Plastic Insulation Research Articles

Method of calculation of temperature parameters and servic life of cable lines with a voltage of 10 kV

RELEVANCE. The paper presents a method for calculating the temperature parameters and service life of cable lines (CL) with a voltage of 10 kV for various types of insulation and operating conditions. Dependencies have been developed that are recommended for clarifying the parameters of the CL, taking into account different operating modes. The results of the study can be used for practical application and will contribute to reducing the number of accidents resulting from thermal breakdowns of CL due to incorrect selection of CL parameters.PURPOSE. To investigate the temperature parameters of 10 kV CL, taking into account various methods of laying them and load factors for the climatic conditions of the Republic of Tatarstan.METHODS. Methods for calculating the temperature parameters of CL and their service life, methods of statistical data processing, and methods for approximating functions are used. The ELCUT software package is used to visualize the results obtained during calculations. results. The results of calculations of the temperature parameters of 10 kV CL with paper-impregnated insulation (BPI), polyvinyl chloride plastic (PVC) insulation and polyethylene (PE) insulation during their laying in air, in the ground, in the ground in a pipe, taking into account the load coefficients of cable lines, are presented. The results of calculations of the service life of the CL are shown. The values of the optimal load coefficients of the CL are determined to reduce the rate of thermal aging of insulation under various operating conditions. conclusion. The results of the conducted research and calculations can be used to evaluate and select the optimal load of 10 kV CL at the stages of operation and design of power supply systems.

Comprehensive Analysis of Insulator Performance in High Voltage Transmission Systems: Implications for Efficient Power Transfer

This research article examines the performance of insulators in high-voltage transmission systems, specifically focusing on their role in facilitating efficient power transfer along transmission lines. The study evaluates different types of insulators used in various geographical regions and assesses their withstand voltage characteristics. The research demonstrates that glass insulators outperform plastic and ceramic insulators in terms of electric field behavior. The study also investigates the behavior of AC-energized insulators in polluted and non-polluted conditions, providing insights for improving HVAC insulation design in polluted environments. The research recommends further experiments to examine insulator behavior under different applied voltage scenarios. Overall, the study emphasizes the importance of insulators in high-voltage transmission systems and provides valuable insights for developing advanced insulator technologies to enhance power transfer efficiency.

Mechanical and electrical performance of glass fiber reinforced plastic insulation for cryogenic application in fusion magnet irradiated in fast breeder reactor

In a superconducting (SC) magnet fusion reactor, the insulation material used has to withstand significant fluxes of neutrons and neutron-induced gamma radiation. Epoxy-based glass fiber-reinforced plastic (GFRP) composites are the insulation system for fusion magnets and are highly demanding. This insulation system requires excellent mechanical and electrical performance under mixed neutron and gamma radiation at cryogenic temperatures. The insulation material developed consists of boron-free S-glass fiber impregnated with a two-component modified Diglycidyl ether of Bisphenol-A (DGEBA) epoxy resin. An anhydride-cured DGEBA resin system is not suitable for cryogenic temperatures. Therefore, to overcome this thermal stress issue in cryogenic components of SC magnets, a high-toughness, flexible, aromatic amine-cured epoxy resin system was developed for the insulation system. In order to assess the radiation resistance for mechanical and electrical properties, the composite samples were irradiated in the fast breeder test reactor (FBTR) at IGCAR, Kalpakkam, India. The irradiation experiment was carried out for a neutron fluence of 1.0E+21 n/m2 and a gamma dose of 0.4 MGy at a full reactor power of 32 MWt. The tensile strength, interlaminar shear strength, and breakdown strength measurements were investigated before and after irradiation at room temperature and 77 K. The test results indicate that no significant degradation was observed in the properties of the irradiated samples up to the above-mentioned radiation doses.

