The effect of electric field on the creep characteristics of low-density polyethylene (LDPE)

1989 ◽  
Vol 21 (1) ◽  
pp. 113-118
Author(s):  
M. Amin ◽  
H. M. Osman ◽  
S. S. Hamza ◽  
N. El-Nashar ◽  
S. F. Moghazy
Keyword(s):  
Electric Field ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Creep Characteristics

scholarly journals Review of space charge measurement by pulsed electro-acoustic technique

2020 ◽  
Vol 20 (2) ◽  
pp. 646
Author(s):  
Mohd Haris Asyraf Shee Kandar ◽  
Nor Akmal Mohd Jamail ◽  
Nordiana Azlin Othman ◽  
Qamarul Ezani Kamarudin ◽  
Nor Shahida Mohd Jamail ◽  
...  
Keyword(s):  
Electric Field ◽  
Space Charge ◽  
Electrical Breakdown ◽  
Ethylene Vinyl Acetate ◽  
Low Density Polyethylene ◽  
Time Interval ◽  
Specimen Thickness ◽  
Low Density ◽  
Internal Electric Field ◽  
Acoustic Technique

<p>Pulsed electro-acoustic (PEA) is well known as a non-destructive technique for testing and describing space charge profiles in the insulation. Degradation due to moisture, ageing, external flashover, partial discharge and space charge are considered as insulation defects that is an issue in high voltage insulator. Space charge may distort the internal electric field that may lead to an electrical breakdown. For instance, a method based on an acoustic phenomenon can be used to describe the space charge profiles. This paper compares several earlier researches on different specimen of PEA method and reviews their results to find the space charge distribution profiles. The scope of the review includes types of methods used. The acoustic technique is considered for this study. It has been observed that the PEA technique successfully gives the same result as theoretical that is based on the obtained profile. Linear low-density polyethylene (LLDPE) composite demonstrates about 89 % lower charge density value compared to cross-linked polyethylene (XLPE) and polypropylene (PP) composite. While the electric field value of ethylene-vinyl acetate (EVA) sample is 75 % lower than low-density polyethylene (LDPE) sample. This study found that the time interval, specimen thickness and the electric field sway the space charge profiles. </p>

scholarly journals THE EFFECT OF FISH BONE ON THE DEVELOPMENT OF DENDRITES IN POLYETHYLENE AT BREAKDOWN VOLTAGE

2021 ◽  
Vol 5 (1(82)) ◽  
pp. 42-45
Author(s):  
E. Gojayev ◽  
Sh. Aliyeva ◽  
V. Salimova ◽  
Sh. Mekhtiyeva
Keyword(s):  
Thermal Decomposition ◽  
Electric Field ◽  
Induction Period ◽  
Breakdown Voltage ◽  
Strong Electric Field ◽  
Local Heating ◽  
Fish Bone ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Optimal Amount

The paper presents the results of a study of the effect of fish bone additives on the development of dendrites in low-density polyethylene during its breakdown. It was found that with the introduction of additives from fish bone in an optimal amount it promotes an increase in the induction period of the appearance of dendrites in lowdensity polyethylene, due to a slowdown in the process of the appearance of local heating near the tip in a strong electric field and the appearance of an initial defect due to thermal decomposition of the polymer.

scholarly journals An Experimental Study of the Crystallinity of Different Density Polyethylenes on the Breakdown Characteristics and the Conductance Mechanism Transformation under High Electric Field

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2657 ◽  
Author(s):  
Liwei Zhou ◽  
Xuan Wang ◽  
Yongqi Zhang ◽  
Peng Zhang ◽  
Zhi Li
Keyword(s):  
Experimental Study ◽  
Field Strength ◽  
Electric Field ◽  
High Field ◽  
High Electric Field ◽  
Low Density Polyethylene ◽  
Breakdown Field ◽  
Low Density ◽  
High Field Strength ◽  
Continuous Increase

In order to study the crystallinity of different density polyethylenes, this paper conducts an experimental study on the transformation of the conductance mechanism under a high electric field. In this experiment, X-ray diffraction (XRD), differentials scanning calorimetry (DSC), direct current (DC) breakdown of low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE) and high-density polyethylene (HDPE), as well as the conductivity characteristics under an electric field of 5–200 kV/mm are tested. In addition, the electric field–current density curves of the four kinds of polyethylene are fitted to analyze their conductance transition in non-ohmic regions under different high field strengths, through applying the mathematical formula of a variety of conductance mechanisms. The experimental results are as follows: as the density of polyethylene increases, the crystallinity increases continuously. Moreover, the continuous increase of crystallinity causes the electric conduction flow under the same field strength to decrease significantly. The field strength corresponding to the two turning points in the conductance characteristic curve increases simultaneously, and the breakdown field strength increases accordingly; through analysis, it is found that in the high field, as the electric field increases, the conductance mechanism develops from the ohmic conductance of the low field strength region to the bulk effect of the high field strength region (Poole–Frenkel effect). Then, it develops into the electrode effect to the high field strength (Schottky effect), although the threshold field strength of this conductance mechanism transition increases with the increase of crystallinity.

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