Browse Topic: Insulation
Plastic waste, in the past few years, has risen to be one of the most concerning and endangering pollutants to environment and life, making its effective management and reduction a major domain of focus among researchers and industrialists. This comparative study is an attempt to utilize recycled Polyethylene Terephthalate (rPET) fibres combined with Epoxy Resin in various combinations, to provide effective and low-cost insulation in moderate to low requirements. The above-mentioned components serve as viable insulators. Moisture resistance of both materials and temperature resistance of Epoxy resins ranging from 120°C to 150°C (depending upon the grade of Epoxy used) indicate a good stability in harsh external operating environment. While Epoxy resins are not inherently flame retardants, additives are introduced for this purpose in order to render the composite safer to use. Owing to the excellent adhesive properties of the Epoxy resin, the rPET fibres are allowed to bond together
The AS6224 specification covers environment resistant, permanent insulation repair sleeves for repairing different types of insulation damages of wire or cable jackets in installed applications. The repair sleeve is intended to repair damaged primary wire or cable jacket covers where the shielding and wire conductors are not damaged.
This document specifies dimensional, functional and visual requirements for Automotive grade coaxial cable. This material will be designated AG for general-purpose automotive applications or AG LL for low loss applications. It is the responsibility of the user of this cable to verify the suitability of the selected product (based on dimensional, mechanical, electrical and environmental requirements) for its intended application. It is the responsibility of the supplier to retain and maintain records as evidence of compliance to the requirements detailed in this standard.
This specification covers polyvinyl chloride insulated single conductor electric wires made with tin-coated copper conductors or silver-coated copper alloy conductors. The polyvinyl chloride insulation of these wires may be used alone or in combination with other insulating or protective materials.
This SAE Aerospace Recommended Practice (ARP) describes the etching of fluoropolymer electrical wire insulations to ensure that all facets of the process from the chemistry to the processing, to the storage and handling are well defined.
Wire and cable products progress through a series of handling or operational steps from the time they leave the manufacturer, and until a finished harness or assembly is ready for installation on a vehicle. Throughout these many steps, environmental or processing conditions may be present which can generate damage detrimental to the wire or cable and/or its intended application.
The purpose of air conditioning (AC) duct packing is multifaceted, serving to prevent condensation, eliminate rattle noise, and provide thermal insulation. A critical aspect of duct packing is its adhesive quality, which is essential for maintaining the longevity and effectiveness of the packing's functions. Indeed, the challenge of achieving adequate adhesivity on AC ducting parts is significant due to the harsh operating conditions to which these components are subjected. The high temperatures and presence of condensation within the AC system can severely compromise the adhesive's ability to maintain a strong bond. Moreover, the materials used for these parts, such as HDPE, often have low surface energy, which further hinders the formation of a durable adhesive bond. The failure of the adhesive under these conditions can lead to delamination of the duct packing, which can result in customer inconvenience due to rattling noises, potential electrical failures if condensed water
Thermo-mechanical fatigue and natural aging due to environmental conditions are challenging to simulate in an actual test with advanced fiber-reinforced composites, where their fatigue and aging behavior are little understood. Predictive modeling of these processes is challenging. Thermal cyclic tests take a prohibitively long time, although the strain rate effect can be scaled well for accelerating the mechanical stress cycles. Glass fabric composites have important applications in pipes, aircraft, and spacecraft structures, including microwave transparent structures, impact-resistant parts of the wing, fuselage deck and many other load-bearing structures. Often additional additively manufactured features and coatings on glass fabric composites are employed for thermal and anti-corrosion insulations. In this paper, we employ a thermo-mechanical fatigue model based on an accelerated fatigue test and life prediction under hot-to-cold cycles. Thermo-mechanical strain-controlled stress
Focused on the permanent magnet synchronous motor (PMSM) used in electric, this paper proposes an online insulation testing method based on voltage injection under high-temperature and high-humidity conditions. The effect of constant humidity and temperature on the insulation performance has been also studied. Firstly, the high-voltage insulation structure and principle of PMSM are analyzed, while an electrical insulation testing method considered constant humidity and temperature is proposed. Finally, a temperature and humidity experimental cycling test is carried out on a certain prototype PMSM, taking heat conduction and radiation models, water vapor, and partial discharge into account. The results show that the electrical insulation performance of the motor under constant humidity and temperature operation environment exhibits a decreasing trend. This study can provide theoretical and practical references for the reliable durability design of PMSM.
