Whitepapers - Aircraft
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resources like a Terms & Definitions document and an Adhesive / Primer study. While some papers are
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For further reading, please see our Technical Resources section.
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May 22, 2012
Characterization of Fuel Resistant Fluorosilicones
Silicones are commonly used in automotive applications as potting compounds, adhesives, gaskets, seals and encapsulants due to their ability to remain elastic at low temperatures and resist breakdown at high temperatures or in UV light. In addition to a broad operating temperature range, silicones inherently possess high dielectric strength (=...
Silicones are commonly used in automotive applications as potting compounds, adhesives, gaskets, seals and encapsulants due to their ability to remain elastic at low temperatures and resist breakdown at high temperatures or in UV light. In addition to a broad operating temperature range, silicones inherently possess high dielectric strength (= 500 V/mil), low modulus and a low glass transition point (Tg), as compared to organic-based rubbers. These characteristics make silicones ideal for use in high-power electronic applications, yet gentle enough for delicate wire bond encapsulation and other applications in which thermal cycling is a concern. Ultimately, the quality that contributes most to silicone’s wide use in the automotive and other industries is the opportunity for formulation flexibility.
May 21, 2012
Novel Adhesions Methods for Solar Cell Assemblies
Traditionally, engineers and solar cell assemblers have used liquid silicone adhesives to bond solar cells to panel substrates such as satellites, and silicones with high light transmittance to bond cover glasses to cells. Using next generation silicone technology, low outgassing silicone pressure sensitive adhesives (PSA) and thin film sheeting can...
Traditionally, engineers and solar cell assemblers have used liquid silicone adhesives to bond solar cells to panel substrates such as satellites, and silicones with high light transmittance to bond cover glasses to cells. Using next generation silicone technology, low outgassing silicone pressure sensitive adhesives (PSA) and thin film sheeting can serve the same purpose as liquid adhesives but eliminate long wait times for room temperature cures or additional equipment, such as ovens, required to heat accelerate the cure process. Moreover, the processing these low outgassing materials undergo allows them to be used on extraterrestrial applications like satellites as mentioned above.
Jan 9, 2012
Choosing a Silicone for Joining Technologies
Engineers and material scientists are constantly looking for a polymeric adhesive that can perform in a broad operating temperature range, maintain chemical stability and offer unique mechanical properties. The dynamic attributes of silicone adhesives, sealants, coatings and encapsulants provide design engineers with a variety of solutions to the complex challenges...
Engineers and material scientists are constantly looking for a polymeric adhesive that can perform in a broad operating temperature range, maintain chemical stability and offer unique mechanical properties. The dynamic attributes of silicone adhesives, sealants, coatings and encapsulants provide design engineers with a variety of solutions to the complex challenges they face. The advantages of silicone lie in the chemistry of the polymer chain, which can be modified to achieve desired mechanical properties.
Oct 21, 2011
Fluorosilicones in the Aerospace Industry
Fluorosilicone’s advent into the commercial marketplace offers opportunities for manufacturers to pursue new applications for silicones in the automotive, aircraft and general markets. The unique properties of fluorosilicones provide a solution for products that need broad operating temperatures, fuel resistance and long-term reliability. Conventional dimethyl silicones cannot survive the harsh...
Fluorosilicone’s advent into the commercial marketplace offers opportunities for manufacturers to pursue new applications for silicones in the automotive, aircraft and general markets. The unique properties of fluorosilicones provide a solution for products that need broad operating temperatures, fuel resistance and long-term reliability. Conventional dimethyl silicones cannot survive the harsh environments that fluorosilicones can endure. Similar to other silicones, fluorosilicones can be provided as high consistency rubbers (HCRs), liquid silicone rubbers (LSRs), dispersions, gels and even foams. Silicone manufacturers offer a variety of fluorosilicone solutions that fit the unique processes of any end-user. Whether fluorosilicones are used as adhesives, molded parts or protective coatings, flexibility of application is possible.
May 18, 2008
Material and Process Innovations with Filled Silicone Elastomers
Today the technological progress of modern military aircraft design has been greatly influenced by the use of advanced composite materials. These materials permit design of lighter stronger more flexible aircraft yet offers a new set of challenges in design, production and quality.
Today the technological progress of modern military aircraft design has been greatly influenced by the use of advanced composite materials. These materials permit design of lighter stronger more flexible aircraft yet offers a new set of challenges in design, production and quality.
