Anaerobic Adhesives and Anaerobic Sealants Information
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.
Anerobic adhesives and sealants cure when exposed to metal ion, typcially from metal surfaces of threads or joints on fasteners, fittings, and connectors. Heat, primers or activators can be used to accelerate the cure.
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
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:
- Polyester / Vinyl Ester
- Vinyl / PVC
- Rubber / Elastomer
Monomer - methacrylate esters are used in almost all anaerobic products. Acrylates, acrylic and methacrylic acids, and other vinyl polymerizable monomers may be used for special purposes.
Selecting anaerobic adhesives and anaerobic sealants requires an analysis of mechanical, thermal, electrical and optical properties. Mechanical properties include:
Tensile strength (break)
Thermal properties for anaerobic adhesives and anaerobic sealants include:
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:
- Tooling application
Others are designed for use with:
Electrical power products
High voltage applications
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).
ASTM D5363 - Standard specification for anaerobic single-component adhesives (AN).
BS 5350-G2 - Methods of test for adhesives - part g2: determination of static shear strength of anaerobic adhesives.
BS EN 15275 - Structural adhesives - characterisation of anaerobic adhesives for co-axial metallic assembly in building and civil engineering structures.
DIN EN 15865 - Adhesives - determination of torque strength of anaerobic adhesives on threaded fasteners.
9985253 - Sealant compound, pipe, anaerobic, grade 253.