Resistance of Polyethylene Geonets against Thermo-Oxidation

2012 ◽  
Vol 730-732 ◽  
pp. 480-485
Author(s):  
José Ricardo Carneiro ◽  
Paulo Joaquim Almeida ◽  
M. Lurdes Lopes
Keyword(s):  
Tensile Strength ◽  
High Density Polyethylene ◽  
Research Team ◽  
Maximum Load ◽  
Tensile Tests ◽  
High Density ◽  
New Method

This paper studies the resistance of two high-density polyethylene geonets (manufactured with or without the additive Tinuvin 783) against thermo-oxidation. The materials were exposed to thermo-oxidation by two methods: oven-ageing tests at 100 °C and a new method developed by our research team. The damages suffered by the geonets were evaluated by tensile tests (determination of tensile strength, elongation at maximum load and toughness). Finally, the results obtained in the oven-ageing tests were compared with the results obtained by the new method.

A Study on Small Punch Test to Characterize Mechanical Property of Aged High-Density Polyethylene (HDPE)

2017 ◽  
Vol 734 ◽  
pp. 104-115 ◽  
Author(s):  
Bo Zhao ◽  
Jing Guo ◽  
Yu Xin Yu ◽  
Xue Tao Zhang ◽  
Tong Xu ◽  
...  
Keyword(s):  
High Density Polyethylene ◽  
Irradiation Time ◽  
Hardness Test ◽  
Maximum Load ◽  
Tensile Tests ◽  
High Density ◽  
Tensile Fracture ◽  
Small Punch Test ◽  
Small Punch ◽  
Punch Test

In this work, accelerated ultraviolet (UV) aging of high density polyethylene (HDPE) was prepared, and tensile tests, Shore D hardness test and small punch test (SPT) were carried out. The macroscopical morphology of tensile fracture and microscopical morphology of SPT have been observed successively. The result showed that HDPE aging significantly increased with the UV irradiation time, because of amount of microfiber dropping, the entanglement of molecular segments on the non-crystalline decreasing, and the difficulty degree of craze microfiber fracture reducing.After aging for over 504 hours, aged layer can be observed on specimens’ surface, meanwhile, polymer brittleness increased, tensile strength had no significant change, elongation at break declined 29.53%, and Shore hardness value increased 6.9%. SPT performed more susceptibly on aged HDPE, and the maximum load dropped more than 39%. This illustrated that SPT is more suitable for the assessment to aged HDPE, which could more focus on aged layer.

Resistance Welding Process Development and Optimization for Recycled High-Density Polyethylene (HDPE)

2015 ◽  
Author(s):  
Peter F. Baumann ◽  
Lucas Sendrowski
Keyword(s):  
Tensile Strength ◽  
Response Surface ◽  
High Density Polyethylene ◽  
Heating Temperature ◽  
Base Material ◽  
Heating Time ◽  
High Density ◽  
Hot Plate ◽  
Initial Testing ◽  
Hot Plate Welding

Large recycled high-density polyethylene (HDPE) structural members, difficult to manufacture by extrusion processes, have been created by the hot plate welding of simple plastic lumber sections. Hot plate welding generates better joint strength than any other welding method currently employed in plastic manufacturing. However, to achieve the desired temperature of the thick plate to melt the polymer uniformly, the process needs a high amount of heat energy requiring furnace (or resistance) heating of a considerable mass. A new method which could combine the heating element and a thin plate into one source could be more efficient in terms of heat loss and thus energy used. The premise of this investigation is to replace the hot plate with a very thin piece of high resistance nickel-chromium alloy ribbon to localize the application of heat within a plastic weld joint in order to reduce energy loss and its associated costs. This resistance ribbon method uses electrical current to reach an adequate temperature to allow for the welding of the HDPE plastic. The ribbon is only slightly larger than the welding surface and very thin to reduce the loss of excess heat through unused surface area and thick sides. The purpose of this project was to weld recycled high-density polyethylene (HDPE) using resistance welding and to match the tensile strength results considered acceptable in industry for hot plate welding, that is, equal to or greater than 80% of the base material strength. Information obtained through literature review and previous investigations in our laboratories established welding (heating) temperature and time as testing factors. Designed experimentation considered these factors in optimizing the process to maximize the weld tensile strength. A wide-ranging full-factorial experimental design using many levels was created for the initial testing plan. Tensile strengths obtained after welding under the various condition combinations of weld temperature and time revealed a region of higher strength values in the response surface. After the wide-range initial testing, the two control parameters, heating temperature and heating time, were ultimately set up in a focused Face Centered Cubic (FCC) Response Surface Method (RSM) testing design and the tensile strength response was then analyzed using statistical software. The results obtained indicated a strong correlation between heating time and heating temperature with strength. All welded samples in the final testing set exhibited tensile strength of over 90% base material, meeting the goal requirements. A full quadratic equation relationship for tensile strength as a function of welding time and temperature was developed and the maximum tensile strength was achieved when using 280°C for 60 seconds.

