Propriétés

What should engineers consider when choosing a low outgassing adhesive system for their application? The aerospace, electronic, and optical industries often involve environments where outgassing from adhesives can pose significant challenges. This is particularly true in the space industry, where the extreme environment of space can cause conventional adhesives to release volatile compounds. This ebook will equip you with information about the ASTM E595 standard, initially developed by NASA, that serves as a benchmark for assessing the outgassing characteristics of materials, as well as guide you through the adhesive selection process.

Many Master Bond epoxy systems are formulated with superior acid resistance. We continually test our materials by exposing them to specific chemicals over a long period of time. A common way of testing the chemical compatibility of an epoxy is by immersing a sample in a chemical and measuring its change in weight over time. A significant loss or gain in weight would indicate a decreased ability of a material to stand up to chemical exposure. These tests allow us to more accurately recommend the right product based on specific application requirements.IIn this experiment, we focused on testing our epoxies for their resistance to nitric acid. The compounds Master Bond used for testing are a variety of two-component and one-component epoxies with good overall chemical resistance. For the first round of testing, which involved exposure to 10% nitric acid, the products tested were EP125, EP62-1HT, EP21ARHT, EP62-1BF, EP17HT, and EP41S-5. For the second round of testing, which involved exposure to 20% nitric acid, the same products were tested. For both tests, these products were compared against the resistance of a generic or standard non-chemically resistant epoxy. A few thin castings were made for each product and cured in accordance with their specifications. Once the cured samples were created and initial weight was recorded, the castings were immersed in either 10% or 20% nitric acid. Then, we continued recording frequent weight measurements. Below you will see the results of soaking for more than one year in each concentration at room temperature ~ 75°F. The castings were weighed periodically, and the graphs shown below demonstrate the percentage of weight change over time.For comparison, note that for each concentration, a casting of a standard epoxy was also tested under these same conditions which served as a reference. As can be seen in the graphs, the standard epoxy was markedly less resistant to nitric acid than the other epoxies tested. It demonstrated a significantly greater change in weight over time, and at both 10% and 20% concentration levels, the casting ultimately dissolved in nitric acid after approximately seven months.Acids can etch the surface of an epoxy (resulting in loss of weight), or they can cause swelling of the sample (resulting in weight gain). In general, a weight change of less than 4-5% (gain or loss) can be considered excellent, especially since these tests may be more rigorous compared to actual service conditions. It is also worth noting that in the context of a bonded joint or a potted assembly the exposure to nitric acid might not be as severe or direct as in the above test conditions.Please note, when choosing an epoxy for an application where the resistance to nitric acid is critical, many other factors must be considered in addition to the chemical resistance. Depending on the concentration level of nitric acid, each of the epoxies in the charts above offers a distinct set of performance properties. For example, at both 10% and 20% concentrations, if electrical insulation and high temperature resistance are needed, EP125 may be a good option. If moderate viscosity and a moderate heat cure is needed EP62-1HT can be considered. If a one-part system is needed at either concentration, EP17HT is an excellent candidate. These products all need to be processed or cured differently but the key in all cases is the addition of heat for enhancing/optimizing chemical resistance especially to nitric acid.Disclaimer: The findings in this article are not meant to be used for specification purposes.

Manufacturers of wearables and other medical devices can find suitable solutions among a number of medically safe adhesive systems, which are available in a wide variety of chemistries including epoxies, silicones and UV/LED-curable compounds. The use of biocompatible, non-toxic materials to avoid negative effects on skin and tissue, drives a fundamental need for safe adhesive, sealant, coating, and encapsulant compounds. Designed to address these concerns, a class of compounds combines proven biocompatibility and non-cytotoxic characteristics with performance properties required for the manufacture of medical devices and wearables intended for contact with the human body.

Watch this video to learn about dual curing adhesives that use both UV light, as well as heat for curing. These adhesives are ideal for use where complete UV curing is either too difficult or impossible to achieve, such as applications with complex geometries and concealed, “shadowed out” areas.

The rise of electric vehicles and driver aids along with the proliferation of electronic sensors and safety features point towards continued growth in automotive electronics. Due to their lightweight, functional properties, adhesives, encapsulants and coatings will be of increased importance for use in structural bonding, as well as in non-structural applications for electronic, optical and mechanical components in electric vehicle manufacturing. Read more about the properties, uses and future developments of these compounds as they pertain to the automotive industry.