Jan 18, 2008
A Silicone-Based Ice-Phobic Coating for Aircraft
The problem of ice build-up in an engine or on the leading edges of a plane is a significant
problem in the aircraft industry. Ice build up can affect many aspects of flying such as lift, drag,
and thrust. Under the direction of Pratt & Whitney in 2004, the Department of the...
The problem of ice build-up in an engine or on the leading edges of a plane is a significant
problem in the aircraft industry. Ice build up can affect many aspects of flying such as lift, drag,
and thrust. Under the direction of Pratt & Whitney in 2004, the Department of the Army,
Engineer Research and Development Center, Cold Regions Research and Engineering
Laboratory (CRREL) in Hanover, NH, U.S, performed adhesion strength tests designed to
measure the adhesion strength of ice to several different commercially available ice-phobic
coatings. The results show that the silicone material, R-2180, dropped the adhesion strength by a
factor of 40 over bare steel and aluminum surfaces. These results were the lowest mean failure
stress that CRREL has ever seen at 37 kPa while Teflon was previously the lowest tested value
measured at 238 kPa.
Jan 18, 2008
A Silicone-Based Ice-Phobic Coating for Aircraft
The problem of ice build-up in an engine or on the leading edges of a plane is a significant
problem in the aircraft industry. Ice build up can affect many aspects of flying such as lift, drag,
and thrust. Under the direction of Pratt & Whitney in 2004, the Department of the...
The problem of ice build-up in an engine or on the leading edges of a plane is a significant
problem in the aircraft industry. Ice build up can affect many aspects of flying such as lift, drag,
and thrust. Under the direction of Pratt & Whitney in 2004, the Department of the Army,
Engineer Research and Development Center, Cold Regions Research and Engineering
Laboratory (CRREL) in Hanover, NH, U.S, performed adhesion strength tests designed to
measure the adhesion strength of ice to several different commercially available ice-phobic
coatings. The results show that the silicone material, R-2180, dropped the adhesion strength by a
factor of 40 over bare steel and aluminum surfaces. These results were the lowest mean failure
stress that CRREL has ever seen at 37 kPa while Teflon was previously the lowest tested value
measured at 238 kPa.
Nov 8, 2007
A Silicone-Based Ice-Phobic Coating for Aircraft
The problem of ice build-up in an engine or on the leading edges of a plane is a significant
problem in the aircraft industry. Ice build-up can affect many aspects of flying such as lift, drag,
and thrust. Under the direction of Pratt & Whitney in 2004, the Department of the Army,
Engineer...
The problem of ice build-up in an engine or on the leading edges of a plane is a significant
problem in the aircraft industry. Ice build-up can affect many aspects of flying such as lift, drag,
and thrust. Under the direction of Pratt & Whitney in 2004, the Department of the Army,
Engineer Research and Development Center, Cold Regions Research and Engineering
Laboratory (CRREL) in Hanover, NH, U.S, performed adhesion strength tests designed to
measure the adhesion strength of ice to several different commercially available ice-phobic
coatings. The results show that the silicone material, R-2180, dropped the adhesion strength by a
factor of 40 over bare steel and aluminum surfaces. These results were the lowest mean failure
stress that CRREL has ever seen at 37 kPa while Teflon® was previously the lowest tested value
measured at 238 kPa.
Dec 19, 2005
Low Outgas Silicone Pressure Sensitive Adhesive for Aerospace Applications II
The aerospace industry, primarily satellite manufacturers, have expressed the need for a low outgas, thermally stable, adhesive tape. The current products in the marketplace have limitations at both high, 175ºC, and low, -100ºC, temperatures. A new silicone Pressure Sensitive Adhesive (PSA) was developed to pass ASTM E-595(1), low outgassing requirements...
The aerospace industry, primarily satellite manufacturers, have expressed the need for a low outgas, thermally stable, adhesive tape. The current products in the marketplace have limitations at both high, 175ºC, and low, -100ºC, temperatures. A new silicone Pressure Sensitive Adhesive (PSA) was developed to pass ASTM E-595(1), low outgassing requirements of 1% or less Total Mass Loss (TML) and 0.1% or less Collectable Volatile Condensable Materials (CVCM). This PSA was then fabricated into a tape and measured for performance and compared to other non-low outgassing silicone PSAs. The basics were outlined in a presentation presented at the SAMPE technical conference in Long Beach, CA, May 2004(2). This paper will expand on this technology by providing testing data at both high and low temperatures, comparative testing under different conditions with industry standard acrylate tapes, and more details on the fabrication of the tape.
