Insights on How to Work Best with Epoxies from EPO-TEK® Quality Control Department

By Dawna Bellerose, Quality Control Supervisor

Upon receipt of your specialty EPO-TEK adhesive, it’s important to perform an incoming inspection of the product.  This ensures your product was received in good condition.  For optimal results, here are some important insights for receiving and using our products:

1.     Make sure the product is being properly stored.  (EPO-TEK product data sheets outline recommended storage conditions).

2.     Check the EPO-TEK product MSDS to be sure all employees coming into contact with the adhesive are aware of proper chemical hygiene, to avoid any potential mishandling. 

3.     Each time you open your product container, be sure to clean the threads and lid with a lint-free wipe (we recommend Kim Wipes) before resealing.  This will allow for a tight seal and avoid any possible contamination.  (ALWAYS store your product in the upright position). 

4.     If using a two component system, avoid cross contamination between parts A and B.  (This can easily happen when mixing each product separately and not wiping the spatula in between). 

5.     Be mindful of pot life.  (Found on the EPO-TEK product data sheet in the upper section under shelf life).  Exposing the adhesive to air can shorten its pot life by thickening viscosity and, although the viscosity can increase, it will not affect the integrity of the product.  (See EPO-TEK Tech Tip 26 for additional information on pot life, working life and gel time).

6.     Clean your substrates!  A common problem with bonding is often a contaminated or dirty substrate.  (See EPO-TEK Tech Tip 13 for recommendations based on your specific substrate).

7.     Provide a proper cure time and temperature.  Each data sheet will also provide cure recommendations.  (See EPO-TEK Tech Tip 6 for additional information on curing).

Following these easy steps will help ensure your product is ready to use, is stored and applied properly and will provide the best possible bond.  This information, and even more details, are available on our website under our Technical Information/Brochures section entitled, How To Work Properly With Epoxies - Step by Step Sheet.

EPO-TEK® Epoxy Adhesives for Acoustic and Ultrasound Applications

                                                                                                                                                                                                                                                                                                                                                                                             

By Michael J. Hodgin

Strategic Applications Manager

Epoxy Technology, Inc.

Epoxy Technology offers many types of high performance, specialty adhesives for ultrasonic technologies and devices.  Here is some information on how we provide value to sound engineers in the various industries we serve.

Industries

Ultrasound technology is one of the most well known in the medical /healthcare industry, not only for the fetal screening of the unborn, but for imaging in general.  It is an easy and less invasive procedure over endoscopic types.  Ultrasonics can also enable cleaning technologies for dental and electronic devices.  

Today, acoustical engineering serves an industrial purpose for industries such as the oil and gas industry (motion and flow),  joining technologies (welding of plastics) and consumer devices (speakerphone and microphone components).  The scientific test industry used ultrasound for detection and ranging, whether climatic, oceanographic, or geologic related, as well as non-destructive testing (NDT) for inspecting cracks in the steel skeleton of a skyscraper, airplane or semiconductor chips.

Technology Basics

Ultrasonic technology is achieved by means of a transducer which not only detects waves, but creates them via an actuator (piezo-electric device or PZT).  Once the waves are made, they have to be shaped, or channeled correctly.  This is done by a lens layer.  Finally, acoustic matching and backing layers (i.e. blocking) are used in combination to produce waves of significance and avoiding waves of waste or interference.

Epoxy Technology Value

Our company provides products of significant value to ultrasonic and acoustical engineers for accomplishing their technological challenges.  Our dielectric epoxy products laminate the PZT structures to the ceramic carriers for creating the waves.   We also offer adhesives with varied specific gravities for acoustical matching and backing (1.0 g/mL to 4.0 g/mL) and flexible potting epoxies used at the lens level.  Our thermally conductive epoxies are used for wicking away the heat generated by many of these ultrasonic devices.

Acoustical characterization of our products, including impedance and velocity, has been performed by our university partnerships, enabling >20MHz ultrasound frequency performance and has resulted in several technical papers for review on epotek.com.  Acoustical properties of adhesives in general, are relatively unknown across the world, and certainly not typically characterized on data sheets.  EPO-TEK adhesives can be tailored to a specific gravity requirement and can be custom formulated to meet other desired properties.   

                        EPO-TEK Adhesives for Acoustic /Ultrasound Applications

Epoxy Color Change as a Result of Cure Profile

By Brian Bruce
Technical Applications Engineer
Epoxy Technology, Inc.

Here is an interesting question that came in to Technical Services recently:

“We recently switched from a low temperature minimum alternate cure to the recommended            data sheet cure and the epoxy cured darker than usual. Is the higher cure temperature degrading      the epoxy?”

Our short answer was no.  Here’s a short explanation why:    

Color variation related to cure profiles is a well-known phenomenon and is most commonly seen in epoxies with imidazole-based epoxy hardeners (Part B’s).  In general, higher cure temperatures lead to a darker cured epoxy color. Certain imidazoles have a higher activation energy required to complete the reaction.  Higher cure temperatures more fully activate the adhesive curing mechanism and results in a darker colored cured product.  In some cases a higher temperature cure and darker color can even lead to increased percent polymerization and higher strength.

Epoxy Technology is very familiar with cured epoxy color changes for many of our adhesives as it relates to various     cure temperature.  As an example, let’s look at a photo illustrating this phenomenon with one of our custom    formulated products:

                                                Color Change at Various Cure Temperatures

                EPO-TEK 108-115-LH

 

 

EPO-TEK 108-115-LH is a custom formulated, low halogen epoxy for sealing wafer level MEMS devices. Our customer was concerned after an EPO-TEK technical application engineer recommended a cure temperature increase (for enhanced performance) that resulted in a color change from what they were used to (orange) to dark brown.   (Our application engineers often recommend alternate cure schedules in order to optimize material performance based on a specific application and that can include a higher temperature cure.)  Upon explanation and the short curing experiment shown above, our customer accepted this new curing profile for 108-115LH and has received better performance of the material in their end product.

To recap, it is important to note that this color change is not always a quality issue and, in this case, does not indicate  the epoxy has degraded.





Welcome to the new EPO-TEK website!

We are happy to announce a new and greatly improved www.epotek.com. 

This new site has all of the great, technical information and references you were able to access on our old site along with:

• Aesthetically more pleasing
• Improved search function
• More ease of use
• Additional technical reference documents
• New FAQ section
• Easier to find information with less clicks
• New Blogging area!

We hope you like the new site as much as we do.  As always, we welcome your comments so that we can continue to improve this great tool for our customers.

-EPO-TEK Sales & Marketing Team