Environmental potential of fungal insulation: a prospective life cycle assessment of mycelium-based composites

PurposeBio-based insulation materials are one of the most promising solutions for reducing the environmental impacts of building envelopes. Among these materials, the environmental benefits of mycelium-based materials have merely been investigated, despite their promising technical and thermal properties. In this paper, we perform a first prospective cradle-to-grave life cycle assessment (LCA) of mycelium-based composite blocks.MethodsAn attributional cradle-to-gate LCA of the laboratory production of mycelium-based composites was first performed, including 11 environmental impact indicators. Then, scenarios were defined to scale up the technology to the level of industrial production, including the remaining life cycle modules to perform a cradle-to-grave analysis. Biogenic and metabolic carbon were considered by applying the static −1/+1 approach and following the current LCA standards. Future-oriented energy and transport mixes were also included as an additional scenario, systematically modifying both the foreground and background data. Finally, the industrially scaled-up technology and alternative insulation materials were compared with these future conditions (as applied to both materials).Results and discussionConsidering climate change, the results are encouraging in comparison to those for traditional plastic insulation, but do not necessarily surpass those for other existing materials such as rock wool. However, trade-offs are observed in other indicators, for which mycelium-based composites tend to perform worse than traditional insulation materials. The industrial scale-up reduced impacts for most indicators, but a considerable trade-off was observed with regard to terrestrial ecotoxicity. The main driver for the remaining greenhouse gas (GHG) emissions was found to be the electricity use during the manufacturing phase. We consider the inclusion of the other life cycle stages as relevant, as this increased the GHG emissions by 10%. Limitations of the current LCA standards, however, are noted and discussed, especially regarding the cascading use of biogenic materials, and highlight the relevance of this case study.ConclusionsMycelium-based composites show a potential for future development, but careful attention should be paid to reducing electricity needs in their manufacturing process. Further improvements could also be made by using fast-growing biogenic materials as a substrate. In particular, we encourage researchers to include all of the life cycle stages in future studies, especially if biogenic emissions are considered.

Fabrication and testing of two-dimensional Micro-Edge Gas Chamber (2D-MEGC)

This work proposes using silver flat ribbon cable to fabricate a new type of position-sensitive gaseous detector. This structure consists of a thin conductive silver of flat ribbon cable (anodes) and thicker copper sheets (cathodes) separated by a plastic insulator. To fix the position of the anodes and the cathodes, a holder compressed the layers. The layers are cut from the edges and polished at several steps to have a smooth surface. These arrays of anodes and cathodes, created by the proposed method, act as a two-dimensional position-sensitive proportional detector. Applying a suitable voltage between the anodes and cathodes produces a strong electric field near the vicinity of the anodes. This electric field multiplies primary electrons generated by ionizing radiation. The experimental results show that for the proposed two Dimensional Micro Edge Gas Chamber (2D-MEGC), at HV1=350 with the gas mixture of (Ar 85% - CO2 15%), the maximum multiplication factor without electric discharge is around 250. All pixels were separately connected to the preamplifier-amplifier setup to test the position sensitivity of 2D-MEGC. As expected for a non-collimated alpha source, the maximum recorded interactions are related to the closest pixel to the radioactive source. The Raether limit is a good benchmark concerning the quality of fabricated gaseous detectors. In the best design conditions, this value for Micro Strip Gas Chamber (MSGCs) is 4 × 107. For the fabricated 2D-MEGC, this number is 2.5 × 107. This result shows that the proposed 2D-MEGC performs well despite its simple structure and fabrication.

Change of polymeric gel structure of several foamed plastic insulations deteriorated by moisture

Foamed plastic insulations require long-term performance under sustainable development goals. However, in recent years, it has been reported that foamed plastic insulations installed in high-humidity environments, such as under waterproof sheets on a rooftop, absorb moisture and subsequently increase thermal conductivity.The study aims to estimate both moisture absorption and changes in physical properties of foamed plastic insulations after exposure to high humidity and discuss the moisture-induced deterioration based on the results of several experiments.We observe what changes occur in three types of foamed plastic insulation, phenolic foam, polyurethane foam, and extruded polystyrene foam, in a deterioration condition with moisture. In the first step, we verify that the moisture exists in what form and whether moisture condenses inside or blends with the material after deterioration occurs. Precisely, comparing weight changes before and after high-temperature humidity deterioration with two test results. One is changing a polymeric gel structure of the deteriorated insulation with X-ray CT, and another is the amount of adsorbed water vapor on the surface of each insulation with the gas adsorption method. Results from these studies refer that the deteriorated phenolic foam and moisture are assumingly miscible to transform polymeric gel structure.The second step compares how moisture deterioration affects insulation’s thermal characteristics. We evaluated in our previous study when insulations are exposed to the seasonal humidity cycle to apply typical seasonal fluctuation in Northeast Asian countries, affecting more critical damage than a persistent condition to samples. Therefore, we examine the relationship between thermal characteristics and moisture deterioration effect in humidity fluctuations. Resultantly, the phenolic foam’s polymeric gel structure is changed, and its thermal property is affected by humidity swings.The results provide a part of the moisture deterioration mechanism, miscible behavior between moisture and foamed plastic insulations to change polymeric gel structure, which shifts thermal properties.

