June 2004 - Volume 13

Using Hernon Instantbond and Quantum Adhesives in Your Design

Cyanoacrylate adhesives such as Hernon Instantbond™ and Quantum™ are another of those amazing developments during the 20th century that started with an accident. Dr. Harry Coover, in 1942, while working for Kodak Research Laboratories accidentally developed cyanoacrylate adhesive while attempting to formulate clear plastic for gun sights. Later, Dr. Coover working with Dr. Fred Joyner at the Eastman Company ran across cyanoacrylate adhesive while developing an acrylate polymer for jet aircraft canopies. Dr. Coover finally realized the value of cyanoacrylate adhesive and the Eastman Company began marketed compound #910. Hernon has developed a broad line of Quantum™ and Instantbond™ adhesives from this accidental beginning.

Cyanoacrylate monomer, the base of products such as Hernon Instantbond™ and Quantum, is actually a very reactive material. Cyanoacrylate monomer would cure almost immediately without the addition of an acid stabilizer material. Cyanoacrylate cures when it is exposed to the moisture found on a surface.

To properly use Hernon Instantbond™ and Quantum™ considerations must taken early in the design process. Design of the bond area is critical. As with all adhesive bonds, an overlap joint is far superior to an end-to-end butte joint. The maximum allowed surface area presented to the adhesive would yield an ever-higher amount of final bond strength. Remember in your design that cyanoacrylate adhesives resist pulling forces versus peeling forces. See diagram below for an explanation.

Environmental conditions of the final assembly must also be taken into consideration. Be sure to use the Hernon Technical Data Sheets for a guide as you design, and finally run a comprehensive amount of testing in the intended environment of your application. Generally, Hernon Quantum™ and Instantbond™ like all cyanoacrylate products have temperature limitations that are lower than most substrates. In addition, these products do not resist excess moisture such as submersion in water for extended periods of time.

The next step is to be sure that the surfaces are clean and free of any contaminants such as mold release agents or oils. These will interfere with the ability of the adhesive to establish a good cohesive contact with the substrate.

Dry fit and position the components in the desired position having any necessary clamping devices within close reach and ready to engage. Apply the Hernon Instantbond™ and Quantum™ adhesive to once surface then quickly mate the parts. Hold or clamp the parts for the amount of time suggested by the product technical data sheet. At this point, you are looking for fixture strength, which is roughly the amount of time needed to bond the parts to handling strength. This is very critical because any movement between the substrates and adhesive will significantly lower the final strength of the bond.

One of the potential drawbacks of using Hernon Instantbond™ or Quantum™ adhesives in assembly applications is the possibility of blooming or frosting. This is caused by small amounts of cyanoacrylate escaping into the surrounding air. The moisture in the air then causes the adhesive to settle on near by surfaces and curing which causes a white mist on parts. (This feature is a positive for crime scene technicians that use cyanoacrylate adhesives to capture fingerprints on surfaces.) This problem can be eliminated by providing a light amount of air movement across the parts being bonded or using Hernon EF™ CA Accelerator 58 on the bond. The EF™ CA Accelerator will quickly cure the bond line, therefore reducing the amount of adhesive that is released onto the neighboring substrate surface.

Many ask why Hernon offers so many different grades of Instantbond™ and Quantum™ adhesives. Hernon offers a wide variety of formulations for various substrates and bonding applications. Just some of the varieties include rubber-fortified adhesives that increase bond peel strength. Gel adhesives for increased gap filling abilities, and low- odor, low blooming for applications that require a minimum amount of frosting. This wide range of grades offers advantages and trade-offs. An experienced Hernon representative can assist you in selecting the right product for your application.

Just like any other adhesive, considerations have to be made in operating environment, design, etc., but Hernon Instantbond™ and Quantum™ cyanoacrylate adhesives remain the most comprehensive and versatile line of cyanoacrylate adhesives on the market, today.

Congratulations to the Hernon team for shipping 99.18% of all orders on time last year. Everyone at Hernon from Customer Service to Batch Makers to Shipping personnel work hard to ship your order as promised. In addition to our measurements of performance, we value your measurement of our performance even more. Anytime, you may share your perception of Hernon's performance via our web site at www.hernonmfg.com/survey.

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