Electric Breakdown of Solution-Grown Polyethylene Films without Spherulite

1982 ◽  
Vol 21 (Part 1, No. 8) ◽  
pp. 1117-1120 ◽  
Author(s):  
Keiichi Kitagawa ◽  
Goro Sawa ◽  
Masayuki Ieda
Keyword(s):  
Electric Breakdown ◽  
Polyethylene Films

scholarly journals Influence of Field Grading in Setup for Electric Breakdown Testing of Polyethylene Films

2019 ◽  
pp. 47-51
Author(s):  
Johan Andersson ◽  
Ulf H. Nilsson ◽  
Susanne Nilsson ◽  
Hedvig Pollak ◽  
Nilena Nilsson
Keyword(s):  
Silicone Rubber ◽  
Breakdown Strength ◽  
High Reliability ◽  
Field Enhancement ◽  
Electric Breakdown ◽  
Electric Strength ◽  
Short Term ◽  
High Permittivity ◽  
Polyethylene Films ◽  
Insulation Materials

High dielectric strength of solid electrical insulation materials for high voltage applications is essential for high reliability and long-term performance.The IEC 60243 and ASTM D149 both describe very similar test methods to determine the short-term electric strength of solid insulation materials. A test sample, usually thin plaque, is placed in an electrode system with surrounding insulating oil. The voltage is then steadily increased until an electric breakdown occurs. Despite the relatively simple test setup, testing materials with high electric strength can be difficult. The breakdown channel is often located outside the active testing area of the electrodes and found at the electrode edge at the triple point between the electrode, test object, and surrounding oil.In this study, we have investigated different possibilities to control the electrical field enhancement in the vicinity of the electrode edges using silicone rubber, field grading silicone rubber, and a high permittivity oil. The testing was performed with semi-spherical electrodes and electrodes as recommended in IEC 60243 on polyethylene films. Electrodes covered with the field grading rubber increased the short-term breakdown strength compared to standard testing without modification. The high permittivity oil and silicone rubber seemed to have limited effect on the breakdown strength.

The analysis of “Gels” in polymer films

1989 ◽  
Vol 47 ◽  
pp. 362-363
Author(s):  
G. M. Brown ◽  
D. F. Brown ◽  
J. H. Butler
Keyword(s):  
Molecular Weight ◽  
Film Industry ◽  
Local Stress ◽  
Melt Index ◽  
Polyethylene Films ◽  
Crosslinked Polymer ◽  
Polymeric Gels ◽  
Mineral Particles ◽  
Polymeric Species ◽  
Special Concern

The term “gel”, in the jargon of the plastics film industry, may refer to any inclusion that produces a visible artifact in a polymeric film. Although they can occur in any plastic product, gels are a principle concern in films where they detract from the cosmetic appearance of the product and may compromise its mechanical strength by acting as local stress concentrators. Many film gels are small spheres or ellipsoids less than one millimeter in diameter whereas other gels are fusiform-shaped and may reach several centimeters in length. The actual composition of gel inclusions may vary from miscellaneous inorganics (i.e. glass and mineral particles) and processing additives to heavily oxidized, charred or crosslinked polymer. The most commonly observed gels contain polymer differing from the bulk of the sample in its melt viscosity, density or molecular weight.Polymeric gels are a special concern in polyethylene films. Over the years and with the examination of a variety of these samples three predominant polymeric species have been observed: density gels which have different crystallinity than the film; melt-index gels in which the molecular weight is different than the film and crosslinked gels which are comprised of crosslinked polyethylene.

Electric breakdown in gases

1958 ◽  
Vol 4 (40) ◽  
pp. 192-194
Author(s):  
A.E.D. Heylen
Keyword(s):  
Electric Breakdown

scholarly journals Low-Density Polyethylene Films Carrying ferula asafoetida Extract for Active Food Packaging: Thermal, Mechanical, Optical, Barrier, and Antifungal Properties

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Razieh Niazmand ◽  
Bibi Marzieh Razavizadeh ◽  
Farzaneh Sabbagh
Keyword(s):  
Polymer Matrix ◽  
Food Packaging ◽  
Barrier Properties ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Optical Barrier ◽  
Leaf Extracts ◽  
Polyethylene Films ◽  
Active Food Packaging ◽  
Ferula Asafoetida

The physical, thermal, mechanical, optical, microstructural, and barrier properties of low-density polyethylene films (LDPE) containing ferula asafoetida leaf and gum extracts were investigated. Results showed a reduction in elasticity and tensile strength with increasing extract concentration in the polymer matrix. The melting temperature and enthalpy increased with increasing concentration of extracts. The films containing extracts had lower L∗ and a∗ and higher b∗ indices. The films containing leaf extract had more barrier potential to UV than the gum extracts. The oxygen permeability in films containing 5% of leaf and gum extracts increased by 2.3 and 2.1 times, respectively. The morphology of the active films was similar to bubble swollen islands, which was more pronounced at higher concentrations of gum and leaf extracts. FTIR results confirmed some chemical interactions of ferula extracts with the polymer matrix. At the end of day 14th, the growth rate of Aspergillus niger and Saccharomyces cerevisea in the presence of the PE-Gum-5 reduced more than PE-Leaf-5 (3.7 and 2.4 logarithmic cycles, respectively) compared to the first day. Our findings showed that active LDPE films have desire thermo-mechanical and barrier properties for food packaging.

The use of recycled low‐density polyethylene films from protective prepreg for the development of nanocomposites with bentonite clay

2021 ◽  
pp. 50559
Author(s):  
Pamela Rodrigues Passos Severino ◽  
Natália Ferreira Braga ◽  
Guilherme Ferreira Morgado ◽  
Juliano Marini ◽  
Orestes Ferro ◽  
...  
Keyword(s):  
Bentonite Clay ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Polyethylene Films ◽  
Recycled Low Density Polyethylene

Radio pulse generation at electric breakdown of polypropylene thin film

2020 ◽  
Author(s):  
Viktoria Kapralova ◽  
Vladimir Pakhotin ◽  
Nicolay Sudar
Keyword(s):  
Thin Film ◽  
Radio Pulse ◽  
Pulse Generation ◽  
Electric Breakdown
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