Influence of nest box design on internal microclimate: Comparisons of plastic prototypes

AbstractHollow‐dependent fauna are declining worldwide, due primarily to the widespread clearing of hollow‐bearing trees. Artificial cavities such as timber and plywood boxes are commonly used to increase hollow availability, yet there is increasing evidence that they are poor facsimiles of natural cavities, characterized by lower insulative properties and a shorter field life. We evaluated whether plastic materials could create a nest box with a stable thermal profile that more closely resembles the complex shapes and textures of natural tree hollows while containing fewer mechanical joins that represent potential failure points when installed. We developed three sets of prototype nest boxes comprising various combinations of plastic density (10%, 25% and 50%), insulation (single vs. double wall with or without sawdust between them), nesting chamber (with or without timber inserts) and bedding (with or without decomposed heartwood) and compared their thermal performance in a temperature‐controlled laboratory to compare internal temperature and relative humidity. We found double‐walled plastic nest box with an internal timber‐lined chamber was best able to buffer ambient temperature fluctuations, consistently recording internal temperatures of 6+°C below maximum ambient temperature, maintaining high levels of relative humidity (76%–92%) when furnished with decomposed timber heartwood. This design also performed better during a simulated hot day; internal temperatures exhibiting twice the lag time of single‐walled designs, noting that plastic density had little influence on internal conditions. While the recruitment and protection of hollow‐bearing trees must be a priority, this work shows significant potential in improving the design and functionality of artificial hollows that are critical to the conservation of hollow‐dependent species.

Analytic Methods of Foamed Plastic Insulation Deteriorated by Moisture

AbstractFoamed plastic insulations installed into buildings are now expected to be long‐lasting materials. However, in recent years, it has been reported that foamed plastic insulations installed in high‐humid environments, such as under waterproof sheets on a rooftop, absorb moisture, and subsequently increase thermal conductivity. This paper studies both moisture absorption and changes in physical properties of foamed plastic insulations after exposure to high humidity and discusses the moisture‐induced deterioration based on the results of several experiments.

An Effective Expanded Graphite Coating on Polystyrene Bead for Improving Flame Retardancy.

Although foamed plastic insulation is widely used in construction in the Korean market, it is vulnerable to fire. To improve the flame retardancy, the method of flame-retardant coating with the EG in water-soluble state on the surface of expanded polystyrene (EPS) beads has been widely used. However, polystyrene beads coated with a water-soluble flame retardant easily separate the coated flame retardant in manufacturing. In this study is devised a flame-retardant coating and two steps of coating process for adhering the flame-retardant coating film evenly to the surface of the polystyrene bead without exfoliation. It was analyzed whether a flame-retardant EPS (FR-EPS) with excellent flame retardancy could be manufactured using polystyrene beads coated in this way. Ten FR-EPS samples satisfied the HF-1 and V-0 levels in horizontal and vertical burning tests, respectively. The THR of eight FR-EPS samples for ten minutes did not exceed 8 MJ∙m−2 and the maximum HRR did not exceed 200 kW∙m−2 for more than ten consecutive seconds. FR-EPS passed the building material standard of semi-nonflammability in Korean regulations, in contrast to commercial EPS, which have not passed the semi-nonflammability standard. It was also analyzed how effective the designed coating is in this study, comparing it with composites that were planned to improve the flame resistance of polystyrene, as reported in the literature. Flame Retardancy Index (FRI) values of FR-EPS proved the “excellent” level and had higher values compared with other polystyrene composites. These results demonstrated that the coated EPS containing a water-soluble flame retardant manufactured from EG and two steps of application with the coating solution achieved fire safety standard regulations.

