Selecting the Appropriate Adhesive for Your Application

Choosing the right adhesive to use can sometimes be difficult. The things to consider when choosing the right adhesive products for your application will be discussed in this article. 
Understanding your options is the next thing to consider after deciding to use adhesives. Before looking for a solution, it is important to put your needs into consideration because there are advantages and disadvantages associated with each chemistry.

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 any 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?

For you to better understand the adhesives that can satisfy your application needs, it is important you have a basic knowledge of different types of adhesives. A quick overview is presented below. 

Cyanoacrylates
Cyanoacrylates (CA’s) is a typical example of an all-purpose adhesive. They are popularly known as “super glue” in the consumer market. What makes them great is that they can bond very quickly and can be used on almost all types of materials. Glass is the only material for which it is not recommended to use CA’s. Apart from this, they are very suitable for bonding rubbers, polymers, metals, wood products, painted metals and others. Speaker component bonding and gasket bonding are some common ways of applying CA’s. 

Nevertheless, there are some limitations associated with using CA’s. For instance, they are known to have poor impact resistance and can’t be used for joints that need large gap filling. In addition, the shelf life of CA’s is shorter than that of other adhesives when opened. Thus, it is important you consider this if you won’t be using them often.

Light Cure Adhesives
Applications such as catheter and needle bonding as well as in the optical industry and medical technology are where light cure solutions are usually applied. Due to the fact that they are very fast, exceptionally stable and highly transparent, they are very good for glass.

To bond two substrates, a transparent surface, as well as an extra equipment, is needed in order to allow light pass through since these adhesives are light cure solutions. 

Epoxies
The high strength of epoxies as well as their heat and chemical resistance, and their excellent electrical insulating and mechanical properties makes them stand out among other adhesives. 

Epoxies are usually applied in the electronics and computer industries, especially for joining printed circuit boards. Automobiles, aircraft construction, boats, bicycles, golf clubs and others are some of the applications which require a strong bond like epoxies.

A combination of a hardener and heat curing or resin is required for epoxies, and they are less convenient compared to other adhesive products. In addition, it is not recommended to use epoxies for joints that require flexibility as well as for various types of plastic.

Two-Part Acrylics
Two-part acrylics are suitable for complex environments that are exposed to harsh elements and moisture due to their peel resistance and durable impact as well as their high shear strength. They are used in the marine industry, especially for bonding FRP boats as well as a rivet replacement in panel bonding and an alternative to spot welding. 

Similar to epoxies, these solutions require a mixing procedure, which involves combining an activator and a resin. They should only be used in facilities that have a good ventilation because of their strong odour.

Two-Step Acrylics
These adhesive solutions have an advantage over their two-part counterparts because they don't require mixing. In terms of durability and toughness, they also have a high ranking. Nameplate bonding and magnet bonding in speakers or electric motors are areas where they are applied.

Notwithstanding, they still need an activator and their gap-filling capacity is restricted.

SMPs
Silane-modified polymers (SMPs) have been used for the production of sealants and adhesives since the 1980s. This polymer type is flexible and paintable and has both the properties of polyurethanes and silicones. SMPs are used in making seam sealing, truck and trailer bonding.

However, they are very limited in terms of their high-temperature resistance and gap-filling ability.

Urethanes
Urethanes, which are also flexible and paintable, are another types of adhesives suitable for the clean energy industries (wind turbine blade bonding) as well as the automobile industries (window glazing). 

The shortcomings of urethanes are same as those for SMPs (that is limited temperature resistance and gap filling).

Silicones
Silicone adhesives are well-known for their excellent sealing abilities on windows and in gaskets for oil pans and differentials. These adhesives are common flexible adhesive options which offer superb temperature and UV resistance.

However, they have poor adhesion capability. Also, the applications of silicones are limited due to the fact that they are non-paintable.  

Anaerobics
Anaerobics (also known as machinery adhesives) are generally known to enhance the seal or holding force of a mechanically connected assembly. They are used for thread locking, retaining, thread sealing and flange sealing. Loosening of joint resulting from vibration are prevented by Anaerobics. Anaerobics also prevent corrosion of joints which is likely to occur due to moisture. They are cured in the presence of metal and absence of air.

Although anaerobics possess high shear strength, they have low peel strength.

Hot Melts 
Hot melts are quick, effective and economical solution for particular applications such as filter bonding or low-pressure moulding. They work with a variety of part sizes. However, they are not as adaptable as other adhesive types owing to their limited temperature resistance and weak adhesion to metals.

Making the Right Choice
Choosing the right adhesive for the job from so many available options can be a very difficult task. However, this can be made easy by testing the adhesive to determine those that suit your need. You may even discover a number of adhesives that can do the job. In such case, you can then consider other factors such as economical and infrastructural factors.

You can notify us if you need assistance in evaluating these options to get a suitable adhesive for the job. We will be very glad to offer you our assistance. You can also browse through the product selector charts in our interactive adhesives website.

Feel free to contact us if you have any questions about the different types of adhesives!