Tag Archives: epoxy adhesives

UV Cure Adhesives

UV-Cure (Light Cure) adhesives are generally single component polymers systems specifically designed to cure when exposed to certain wavelengths of light. This technology has developed over time to include UV, UV-Vis, and LED light curing adhesives. The most common chemistries utilized in light curing adhesives are acrylics and epoxies. Just like standard adhesives, light cure adhesives have a wide range of physical and cured properties.

Properties

  • Single-component light-curing adhesive
  • Curing with visible, UV, and/or LED light
  • Bonding of different materials such as glass, ceramics, metals, and plastics
  • Suitable for bonding with high requirements to the finished product’s aesthetics
  • Wide range of elasticity

 

UV-8504E

An epoxy-based, cationic-curable adhesive and/or sealant. This product is activated by exposure to medium intensity UV radiation resulting in a high strength, chemical resistant, low outgassing polymer system capable of surviving exposure up to 200°C. It is RoHS and REACH compliant, has excellent chemical resistance and cures very quickly when exposed to UV light. It has an optimum wavelength of 310nm. It bonds to several substrates including most metals, ceramics, and glass. UV-8504E has a very low viscosity making it excellent choice for thin bond line applications and small encapsulating. It can also be used as a sealant and coating. Epoxyset provides UV-8504E in 3mL, 10mL, and 30mL syringes as well as 1L and 1-Gal bulk containers.

 

TW-046201

TW-406201 is a thixotropic, UV cure adhesive and sealant. It is a high viscosity, non-sag epoxy with excellent bond strength and temperature resistance. TW-046201 bonds well to most metals, ceramics, and glass as well as for PCB assembly applications. This UV-cure adhesives is also used for edge bonding on printed circuit boards. TW-046201 cures within 30 seconds at 365nm with high intensity light. It can also be cured using lower intensity light with longer cure times.

 

UV-8509R

A urethane-acrylate UV cure adhesive, 8509R is designed for rapid bonding to a variety of plastics. When cured properly, the material will cure very quickly creating an excellent bond to not only plastics but also metals, ceramics and glass. UV-8509R is a low viscosity, thixotropic material making it very easily to apply and spread but will not run or sag. When cured with spot lamps, focused beam lamps, or flood lamps, it delivers optimum speed and performance for plastic assembly.  8509R cures within seconds at 365nm with a minimum intensity of 200 mW/cm2.

 

TW-041001

A urethane acrylate UV cure adhesive, TW-041001 is a unique product that is a red, thixotropic liquid when uncured and turns clear when fully cured. Used as a cure indicator the color change is an excellent way to gauge cure. This UV cure adhesive cures within seconds between 300-400nm. It is designed to bond to engineered plastics such as Ultem, Lexan, ABS, and PVS in addition to most metals and glass.

Contact us for more information about these products at 401-726-4500 or email us at info@epoxyset.com

EC-1030FL – High Temperature Potting Compound

EpoxySet (Lincoln, RI) introduces EC-1030FL, a flexible, two part epoxy potting compound. This high temperature potting compound is designed to replace silicone potting compounds where superior bond strength is needed. EC-1030FL, a high temperature potting compound, will prevent stresses to components while temperature cycling without degradation. Advantages over other high temperature potting compound include better adhesion, higher impact resistance, and lower cost.

  • A 10-15 minute work time (at elevated temperature), making it ideal for production environments.
  • Ease of use 2:1 mix ratio by weight allows for easy mix and use in meter mix dispensing machines.

 

Contact us at (401)-726-4500 to learn more about this product or for recommendations for your application.

 

See our article on Industrial Equipment News (IEN) by clicking here.

Epoxyset on Radio Entrepreneurs

Epoxyset would like to thank Jeffrey Davis, David Soper, Alexander Steblovskiy and the rest of the crew at Radio Entrepreneurs to for allowing us to be on their show. Radio Entrepreneurs is a great forum for entrepreneurial enterprises to present their stories and advise on succeeding in very difficult markets. The Youtube video below has our interview hosted by Jeffrey Davis and David Soper.

 

Common Causes for Adhesive Problems

High tech adhesives are very reliable and issues do not occur often. When used correctly, these adhesives can resolve many design issues while also saving money, time and effort.  However, there are many potential reasons for a possible failure when using these materials.  Failure can be defined as no adhesion upon cure, reduced adhesive strength, or loss of adhesion over time. When any problem occurs, the adhesive is very often one of the first components to be examined. Finding the cause of a failure can sometimes become difficult, especially when a failure is intermittent or it started after a long period of success.  There are a number of standard issues that should be considered to determine the cause of a failure.

  • Contamination should be one of the first considerations. Any grease, oil or other impurity on the surface can potentially cause loss of adhesion. Dirty substrates are an obvious potential problem but contamination can be inadvertent.  Oils from skin contact, especially on very small parts, could be enough to cause a problem.  Components may have been improperly cleaned. Component manufacturers sometimes change a production process that does not affect the component performance or tolerances but can unintentionally effect the bonding of that component. Controlling the cleaning process at the usage sight is the best method to ensure occurrence of this potential problem does not arise.

 

 

Another possible source of contamination is silicone release agents that can settle onto surfaces and prevent adhesion. Care must be taken to prevent cross contamination if using silicones or any release agent. For this reason, some manufacturing facilities will not allow the use of any silicone compounds.