Effects of Atmospheric Pressure on Water Absorption in Plastic Insulation – A Laboratory Investigation

Abstract Plastic insulation materials, particularly polystyrene insulation, are widely used in the construction sector because of their good insulating capabilities and mechanical stability. However, in many building applications, the insulation materials are exposed to high levels of moisture over prolonged periods, which increases the thermal conductivity of the material and may facilitate growth of fungi. In order to minimize the extent and impact of moisture absorption in plastic insulation, more knowledge is sought on the exact process by which water is absorbed. In this article, tests of water absorption by complete immersion are carried out on expanded polystyrene (EPS) and extruded polystyrene (XPS), following Method 2A of the European Standard EN 12087:2013, Thermal Insulating Products for Building Applications - Determination of Long Term Water Absorption by Immersion, but over a longer duration (227 days) and with more frequent measurements than mandated by the standard. Over 91 days, EPS was found to absorb an amount of water approximately four times its dry mass. Observations indicate that the water absorption of EPS is significantly influenced by fluctuations in atmospheric pressure. A drop in pressure of 50 hPa between two measurements 1 week apart led to a 15 wt.% decrease in the water content of submerged EPS samples. XPS was found to absorb significantly less moisture than EPS, with a weight increase less than 15% over 91 days and with negligible influence from variations in atmospheric pressure. The impact of atmospheric pressure fluctuation is currently not accounted for in any testing standards. As such, this article uncovers a major source of uncertainty in the testing procedure of EN 12087:2013 and its ASTM counterparts.

Strategi Bertahan Pengemudi Ojol di Masa Pandemi Covid-19 di Kota Makassar

The online motorcycle taxi application (ojol) has become one of the most widely used applications by the people of Indonesia. However, since the outbreak of Covid-19 in Indonesia, including Makassar, something has been "missing" from the applications, such as Gojek and Grab. At Gojek there is no longer a motorbike ordering menu (Goride); while in Grab, the GrabBike menu also disappeared. The menu disappeared as a result of government policies through the implementation of Large-Scale Social Restrictions (PSBB) in order to break the chain of the spread of Covid-19. In order to continue to work in the midst of the Covid-19 pandemic, ojol drivers use various strategies. This article focuses on how the strategy of ojol drivers to survive during the Covid-19 pandemic.
 Using qualitative approach, this study was carried out in Makassar as a metropolitan city, as one of the cities where ojol transportation drivers operate, as well as the city with the highest number of Covid-19 cases. There are fifteen informants who participated in this study, consisting of eight Gojek drivers and the rest were Grab drivers. Data was collected using the combination of observation and in-depth interview techniques. The study shows that the income of ojol drivers has decreased drastically since the Covid-19 outbreak, as the consequence of government policies through the PSBB which limited people’s mobility, including ojol drivers. In order to survive, ojol drivers use various strategies, such as living in a state of frugality, taking additional work (such as selling food in offline system, being a construction worker, opening a small tavern, etc.).
 When conditions gradually improve and the PSBB policy is relaxed, they can again work with the application of general health protocols (3M: wearing masks, washing hands, and maintaining distance) and the application of specific health protocols is also enforced (such as the use of plastic insulators for taxi drivers or passengers carrying their own helmets for motorcycle taxis), so that they can continue to work to make a living in the middle of pandemic Covid-19, even though the income is not yet fully recovered.

