. However, all experiments, previous to those here reported, are limited to the determination of the tensile strength of rubber, and no attempt was made to extend the investigations to the determination of the resistance of rubber at different elongations. The machine here illustrated is designed to measure not only the energy absorbed at break, under conditions of high speed, by impact, but also the stress-strain relation.

Application of Miniature Small Punch Test Specimen in Determination of Tensile Properties

2015 ◽  
pp. 1-8 ◽  
Author(s):  
R. Kopriva ◽  
M. Brumovsky ◽  
M. Kytka ◽  
M. Lasan ◽  
J. Siegl ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Test Specimen ◽  
Small Punch Test ◽  
Small Punch ◽  
Punch Test

Determination of Full Range Stress-Strain Behavior of Pipeline Steels Using Tensile Characteristics

2010 ◽  
Author(s):  
Stijn Hertele´ ◽  
Wim De Waele ◽  
Rudi Denys
Keyword(s):  
Full Range ◽  
Tensile Tests ◽  
Proof Stress ◽  
Stress Strain ◽  
Pipeline Steels ◽  
Strain Behavior ◽  
Parameter Values ◽  
Near Future ◽  
Strain Model

It is standard practice to approximate the post-yield behavior of pipeline steels by means of the Ramberg-Osgood equation. However, the Ramberg-Osgood equation is often unable to accurately describe the stress-strain behavior of contemporary pipeline steels with a high Y/T ratio. This is due to the occurrence of two distinct, independent stages of strain hardening. To address this problem, the authors recently developed a new ‘UGent’ stress-strain model which provides a better description of those steels. This paper elaborates a methodology to estimate suited parameter values for the UGent model, starting from a set of tensile characteristics. Using the proposed methodology, good approximations have been obtained for a preliminary series of eight investigated stress-strain curves. Next to all common tensile characteristics, the 1% proof stress is needed. The authors therefore encourage the future acquisition of this stress level during tensile tests. Currently, the authors perform a further in-depth validation which will be reported in the near future.

Stress-Strain Properties of Natural Rubber under Biaxial Strain

1951 ◽  
Vol 24 (1) ◽  
pp. 70-82 ◽  
Author(s):  
B. B. S. T. Boonstra
Keyword(s):  
Natural Rubber ◽  
Biaxial Strain ◽  
Stress Strain ◽  
Relaxation Constant ◽  
Vulcanized Rubber ◽  
Stress Curve

Abstract (1) The stress-strain curves of vulcanized rubber held at definite tangential elongations during stretching differ more from the simple unidirectional-extension-stress curve than the theory predicts. The differences are larger at higher tangential elongations. (2) The relaxation constant determined at 600 per cent elongation is practically unaffected by tangential elongations up to 300 per cent.

COMPARATIVE ANALYSIS OF 14C AND TGA TECHNIQUES FOR THE QUANTIFICATION OF THE BIOMASS CONTENT OF END-OF-LIFE TIRES

2014 ◽  
Vol 87 (4) ◽  
pp. 664-678 ◽  
Author(s):  
Leticia Saiz-Rodríguez ◽  
José María Bermejo-Muñoz ◽  
Andrés Rodríguez-Díaz ◽  
Alberto Fernández-Torres ◽  
Antonio Rubinos-Pérez
Keyword(s):  
Thermogravimetric Analysis ◽  
Stearic Acid ◽  
Natural Rubber ◽  
End Of Life ◽  
Rubber Content ◽  
Thermogravimetric Method ◽  
Precise Method ◽  
Different Types ◽  
Reference Samples

ABSTRACT Thermogravimetric analysis (TGA) and 14C techniques were compared for the determination of the biomass content of end-of-life tires (ELTs). Samples of different types (of ELTs) were prepared, and the biomass fraction of each sample was measured using the two methods (TGA and 14C). Six reference samples were also prepared with known quantities of natural rubber and stearic acid in order to establish the calibration curve necessary for the thermogravimetric analysis and to verify the accuracy of the results of the 14C analysis. The conclusions were that the 14C technique is the more valid, reliable, and precise method for determining the biomass content of end-of-life tires, since the results of the 14C tests of the reference samples coincided perfectly with the actual natural rubber and stearic acid content. On the other hand, the results of the thermogravimetric method differed considerably from the known natural rubber content of the reference samples as well as from the results of the 14C technique. This method is therefore not appropriate for use in determining the biomass content of end-of-life tires.

