High-performance adhesives

Citation

(2001), "High-performance adhesives", Aircraft Engineering and Aerospace Technology, Vol. 73 No. 4. https://doi.org/10.1108/aeat.2001.12773dad.019

High-performance adhesives

High-performance adhesivesKeywords: Axson, Adhesives

French adhesive manufacturer Axson, reports that it is promoting the definitive range of polyurethane, epoxy and methacrylate adhesives designed to meet all bonding requirements, from the simplest to the most complicated.

The new range, which is marketed under the name ADEKIT, comprises three product families: epoxies, polyurethanes and methacrylates. Said to be certified by independent laboratories, these products are designed to meet bonding needs in a wide range of industries, including aerospace, such as leading edge of helicopter blades.

Epoxy adhesives are used for structural bonding. They claim superlative mechanical properties, including stiffness and dimensional stability, chemical resistance and an ability to withstand high temperatures. With a lap-shear strength of 15-26Mpa and elongation at break of 3-10 per cent, they are believed to be ideal for bonding honeycomb structures.

Polyurethane adhesives are used where flexible bonding is required. They are said to offer flexibility and elasticity, which give them excellent resistance to vibrations, shocks and low temperatures. Lap-shear strength is reported to be 6-18Mpa and elongation at break goes from 10 per cent to 300 per cent.

Methacrylate adhesives combine flexibility and mechanical resistance. They also claim excellent adhesive properties for a wide range of materials, including plastics that are known to be difficult to bond. Lap-shear strength is said to be 15-22Mpa and elongation at break goes from 10 per cent to 30 per cent.

Axson also considers that in addition to their mechanical properties, the methacrylates stand out from other adhesives because of their quick bonding properties, low density and ease of implementation. The company also believes that they are environmentally friendly because they can be recycled.

They are described as perfect for bonding composite and assembling thermoplastic parts. ADEKIT adhesives come in 50ml and 400ml cartridges. Some are also available in industrial packaging. Ready for immediate use, they can be applied with a manual or pneumatic application gun or using a dual-component dispensing machine.

Axson also informs us that it has recently launched a new range of high-performance dielectric resins designed to protect electronic and electric systems or components against vibration, dust, electromagnetic fields and other sources of damage.

Axson's dielectric resins are said to be ideally suited to all applications, but Axson has become the specialist in encapsulation of on-board electronic systems for the aerospace industry. Axson's range is divided into two chemical families: polyurethane resins and epoxy resins. These resins, stated to be certified by independent laboratories, claim outstanding insulation, superlative to thermal shocks, low exothermal qualities and ease of use.

The polyurethane resins are stated to provide excellent insulation and good thermal resistance. They are recommended by Axson for a wide range of applications thanks to their hardness and rapid reticulation. They are used to coat condensers, switches and relays, to provide over moulding for low and medium voltage transformers, and to protect or coat electronic components. The polyurethane resins are employed in many different sectors, including on-board electronics for the aeronautics sector.

The RE 11880 flexible polyurethane resin, can reportedly withstand thermal shocks of between –40°C and +130°C. According to Axson the RE11880 resin can be used wherever resistance is required to thermal shocks and vibrations, such as in railway equipment.

Axson's epoxy resins claim high thermal conductivity. Cold epoxy resins are described as ideal for the encapsulation and impregnation of components. They have excellent resistance to dielectric and mechani-chemical agents and to high temperatures. Hot epoxy resins are recommended by Axson for applications requiring good temperature resistance, such as the coating of medium and high voltage transformers and the protection and impregnation of motors. In addition to offering thermal and chemical resistance, these resins are said to be unaffected by moisture and have excellent dielectric properties.

A new epoxy resin, the RE 22946 for the coating of alternator coils will be marketed soon. This fire-resistant resin claims an excellent thermal resistance as well as a good resistance to engine fluids. Furthermore, the thermal conductivity is believed to be very high (2.6W/m.K) and still processing remains easy.

Further details are available from FTPB, Tel: +1 020 7235 5330; Fax: +1 020 7235 2773.