PEMBUATAN ANTI DROPLED BOARD BAGI PEDAGANG PASAR MENYAMBUT NEW NORMAL WABAH COVID 19

Facing the new normal era of the Covid 19 outbreak, people are returning to activities like before the Covid 19 outbreak, amid the transmission of the Covid outbreak which is still quite high, all people are required to be able to maintain distance and transmission of firus covid 19 through dropled. For people who work in traditional market markets who are susceptible to contracting the Covid 19 virus, they need an anti-dropled board insulation tool so that dropled splashes are blocked. The goal is to find a solution to prevent the spread of the corona / Covid virus 19 Making anti-dropled boards for market traders to welcome the new normal 19 outbreak. The results of this PKM goal are according to the target, namely preventing the COVID-19 pandemic. In response to the new normal by maintaining vigilance against the transmission of covid, all caution must be done, especially traditional market traders, to prevent the spread of the Covid 19 virus through droplets, it is necessary to make special tools Virus prevention through these droplets is called a thick PVC plastic insulator / anti-dropled board combined with a lightweight iron frame so that communication between traders and buyers does not occur but is blocked by the tool.

Improving on the Fire Safety of EPS Foamed Plastic Insulation Materials Using Expanded Graphite

Improving on the Fire Safety of EPS Foamed Plastic Insulation Materials Using Expanded Graphite

Numerical Studies of the Electric Field of a Power Cable with Sector Strands and Impregnated Paper–Plastic Insulation for a Voltage of 20 kV

In power cables with sector current-carrying strands (SCSs), impregnated with paper insulation, there is a tangential electric field component along the layers. The permissible electric strength along the paper tapes is about ten times less than in the normal direction, which is taken into account when developing three-wire power cables impregnated with paper insulation for voltages of 20 and 35 kV. The use of modern paper—plastic-impregnated insulation having higher performance characteristics than conventional impregnated paper insulation, can promote the creation of more efficient cable designs with individually shielded sector-shape conductors in a common lead sheath for a voltage of 20 kV. Each insulated strand of such cables has a copper shield, and so it is enough to consider the electric field in the cross section of the insulation of one SCS. The electric potential distribution is described by the Laplace differential equation, the solution of which is implemented by the finite element method using the Ansys Maxwell software package. A numerical study of the electric fields has been carried out for power cables with SCSs that have a cross section of 400 mm2 for a voltage of 20 kV. The curvature radius of the cable sectors varied from 5 to 7 mm with an insulation thickness of 7 to 9 mm. Based on the research results, the maximum values of the normal and tangential electric field components depending on the curvature radius of the sector strand and insulation thickness have been obtained. Insulation areas have been allocated in which the maximum absolute values of the tangential electric field strength components have been observed. The allowable values of the sector curvature radius and the thickness of insulation for power cables with paper-impregnated insulation for 20 kV have been determined.

The Thermal Conductivity of 3D Printed Plastic Insulation Materials-The Effect of Optimizing the Regular Structure of Closures.

In the interest of environmental protection, attention should be paid to improving energy efficiency, through the use of appropriate insulations. They can be used in the construction industry, for plastic window frames, and the thermal insulation of buildings. It is also possible to use these materials in the electronics industry, for hermetic casings of devices, in the aviation industry, as well as in the food industry, as collective packaging for frozen food. The technology of using additive 3D printing to create prototype insulating materials made of plastic is proposed in this article. Multi-layer materials, with quadrangle, hexagonal, and triangle closures were designed and printed. A mathematical model was developed, and then experimentally verified. Quadrangle and hexagonal structures were shown to be useful, and triangle structures to be of little use. The optimal size of closure was determined to be 10 mm, with no convection, and 6 mm, with possible convection. The lowest thermal conductivity of the insulation was 0.0591 W/(m·K) for 10 mm single-layer quadrangle and hexagonal closures with an insulation density of 180 kg/m3.

Preparation and thermophysical performance of diatomite-based composite PCM wallboard for thermal energy storage in buildings

