Browse Topic: Insulation
This study prepares high-performance PI/VIP composite thermal insulation materials for buildings by integrating polyimide (PI) composite membranes and vacuum insulation panels (VIPs), and uses EnergyPlus to explore their impacts on building energy conservation, operating costs, and carbon emissions under different climates. Experimental results show the materials have low thermal conductivity, long service life, and excellent thermal insulation and flame-retardant properties due to their internal vacuum structure inhibiting heat transfer. Simulations in Jinan (tropical monsoon), Heilongjiang (cold temperate), and Shenzhen (subtropical humid) climates indicate that compared with traditional XPS and rock wool boards, buildings using PI/VIP composites achieve 21.3%, 34.7%, and 18.9% higher annual energy-saving efficiency respectively, with 27%-41% lower carbon emissions; the most significant effects in Heilongjiang highlight the material’s great promotion potential in severe cold areas.
For sustainability reasons, the automotive market is requesting 100% monomaterial noise treatments, particularly for the end-of-life recycling without any part separation operation. But also, OEMs require super light, highly performance insulating noise treatments for electric vehicles in order to extend vehicle autonomy. PP melt-blown fiber felts present good mono-material characteristics with very good absorption, but generally not so good insulation properties behind an airtight barrier due to lack of stiffness. Moreover, these PP melt-blown fiber felts are relatively expensive and not thermoformable, thus forcing them to be used as 2D die-cut parts behind existing hard or soft trims classically. The shown optimization approach proposes to return to 100% thermoformable recycled and recyclable PET formulations blending unusual coarse mechanical specific fibers, in order to optimize the viscothermal exchanges, while maintaining good mechanical properties, with microfibers for best dissipation properties bonded by bi-component fibers. The insulation properties obtained as poroelastic spring behind a barrier allow a weight reduction of -50% compared to cotton felt while being 1 dB better for the Insertion Loss values (2 dB compared to a flexible foam) and perform as well as best PP melt-blown fiber felts while being more competitive as well as thermoformable. It is possible to adjust the sound insulation properties, sound absorption and hardness (static compressibility) using optimal PET fibers formulations but also thanks to felt verticalization processes. These optimization levers will be illustrated in this paper.
Sometimes referred to as “solid smoke,” aerogels are the world’s lightest solid materials, composed of approximately 85 percent air by volume. Polyamide aerogels open up a whole new world of applications due to their unique properties: translucent like silica aerogels; thermoplastic; ultra-low density; superior mechanical properties; low-temperature operating range; and highly flexible (as compared to NASA Glenn’s polyimide aerogels). Polyamide aerogels are further novel because of their tunable glass transition temperatures, meaning that crystallinity, and hence strength, can be controlled via operating temperature. Addressing the key drawbacks of aerogel technology (hydroscopicity, fragility, cost), NASA Glenn’s suite of organic aerogels are cost-competitive with both existing silica aerogels and, with scale-up, high-end foamed polymer insulation.
Live-line operation is a critical technique for maintaining the reliability and continuity of power supply in modern distribution networks. Insulating mats serve as essential protective equipment during such operations by providing both electrical insulation and mechanical shielding. In practical service conditions, insulating mats are subjected to repeated mechanical contact and friction against conductors, metallic fittings, and ground surfaces, which progressively deteriorates their surface integrity and compromises operational safety. Current performance standards for insulating mats emphasize dielectric and tensile properties, while tribological durability remains unaddressed. In this study, an EVA – PA6 composite film fabricated via the tape casting method was selected as the representative outer insulating layer of insulating mats. Reciprocating friction tests were conducted using an SDR339 abrasion tester to evaluate the effects of normal load and sliding speed on wear behavior. The results indicate that wear mass increased monotonically with friction cycles at a given speed, whereas the incremental wear rate gradually decreased due to contact area evolution. A pronounced transition from mild surface abrasion to severe material removal was observed when the applied load reached 5 N, accompanied by surface scratching and exposure of the internal fibrous layer. These findings demonstrate that the wear resistance of the EVA – PA6 composite film is insufficient for long-term service under realistic frictional conditions. The results provide experimental evidence supporting the necessity of incorporating standardized wear resistance evaluation into performance criteria for insulating mats used in live-line operations.
In the electrical machines, detrimental effects resulted often due to the overheating, such as insulation material degradation, demagnetization of the magnet and increased Joule losses which result in decreased lifetime, and reduced efficiency of the motor. Hence, by effective cooling methods, it is vital to optimize the reliability and performance of the electric motors and to reduce the maintenance and operating costs. This study brings the analysis capability of CFD for the air-cooling of an Electric-Motor (E-Motor) powering on Deere Equipment's. With the aggressive focus on electrification in agriculture domain and based on industry needs of tackling rising global warming, there is an increasing need of CFD modeling to perform virtual simulations of the E-Motors to determine the viability of the designs and their performance capabilities. The thermal predictions are extremely vital as they have tremendous impact on the design, spacing and sizes of these motors.
Plastic materials are used for a wide variety of spacecraft applications including seals, bearings, fasteners, electrical insulators, thermal isolators, and radomes. Selecting plastics for use in space is complex due to wide operating temperature ranges, vacuum conditions, and exposure to radiation and atomic oxygen. Additionally, some spacecraft applications require sealing flammable propellants such as hydrogen and oxygen. This article will present some design considerations when selecting plastics for use in spacecraft. It will provide rich data on the performance characteristics of plastics as well as examples of successful spacecraft applications.
