scholarly journals A STUDY ON HEAT HISTORY OF ORGANIC ACCELERATORS IN RUBBER STOCK (BR BASE)

1969 ◽  
Vol 42 (4) ◽  
pp. 265-278 ◽  
Author(s):  
I. Imase
Keyword(s):  
History Of ◽  
Heat History ◽  
Rubber Stock

A Study on Heat History of Organic Accelerators in Rubber Stock (BR Base)

1970 ◽  
Vol 43 (4) ◽  
pp. 799-828
Author(s):  
I. Imase
Keyword(s):  
The Other ◽  
Frictional Heat ◽  
Rubber Matrix ◽  
Rubber Compound ◽  
Incremental Effect ◽  
Rubber Compounds ◽  
History Of ◽  
Curing Agents ◽  
Heat History ◽  
Rubber Stock

Abstract Rubber with some exceptions must generally undergo such processes as mastication, mixing, warming-up, extrusion, spreading, calendering, etc. prior to vulcanization under heat to obtain cured articles. Consequently the rubber matrix receives a heat history caused by mechanical frictional heat or the heat which cannot be avoided during these processes. On the other hand, when an uncured rubber compound, ready for vulcanization, containing such curing agents as sulfur, such activators as zinc oxide, and organic accelerators is heated during the processes or during storage between individual processes, each incremental effect of heat is accumulated with time. It is a well-known fact that this accumulation of heat can lead to the trouble of scorching, etc. As a cause for the trouble, organic accelerators seem to play the most important role. A few reports have been published on the action of accelerators under heat, but, to my knowledge, no report is available on the behavior of accelerators in rubber stocks, namely, on the change of the properties of uncured rubber compounds and on its influence on the properties of vulcanizates. This paper shall report these problems, though it describes only the results of the tests carried out under specific conditions.

The additive heat history of PVC stability

1981 ◽  
Vol 3 (2) ◽  
pp. 125-129 ◽  
Author(s):  
Randy Brown
Keyword(s):  
History Of ◽  
Heat History

Research on Correlation between Insulation Performances and Damage Degree of Burned Cable

2018 ◽  
Vol 922 ◽  
pp. 180-185
Author(s):  
Xin Yu ◽  
Tao Zhang ◽  
Jin Feng Wang ◽  
Zhi Wei Li ◽  
Lin Yi ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Scanning Calorimetry ◽  
Distribution Form ◽  
Microstructure Observation ◽  
Damage Degree ◽  
Characteristic Absorption Peak ◽  
Dielectric Performance ◽  
History Of ◽  
Comprehensive Test ◽  
Heat History

In this paper, the insulation near the fault point of a breakdown 220 kV cable joint for burned cable, which kept burning for about one hour, was investigated. The relationship between insulation performance and damage degree of burned cable was analyzed by comprehensive test of material performance. Differential scanning calorimetry (DSC) test results showed that the shoulder peak temperature could reflect the heat history of the materials. There was a correlation between damage degree and the characteristic absorption peak of spectrum (IR) graph. The result of mechanical performance was different obviously. The results of broadband dielectric spectrum showed that the relative permittivity and dielectric loss factor for samples close to the fault point were smaller. By the microstructure observation of sample crystal distribution form, the above conclusions were proved. As a conclusion, DSC, IR, SEM and dielectric performance analysis results matched the real situation, showed that these methods was feasible and effective to judge the damage degree of burned cable.

The Study on the Orderliness of Change of Microstructure and Mechanical Properties in Simulating the Heating Process of Bending of X80 Pipeline Steels

2012 ◽  
Vol 476-478 ◽  
pp. 174-178 ◽  
Author(s):  
Xiao Li Zhang ◽  
Jian Xun Liu
Keyword(s):  
Mechanical Properties ◽  
Pipeline Steel ◽  
Heating Process ◽  
Long Distance ◽  
Pipeline Steels ◽  
Microstructure And Mechanical Properties ◽  
The World ◽  
History Of ◽  
Optimum Heat ◽  
Heat History

As the development of oil gas transportation project for long distance over the world, the pipeline steel are developed to high grade to reduce the construction cost and increase the efficiency of the gas transportation. But the statistics of the built pipeline engineering in the world showed that most of the steels are below the grade of X70, and the used X80 grade steels are less than 5000km. In 2008, the second west-east pipeline project will startup in China, and the whole line will use X80 grade pipeline steels. So the matched bend pipes should be studied. In this paper, the X80 pipeline steels were reheated under selected condition to simulate the heat history of bending process of it. And the deduced microstructure was observed, also the relationship between microstructure and mechanical properties were discussed. The optimum heat treatment technics were gained. This research will be helpful to the field hot bending in the second west-east gas project.