Effect of Cleaning Agent on Tensile and Swelling Properties of Natural Rubber Latex Film

2013 ◽  
Vol 858 ◽  
pp. 46-51 ◽  
Author(s):  
Mufidah Md Sidek ◽  
A. Rashid Azura ◽  
Baharin Azahari
Keyword(s):  
Natural Rubber ◽  
Tensile Properties ◽  
Control Sample ◽  
Natural Rubber Latex ◽  
Latex Film ◽  
Rubber Latex ◽  
Swelling Properties ◽  
Cleaning Agent ◽  
Cleaning Agents ◽  
Different Types

The effect of different types and loading of cleaning agent on the tensile properties and swelling properties of natural rubber latex film were investigated. The aim for this study is to find the cleaning agent which is compatible with natural rubber latex with optimum loading. In this study, there are two different amine based cleaning agent used which are Monoethanolamine (MEA) and Di-(3-aminopropyl) ether of diethylene glycol (DG). Swelling test was done to support the tensile results. It is found that tensile properties of the sample with MEA cleaning agent is higher than control sample (without cleaning agent) and sample with DG cleaning agent. For the best cleaning agent compound, the different loading has been tested and results showed that optimum loading of cleaning agent are achieved at 5 phr. The effects of both types of cleaning agents and different loading of cleaning agents on tensile properties and swelling properties for cleaning mold application are discuss.

Thermodynamics of Crystallization in High Polymers. VI. Incipient Crystallization in Stretched Vulcanized Rubber

1950 ◽  
Vol 23 (3) ◽  
pp. 576-580 ◽  
Author(s):  
Thomas G. Fox ◽  
Paul J. Flory ◽  
Robert E. Marshall
Keyword(s):  
Theoretical Prediction ◽  
Experimental Determination ◽  
Strain Curve ◽  
Steep Slope ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Hydrostatic Method ◽  
Vulcanized Rubber ◽  
High Polymers

Abstract Experimental determination of the elongation at which crystallization commences in vulcanized rubber has been attempted through measurement of density changes by a hydrostatic method. The critical elongation for incipient crystallization appears to depend on the temperature, in approximate accordance with theoretical prediction. Crystallization sets in at an elongation well below that at which the stress-strain curve assumes a steep slope.

The Chemistry of Soft Rubber Vulcanization. III. Comparison of Vulcanized Rubber with Unmilled Crude Rubber Reclaims, and Unvulcanized Stocks Containing Stiffeners or Gas Black

1934 ◽  
Vol 7 (3) ◽  
pp. 538-545
Author(s):  
B. S. Garvey
Keyword(s):  
Standard Method ◽  
Stress Strain ◽  
Vulcanized Rubber ◽  
Soft Rubber

Abstract IN PART I (1) of this series it was pointed out that the measurement of vulcanization is complicated by the use of unmilled rubber (e. g., latex stocks), stiffeners, gas black, and reclaims. Therefore limitations in compounding were accepted and a standard method of processing was adopted. These limitations were accepted in recognition of the fact that compounds containing these materials show some properties akin to those of vulcanized rubber. For example, some crude rubbers have stress-strain characteristics almost identical with those of certain types of vulcanizate. Uncured gas black stocks likewise show some of the characteristics of vulcanized rubber, and the reënforcing action of gas black is sometimes spoken of as a sort of vulcanization (2). Such limitations are desirable only if it can be shown that the phenomena excluded are different from those being studied. The experiments reported in this paper show how the tough, hard, crude rubbers can be differentiated from vulcanized rubber and how the effect of gas black and stiffeners can be differentiated from that of vulcanization. The generally accepted view that reclaims are distinct in character from either vulcanized or unvulcanized rubber is supported by this investigation. The. experiments also show why it is desirable, for the present, to exclude these materials from the compounds used to study vulcanization.

The Oxidation Products of Rubber

1939 ◽  
Vol 12 (2) ◽  
pp. 225-234
Author(s):  
A. van Rossem ◽  
P. Dekker
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Tensile Properties ◽  
High Speed ◽  
Accelerated Aging ◽  
Direct Determination ◽  
Oxidation Products ◽  
Vulcanized Rubber

Abstract In their summary of the aging of vulcanized rubber, Porritt and Scott state that three factors are responsible for the changes in mechanical properties of vulcanized rubber during aging, viz.: (a) oxidation of the rubber; (b) after-vulcanization; (c) some colloidal change of the rubber, sometimes termed aggregation. Of these factors, oxidation is by far the most important because it is responsible for the decrease in mechanical properties, which leads to the general deterioration of rubber from a technical standpoint. It was Marzetti who proved that the decrease of mechanical properties in accelerated aging is due to oxidation. Later, Kohman confirmed this in a more concise way and showed that even such small amounts as 0.5% of oxygen absorbed by vulcanized rubber are sufficient to decrease tensile properties to 50% of their original value. When studying aging, three ways of tackling this problem are possible, viz.: (1) Investigations of the mechanical properties, either under normal conditions, or under special conditions such as elevated temperature or high speed. (2) Determination of oxidation products, which are formed during oxidation of the rubber. (3) Direct determination of the amount of oxygen which is absorbed by the rubber. It is clear that any of these methods may be combined with accelerated aging tests.

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