Hood insulators are widely used in automotive industry to improve noise insulation, pedestrian impact protection and to provide aesthetic appeal. They are attached below the hood panel and are often complex in shape and size. Pedestrian head impacts are highly dynamic events with a compressive strain rate experienced by the insulator exceeding 300/s. The energy generated by the impact is partly absorbed by the hood insulators thus reducing the head injury to the pedestrian. During this process, the insulator experiences multi-axial stress states. The insulators are usually made of soft multi-layered materials, such as polyurethane or fiberglass, and have a thin scrim layer on either side. These materials are foamed to their nominal thickness and are compression molded to take the required shape of the hood. During this process they undergo thickness reduction, thereby increasing their density. Hence, the material properties vary greatly based on the thickness and strain rate
A crucial component utilized in the trunk space is the luggage board. Positioned at the bottom of the trunk, the trunk board separates the vehicle body from the interior and supports for luggage. The luggage board serves multiple functions, including load-bearing stiffness for luggage, partition structure functionality, noise insulation, and thermal insulation. There is a need for a competitive new luggage board manufacturing method to meet the increasing demand for luggage boards in response to the changing market environment. To address this, the "integrated sandwich molding method" is required. The integrated sandwich molding method utilizes three key methodologies: grouping processes to integrate similar functions, analyzing materials to replace them with suitable alternatives, and overcoming any lacking functionality through integrated design structures. This paper presents a methodology for developing the integrated sandwich molding method. It aims to validate the key performance
This research looks at the acoustic and mechanical characteristics of polypropylene (PP) composites supplemented with natural fibers to determine whether they are appropriate for automotive use. To generate composites that are hybrids, four diverse natural fibers, including Calotropis gigantea (CGF), jute, sisal, and kenaf, were mixed into PP matrices. The study examines how fiber type, frequency, and thickness affect sound absorption and mechanical strength. The results show that these natural fiber-reinforced composites have improved mechanical characteristics, with CGF (73.26 shore D value of Hardness), sisal (42.35 MPa tensile) and jute fibers showing particularly promising materials. Furthermore, the acoustic study emphasizes these materials’ frequency-dependent sound absorption properties, with particular efficacy in mid-frequency regions. Such organic reinforcement fiber materials’ acoustic performance is tested at 5 mm and 10 mm thicknesses. When a 5 mm thick sample is examined
The objective of this report is to serve as an introductory (educational) document to cover the potential failure mechanisms related to EIS in high voltage electrical component or HV electrical equipment in aircraft power systems. It has the following contents: (1) an overview of the current understandings of potential failure mechanisms related to EIS for high voltage and high-power application in aircraft; (2) main aging stressors and aging processes of EIS in electrical components used in the aircraft power systems and their common failure modes, and (3) the key indicators to assess the status of electrical insulation degradation and related testing needs. This document aims to assist HV power system designers in understanding the key considerations for EIS design and testing of HV components in aircraft, as well as the requirements for predicting their designed service life. Detailed testing guideline including testing methods will be provided in ARP7375, and life modeling in
Silicone and rubber composite, often called Ceramifiable Silicone Rubber Composites(CSRCs), has proven to show excellent mechanical and thermal properties. CSRC materials have been mainly used in industrial applications like electrical insulating cables, decorations, and fire-proof materials. The mechanical and ceramifiable properties of CSRC can be altered by changing the silicone rubber matrix and by adding the right additives or fillers. In this work, we prove the potential of CSRCs as thermal insulating materials in battery packs. Specifically, we explore the usage of CSRC inside the battery pack to improve safety during thermal events. We also characterize the material properties before and after exposing the CSRC to elevated temperatures and flame. Finally, we investigate the effectiveness of the CSRC sheet in preventing or delaying cell-to-cell thermal propagation during a thermal runaway event inside the battery pack. Our experiments show that the CSRC sheet significantly