The interaction of electric, electronic (E/E) and mechanical components defines the quality of a BEV’s powertrain. Component selection, their integration and calibration aim at meeting legal requirements for EMC and safety as well as competitive targets for efficiency, NVH and driving comfort. These tasks in particular need attention on electromagnetic events on the DC bus, the high-power electronics of inverters, the e-motors, and the drive shaft. Each component within this environment is defined by its electromechanical features with variabilities selected from a large set of operating parameters. Consequently, a complete powertrain and its controllers give rise to endless combinations for powertrain operation. How to understand and avoid risk laden and ineffective parameter options, how to find powertrain control parameters for safe, efficient and comfortable operation? And how to find solutions within competitive development timeframes? Particular issues include high voltage risks on AC and DC bus, AC resonant ripple currents on the DC lines, or risks arising from powertrain dynamics and impacting NVH quality and driving comfort. Such issues are addressed with extensive system simulations and, finally, with comprehensive testing a powertrain’s electric, electronic and mechanical behavior. The focus of this paper is on E/E and NVH signal analytics guiding the integration of powertrain modules: E/E challenges arise from voltage bursts at MHz frequencies endangering insulation of stator windings and cables. Current ripples on the HV-DC bus may endanger auxiliary components. Motor operation and drive shaft dynamics must not compromise NVH quality and component durability.
The desert landscapes of the western United States have changed since Mr. Duke and Dr. Gonzo blazed a trail across them in a drug-infused haze. But their advice to buy the ticket and take the ride is still a wise mantra - especially in the serene comfort of a modern full-size pickup. As inhospitable as southern Nevada can be outside Sin City, the amenities within the climate-controlled and leather-lined cabin of the latest Ram pickups insulate you from those realities. SAE Media was invited to sample the latest heavy haulers in Ram's portfolio, including the new 2500 and 3500 models with the high-output version of the Cummins B6.7 diesel.
This article follows a companion article [1] presented at the SAE NVC 2021, in which a new system for the measurement on small samples of the normal-incidence Insertion Loss (IL) of multilayers used for the manufacturing of automotive sound package parts was first introduced. In addition to simplifying the evaluation of the sound-insulation of multi-layers used to produce sound-package components, the system aims at overcoming the limitations of the test procedure based on the ASTM E2611 standard. In this article, the latter point is demonstrated by comparing the insertion loss results obtained with the new system with those obtained with the test procedure based on the ASTM E2611 standard on a few multilayers commonly used for the manufacturing of automotive sound package parts. Results indicate that the data obtained by means of the newly developed system are more meaningful, practically usable and less prone to edge-effects, compared to those obtained according to the ASTM E2611 test procedure. In addition to this, the article compares also the results obtained by means of the new system with those obtained in a compact two-cabins facility commonly used for the evaluation of diffuse-field insertion loss following the ASTM E90 standard, a quantity customarily employed in the automotive industry for the assessment of the sound insulation of acoustic multilayers. Results indicate that the data obtained with the new system compare well with those obtained with the two-cabins facility, both quantitatively and qualitatively. This indicates that sound-insulation tests with the new system may be a valid alternative to much more resource-consuming tests in two-chamber facilities, in particular (but not only) when the sound insulation of moulded parts must be assessed.
Researchers have demonstrated the ability to engineer materials that are both stiff and capable of insulating against heat. This combination of properties is extremely unusual and holds promise for a range of applications, such as the development of new thermal insulation coatings for electronic devices.
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 contacts electrical components beneath the ducting, or loss of thermal energy, thereby reducing the AC system's thermal efficiency. This paper primarily focuses on developing an experimental methodology to identify the most appropriate adhesive for use in ducting applications. This involves a detailed examination of various adhesive types and designing suitable experiments to evaluate the adhesive bond's resilience, particularly when applied to HDPE blow-molded ducts. The methodology aims to ascertain the conditions under which the adhesive bond fails, ensuring that the selected adhesive can maintain its integrity under the rigors of operational stress and environmental factors. Additional insights gained from the study highlight the influence of surface roughness, resting time, and exposure to extreme temperatures on the lamination quality of duct packing. These findings are crucial for manufacturers to consider when selecting adhesives for AC duct systems, ensuring that the chosen solutions are robust enough to withstand the demanding conditions of automotive environments and maintain the integrity and functionality of the duct packing over time.
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 experienced by the material. This paper presents a methodology for characterization of hood insulator materials at strain rates ranging from 0.01/s to 300/s for use in finite element (FE) simulations. A rate dependent material model is validated against the results of hemispherical punch tests. Unique tensile response of the hood insulator materials at high strain rates and the challenges it poses for material modeling is discussed in detail. In addition, challenges with specimen extraction and tensile testing of soft multilayer materials are presented, and the improved tensile testing procedure is proposed.
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.
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, it is clear that the coefficient of sound absorption is continuously less than 0.30 at 500 Hz and climbs to a range around 0.87 and 0.96 at 2000 Hz. Only Calotropis gigantea (CGF) and kenaf fibres show a steady rise in their sound absorption coefficient from 500 Hz to 2000 Hz as the sample thickness increases to 10 mm. This study contributes to developing environmentally friendly and superior materials for future automobile uses by providing helpful insights into the optimal configuration of naturally derived fiber-based composites for sound insulation and reinforcement of frameworks in the automobile industry.
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