Anaerobic adhesives and anaerobic sealants cure in the absence of air or oxygen. They are designed for fastening and sealing applications in which a tight seal must be formed without light, heat or oxygen. Substrate or material compatibility is an important factor to consider when selecting anaerobic adhesives and anaerobic sealants. Some products adhere to ceramics or glass, concrete or masonry, metal, paper, plastic, rubber or porous surfaces. Others are compatible with substrates or materials made from composites, textiles, fabrics, wood, rubber, or elastomers. Products that can bond dissimilar substrates such as metal to rubber are also available.
Chemical and Polymer Systems
Anaerobic adhesives and anaerobic sealants use many different chemical and polymer systems. Some systems contain acrylonitrile-butadiene-styrene (ABS), acetal materials, acrylic polymers, bituminous substances, butyl, cellulose, ceramics, cyanoacrylates, or epoxy resins. Other chemical and polymer systems include ethylene copolymers, fluropolymers, ionomer polymers, isoprene or polyisoprene, liquid crystal polymer (LCP), ketones, phenolic and formaldehyde resins, polyamides, and polyamide-imides. Chemical and polymer systems for anaerobic adhesives and anaerobic sealants also include polybutadiene, polycarbonate (PC), polyethylene (PE), polyethylene terphthalate (PET), polyester, polyether block amide (PEBA), polyetherimide, polyolefin, polyphenylene oxide (PPO), polypropylene (PP), polysulphide, and polysuphone. Silicone, styrene, vinyl, and wax-based systems are also available.
Selecting Anaerobic Adhesives and Anaerobic Sealants
Selecting anaerobic adhesives and anaerobic sealants requires an analysis of mechanical, thermal, electrical and optical properties. Mechanical properties include tensile strength (break), tensile modulus, and elongation. Thermal properties for anaerobic adhesives and anaerobic sealants include use temperature, thermal conductivity, and coefficient of thermal expansion (CTE). Thermal conductivity is the linear heat transfer per unit area for a specific temperature. CTE is the amount of linear expansion or shrinkage that occurs in a material with a change in temperature. Resistivity, dielectric strength, and dielectric constant are important electrical properties for hot melt adhesives. Optical properties include index of refraction, a measure of the speed of light in a material.
Anaerobic adhesives and anaerobic sealants differ in terms of features. Flame retardant products are designed to reduce the spread of flame or resist ignition when exposed to high temperatures. Flexible or dampening products are designed to reduce sound, shock, or vibration. Solvent-based anaerobic adhesives use a volatile organic compound (VOC) to thin or alter viscosity. Water-based or water borne adhesive resins do not. In terms of shape or form, anaerobic adhesives and anaerobic sealants can be cast, extruded, or molded. Thermal interface materials use a phase change to enhance thermal characteristics or heat absorption from electronic devices or electrical components.
Anaerobic adhesives and anaerobic sealants are used in many industries and applications. For example, some products are used in aerospace, automotive, marine, military, photonics, optical, or tooling applications. Others are designed for use with electronic devices, electrical power products, high voltage applications, semiconductors, or integrated circuit (IC) packaging. Anaerobic adhesives and anaerobic sealants that are suitable for medical, pharmaceutical and food processing applications meet requirements established by the Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA).
Related Products & Services
Conformal coatings encapsulate circuit boards and their electronic components in order to prevent the ingress of moisture, fungus, dust and other environmental contaminants.
Epoxy adhesives are chemical compounds for joining components. They require clean surfaces and are valued for their toughness and resistance to chemical and environmental damage.
Gel elastomers are highly viscoelastic polymer gel materials that have excellent shock absorption and damping characteristics. They are available in a variety of material types and grades.
Pressure Sensitive Adhesives (PSA) and Contact Adhesives
Pressure sensitive adhesives (PSA) and contact adhesives adhere to most surfaces with very slight pressure. They are available in solvent and latex or water-based forms.
Silicone Adhesives and Sealants
Silicone adhesives and sealants have a high degree of flexibility and a very high temperature resistance (up to 600° F), but lack the strength of other epoxy or acrylic resins.
Thermoplastics and Thermoplastic Materials
Thermoplastics and thermoplastic materials soften when heated and harden when cooled. They can withstand many heating and cooling cycles and are often suitable for recycling.
Thermosets and Thermoset Materials
Thermosets and thermoset materials are crosslinked polymeric resins that are cured or set using heat or heat and pressure. They generally have a higher resistance to heat than thermoplastics.