As we all know, automotive headliners are an essential component of any car’s interior as they cover all the internal components and provide a clean and finished look. Headliners not only increase the aesthetic appeal of a car’s interior, but also acts as an insulation and sound absorption source. As per the latest Government norms, Curtain Airbag (henceforth called as CAB) has been made mandatory and this change calls for the corresponding changes in the Headliner packaging of all passenger vehicles. In general, curtain air-bag deployment calls for a twist open of Headliner at lateral sides (a portion below Hinge-line) during the deployment. This enables the inflated airbag to flow inside the passenger cabin to protect the passenger from any injury. Conventionally no components are packaged below the hinge-line area of headliner to avoid obstruction for CAB deployment and any part fly-off concerns. For this reason, no foams/components are kept below the hinge-line region of the
The lithium-ion batteries are susceptible to fires or explosions due to their extremely volatile nature. The energy-dense batteries, such as Li Ni0.8Mn0.1Co0.1 O2/Graphite(NMC811) battery that meets the consumer range demands, are most vulnerable under thermal events. A wide number of solutions are being explored to suppress or prevent battery fires. The solutions range from integrating active cooling techniques, passive heat dissipation using heat carrier pads, thermal insulating materials to prevent thermal propagation, safety vents to remove ejecta, and protection circuitry with an advanced battery management system. This paper reviews various safety solutions employed in battery packs for preventing or suppressing potential fire during any thermal runaway event. The identified safety solutions also feature distinctive methods such as using hydrogel agents, aerosol fire suppressants, and design features. Among the reviewed countermeasures, we provide a detailed analysis of the
This specification establishes the requirements for various types and colors of electrical insulating sleeving that will shrink to a predetermined size upon the application of heat. This specification includes provisions for demonstrating compliance with qualification requirements (see Section 4 and 7.3), in process inspection, and statistical process control inspections (see 4.4). The continuous operating temperature ranges for the sleeving classes covered by this specification are from -112 to +482 °F (-80 to +250 °C). The continuous operating temperature range for each sleeving class is given in the applicable detail specification.
Nylon polymer with an optimal blend of Kevlar, fiberglass, and high-speed, high temperature (HSHT) Fiberglass offers improved characteristics such as flexural strength, wear resistance, electrical insulation, shock absorption, and a low friction coefficient. For this reason, the polymer composite manufactured by combining HSHT, Kevlar, and fiberglass with nylon as base material will expand the uses of nylon in the aerospace, automotive, and other industrial applications related to ergonomic tools, assembly trays, and so forth. The proposed work was carried out to investigate the continuous fiber reinforcement (CFR) in nylon polymer using a dual extrusion system. Twenty experimental runs were designed using a face-centered central composite design (FCCD) approach to analyze the influence of significant factors such as reinforcement material, infill pattern, and fiber angle on the fabricated specimen as per American Society for Testing Materials (ASTM) standards. The tensile strength
Squeal noise phenomenon in disc brakes is a complicated dynamic challenge which brake manufacturers have confronted for decades. The most prevalent technique apprehended by the brake manufactures is to simulate the braking conditions using a noise dynamometer. This is a well-established, expensive technique which is time-consuming. The objective of this paper is to understand the phenomenon of brake squeal, modal coupling and publish an analytical approach to predict a suitable damping material and thereby to optimize the dynamometer tests and time. As the temperature increases the stiffness of the component decreases thereby the resonance frequency tends to decrease. Compressing the pad increases its stiffness and thereby its resonance frequency. Compressibility being inversely proportional to stiffness has direct influence over the frequency response function of the brake components. Shim suppliers use generic structure to obtain the damping ratio at its resonance at every other
This SAE Standard presents a test procedure for determining the airborne sound insulation performance of materials and composite layers of materials commonly found in mobility, industrial, and commercial products under conditions of representative size and sound incidence so as to allow better correlation with in-use sound insulator performance. The frequency range of interest is typically 100 to 10000 Hz 1/3-octave band center frequencies. This test method is designed for testing flat samples with uniform cross section, although in some applications the methodology can be extended to evaluate formed parts, pass-throughs, or other assemblies to determine their acoustical properties. For non-flat parts or assemblies where transmitted sound varies strongly across the test sample surface, a more appropriate methodology would be ASTM E90 (with a reverberant receiving chamber) or ASTM E2249 (intensity method with an anechoic or hemi-anechoic receiving chamber).
