Thermal Properties of Rubber Compounds II. Heat Generation of Pigmented Rubber Compounds

1934 ◽  
Vol 26 (12) ◽  
pp. 1292-1296 ◽  
Author(s):  
C. E. Barnett ◽  
W. C. Mathews
Keyword(s):  
Thermal Properties ◽  
Heat Generation ◽  
Rubber Compounds

Thermal Properties of Rubber Compounds. II. Heat Generation of Pigmented Rubber Compounds

1935 ◽  
Vol 8 (1) ◽  
pp. 138-149 ◽  
Author(s):  
C. E. Barnett ◽  
W. C. Mathews
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Laboratory Test ◽  
Heat Generation ◽  
The Other ◽  
Moving Plate ◽  
Rubber Compounds ◽  
Time Required ◽  
Two Machines ◽  
Rubber Block

Abstract THE first paper (1) of this series discussed thermal conductivity of rubber and a number of compounding ingredients which were measured using the electric current as the source of heat. In this article the fundamental factors controlling the generation of heat and the variations possible by pigmentation are being studied. Results obtained for pigmented rubber in the pendulum and flexometer will be discussed and correlated. In the writers' laboratory two machines have been used extensively in studying the temperature developed in rubber compounds subjected to distortion by compressive forces. The first of these is a flexometer described by Cooper (2), and the second a compression machine in which a rubber block 14 cm. (5.5 inches) in diameter and 9.53 cm. (3.75 inches) high is pounded with a definite load a specified number of times per minute. The laboratory test block used in the flexometer is in the shape of a frustrum of a rectangular pyramid, of which the base is 5.4 × 2.86 cm. (2.126 × 1.125 inches), the top 5.08 × 2.54 cm. (2 × 1 inches), and the altitude 3.81 cm. (1.5 inches). This block of rubber is compressed between two plates under definite load, one of the plates being stationary while the other travels in a circular motion of definite magnitude. After the sample has been placed in the machine, the moving plate is set to one side of the center. Both the loading and the amount of offset may be varied within wide limits. With this machine one may study either the temperature developed over a period of flexing or the time required to compress the sample a predetermined amount.

Thermal Problems in Rubber Manufacture

1941 ◽  
Vol 14 (3) ◽  
pp. 683-695
Author(s):  
Stuart H. Hahn
Keyword(s):  
Thermal Properties ◽  
Heat Generation ◽  
Lower Cost ◽  
Raw Materials ◽  
Cyclic Stress ◽  
Stress Conditions ◽  
Structural Elements ◽  
Physics Laboratory ◽  
Heating And Cooling ◽  
Rubber Compounds

Abstract The threefold heat problems of the industry are, in order of their occurrence: (1) Controlled removal of heat generated in processing crude rubber. (2) Regulation of heating and cooling processes to give the most nearly uniform vulcanization in the shortest possible time. (3) Measurement and reduction of heat generation in products subject in service to cyclic stress conditions. Each of the three types of problems engages the attention of chemists and engineers as well as physicists. The chemist is constantly searching for new ingredients and combinations of materials which will promote rapid vulcanization at curing temperatures, that is, 240 to 320° F. The same rubber compounds, when unvulcanized, must be relatively insensitive to processing temperatures up to about 220° F; when vulcanized they must withstand prolonged use at temperatures above 200° F. The engineer must design curing equipment and related automatic controls. He also must design the combinations of rubber compounds and structural elements which make up the products of the industry. The physicist must measure and analyze the thermal properties of the raw materials, the rubber compounds and the finished products. He also must apply the methods of the physics laboratory to the study in the factory of thermal problems connected with production operations. The cooperation of all is essential in producing for the consumer better products at lower cost.

Correlation of Electronic and Thermal Properties of Short Channel nMOSFETS

1999 ◽  
Author(s):  
M. Palaniappan ◽  
V. Ng ◽  
R. Heiderhoff ◽  
J.C.H. Phang ◽  
G.B.M. Fiege ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Temperature Distribution ◽  
Heat Generation ◽  
Hot Spots ◽  
Light Emission ◽  
Photon Emission ◽  
Thermal Image ◽  
Short Channel ◽  
Physical Phenomena ◽  
Backside Illuminated

Abstract Light emission and heat generation of Si devices have become important in understanding physical phenomena in device degradation and breakdown mechanisms. This paper correlates the photon emission with the temperature distribution of a short channel nMOSFET. Investigations have been carried out to localize and characterize the hot spots using a spectroscopic photon emission microscope and a scanning thermal microscope. Frontside investigations have been carried out and are compared and discussed with backside investigations. A method has been developed to register the backside thermal image with the backside illuminated image.

