Understanding Two-Part Adhesives

There are so many adhesives to choose from. Some have specific applications. Others have special properties. Some need a lot of surface preparation. Others need little to none. While some come ready to be applied as they are, others come in two parts that need to be combined first.  

Infinity Bond MMA 420What Is a Two-Part Adhesive? 

A two-part adhesive, also known as a reactive adhesive, is an adhesive that comes in two separate components and needs a chemical reaction to cure.

These two parts are often resin and a curing agent. The needed chemical reaction for a good cure occurs when the two components are thoroughly mixed together (in the right ratio). 


How Do Two-Component Adhesives Work? 

Two-part adhesives work because of a chemical reaction that occurs when the two solutions are combined. In order to get a strong and lasting cure, the chemical reaction needs to be just right.

The ratio of the substances needs to be exact. Common mixing ratios for adhesives with two components include 1:1, 10:1, and 2:1. Along with getting the correct ratio, the two substances need to be mixed sufficiently before application. Together, they should create one homogenous substance before their application.  

To achieve these two prerequisites, two-part adhesives are often applied with double-chamber or side-by-side cartridge guns. These dispensers are designed to keep the solutions separate until application when they are pressed though the mixing tube in the desired ratio and combined appropriately.  

Advantages of Two-Part Adhesives 

There are several advantages to an adhesive with two parts. One major benefit of two-part glues is that they generally create stronger bonds than one-part adhesives. Along with their great strength, two-component adhesives tend to have a fast cure time. This quick turnaround can speed up production times.

Another pro to two-part glues is the shelf life. Because they are stored separately until application, these adhesives have a shelf life anywhere from one year to five years when stored under the correct conditions and depending on the specific product. 

One downfall to mixed adhesives is that the chemical reaction needs to be exact for the adhesive to cure properly. Without the proper equipment, there is some room for error. 

What Adhesives Are Supplied in Two Parts? 

There are several different types of two-part adhesives to meet different application needs. Two-component epoxy adhesives are some of the most commonly recognized, but there are also two component urethane adhesives, two-component polyurethanes, two-component acrylics, and more.  

Applications for Adhesives with Two Components 

Because of their great strength, two-part adhesives are often used in structural bonds, especially when high strength is required. They can be great for a variety of substrates depending on the specific product and may be used in place of traditional fasteners. As a result, they have applications in a variety of industries including construction, automotive, marine, aerospace, and more.  

Need a high-strength bond? A two-part adhesive may be the right choice for you. We can help you find the best product for your needs. Just contact us today, and one of our adhesive experts will be able to offer you guidance on a wide range of products.  

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