Cyclic uniaxial stress-strain test and rheological behavior of carbon black/metakaolin dual-filler system used in nitrile rubber compounds

2019 ◽  
Vol 77 ◽  
pp. 105906 ◽  
Author(s):  
Elisson Brum Dutra da Rocha ◽  
Matheus Rocha Batista ◽  
Felipe Nunes Linhares ◽  
Ana Lucia Nazareth da Silva ◽  
Marcia Cerqueira Delpech ◽  
...  
2020 ◽  
pp. 101884
Author(s):  
Ricardo Bruno Pereira Negri ◽  
Antonio Henrique Monteiro Fonseca Thomé da Silva ◽  
Ana Maria Furtado de Sousa ◽  
Ana Lúcia Nazareth da Silva ◽  
Elisson Brum Dutra da Rocha

2001 ◽  
Vol 74 (5) ◽  
pp. 899-914
Author(s):  
A. Limper ◽  
D. Schramm

Abstract In comparison to plastics processing, rubber processors handle a much more complex material. Due to active fillers used in rubber compounds, such as carbon black and silica, in some cases extraordinary filler/filler interactions occur. In general the multi-component system leads to a very complex rheological behavior. If silica compounds e.g. are processed the chemical modification of the filler surface (by organosilanes) has to be taken into account. By this the rheological behavior of the material changes dramatically. All these circumstances make rubber processing to a very complex theme. This paper presents results which are obtained within an European research project. The work is focussing on a better process description of the extrusion process of rubber compounds. It handles both applications of the extrusion process, i. e. for technical rubber goods or for making tire parts like the extrusion of tread stripes. Hence in this paper a new approach for modeling the flow in the extruder screw will be presented. Using this as a simulation tool a systematic analysis of the extrusion process is possible in reasonable time. Another field of interest in this context is the rheological characterization of rubber compounds with a so called „Extrusion-Rheometer“. The advantages of this device will be shown for the investigation of processability and gathering representative rheological data for recalculations of screw and die flow in the extrusion process.


1940 ◽  
Vol 13 (2) ◽  
pp. 348-360 ◽  
Author(s):  
Frank L. Roth ◽  
William L. Holt

Abstract Stress-strain relationships and the work of extension for four rubber compounds were studied for a rate of stretching of the order of 1,000 per cent per second. This rate is sufficiently great so that the test may be considered to approach adiabatic conditions. A comparison of these data with similar data for a rate of stretching which lies in the range of speeds common to the usual routine tests shows that increased speed of stretching affects the observed tensile properties as follows: (1) the stresses' are increased at elongations up to about 500 per cent for the loaded compounds and up to 600 per cent for the pure-gum compound, the maximum increases ranging from 75 pounds per square inch for the pure-gum compound to 245 pounds per square inch for the clay compound; (2) the stresses in the carbon-black compounds are decreased slightly at elongations near rupture; (3) the work of extension to rupture is increased for the pure-gum and clay compounds and decreased for the carbon-black compounds, and (4) the work of extension for a given elongation is increased for all the compounds. The stresses and the work of extension at the higher speed reveal no information indicative of resistance to abrasive wear that cannot be gained from similar studies of data obtained in stretching the specimen slowly.


TAPPI Journal ◽  
2012 ◽  
Vol 11 (1) ◽  
pp. 61-66 ◽  
Author(s):  
DOEUNG D. CHOI ◽  
SERGIY A. LAVRYKOV ◽  
BANDARU V. RAMARAO

Delamination between layers occurs during the creasing and subsequent folding of paperboard. Delamination is necessary to provide some stiffness properties, but excessive or uncontrolled delamination can weaken the fold, and therefore needs to be controlled. An understanding of the mechanics of delamination is predicated upon the availability of reliable and properly calibrated simulation tools to predict experimental observations. This paper describes a finite element simulation of paper mechanics applied to the scoring and folding of multi-ply carton board. Our goal was to provide an understanding of the mechanics of these operations and the proper models of elastic and plastic behavior of the material that enable us to simulate the deformation and delamination behavior. Our material model accounted for plasticity and sheet anisotropy in the in-plane and z-direction (ZD) dimensions. We used different ZD stress-strain curves during loading and unloading. Material parameters for in-plane deformation were obtained by fitting uniaxial stress-strain data to Ramberg-Osgood plasticity models and the ZD deformation was modeled using a modified power law. Two-dimensional strain fields resulting from loading board typical of a scoring operation were calculated. The strain field was symmetric in the initial stages, but increasing deformation led to asymmetry and heterogeneity. These regions were precursors to delamination and failure. Delamination of the layers occurred in regions of significant shear strain and resulted primarily from the development of large plastic strains. The model predictions were confirmed by experimental observation of the local strain fields using visual microscopy and linear image strain analysis. The finite element model predicted sheet delamination matching the patterns and effects that were observed in experiments.


2017 ◽  
Vol 59 (11-12) ◽  
pp. 1054-1060 ◽  
Author(s):  
Mohan Kumar Harikrishna Kumar ◽  
Subramaniam Shankar ◽  
Rathanasamy Rajasekar ◽  
Pal Samir Kumar ◽  
Palaniappan Sathish Kumar

2005 ◽  
Vol 24 (4) ◽  
pp. 209-222 ◽  
Author(s):  
S.P. Mahapatra ◽  
D.K. Tripathy

Compressive stress-strain properties of unfilled and conductive carbon black (VulcanXC 72) filled oil extended EPDM (keltan 7341A) microcellular vulcanizates were studied as a function of blowing agent (density) and filler loading. With decrease in density, the compressive stress-strain curves for microcellular vulcanizates behaved differently from those of solid vulcanizates. The compressive stress-strain properties were found to be strain rate dependent. The log-log plots of relative density of the microcellular vulcanizates showed a fairly linear correlation with the relative modulus. The compression set at a constant stress increased with decrease in density. The efficiency of energy absorption E, was also studied as a function of filler and blowing agent loading. From the compressive stress-strain plots the efficiency E and the ideality parameter I, were evaluated. These parameters were plotted against stress to obtain maximum efficiency and the maximum ideality region, which will make these materials suitable for cushioning and packaging applications in electronic devices.


2020 ◽  
Vol 39 (1) ◽  
pp. 81-90
Author(s):  
An Zhao ◽  
Xuan-Yu Shi ◽  
Shi-Hao Sun ◽  
Hai-Mo Zhang ◽  
Min Zuo ◽  
...  

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