What are epoxy adhesives or "epoxy glue?" Epoxy resins have been in use for decades in industries as diverse as marine, industrial, electrical and aerospace. Epoxies are very versatile adhesives that are suitable for many substrates. Epoxy adhesives tend to be low-odor, viscous liquids or pastes (although self-leveling liquids are available). They are usually packaged in dual cartridges containing two separate components in the unreacted state—one a resin and one a hardener. Different mix ratios may be specified depending on desired final physical properties, and in general the adhesives are less sensitive (compared to some chemistries) to slight variations in mix ratio.
Advantages to Using Epoxy Adhesives
Epoxies offer long open times, which allows for repositioning and assembly of complex shapes, and are relatively unaffected by humidity while curing. They have excellent chemical resistance and good high temperature strength, being chemically stable up to 125°C (250°F) and some even to 200°C (400°F). They have high tensile strength. Their formulations can also be thermally and/or electrically conductive and flame retardant.
8 Uses for Bonding with Epoxies (Epoxy Substrates):
- Plastics: Thermoplastic Polyurethane (TPU) & Thermoplastic Elastomer (TPE)
- Prepared Metals
- Bare Metals
4 Things to Know About Epoxy Adhesives:
- Epoxy-based structural adhesives adhere to the widest variety of materials, including bare metals, prepared metals, plastics, composites, concrete, wood, rubber and foam.
- The final properties of epoxy adhesives develop within 24 hours at room temperature, but their cure rates can be accelerated dramatically with heat.
- Epoxies have relatively low elongation and are often considered rigid (stiff/not flexible) in comparison to acrylics and urethanes.
- Storing epoxy adhesives are easy and should be kept at room temperature. If stored in a cooler location, you will need to let the product come to room temperature before dispensing.