Phase change materials (PCMs) are commonly used in latent heat storage systems. Two novel diatomite-based, shape-stabilized composite phase change materials (PCMs) were compounded by incorporating organic alcohol PCMs into diatomite. The chemical, morphological, and thermal performances of the composite PCMs were evaluated using Fourier transform infrared spectroscopy, scanning electron microscopy, and differential scanning calorimeter analyses. As the organic alcohol PCMs were incorporated into the diatomite pore structure, the resulting composite PCMs presented good chemical stability. The phase-change temperatures of the two composite PCMs (designated TC35 and HC42) were in the ranges 33.1–35.1 °C and 41.7–42.7 °C, respectively. The latent heats were 90.5 ± 1.5 J/g and 92.6 ± 1.3 J/g, respectively. PCM-contained wallboards (PCMWs) were then fabricated and attached to the exterior surface of a test room wall to evaluate their thermal performance against that of polystyrene plastic insulation wallboards. The impacts of both the wallboard location and the phase transition temperature on the PCMWs were investigated. It was observed that the external surface temperature of the PCMW was lower than that of the traditional polystyrene plastic insulation wallboard owing to the former's more favorable thermal storage capacity. The thermal resistance of the PCMWs, however, was too small to reduce the indoor cooling loads in summer. Enhancing the thermal insulation performance of the wallboard is required in order to obstruct the outdoor-to-indoor heat transfer and thus save daytime energy; however, this is unfavorable for heat dissipation at night. The optimal phase transition temperature was found to depend on not only the outdoor meteorological conditions but also the location of the PCMW.

Façade requirements in the 2021 edition of the US International Building Code

SummaryFollowing the Grenfell Tower tragedy in London, the US requirements for fire safety of façades were revisited. The 2018 edition of the key US regulation, the IBC, had associated shortcomings, in spite of the fact that no US fire losses with fatalities have resulted from complying wall assemblies. This is contained in Chapter 14, Exterior Walls.The key fire test used for exterior assemblies (façades) in the US is a large‐scale test, namely NFPA 285. The test evaluates the vertical and lateral flame‐propagation potential of any exterior wall assembly system with combustible components, typically including insulation. The systems are evaluated as flat specimens containing neither corners nor projections. The “typical” fire scenario modeled corresponds to a fire in a room, venting through a window opening and exposing the exterior wall from both inside and outside. The fire test equipment is a two‐story structure with a test room on each story and a window opening. Two burners expose the test specimen: one is placed inside the ground floor test room and the other one is placed outside, near the window opening. The fire test contains pass/fail criteria based on measuring the following phenomena:• Vertical and lateral flame propagation over the exterior,• Vertical and lateral flame propagation inside the combustible core,• Vertical flame penetration into the second story,• Temperature rise on the exterior and within any wall cavities.The IBC includes requirements for a variety of products and also detailed requirements for three specific assemblies: metal composite materials, high‐pressure decorative exterior‐grade compact laminates, and exterior insulation and finish systems (known in Europe as external thermal insulation composite systems). It also includes requirements for fire‐retardant‐treated wood, water‐resistive barriers, and exterior wall coverings, such as siding and very detailed requirements for foam plastic insulation (as tested on its own and within the assemblies). This work shows multiple changes made when revising the 2018 IBC to the 2021 IBC.Concerns have been expressed regarding the applicability of NFPA 285 to fire scenarios associated with the twin effects of either (a) vertical (such as angled walls) or horizontal (such as balconies) projections or (b) wind. No changes to that effect were made for the 2021 IBC.Three concepts were discussed in detail but not adopted into the code using the “16 ft. parallel panel test” (from FM 4880), either as an alternate or as an additional test, incorporating the effect of wind during the NFPA 285 test and considering the effect of corners and/or projections from flat surface during a modified NFPA 285 test. Also a requirement was incorporated into the International Existing Building Code to conduct an NFPA 285 test when façades are added, replaced, or modified.In summary, this work provides a comprehensive overview of the requirements for façades (both materials and assemblies) in the USA in the presently applicable building code (IBC 2018) and in the next edition (2021) of the applicable building code.

Development of recycled blends based on cables and wires with plastic cabinets: An effective solution for value addition of hazardous waste plastics.