Jun 16, 2004
Low Outgas Silicone Pressure Sensitive Adhesive for Aerospace Applications
The need for a low outgas, thermally stable, high performance adhesive has initiated the development of a new experimental silicone Pressure Sensitive Adhesive (PSA) able to pass ASTM E-595, low outgassing requirements of 1% or less Total Mass Loss (TML) and 0.1% or less Collectable Volatile Condensable Materials (CVCM). The...
The need for a low outgas, thermally stable, high performance adhesive has initiated the development of a new experimental silicone Pressure Sensitive Adhesive (PSA) able to pass ASTM E-595, low outgassing requirements of 1% or less Total Mass Loss (TML) and 0.1% or less Collectable Volatile Condensable Materials (CVCM). The performance goals were to maintain performance under load at temperatures above 175°C and have similar properties to other low outgassed silicone PSA’s as tested by peel, loop tack, shear, release force and Blunt probe tack.
Jun 8, 2004
Adhering to Difficult Substrates
Adhesive echnology is equal parts chemistry and ‘black magic’. Because there are so many different substrates, each adhesive can not be actually tested before hand on each and everyone. However, by testing on some novel substrates, or difficult to adhere to, inferences can be made which can narrow the choices...
Adhesive echnology is equal parts chemistry and ‘black magic’. Because there are so many different substrates, each adhesive can not be actually tested before hand on each and everyone. However, by testing on some novel substrates, or difficult to adhere to, inferences can be made which can narrow the choices of adhesives. We can define adhesion as the chemical bonding of two substrates. Substrates that have reactive groups available for bonding like OH groups on glass and aluminum make this chemical bond easier. Substrates with nothing to react to make adhesion difficult; graphite and PTFE. Multiple other substrates fit somewhere in-between.
Sep 25, 2003
Silicone Adhesives and Primers on Low Surface Energy Plastics and High Strength Metals
This paper will demonstrate the ability of silicone adhesives, with the aid of primers, to adhere to low surface energy plastics and to high strength metals. In general, some plastics are difficult to adhere to because of their low surface energy, available bond sites, and chemical interaction. Most plastic have...
This paper will demonstrate the ability of silicone adhesives, with the aid of primers, to adhere to low surface energy plastics and to high strength metals. In general, some plastics are difficult to adhere to because of their low surface energy, available bond sites, and chemical interaction. Most plastic have a surface energy under 50 dynes/cm while aluminum, an easier substrate to adhere to, is closer to 825 dynes/cm. Surface energy is a thermodynamic effect of how a liquid will ‘wet out’ on a surface. Low surface energy materials, like plastics, do not allow a liquid, like an adhesive, to ‘wet out’ on its surface. Adhesion chemistry tells us that the better an adhesive can ‘wet out’ on a substrate, the more surface area it can cover and allow more reactive groups to bond, making a stronger bond. Several low surface energy plastics and high strength metals were tested with silicone adhesives and primers to achieve cohesive bond failure when performing lap-shear testing. This list of substrates evaluated include polycarbonate, polyetherimide, polyamide, polyurethane, polymethylmethacrylate, polysulphone, titanium, stainless steel, and aluminum.
Feb 17, 2003
Accelerating Cure of Silicone Adhesives
This paper will demonstrate the availability of dramatically accelerating the cure of certain silicone adhesives and their advantage to the manufacturing process. A ‘fast cure’ adhesive is defined as full cure in less than ten minutes—or partial cure for handling under five minutes and full cure at room temperature in...
This paper will demonstrate the availability of dramatically accelerating the cure of certain silicone adhesives and their advantage to the manufacturing process. A ‘fast cure’ adhesive is defined as full cure in less than ten minutes—or partial cure for handling under five minutes and full cure at room temperature in 8 hours or one shift. Using a specific cure system and materials that have been developed to obtain fast-cure with heat acceleration, an experiment was performed to determine how fast, and at what temperatures these adhesives will cure. In conclusion, to obtain fast-cure at low temperature, 65ºC, R31-2186 can be fully cured in one minute. When adhering to temperature sensitive substrates, this provides a fast-cure choice. Although needing a higher temperature to obtain ‘fast-cure’, R32-2186 fully cures in 2 minutes at 100ºC. This can be useful because of R32-2186’s extended worktime. LSR-9820-20 proves the best choice for high temperature cure, 185ºC. In just 30 seconds it has a 300psi lap shear. Although this figure reaches optimum over time, for many applications this is a great partial cure.