Instant adhesives, or cyanoacrylates, are known for their rapid curing capabilities. They utilize moisture to cure, specifically the ion catalysts within water, instigating a chemical reaction of anionic polymerization to complete an adhesive bond virtually instantly. This guide is a collection of the common terminology you’re likely to encounter when working with cyanoacrylates and related adhesives.
Diverse industries use cyanoacrylate adhesives for fast cure times and strong adhesion, including:
Accelerators: Additives that initiate polymerization and speed up cure times in cyanoacrylate, modified acrylic, or anaerobic adhesives
Acrylic adhesives: Structural adhesives consisting of methacrylic or acrylic polymers
Acrylic glue: Less formal name for acrylic adhesive
Activators: Additives that accelerate cure times for anaerobic adhesives on non-metallic or passive metal surfaces
Adherends: Substrates that are bonding with another material or component
Adhesion chemistry: Science that examines intermolecular forces and interlocking action at the point of adhesion to see how two components bond
Adhesives: Sticky materials for holding components together or fastening something to a surface
Ambient conditions: Normal environmental conditions within a space, including sunlight, humidity, room temperature, and atmospheric pressure
Anaerobic adhesives: Adhesives that cure in the presence of metal ions, but only with the exclusion of air
Bead-on-bead acrylic adhesives: Fast-curing adhesives with two components that combine and cure after a bead of component A is applied and topped with a bead of component B
Bond: Interface of a substrate and an adhesive
Breakaway torque: Amount of force necessary to cause loosening-direction motion for an unseated fastener
CA glue: Another name for a cyanoacrylate adhesive
Coefficient of thermal expansion (CtE): A material’s size change based on alterations to temperature, with higher CtE values indicating an adhesive with more give that’s unlikely to crack
Cohesive failure: When an adhesive and its bond fail
Cure speed: Amount of time it takes for adhesive to reach a full-strength bond
Curing time: Amount of time adhesives require to reach full cure strength, factoring in working strength, pot life, fixture speed, handling time, and skin-over time
Cyanoacrylate adhesives: Category of adhesives including superglue and instant adhesives that are defined by their quick cure rates under exposure to alkalines
Electrical conductivity: Measurement of a material’s capability to serve as an electrical current conductor
Epoxies: One- or two-part adhesives that consist of synthetic thermosetting polymers with epoxide groups
Epoxy 1 part: A single-component thermosetting epoxy adhesive with epoxide groups that cures at high temperatures (also known as 1K epoxy or one-component epoxy)
Epoxy 2 part: Two-component epoxy adhesive derived from thermosetting polymers that cure when an epoxy resin and hardener combine (also known as 2K epoxy, two-part epoxy, or 2-part epoxy)
Epoxy food grade: Epoxies that are considered safe for food-contact applications per the FDA
Epoxy glue: Another name for epoxy adhesive
Epoxy paste: One- or two-component epoxy adhesive with high viscosity
Epoxy putty: One- or two-component epoxy adhesive that has a very high viscosity
Exotherm: Amount of heat that exothermic materials give off during curing, which is sometimes high enough to cause plastics to melt
Fixture time: Required time for adhesives to achieve adequate cure strength for component handling
Form-in-place (FIP) gaskets: Semi-liquid or liquid adhesives that generate a gasket, with the liquid variety enabling full contact between metal components
Gap fill: Adhesive’s ability to fill in the area between substrates to keep them in place
Heat aging: Measure of adhesive strength at room temperature, post higher-temperature aging
Heat-cure epoxies: One-part epoxies that cure at higher temperatures and contain thermoset polymers with epoxide groups
Heat-resistant epoxies: Epoxy adhesives that can tolerate above-average temperatures, up to 212° F or 355° F for two- and one-part epoxies, respectively
High-temperature epoxies: Another name for heat-resistant epoxies
Hot strength: Strength of an adhesive calculated at raised temperatures
Impact strength: Resistance of an adhesive bond when it’s faced with the force of impact
Industrial adhesives: Adhesives that are more specific to their application than those packaged for consumers
Lap shear: Test that joins overlapping flat bar ends to evaluate shear stress
Locking torque: Test that examines a thread locking adhesive-coated threaded piece for its prevailing or breakaway torque
Metal adhesives: Adhesives that are intended for metal substrates
Methyl methacrylate adhesives: Acrylic adhesives containing methacrylic polymers
Monomers: A molecule that can be bonded to other identical molecules to form a polymer
MRO: Maintenance, Repair and Operations (MRO) refers to the equipment, tools and activities associated with the daily operations of a business.