Configuration and Adjustment of Substrate Preheating Device

2011 ◽  
Vol 480-481 ◽  
pp. 1516-1520
Author(s):  
Kai Zhang ◽  
Ri Sheng Long ◽  
Wei Jun Liu
Keyword(s):  
Control Method ◽  
Factors Affecting ◽  
Dual Channel ◽  
History Of ◽  
Substrate Preheating ◽  
Intelligent Pid ◽  
Heat History ◽  
And Performance ◽  
Channel Control ◽  
Heating Up

Laser Metal Deposition Shaping (LMDS) is a state-of-the-art technology that combines rapid prototyping and laser processing. There are many factors affecting the quality, precision, microstructure and performance of LMDS-deposited parts. Among them, substrate preheating is a significant one since it can change the heat history of the LMDS process. Preheating is often used to reduce the residual stresses and the risk of thermal distortion and cracking. In this work a set of substrate preheating device for LMDS system employed with dual-channel control, namely intelligent PID temperature control and realtime serial-port temperature acquisition and feedback control, is designed and developed. In addition, the heating up rule gained through the relative experiment is introduced to reduce the overshoot amplitude of substrate preheating device by cascade control method. The results show that not only can this substrate preheating device realize the dual-channel control and continuous adjustment of substrate preheating temperature, but also can realtime collect and record the substrate temperature.

Kinetic Effects Associated with the Glass Transition of Polyisoprene

1977 ◽  
Vol 50 (5) ◽  
pp. 922-933
Author(s):  
J. Prud'homme ◽  
P. Goursot ◽  
A. Laramée
Keyword(s):  
Glass Transition ◽  
Heating Rate ◽  
Inflection Point ◽  
Amorphous Polymers ◽  
Measurement Analysis ◽  
History Of ◽  
Rate Of Cooling ◽  
Heat History ◽  
Kinetic Effects ◽  
The Individual

Abstract In this study we have found that the glass transition temperature of polyisoprene as determined by DSC is not a linear function of the heating rate. An equivalent study of polystyrene suggests that this behavior is general for all amorphous polymers. When the heat history of the polymer is fixed by linear cooling, Tg measured as the inflection point of the DSC curve is a function of the type q=C exp (−E/RTg), where E varies slightly with the rate of cooling before the measurement. Analysis of the individual curves according to the method of Ellerstein shows that this behavior is compatible with a kinetic model of the glass transition which implies a simple relaxation process with an activation energy only slightly above the value of E determined from the dependence of Tg upon the heating rate.

Effects of Various Suessen Heat Setting Variables on Thermal Stress Analysis Measurement

1988 ◽  
Vol 58 (1) ◽  
pp. 7-11
Author(s):  
James E. Rodgers
Keyword(s):  
Thermal Stress ◽  
Stress Analysis ◽  
Steam Pressure ◽  
Heat Setting ◽  
Thermal Stress Analysis ◽  
Effective Heat ◽  
Analysis Measurement ◽  
History Of ◽  
Heat History ◽  
Sample Set

A thermal stress analysis (TSA) technique had previously been developed to determine the heat history and effective heat set temperature of Suessen heat set nylon 66 carpet yarns. In this investigation, the Kanebo KE-2L thermal stress tester was used with yarns heat set with the standard and energy conservation package (ECP) Suessen units. In each sample set, the greige carpet yarns had been subjected to changes in heat set temperature, flyer speed, and steam pressure. The KE-2L accurately measured the effective heat set temperature and heat history of the yarn samples. Low standard errors of prediction and high multiple coefficients of determination ( R2) between the TSA-determined and Suessen heat set temperatures were obtained for both the standard and ECP Suessen yarns. The major Suessen heat setting variable influencing the TSA results is heat set temperature. For the standard Suessen yarns, flyer speed and steam pressure influences on the TSA results were minor and nonsignificant. For the ECP Suessen yarns, the small changes induced in the yarn from flyer speed and a heat set temperature/steam pressure interaction were significant, though still minor, and were measured by the TSA.

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