Browse Topic: Polymers
This specification covers a fluorosilicone (FVMQ) rubber in the form of molded rings.
This specification covers an acrylonitrile-butadiene rubber in the form of molded rings, compression seals, O-ring cord, and molded-in-place gaskets for aeronautical and aerospace applications.
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.
FibreCoat, the German materials startup, has developed a groundbreaking fiber reinforced composite that is capable of making aircraft, tanks and spacecraft invisible to radar surveillance. The company was officially founded in Aachen, Germany, in 2020, however its core founding team first began developing new approaches to the use of materials that make commercial and military vehicles invisible to radar as back as 2014. FibreCoat is known for inventing a novel technology to coat metals and plastics onto fibers, thus combining the properties of the fibers and the coating material, during the fiber-spinning process.
University of Liège Liège, Belgium
Medical tubing is an essential component of countless healthcare applications, from intravenous (IV) and oxygen lines to catheters and diagnostic equipment. These tubes, often made of clear flexible polymers, must be produced to exacting standards: free of contaminants, strong under pressure, and biocompatible. However, the joining process to connect these tubes can introduce significant manufacturing challenges.
Researchers have developed a soft, thin-film auditory brainstem implant (ABI). The device uses micrometer-scale platinum electrodes embedded in silicone, forming a pliable array just a fraction of a millimeter thick. This novel approach enables better tissue contact, potentially preventing off-target nerve activation and reducing side effects.
This specification covers one type of a non-melting, heat-stable silicone compound, for use in high tension electrical connections, ignition systems, and electronics equipment, for application to unpainted mating threaded or non-threaded surfaces, and as a lubricant for components fabricated from elastomers. This compound is effective in the temperature range from -54 °C (-65 °F) to +204 °C (400 °F) for extended periods. This compound is identified by NATO symbol S-736 (see 6.5).
Researchers at the U.S. Department of Energy (DOE)’s Oak Ridge National Laboratory (ORNL) have developed an innovative new technique using carbon nanofibers to enhance binding in carbon fiber and other fiber-reinforced polymer composites — an advance likely to improve structural materials for automobiles, airplanes and other applications that require lightweight and strong materials.
This standard establishes the dimensional and visual quality requirements, lot requirements, and packaging and labeling requirements for O-rings molded from AMS7274 rubber. It shall be used for procurement purposes.
This standard establishes the dimensional and visual quality requirements, lot requirements, and packaging and labeling requirements for O-rings machined from AMS3617 polyamide material. It shall be used for procurement purposes.
This specification and part standard specifies polytetrafluoroethylene (PTFE) resin material and the dimensional requirements for scarf-cut retainers (backup rings) previously specified by MIL-R-8791 and MIL-R-8791/1. The retainers are intended for use in hydraulic and pneumatic system components as anti-extrusion devices in conjunction with seals and O-rings.
This SAE Aerospace Standard (AS) provides a standardized test procedure that can be used to evaluate material capability in a dynamic sealing application. This procedure will be utilized by applicable elastomer material specifications which are used for production of O-rings and other seals. This specification is applicable to the dynamic testing requirements for aerospace elastomer parts utilizing materials conforming to AMS7XXX series specifications, user specifications, or print on a Purchase Order (PO) that calls out this document for aerospace applications. This procedure is intended for testing NBR. Other elastomers may have different requirements which will require a separate procedure.
This specification establishes the requirements for a waterborne, corrosion-inhibiting, chemical- and solvent-resistant, anodic electrodeposition epoxy primer capable of curing at 200 to 210 °F (93 to 99 °C).
Researchers have created a technique to turn waste polyethylene terephthalate (PET), one of the most recyclable polymers, into components of batteries.
Researchers developed wearable skin sensors that can detect what’s in a person’s sweat. Using the sensors, monitoring perspiration could bypass the need for more invasive procedures like blood draws and provide real-time updates on health problems such as dehydration or fatigue. The sensor design can be rapidly manufactured using a roll-to-roll processing technique that essentially prints the sensors onto a sheet of plastic.