OEM: Abbreviation for original equipment manufacturer.
Open time: The maximum time between applying the adhesive to one surface and ensuring it comes into contact with the other surface.
pH: Measurement of a substance’s acidity, neutrality, or alkalinity
Pipe sealants: Anaerobic adhesives that seal threaded metallic pipework and prevent corrosion and loosening (also known as thread sealants)
Plastic adhesives: Adhesives that are well-suited to plastic substrates
Polymers: A molecule made up of a chain of repeating units which are chemically bonded together.
Prevailing torque: Average amount of force necessary post-seating to ensure continuing motion through an initial turn
Retaining compounds: Anaerobic retaining compounds that securely adhere cylindrical non-threaded metal components to housings or shafts (also known as retainers)
Rheology: Consideration of the effect that a material’s adhesion capability and shear sensitivity have on viscosity
Seal: To close off one side of an entrance from the other, sealing up substrates to keep fluid or gas materials out
Shore hardness: Hardness of an adhesive as measured with a durometer gauge
Skin-over time: Amount of time needed for an adhesive’s surface to be dry to the touch
Static shear: Test that evaluates shear stress resistance, joining a ring or collar with a pin
Structural acrylic adhesives: Adhesives that generate structural, load-bearing bonds
Substrate: Material that’s being bonded
Substrate failure: Failure of a substrate bond when an adhesive’s strength surpasses the material’s internal strength
Surface-activated acrylic adhesives: Two-component acrylic adhesives that use an acrylic resin on one component’s surface and an initiator on the other
Surface primers: Coatings that alter a surface’s characteristics, enhancing its capability for effective adhesion
Thermoplastics: Materials that soften in the presence of high temperatures, transforming into plastic that, when cooled, retains its material strength
Thermoset: Resins that cure only under heat exposure, at which time they become heat-resistant plastics
Thixotropy: Flow characteristics of a paste or liquid material
Threadlockers/thread lockers: Anaerobic adhesives with optimal sealing capabilities and corrosion resistance that lock metal fasteners to prevent loosening
Thread sealants: Corrosion-resistant anaerobic adhesives that seal metal threaded pipework, locking to prevent loosening
Toughened acrylic adhesives: Another name for structural acrylic adhesives
Viscosity: Thickness of a fluid or its flow resistance in centipoise or poise
When applying an adhesive, a dot is a droplet or spot of the substance, and a bead is a glue line. For both, you should carefully manage adhesive volume as well as the dot or bead locations to ensure precision. Changing the nozzle on your application equipment can give you greater control, as needed, over the volume of adhesives you use and where the adhesives go. Knowing your approximate dot and bead size will help you determine how much adhesive you need.
Viscosity scales cover the range of a fluid material’s flow resistance. High values on the scale indicate a thick substance with high flow resistance, and lower values signify a thin fluid with a faster flow. Choosing an adhesive for its uncured viscosity can help you find the right one for your application. Low-viscosity adhesives are ideal for covering a greater surface area in a thin glue film, but they can be runny. High-viscosity adhesives are more difficult to spread, but they can offer superior bonding strength. Remember that heat affects a fluid’s viscosity, so factor in temperature when selecting the optimal viscosity.
Toagosei America, Inc. is a division of the Toagosei Group, which has been in the adhesives business since 1989 in North America. Toagosei launched its cyanoacrylate brand Aron Alpha to industrial manufacturing markets in Japan in 1963 and its Krazy Glue brand to North America consumer markets in 1973. We utilize advanced chemical technology to produce and customize functional adhesive solutions tailored to your unique application. Our Aron Alpha® brand of industrial cyanoacrylate adhesives provides optimal adhesion in everything from manufacturing and general assembly to the automotive and electronics sectors for customers across North America, South America, and Japan.
Browse our website for information on our industrial high-performance instant adhesives, or contact us today to learn more about the Aron Alpha difference.
Toagosei America, Inc. is a division of the Toagosei Group, which has been in the adhesives business since 1989 in North America. Toagosei launched its cyanoacrylate brand Aron Alpha to industrial manufacturing markets in Japan in 1963 and its Krazy Glue brand to North America consumer markets in 1973. We utilize advanced chemical technology to produce and customize functional adhesive solutions tailored to your unique application. Our Aron Alpha® brand of industrial cyanoacrylate adhesives provides optimal adhesion in everything from manufacturing and general assembly to the automotive and electronics sectors for customers across North America, South America, and Japan.
Browse our website for information on our industrial high-performance instant adhesives, or contact us today to learn more about the Aron Alpha difference.
