Author: epoxieuser

Easy to use, two part epoxy resin 20-3301 provides electronic assemblies protection from severe thermal cycling and shock.  It passes the difficult Navy Hex Bar Test, MIL-I16923C which consists of 10 cycles from -55 to 155°C.  This toughened epoxy is low in viscosity and therefore flows quickly around components while giving users a long working time of 4-6 hours.

This product is superior to most room temperature curing epoxies in terms of chemical resistance, wide service temperature range, electrical insulation, and overall physical properties.  20-3301 is typically cured at 80°C for 1-2 hours; however a post cure of 150°C for 3 hours will enhance performance properties.

20-3301 applications include electronic potting and encapsulating, casting, coating, and electrical varnishes.  This epoxy system is a good choice for high temperature applications that require a material that is not rigid or brittle.

With a balance of properties not found in most adhesives, our clear, easy-mix 20-3237 epoxy is ideal for a wide range of potting, bonding and encapsulating applications.

These properties,including flexibility, low exotherm and long working time, allow theepoxy to work in applications that typically favor silicone or urethane.

• Good flexibility. 20-3237’s flexibility fights vibration and mechanical shock in applications such as LED lights and optical electronics.
• Low exotherm. This epoxy’s low exotherm is useful for applications with heat-sensitive potted products like delicate electronics.
• Long working time. The 20-3237’s long working time—and low exotherm—helps larger-potted sections achieve a pot life of up to 8 hours.

In addition, the 20-3237epoxy provides thermal shock and impact resistance, and exhibits lowstress and shrinkage during polymerization.

Mixing a two-component adhesive or potting compound isn’t always practical. Some applications have tiny parts that simply don’t need large volumes of adhesive. Others require only intermittent dispensing.In these cases, a two-component product’s weighing, mixing and de-airing steps may not be worth the time and trouble. What’s more, each of these preparation steps has the potential to cause mixing errors and waste.

One increasingly popular alternative to bulk mixed adhesives are adhesives packaged in single-barrel syringes. Syringe packaging eliminates the prep work associated with two-component products. Syringes can also deliver a high-quality, void-free adhesive in precision quantities—without the high capital costs of expensive meter-mix systems.

These qualities make syringe dispensing a good fit for all kinds of applications that require the bonding or potting of small, precisely-located components. Examples include wire tacking, solder repair and surface mount assembly.

We offer several types of products in single-barrel syringes. These include UV-curable resins and one-component heat cure epoxies as well as two-component adhesives that have been pre-mixed and frozen.  Here’s a closer look at a few of these ready-to-use products:

• UV Curable Illumabond adhesives are room temperature stable compounds that instantly cure when exposed to UV light. They’re packaged in UV-protected black syringes for automated assemblies and individual work stations. 60-7158 is a popular choice because of its adhesion to many substrates.
• One-component, heat cured epoxies also remain stable at room temperature so the user can dispense without pot life concerns, and cure with heat greater than 80°C. 50-3122 is thermally conductive and exhibits outstanding strength over a wide temperature range.
• Pre-mixed and frozen epoxies are packaged in a syringe for ease of use. Stored at -40°C, this packaging option offers a product that’s already mixed, void-free and curable at room or a slightly elevated temperature. Once thawed, the epoxy is ready for dispensing.

June 18, 2015 – UV curable adhesives have a lot going for them. As single-component systems, they eliminate the possibility of mixing errors. They’re also easy to dispense, with many bonding and potting products available in syringe dispensers. Conventional UV curable adhesives, however, can also have a dark side—literally.

Because these adhesives need direct exposure to UV light, any section of the bondline or potting cavity that remains in darkness won’t cure. This need for a line-of-sight to the UV light source has ruled out many applications with opaque materials. UV curables have also run into trouble when applied in deep, shadowed cavities or cross sections.

The good news is that advanced UV curable adhesives and potting compounds can sidestep some line-of-sight issues by offering secondary curing mechanisms.

Take our Illumabond 60–7155, for example. This one-component epoxy cures primarily under either a black or high-intensity UV light source, but it also offers:

• Dark cure capabilities for shadowed sections. After an initial exposure to the UV light source, Illumabond 60–7155 will continue to cure in the absence of light. This capability allows the adhesive to be used when potting or joining substrates with shadowed areas.
• Secondary heat cure for underexposed sections. If needed, Illumabond 60–7155 can also undergo a secondary heat cure, which makes it possible to cure sections that haven’t been adequately exposed to the UV light.
• Viscosity optimized for deep sections. With a viscosity of 1,000 cps at 25º C, Illumabond 60–7155 can flow into and cure in sections up to 3/4 inches deep. In these deeper sections, 60–7155’s dark cure capability also comes into play.

Illumabond 60–7155’s other properties include a water clear color as well as good weatherability and resistance to moisture and chemicals. When properly cured, 60–7155 has a rigid, smooth, and glossy surface finish. It bonds to a variety of metal, plastic, paper and ceramic substrates.

Learn more about Illumabond 60–7155’s physical properties and cure requirements here.

May 12, 2015 – Making sure your products arrive intact and unharmed is just as important to us as high quality, quick delivery and good pricing. To help prevent our gallon cans of epoxies and urethanes from damage and leakage when they’re shipped to customers, we’ve found an efficient way to soften their impact.

After researching and testing numerous boxes and inserts, we developed custom packaging that features a strong, corrugated box with molded inserts to support the can and prevent shifting.

Our new packaging allows us to ship gallon cans up to 18 pounds with no damage. The packaging has been tested by a third party certification agency and received a UN 4G rating under Title 49CFR of the US Department of Transportation (DOT) Performance Oriented Packaging Standards, Section 178.

This packaging complies with domestic and international ground, air and ocean regulations. Certifications include:

• International Maritime Dangerous Goods (IMDG)
• International Civil Aviation Organization (ICAO)
• International Air Transport Association (IATA)
• United Nations Committee of Experts of the Transportation of Dangerous Goods.

For two-component adhesives that need to be mixed by hand, mix ratios can be given by weight or volume. The ratios are usually expressed in terms of parts per hundred (PHR), with the correct amounts of each adhesive component calculated by the following formulas:

PHR/100 x Weight of Resin = Weight of Hardener
PHR/100 x Volume of Resin = Volume of Hardener

To get the right mix, the user has to use the correct PHR spec and calculate the appropriate measurements of the resin and hardener. The ingredients are then weighed out on a scale or measured in a graduated cylinder.

Sounds simple enough, but this measurement process can be fraught with errors.  Mistakes in the PHR calculations and measurement processes happen all the time.

One of the most common errors involves mixing up the by-weight and by-volume mix ratios, which will differ for a given adhesive product.

If you do confuse the two ratios, which is a common mistake, the adhesive properties will suffer. To illustrate this point, we mixed up two batches of our 20-2180, a popular polyurethane potting and encapsulating product. Batch One has the correct 100:60 ratio by weight. Batch Two had a 100:50 ratio by weight—which is the correct by-volume ratio.

You can see that this seemingly small mix error keeps the adhesive from developing its full hardness at room and elevated temperatures. The drop off in hardness as temperatures increase is also more pronounced with the incorrectly mixed batch.

Improper mixing of two-component adhesives and potting compounds ultimately results in reduced yields and scrap.  So mixing errors really can cost you.

Our latest white paper details the consequences of mixing errors and show you how to avoid them through the use of dual-barrel cartridge dispensing systems.