scholarly journals Heat history of vulcanization accelerator and its vulcanization behavior during rubber milling. 1. Sulfenamide vulcanization accelerators.

1987 ◽  
Vol 60 (1) ◽  
pp. 56-57
1981 ◽  
Vol 3 (2) ◽  
pp. 125-129 ◽  
Author(s):  
Randy Brown
Keyword(s):  

2018 ◽  
Vol 922 ◽  
pp. 180-185
Author(s):  
Xin Yu ◽  
Tao Zhang ◽  
Jin Feng Wang ◽  
Zhi Wei Li ◽  
Lin Yi ◽  
...  

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.


2012 ◽  
Vol 476-478 ◽  
pp. 174-178 ◽  
Author(s):  
Xiao Li Zhang ◽  
Jian Xun Liu

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.


2011 ◽  
Vol 480-481 ◽  
pp. 1516-1520
Author(s):  
Kai Zhang ◽  
Ri Sheng Long ◽  
Wei Jun Liu

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.


1970 ◽  
Vol 43 (4) ◽  
pp. 799-828
Author(s):  
I. Imase

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.


Sign in / Sign up

Export Citation Format

Share Document