The recycling of polyvinyl chloride (PVC) recovered from the plastic insulations in wires and cables is a rising concern in the current situation due to its hazardous behaviour during recycling. Similarly, high-impact polystyrene (HIPS) and acrylonitrile butadiene styrene (ABS) used in the structural components of electrical and electronic equipment are also generated in large quantities. In the current work, three agendas were fixed: (a) to determine the effect of recycled polymeric material (HIPS and ABS) recovered from different sources on the mechanical property of the polymeric blends; (b) to formulate a high-impact strength blend; and (c) to deduce a mechanism for improved impact strength. The mechanical characterizations were conducted on the entire blends formulated. Among them, the recycled blend composed of recycled PVC (r-PVC) and recycled ABS (r-ABS) (segregated from uninterrupted power supply housing) and recycled HIPS (r-HIPS; collected from television housing) was confined for further physio-mechanical and thermal analysis. Besides, the r-PVC/r-ABS systems had shown better mechanical properties than r-PVC/r-HIPS systems in similar composition. The impact strength of blend r-PVC/r-ABS (70:30) was found to be 250 J/m, which was 200% more than the blend r-PVC/r-ABS (0:100). The compatibility and non-compatibility in PVC/ABS and PVC/HIPS blends respectively were explained with thermal, mechanical and morphological characterizations. Furthermore, a plausible cross-linking mechanism is developed between ABS and PVC, which controls the release of chlorine atoms into the environment.

The effects causing the burning of plastic coatings of fire-resistant cables and its consequences

Electric wiring is part of the fire protection systems; therefore, it must work reliably for a given period of time. Cable is in the first place among the cause of fire. Fires are always triggered by unsafe and nonstandard conditions, so we can approach safety if we know the properties of cables we want to use. We recommend adding standard ratings (PH, EP) with overload and combustion in increased/higher oxygen ratio. A plastic-coated cable does not burn in normal air, but, in a higher oxygen ratio, it shows specific burning phenomena. Cable fires may have two starting points: One is the heat reaching the plastic insulation of cables, due to the fire created by burning; the other one may be due to the fire generated by the overvoltage in the inappropriately sized cables when the outer plastic coating begins to burn. The basic condition of fire retardancy is that wire breaks or short circuits may not occur in a cable system. During this research, both effects are tested on fire-retardant cables. On the one hand, we exposed wires of various plastic sheaths to flame and to heat, as well as tested at which actual oxygen content they start combustion and flame propagation. In addition, we have investigated how fire-resistant cables react to a possible overvoltage when auto-ignition occurs. The goal was to see how conventional tests reflect requirements caused by a real fire and what the actual fire resistance of cables is, as well as examining whether the cables that have been certified as fire-resistant meet the requirements under real fire. The limited oxygen index (LOI) parameter seemed to be the most appropriate for real fire resistance. Our results have shown that factory certifications are not enough to provide complete fire safety. For example, the PH 180, E90 best rated plastic gave the weakest LOI value. PH 30 and PH 120 has proved correct the flammability. Due to the complex layers their investigation their testing is complex to, requiring a variety of tests to give a complete burn behavior. The most important exothermic peaks of diagraphs give the expected LOI values. The first and second decomposition is only indicative of damage and smoke, that is only by the tests with overload to see.

Determination of Metal Hazard in the Processed E-Waste Types, Floor Dust and Pulverized Epoxy Powder Generated at an E-Waste Handling Site in India

At the e-waste handling site, the obsolete electronic items are dismantled and it releases dust laden with fine metallic fragments, called as floor dust. Further, the broken cables are denuded from its plastic insulation and shredded to fine grained pulverized epoxy powder. These two-processed e-wastes appear to contain metal residues. Hence, the aim is to examine the metal composition and identify the hazard, if any. Pulverized epoxy powder measured high values of Cd (7.43±0.48 μg/g), Pb (338.85±0.13 μg/g), Ni (534.62±53.68 μg/g), Li (30.12±0.02 μg/g), K (508109.90±31605.89 μg/g), Ca (817395.40±2.52 μg/g) and Na (3528.00±539.07 μg/g) while floor dust had high levels of Cr (39.61±5.78 μg/g), Cu (4778.14±861.91 μg/g), Zn (4172.88±821.75 μg/g), Fe (11164.90±1111.61 μg/g) and Se (1613.00±259.04 μg/g) with significant differences (p<0.05). The worn out electronic oddments attributes to high levels of metals. Principal component analysis could extract two components accounting for 78% variance in total. Although the values are less in comparison with the statutory limits, the processed e-wastes still pose a risk of metal toxicity due to their high volume. The composition of metals in the processed e-wastes presents us a new challenge to handle them.