scholarly journals In-Situ Synthesis and Property Evaluation of High-Density Polyethylene Reinforced Groundnut Shell Particulate Composite

2021 ◽  
Vol 6 (4) ◽  
pp. 305-311
Author(s):  
Abdulmumin Adebisi ◽  
Tajudeen Mojisola ◽  
Umar Shehu ◽  
Muhammed Sani Adam ◽  
Yusuf Abdulaziz
Keyword(s):  
Tensile Strength ◽  
Water Absorption ◽  
Impact Energy ◽  
High Density Polyethylene ◽  
In Situ Synthesis ◽  
High Density ◽  
Compression Moulding ◽  
Melt Mixing ◽  
Groundnut Shell

In-situ synthesis of high-density polyethylene (HDPE) reinforced groundnut shell particulate (GSP) composite with treated GSP within the range of 10-30 wt% at 10 wt% has been achieved. The adopted technique used in the production of the composite is melt mixing and compounding using two roll mills with a compression moulding machine. Properties such as hardness, tensile strength, impact energy and water absorption analysis were examined. The result revealed that addition of GSP increases the hardness value from 22.3 to 87 Hv. However, the tensile strength progressively decreased as the GSP increases in the HDPE. This trend arises due to the interaction between neighbouring reinforced particulate which appears to influence the matrix flow, thereby inducing embrittlement of the polymer matrix. It was also observed that water absorption rate steadily increased with an increase in the exposure time and the absorbed amount of water increases by increasing the wt% of the GSP. Analysing the obtained results, it was concluded that there were improvements in the hardness, tensile strength, impact energy and water absorption properties of the HDPE-GSP polymer composite when compared to unreinforced HDPE. On these premises, GSP was found as a promising reinforcement which can positively influence the HDPE properties of modern composites.

scholarly journals Method for determining the maximum load of consumers in city power supply systems

2019 ◽  
Vol 139 ◽  
pp. 01078 ◽  
Author(s):  
A.G. Saidkhodjaev ◽  
A.M. Najimova ◽  
A.K. Bijanov
Keyword(s):  
Power Supply ◽  
Maximum Load ◽  
High Accuracy ◽  
New Method ◽  
Electrical Networks ◽  
Electric Networks ◽  
Reliable Determination ◽  
Supply Systems

In this article, we propose a new method for determining the maximum load of electric consumers in urban electric networks, which differs from existing methods in more accurate and reliable determination of the maximum loads. Based on the determination of the maximum loads of the objects of urban electrical networks, it is concluded that the proposed methods are determined by high accuracy and minor errors.

Tensile and flammability characterizations of corn straw slagging/high-density polyethylene composites

2019 ◽  
Vol 33 (11) ◽  
pp. 1466-1477
Author(s):  
Qingfa Zhang ◽  
Wenyu Lu ◽  
Liang Zhou ◽  
Donghong Zhang ◽  
Hongzhen Cai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Tensile Strength ◽  
Flame Retardant ◽  
High Density Polyethylene ◽  
Oxygen Index ◽  
High Density ◽  
Corn Straw ◽  
Scanning Calorimetry ◽  
Scanning Electron

Biocomposites were prepared with corn straw slagging (CSS) and high-density polyethylene (HDPE) at four loading levels (10, 20, 30, and 40 wt%) by extrusion method. CSS/HDPE composites were tested by tension, oxygen index meter, differential scanning calorimetry, X-ray diffraction, and the scanning electron microscopy. The scanning electron microscopy showed that CSS was dispersed uniformly in the HDPE matrix and strong interfacial interaction was achieved, which had an important influence on the tensile strength of the composites. The tensile strength of the composites could be improved with proper increase of CSS and reached maximum value at 30 wt% content. Furthermore, the addition of CSS played an important role in improving the flame-retardant ability of CSS/HDPE composites, and the limited oxygen index was 31.26% at 40 wt% content, good flame-retardant effect achieved.

scholarly journals Blend of cassava starch and high-density polyethylene with green tea for food packaging

2020 ◽  
Vol 11 (1-2) ◽  
pp. 3-14
Author(s):  
Cassiano MN Romagnolli ◽  
Gabriela P Leite ◽  
Tiago AR Rodrigues ◽  
Carolina L Morelli
Keyword(s):  
Green Tea ◽  
High Density Polyethylene ◽  
Food Packaging ◽  
Antibacterial Properties ◽  
Food Products ◽  
Tensile Tests ◽  
Thermoplastic Starch ◽  
Active Packaging ◽  
High Density ◽  
Service Lifetime