Since its introduction in 1978, Master Bond EP29LPSP has been the epoxy compound of choice in a variety of challenging applications. Ideal for demanding cryogenic environments, two-part EP29LPSP can withstand temperatures as low as 4K and can resist cryogenic shock when, for instance, it is cooled from room temperature to cryogenic temperatures within a 5-10 minute window. Optically clear EP29LPSP has superior physical strength, electrical insulation, and chemical resistance properties. It also meets NASA low outgassing requirements and exhibits a low exotherm during cure. This low viscosity compound is easy to apply and bonds well to metals, glass, ceramics, and many different plastics. Curable at room temperature, EP29LPSP attains its best results when cured at 130-165°F for 6-8 hours. In over a dozen published research articles, patents, and manufacturers’ specifications, scientists and engineers have identified EP29LPSP for use in their applications due to its unparalleled performance in one or more areas. Table 1 highlights several commercial and research applications that use Master Bond EP29LPSP. Table 2 summarizes several patents that reference EP29LPSP. Following each table are brief descriptions of the role Master Bond EP29LPSP plays in each application or invention.Table 1: Commercial and Research Uses of EP29LPSPIndustryApplicationEP29LPSP UseCritical PropertiesPlasma PhysicsExperimental device to study magnetic reconnection events1Fabrication of flux core assembliesCryogenic Low outgassingAstronomyInfrared telescope system2Optical fiber mounting assemblyCryogenic Low outgassing Long cure time Low shrinkageAeronauticsTesting of a miniature ramjet model in a supersonic wind tunnel4Bonding strain gauges to flexure beamsSufficient flexibility at cryogenic temperaturesParticle PhysicsArgon detector5Coat metal rim to electrically insulate itCryogenic Low outgassingElectrical insulationParticle PhysicsRadioactive decay detector6Bond flexible cable to flangeLow outgassingNeuroscienceNeurophysiological mechanism of magnetic stimulus in primates11Mechanism to impregnate mini coil during winding processLow viscosity impregnationSpacecraftAttach MLI blanket to spacecraft to survive acceleration, acoustic nd venting loads while minimizing heat load to tank12Configuration of a standoff with an MLI blanketHigh tensile and shear strengthat cryogenic temperaturesTable 2: Patent Grants that Reference EP29LPSPApplicationEP29LPSP UseCritical PropertiesCryogenic refrigerator7Bond thermally insulated tubes to thermal tube couplersCryogenic Low outgassing Thermal shock resistantProton Exchange Membrane (PEM) fuel cell8Rigidizing a fluid flow plate assemblyElectrical insulationPhysical strengthStructural health monitoring (SHM) system9Affix transducers to structure under testCryogenic Withstand vibrationsFiber optic gyroscopes10Construction of fiber optic sensing coilCryogenic Low outgassingDownload full case studyConclusionThe success of any engineered product depends on the performance of all of its parts, including any chemical compound used to join or protect one or more parts. If an adhesive, coating, or potting compound fails, the product fails. Leading companies, research labs, and inventors around the world rely on Master Bond EP29LPSP to perform unfailingly in extremely demanding applications.Sources1Manufacturing Specification and Statement of Work: FLARE (Facility for Laboratory Reconnection Experiments) Project —Fabrication of Flux Core, FLARE-Spec-03-Rev.00, WP1995, Revision 0, Princeton University Plasma Physics Laboratory, 19 Mar. 2015. https://flare.pppl.gov/Construction/FLARE%20FCSpec-03%2019Mar15.pdf . Accessed September 2023.2Lee, David, et al. Properties of optical fibres at cryogenic temperatures. Monthly Notices of the Royal Astronomical Society, vol. 326, no. 2, 11 Sept. 2001, pp. 774-780. ResearchGate, doi: 10.1046/j.1365-8711.2001.04630.x. Accessed 2 Aug. 2017.3 Reference Surfaces for Scanner Calibration Phoenix Scientific Inc., 2002, www.phnx-sci.com/PPS/Downloads_files/AN2002-01%20Ref%20Surface%20for%20Calibration.pdf. Accessed 2 Aug. 2017.4Chen, Bingqiang. Numerical Performance Prediction of a Miniature Ramjet at Mach 4, MS thesis, Naval Postgraduate School, 2012. https://apps.dtic.mil/sti/citations/tr/ADA567441. Accessed September 2023.5 Xu, Jingke. Study of Argon from Underground Sources for Direct Dark Matter Detection. Dissertation, Princeton University, 2013.6 Hsu, Scott C. Experimental Study of Ion Heating and Acceleration During Magnetic Reconnection. N.P. June 2000. July 2016. http://www.osti.gov/scitech/servlets/purl/7509777Snow, David, et al. “Apparatus and methods for improving vibration isolation, thermal dampening, and optical access in cryogenic refrigerators.” US Patent 8,756,941. 24 Jun. 2014.8Walsh, Michael M. “Fuel cell assembly fluid flow plate having conductive fibers and rigidizing material therein.” US Patent 6,096,450. 1 August 2000.9 Qing, Xinlin, et al. “Method and apparatus for conducting structural health monitoring in a cryogenic, high vibration environment.” US Patent 8,347,722. 8 January 2013.10 Chappell, Charles D. and Kara L. Warrensford. “Systems and methods for controlling the gas conversion in a fiber-optic gyroscope.” US Patent 9,182,230. 10 November 2015.11 Tischler, Hadass. Wolfus, Shuki. Friedman. Alexander. Perel, Eli. Pashut, Tamar. Lavidor, Michal. Alon Korngreen, Alon. Yeshurun, Yosef. Bar-Gad, Izhar. “Mini-coil for magnetic stimulation in the behaving primate.” Bar Ilan University, Ramat Gan, Israel. June 12, 2010. Revised September 28, 2010.12 Alberts, S.J., Doehne, C.J., and Johnson, W.L. “Testing Tensile and Shear Epoxy Strength at Cryogenic Temperatures.” https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20170009145.pdf. Accessed May 2020.

Silver filled electrically conductive, for die attach and general bonding. Low volume resistivity and high temperature resistance. Superior bond strength. Thermally conductive. Thixotropic paste, consistency. Available in syringes that are compatible with various types of automatic dispensers or manual dispensing. Serviceable from -80°F to +400°F.