There are a number of ways to bond different materials or substrates, with epoxy being a popular option due to its durability under harsh conditions. Thermal adhesive epoxy is an umbrella term for any industrial resin-based adhesive consisting of thermosetting polymers that cure or harden via a chemical reaction at room temperature or with heat. When properly applied, thermal epoxy adhesives create ultra-high strength bonds capable of withstanding fluctuating temperatures, chemical exposure, and other stressors, making them particularly suited for mixed substrate applications.
Effective Application of Thermal Adhesive Epoxy
One of the most critical aspects of effective application is ensuring you’re using the correct product for your needs. The type of thermal adhesive epoxy you’ll need will depend on several factors, including but not limited to:
- Material Substrates
- Service Temperature
- Conductivity Requirements
- Desired Viscosity
- Method of Application
- Curing Requirements
- Expected Stressors
In our Selecting Adhesives white paper, we explore the complex process of choosing the correct epoxy in more detail. When available epoxy formulas lack the required performance characteristics, manufacturers can turn to custom formulations. At Epoxyset, our expert chemists work closely with clients to develop thermosetting epoxy tailored to their exact requirements.
Surface Preparation Tips for Optimal Results
For any epoxy to properly adhere, the surface must first undergo thorough cleaning to remove particulates, oils, and other contaminants that would otherwise result in adhesive failures. Surface preparation for thermal adhesive epoxy is a three-step process:
- Degreasing Cleanse
- Surface Abrasion
- Second Degreasing
The method of preparation will vary depending on the type of materials involved. For more detailed instructions, please refer to our Surface Preparation Guide.
Preparing the Epoxy
Another critical step in effective application is ensuring the epoxy compounds are correctly mixed. In dual compound bulk package systems, epoxy can be very finicky, with little tolerances for inaccurate measurements. It’s vital to ensure proper calibration of measuring equipment to prevent diminished performance. Once the compounds are combined, it’s important to make sure they are thoroughly mixed to avoid uneven results.
Removing Air Bubbles from Thermal Adhesive Epoxy
Even the tiniest trapped air pocket can cause detrimental defects throughout the bonding process. It can create weak points during curing, resulting in adhesive, cohesion, and functionality issues. However, there are a few ways you can remove these trapped gasses to ensure proper application and reliable curing.
- Vacuum Degassing
For more details on removing bubbles from liquid epoxy, please refer to Technical Tips: Removing Bubbles from Epoxy. To help streamline the process, our products are available in several packaging options that remove the need to degas mixed epoxy, including premixed and frozen syringes.
Atmosphere for Optimal Curing
Temperature and humidity can drastically alter the cure rate for thermosetting epoxy and, in the case of high humidity, cause weakness or adhesive failure. Lower temperatures can also prolong or even halt curing. For optimal curing performance, aim to keep the relative humidity between 60% and 40%. The ideal curing temperature varies depending on the epoxy, which will be included in the product data-sheet.
Applying Thermal Adhesive Epoxy
When applying the epoxy, make sure to prevent trapped air pockets by placing down a uniform bead of adhesive that doesn’t double back on itself and allow space for the product to spread without oozing into undesired areas. If applicable, clamp the components together or place them in a jig to prevent shifting and follow the curing instructions for the particular epoxy.
Epoxy adhesive is an extremely versatile product used across a diverse range of applications, and custom formulations take this specialized bonding method to a whole new level of performance capabilities. At Epoxyset, we specialize in developing tailored solutions for our client’s adhesive needs. Contact us today to learn more!