Plastic packagings are widely used for several food products. Considering the relatively short service lifetime of this application, it is important to perceive in the search of eco-friendly alternatives to this market, such as polymers from renewable sources, as thermoplastic starch and “green” polyethylene. The incorporation of an antibacterial agent to the packaging can extend food shelf life. Camellia sinensis is a plant with known antibacterial properties used in the preparation of “green tea.” In the present work, green tea was incorporated to a blend of cassava thermoplastic starch and high-density polyethylene (HDPE) by melt extrusion, aiming application as active packaging. Films were obtained by thermopressing and characterized through infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and tensile tests. Their antibacterial properties were evaluated against Staphylococcus aureus and Escherichia coli. The results indicated that the material developed has potential for food packaging applications. Moreover, the methodology applied for green tea incorporation in the Starch/HDPE films can be extended for many extracts from natural components, contributing to the advancement of research in the development of active packaging for food products. To the best of our knowledge, no previous work studied the properties of starch/HDPE blend with green tea.

Investigations into the mechanical, morphological and thermal analyses of friction stir processing of high-density polyethylene composites

2016 ◽  
Vol 232 (7) ◽  
pp. 1193-1200 ◽  
Author(s):  
Jicheng Gao ◽  
Chao Li ◽  
Yifu Shen
Keyword(s):  
Tensile Strength ◽  
Friction Stir Processing ◽  
High Density Polyethylene ◽  
Thermal Analyses ◽  
Experimental Tests ◽  
Traverse Speed ◽  
High Density ◽  
Scanning Calorimetry ◽  
Friction Stir ◽  
Polyethylene Composites

The aim of this work is to fabricate the high-density polyethylene–copper composites by submerged friction stir processing at different traverse speeds. The scanning electron microscopy is used to analyze the distribution of microstructure and particles. The experimental results indicated that the macrostructure morphology, microstructure and tensile strength vary depending on the traverse speed. Compared with the pure high-density polyethylene, Cu-filled polymer composites showed lower tensile strength and higher microhardness. The maximal values of the tensile strength and microhardness were achieved at traverse speeds of 30 and 15 mm/min, respectively. The thermal properties of Cu-filled high-density polyethylene composites were studied by differential scanning calorimetry. The crystalline content of the composites was decreased due to the addition of copper. From the experimental tests, it can be concluded that submerged fiction stir processing has a great potential for producing polymer–metal composites.

scholarly journals Lifetime assessment of high-density polyethylene–silica nanocomposites

2019 ◽  
Vol 9 ◽  
pp. 184798041984998 ◽  
Author(s):  
A Dorigato ◽  
LE Govaert ◽  
A Pegoretti
Keyword(s):  
Fumed Silica ◽  
High Density Polyethylene ◽  
Tensile Tests ◽  
Testing Temperature ◽  
High Density ◽  
Time To Failure ◽  
Creep Tests ◽  
Polyethylene Matrix ◽  
Significant Drop ◽  
Fumed Silica Nanoparticles

In this work, the effect of fumed silica on the long-term resistance of high-density polyethylene was investigated. Different amounts of functionalized fumed silica nanoparticles were dispersed in a high-density polyethylene matrix by melt compounding, and compression molded specimens were tested under tensile mode in the quasi-static ramp and creep conditions. In particular, tensile tests at different speeds and temperatures and the subsequent application of the modified Ree–Eyring model allowed the determination of an analytical expression correlating the strain rate with the yield stress and the testing temperature. It was demonstrated that the introduction of fumed silica led to a significant drop in the deformation rate, especially at elevated filler amounts. Creep tests showed that the nanofiller addition led to a progressive reduction of the critical deformation values. The application of this engineering approach evidenced how nanosilica introduction led to a systematic increase of the time-to-failure values, and good accordance between theoretical prediction and experimental measurements was found.

Mechanical Properties of Selected Types Thermoplastic Materials Modified by High Doses of Ionizing Beta Radiation under Thermal Stress

2017 ◽  
Vol 756 ◽  
pp. 35-43
Author(s):  
Martin Bednarik ◽  
Adam Skrobak ◽  
Vaclav Janostik
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Stress ◽  
High Density Polyethylene ◽  
Thermal Loading ◽  
Tensile Modulus ◽  
High Density ◽  
Beta Radiation ◽  
Measurement Results ◽  
High Doses

This study deals with the effect of high doses of ionizing beta radiation (132, 165 and 198 kGy) on mechanical properties (tensile strength, tensile modulus and elongation) of low and high density polyethylene under thermal loading. The measurement results of this study indicate that with an increasing dose of radiation grows tensile strength and modulus of low and high density polyethylene. For all examined materials were also observed changes in elongation.

Sign in / Sign up

Export Citation Format

Share Document