Selecting the Appropriate Adhesive for Your Application
, by Glues Australia, 3 min reading time
What to Consider When Choosing an Adhesive
Choosing the right product for your application can sometimes be difficult. This article highlights the key factors to consider when selecting adhesive products.
Understanding Your Options
Before choosing an adhesive solution, it is important to assess your needs. Each chemistry has its advantages and disadvantages, so you should ask yourself the following questions:
- What materials do I need to bond (plastic, metal, rubber, etc.)?
- Is the gap size I need to fill small or large?
- Will the bond be affected by environmental factors like polar or nonpolar solvents?
- What temperatures will the bond be exposed to?
- What is the importance of fixture and cure time?
- Do I need to consider flexibility?
Having a basic knowledge of different types of adhesives will help you match the right product to your application. Below is a quick overview.
Cyanoacrylates
Also known as “super glue,” cyanoacrylates (CA’s) bond quickly and work on most materials except glass. They are suitable for bonding rubbers, polymers, metals, wood products, and painted metals. Common applications include speaker component bonding and gasket bonding.
Limitations include poor impact resistance, unsuitability for large gap filling, and shorter shelf life once opened.
Light Cure Adhesives
Used in medical technology and optics, these adhesives are fast, stable, and highly transparent. They are excellent for glass but require transparent substrates and curing equipment that allows light to pass through.
Epoxies
Epoxies provide high strength, heat and chemical resistance, and excellent insulating properties. They are widely used in electronics, automobiles, aircraft, boats, and sports equipment. However, they require mixing and heat curing, are less convenient, and not suitable for flexible joints or some plastics.
Two-Part Acrylics
Ideal for harsh environments, these adhesives have strong impact and peel resistance. They are used in marine applications, panel bonding, and as an alternative to spot welding. They require mixing and proper ventilation due to strong odours.
Two-Step Acrylics
Unlike two-part versions, they don’t require mixing but still need an activator. They are durable and tough, commonly used in nameplate bonding and magnet bonding. Their gap-filling ability is limited.
SMPs (Silane-Modified Polymers)
Flexible and paintable, SMPs combine the benefits of polyurethanes and silicones. They are used in seam sealing, truck, and trailer bonding. However, they have limited high-temperature resistance and gap-filling ability.
Urethanes
Flexible and paintable, urethanes are used in clean energy (wind turbine blades) and automobile industries (window glazing). Their limitations are similar to SMPs.
Silicones
Silicones are excellent for sealing and provide superb temperature and UV resistance. They are often used in windows, gaskets, and oil pans. However, they have poor adhesion and are non-paintable, which limits applications.
Anaerobics
Also called machinery adhesives, anaerobics are used for thread locking, retaining, and sealing. They prevent vibration loosening and corrosion. While they have high shear strength, their peel strength is low.
Hot Melts
Hot melts are quick, effective, and economical, commonly used in filter bonding and low-pressure moulding. They are less adaptable than other adhesives due to limited temperature resistance and poor adhesion to metals.
Making the Right Choice
Choosing the right adhesive can be challenging, but testing helps identify the best solution for your needs. You may find multiple adhesives suitable, in which case economic and infrastructural factors can guide your decision.
If you need help evaluating your options, feel free to contact us. Our team will gladly assist you. You can also explore our product selector charts on our interactive adhesives website.