Partial discharge (PD) detection has been always a fundamental tool, potentially, for the design, quality control, commissioning, and reliability monitoring for the of insulation systems. The word “potentially” stems from the objective consideration of the intrinsic limitations suffered by the existing partial discharge, PD, measurement technologies, especially the need of experts to interpret results and the lack of clear correlation between PD-related quantities, and the condition-based maintenance approach. On the whole, a thorough revision of insulation systems design procedures and of the tools to evaluate aging and failure risk is needed, especially in components of electrical assets which are critical in terms of reliability, resilience, and safety. This paper focuses on critical asset components, such as ships, aircrafts, aerospace, and any type of vehicles, where the coming electrification is significantly increasing nominal voltage, power density and efficiency, and where
To establish design recommendations that will provide a basis for safe and reliable connections to threaded screw-type or stud-type electrical equipment terminations. These recommendations are directed primarily, but not solely, to the aerospace and ground support equipment industries. Since individual design criteria may alter the details as outlined, it is therefore important that this SAE Aerospace Information Report (AIR) not be considered mandatory but be used only as a design guidance.
This specification covers the requirements for flexible shielded electrical conduit for aircraft installations.
Case hardening may be defined as a process for hardening a ferrous material in such a manner that the surface layer, known as the case, is substantially harder than the remaining material, known as the core. The process embraces carburizing, nitriding, carbonitriding, cyaniding, induction, and flame hardening. In every instance, chemical composition, mechanical properties, or both are affected by such practice. This testing procedure describes various methods for measuring the depth to which change has been made in either chemical composition or mechanical properties. Each procedure has its own area of application established through proved practice, and no single method is advocated for all purposes. Methods employed for determining the depth of case are either chemical, mechanical, or visual, and the specimens or parts may be subjected to the described test either in the soft or hardened condition. The measured case depth may then be reported as either effective or total case depth
Foaming materials such as 2C-PUR or expandable baffles are increasingly used in the car body acoustic package of modern passenger vehicles. Over the last several decades the primary function of foaming materials was the moisture sealing and airborne noise absorption / insulation in various areas of the car body such as pillars, door sills or other cavities. Recent developments also show an increasing application of expandable foams, functioning as structural dampers and reducing structure-borne noise transmission through frames and pillars. This paper summarizes the results of various studies that deal with the impact of expandable baffle materials on structure-borne noise in car bodies with special focus on mid and high frequencies which become more relevant in the acoustic optimization efforts of EV’s. Structural vibrations are evaluated experimentally on foamed generic frames and double sheet metal systems under free-free boundary conditions. The most promising candidate among
Automobile exhaust systems help to attenuate the engine combustion noise as well as the high frequency flow noises which are generated as the gas expands and contracts through various ducts and orifices of muffler system. One of the solutions to mitigate the noise generated due to the latter is by means of an absorptive muffler, comprising a fibrous acoustic medium which helps to absorb noise of certain frequencies which are sensitive to the human ear. Typically, the construction of such a system consists of the fibrous acoustic medium encompassing a perforated inner pipe on the inside and enclosed by an outer metal case on the outside. The temperature limitations of the acoustic medium sometimes necessitate the placement of the fibrous acoustic system away from the engine source in order to prevent any damage to the fibers upon direct contact with the flue gas. However, this results in a potential for condensation of engine out gas in and around the inner pipe – fibrous system
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