Natural Rubber Compounds for Truck Tires

1985 ◽  
Vol 58 (4) ◽  
pp. 740-750 ◽  
Author(s):  
D. Barnard ◽  
C. S. L. Baker ◽  
I. R. Wallace
Keyword(s):  
Stearic Acid ◽  
Heat Generation ◽  
Rolling Resistance ◽  
Synthetic Compound ◽  
Wear Performance ◽  
Test Pieces ◽  
Truck Tire ◽  
Truck Tires ◽  
Rubber Compounds ◽  
Lower Severity

Abstract An 80 NR/20 BR truck tread compound containing a semi-EV cure system and modified with a 6.0 phr level of stearic acid has been shown to exhibit excellent resistance to reversion when compared to a similar compound containing a normal 2.0 phr level of stearic acid. Improvements in the retention of laboratory abrasion resistance, heat generation, and most physical properties have been identified on test pieces subjected to typical truck retread overcure conditions. In highway fleet testing trials of 1100 × 22.5 truck retreads fitted to both third and fourth drive axles of tipper trucks, the modified compound displayed a 42% improvement in treadwear performance over the normal compound in the lower severity third axle positions while performance in the higher severity fourth axle positions was inferior by 20%. In comparison to a 55 SBR/45 BR truck tread, both NR compounds displayed superior wear performance on the fourth axles while some further adjustments of the modified compound are required to match the synthetic compound on the third axles. The reversal of wear performances for all compounds between third and fourth axles is due to the different abrasion mechanisms encountered. Laboratory abrasion rankings do not correlate with wear performances of compounds on the fourth drive axle of trucks, but they do correlate with wear performances on third drive axles. Despite the reversion characteristics of the normal semi-EV compound, no significant adverse effect on treadwear performance was evident at the start of tire life. The low heat generation of the modified compound in laboratory tests is confirmed in actual tire testing. Advantages in rolling resistance characteristics are also evident for the modified compound. Current studies at MRPRA suggest that further modifications of cure system design, in combination with the optimization of NR/BR ratios and mixing methods, will potentially provide NR dominant truck tread compounds which will exhibit superior wear performance in both the higher and lower abrasion severities encountered in heavy-duty truck tire service conditions.

A Note on Heat Generation Due to Surface Rubbing

1975 ◽  
Vol 3 (3) ◽  
pp. 189-195
Author(s):  
S. K. Clark
Keyword(s):  
Thermal Properties ◽  
Elastic Properties ◽  
Heat Generation ◽  
Internal Heat ◽  
Point Of View ◽  
High Modulus ◽  
Low Modulus

Abstract The question of heat generation by frictional rubbing is examined from the point of view of material elastic properties. Theory suggests and evidence is presented that low modulus materials tend to generate more internal heat during rubbing then high modulus materials of similar thermal properties.

scholarly journals Fatigue of Rubber

1964 ◽  
Vol 37 (5) ◽  
pp. 1341-1364 ◽  
Author(s):  
J. R. Beatty
Keyword(s):  
Heat Generation ◽  
Vibration Isolation ◽  
Dynamic Stress ◽  
Static Loads ◽  
Cyclic Stresses ◽  
Large Samples ◽  
Rubber Compounds ◽  
Compression Springs ◽  
Torsion Springs ◽  
Fatigue Failures

Abstract The long-range elastic properties of rubber suit it ideally to dynamic service applications. Vibration isolation, suspension, and force transmittal are examples of such uses of rubber compounds. Common examples illustrating these uses are isolation devices of all types, e.g., motor mounts, torsion, shear and compression springs, and tires—just to name a few. While fatigue failures may occur under static loads, they are generally accelerated by cyclic stresses. In most applications of rubber, a failure is critical in that the device depends for its functioning on the properties of the rubber and ceases to function when fatigue or other types of failure occur. Examples of fatigue failures are groove cracking in tires, tread and ply separations in tires, failures in torsion springs and motor mounts, etc. This review is concerned with fatigue of rubber under conditions of dynamic stress. Two specific areas are treated, the case where frequency of stressing is low enough and the samples are small enough that heat generation is not an important factor in failure and, to a lesser extent, the case where heat generation due to large samples and high frequency load application builds up temperatures which contribute to failure. Both of these cases of fatigue failure are encountered widely in service. For example, the first is found in vibration isolation devices such as motor mounts, and the latter in the shoulder area of heavy duty tires.