Mechanical light detection and ranging (LiDAR) units utilize spinning lasers to scan surrounding areas to enable limited autonomous driving. The motors within the LiDAR modules create vibration that can propagate through the vehicle frame and become unwanted noise in the cabin of a vehicle. Decoupling the module from the body of the vehicle with highly damped elastomers can reduce the acoustic noise in the cabin and improve the driving experience. Damped elastomers work by absorbing the vibrational energy and dispelling it as low-grade heat. By creating a unique test method to model the behavior of the elastomers, a predictable pattern of the damping ratio yielded insight into the performance of the elastomer throughout the operating temperature range of the LiDAR module. The test method also provides an objective analysis of elastomer durability when exposed to extreme temperatures and loading conditions for extended periods of time. Confidence in elastomer behavior and life span was
Road noise caused by road excitation is a critical factor for vehicle NVH (Noise, Vibration, and Harshness) performance. However, assessing the individual contribution of components, particularly bushings, to NVH performance is generally challenging, as automobiles are composed of numerous interconnected parts. This study describes the application of Component Transfer Path Analysis (CTPA) on a full vehicle to provide insights into improving NVH performance. With the aid of Virtual Point Transformation (VPT), blocked forces are determined at the wheel hubs; afterward, a TPA is carried out. As blocked forces at the wheel hub are independent of the vehicle dynamics, these forces can be used in simulations of modified vehicle components. These results allow for the estimation of vehicle road noise. To simulate changes in vehicle components, including wheel/tire and rubber bushings, Frequency-Based Substructuring (FBS) is used to modify the vehicle setup in a simulation model. In this
High-frequency whine noise in electric vehicles (EVs) is a significant issue that impacts customer perception and alters their overall view of the vehicle. This undesirable acoustic environment arises from the interaction between motor polar resonance and the resonance of the engine mount rubber. To address this challenge, the proposal introduces an innovative approach to predicting and tuning the frequency response by precisely adjusting the shape of rubber flaps, specifically their length and width. The approach includes the cumulation of two solutions: a precise adjustment of rubber flap dimensions and the integration of ML. The ML model is trained on historical data, derived from a mixture of physical testing conducted over the years and CAE simulations, to predict the effects of different flap dimensions on frequency response, providing a data-driven basis for optimization. This predictive capability is further enhanced by a Python program that automates the optimization of flap
This specification covers a synthetic rubber in the form of sheet, strip, tubing, molded shapes, and extrusions. This specification should not be used for molded rings, compression seals, molded O-ring cord, and molded-in-place gaskets for aeronautical and aerospace applications
This SAE Standard outlines the requirements for a preformed thermosetting hose intended for use in heavy-duty vehicle engines, such as air cleaner inlet, crank case vent, or air cleaner to turbo or to engine inlet.
Climate-neutral aviation requires resource-efficient composite manufacturing technologies and solutions for the reuse of carbon fibers (CF). In this context, thermoplastic composites (TPC) can make a strong contribution. Thermoforming of TPC is an efficient and established process for aerospace components. Its efficiency could be further increased by integration of joining processes, which would otherwise be separate processes requiring additional time and equipment. In this work, an integrative two-step thermoforming process for hollow box structures is presented. The starting point are two organosheets, i.e. fiber-reinforced thermoplastic sheets. First, one of the organosheets, intended for the bottom skin of the uplift structure, is thermoformed. After cooling, the press opens, the organosheet remains in the press and an infrared heater is pivoted in, to locally heat up just the joining area. Meanwhile, a second organosheet, intended for the top skin, is heated and thermoformed and
Traditional silicon-based solar cells are completely opaque, which works for solar farms and roofs but would defeat the purpose of windows. However, organic solar cells, in which the light absorber is a kind of plastic, can be transparent.
Electric vehicles (EVs) are particularly susceptible to high-frequency noise, with rubber eigenmodes significantly influencing these noise characteristics. Unlike internal combustion engine (ICE) vehicles, EVs experience pronounced variations in dynamic preload during torque rise, which are substantially higher. This dynamic preload variation can markedly impact the high-frequency behaviour of preloaded rubber bushings in their installed state. This study investigates the effects of preload and amplitude on the high-frequency dynamic performance of rubber bushings specifically designed for EV applications. These bushings are crucial for vibration isolation and noise reduction, with their role in noise, vibration, and harshness (NVH) management being more critical in EVs due to the absence of traditional engine noise. The experimental investigation examines how preload and excitation amplitude variations influence the dynamic stiffness, damping properties, and overall performance of
Items per page:
50
1 – 50 of 8766