Estimation of Heat Generation From Power Si MOSFET Using Electro-Thermal Analysis

2013 ◽  
Author(s):  
Risako Kibushi ◽  
Tomoyuki Hatakeyama ◽  
Masaru Ishizuka
Keyword(s):  
Thermal Analysis ◽  
Thermal Properties ◽  
Thermal Management ◽  
Heat Generation ◽  
Thermal Energy ◽  
Hot Spot ◽  
Energy State ◽  
High Current ◽  
The Impact ◽  
Spot Temperature

This paper describes thermal properties of power Si MOSFET. The problem of hot spot in sub-micron scale Si MOSFET has been widely known. Recently, power Si MOSFET is a key device in a lot of area, for example car electronics. In power Si MOSFET, high voltage is applied and high current is generated. Therefore, heat generation becomes higher and thermal management is important. In this paper, thermal properties of power Si MOSFET is evaluated with Electro-Thermal Analysis and impurity dependency of temperature of power Si MOSFET is discussed. Under high electric field, electron thermal energy becomes much higher than thermal energy of crystal lattice. Therefore, in this paper, non-equilibrium energy state between electron and lattice is considered. Calculated results showed that hot spot appears in power Si MOSFET. Further, it is investigated that the impact of donor density on hot spot temperature is strong.

Influence of Processing Oil Based on Modified Epoxidized Vegetable Oil with N-Phenyl-p-Phenylenediamine (PPD) on Extrusion Process Behaviors of Natural Rubber Compounds

2015 ◽  
Vol 659 ◽  
pp. 423-427 ◽  
Author(s):  
Chalida Moojea-Te ◽  
Adisai Rungvichaniwat ◽  
Kannika Sahakaro
Keyword(s):  
Natural Rubber ◽  
Heat Generation ◽  
Extrusion Process ◽  
Die Swell ◽  
Rubber Compound ◽  
Output Rate ◽  
Extrusion Rate ◽  
Rubber Compounds ◽  
Filler Dispersion ◽  
Mooney Viscosity

Rubber processing oil based on modified epoxidized vegetable oils (m-EVO) was prepared by a reaction of epoxidized palm oil EPO) or epoxidized soybean oil (ESBO) with N-Phenyl-ρ-phenylenediamine (PPD) at a mole ratio of 1:0.5. The comparison of m-EVO with aromatic oil (Treated distillate aromatic extract, TDAE) on extrusion process behaviors (output rate, extrusion rate, screw efficiency, heat generation, die swell, extrudate appearance) of carbon black (N330) filled natural rubber (NR) compound was made. It was found that the mooney viscosity of m-EVO based natural rubber compounds are slightly higher than that of the TDAE based natural rubber compound (ML(1+4)100°C: m-ESBO 65.5±0.7; m-EPO 59.7±0.2; TDAE 56.5±1.0), which probably due to the poorer filler dispersion in the compounds. The extrusion process behaviors for output rate (g/min: m-ESBO 191.0±0.6; m-EPO 191.2±0.4; TDAE 195.5±0.6), extrusion rate (cm3/min: m-ESBO 179.6±0.6; m-EPO 183.2±0.4; TDAE 186.4±0.6) and screw efficiency (%: m-ESBO 30.8±0.6; m-EPO 31.4±0.4; TDAE 32.0±0.6). All the three compounds show similar extrusion process behaviors in which the TDAE based compounds shows a marginal higher values than the m-EVO as its lower mooney viscosity lead to a better flow. The m-EPO and m-ESBO based natural rubber compounds show very similar extrusion process behaviors. The heat generation (°C: m-ESBO 61.0±0.8; m-EPO 62.1±0.4; TDAE 63.1±1.0) and die swell (%: m-ESBO 11.0±0.7; m-EPO 11.0±0.5; TDAE 12.7±0.3) of the m-EVO based natural rubber compounds are slightly lower than those of the TDAE based natural rubber compound. As there are no significant differences in the extrusion process behaviors, with respect to extrusion process, m-EVO can be used to replace TDAE oil.

Analyzing patterns of heat generated by the tensile loading of steel rods containing discontinuity-like defects

2017 ◽  
Vol 27 (6) ◽  
pp. 950-960 ◽  
Author(s):  
Eugeny A Moyseychik ◽  
Vladimir P Vavilov
Keyword(s):  
Thermal Properties ◽  
Heat Exchange ◽  
Infrared Thermography ◽  
Heat Generation ◽  
Shear Bands ◽  
Tensile Loading ◽  
Heat Sources ◽  
Sample Mean ◽  
Mean Temperature

Heat generation in steel samples with discontinuity-like defects subjected to tensile loading is analyzed by using the technique of infrared thermography. It is shown that the heat is predominantly generated in shear bands where one observes a considerable rise in temperature. The sample mean temperature is conditioned by the sum of all heat sources (shear bands), as well as the thermal properties of the material and the magnitude of the heat exchange with the environment. It also depends on the mass of elastically deformed material adjacent to the shear bands.

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