 

  • Surface preparation is essential for bond consistency. There are many methods to prepare surfaces, including washing, abrasion and plasma/corona treatment.  The best surface preparation will depend upon the specific substrate and adhesive chemistry used.  Consult with your substrate provider or adhesive manufacturer for the appropriate preparation. Lack of consistent surface preparation can be a big contributor to adhesion issues.

 

  • Mix Ratio for many two part materials can be a major issue. Some systems are very sensitive to minor changes in the mix ratio.  Many materials are stoichiometrically balanced and an off ratio mix may cause the material to cure erratically and/or not perform to its optimal capability.

 

Even some materials that are not as sensitive to the mix ratio may exhibit slightly different characteristics when the ratio is varied.  Materials that do cure with an off ratio mix may have slightly different finished hardness and tensile strength thus effecting the final performance.

 

  • Mixing of two part adhesives is a basic process function but is essential for of these adhesives to work properly. Insufficient mix may result in a partial chemical reaction which leads to partial curing. An insufficient cured material will most likely result in poor bond strength and lower physical properties.

 

Also, mixing of the original container can be very important.  Fillers or other constituents could settle. Ensuring a homogenous mix of each component prior to mixing (for two parts) is vital to achieve maximum properties.

 

  • Application technique can be critical. If material is manually applied, ensure that the amount is consistent for each unit. Most adhesives work best with an appropriate bond line.  Too much or too little material could produce variable cured strengths.  If applicable, make sure that the adhesive is applied in the same location on every component.

 

If automated placement is used, ensure that the equipment is clean when starting and remains clean during use.  Some adhesives can partially cure in the dispensing apparatus thus clogging the unit and preventing a consistent amount of material being applied to each part.  Less adhesive could result in decreased strength.

 

Air entrapment can be a source of inconsistent failure especially in small applications.  Removal of air from a system, prior to application, may be a necessary processing step. Air gaps could prevent the adhesive from interfacing fully with the substrate surface which may result in decreased strength.

 

  • Incompatibility with substrates can also be a contributor to failure with some adhesives. Certain plastics may contain plasticizers which could seep to the surface over time, causing a bond to fail.  This seepage could be inconsistent from lot to lot so that some parts never fail while others lose adhesion.

 

Some substrates can actually interfere with the cure mechanism of an adhesive.  This is usually an issue that is addressed when selecting the adhesive but sometimes appears later.

 

  • Cure time and temperature can be major factors contributing to incomplete cure and performance of many systems. Some materials must be exposed to certain temperatures in order to cure.  Many ovens can vary considerably and thus an adhesive does not seem to cure in its allotted time.  Too high a temperature may cause a material to polymerize incorrectly and cause degraded properties.

 

Some materials may cure at lower temperatures but not produce the same physical characteristics as when cured with elevated temperatures.  Alternatively, certain chemistries designed for low temperature cure should not be heated when cured.

 

Products cured with UV energy have the same issues.  They must be cured with the correct wavelength and energy level.  Certain chemistries will not cure with low light exposure and others can burn if subjected to high dosage.  Some of the UV chemistries must be heat post cured to achieve their maximum performance.

 

  • Environmental conditions should also be noted as many materials can be effected by their surroundings. For example, high moisture levels can prevent cure in some materials while it speeds up the reaction in others.  Carbon dioxide, PH, Oxygen and environmental temperature could all adversely affect the finished adhesive.

As stated earlier, intermittent problems are the hardest to resolve. These are almost always due to a factor other than the adhesive.  Of course a batch of adhesive may have been produced incorrectly but this is actually very rare as reputable manufacturers use reliable raw materials and process controls to ensure a consistent finished product.  Greater than 98% of problems with adhesives are not due to the adhesive itself but due to one of the causes previously discussed.

What to Consider Before Selecting an Adhesive

Choosing the best adhesive for a specific application can be complex. There are many variables to be considered and numerous types of chemistries with different capabilities. An understanding of the following parameters will help narrow the choices. Selecting the correct adhesive will reduce the number of products to be evaluated and increase the likelihood of success.

  1. Substrates: Knowing the materials to be bonded is very important. Certain adhesives may adhere better to ceramic or glass. “Metal” and “plastic” are generic terms that encompass many different types of materials, so knowing the exact substrate is essential for determining the correct adhesive. For example, ABS and polytetrafluoroethylene (Teflon) are both plastics, but PTFE requires an acid etch to achieve a bond whereas ABS can usually be bonded with just an alcohol cleaning.
  2. Cleanliness of the parts: Most adhesives require that the substrates be prepared properly. Whether it’s just a simple cleaning or the ability to do more complex operations (such as abrasion, chemical etch, or plasma treatment) will all come into play in selecting an adhesive.
  3. Viscosity: The viscosity must be considered. Low viscosity (thin) products are best for thin bonds or for applications requiring wicking. Thixotropic materials (won’t run) are best for use in vertical applications.
  4. Thermal cure versus UV cure: UV cure adhesives are usually one part and can be cured quickly. They must be exposed to UV light to cure, so at least one of the substrates must allow transmission of UV light. Thermal cure materials can be cured at room temperature and/or with heat. Heat-cured thermal adhesives can require high temperatures, which might be detrimental to components, but, in general, they will cure faster with higher properties.
  5. Working life: Determine how much work life is desired. Remember that working life (time before the material gels) is generally related to cure time. For thermal cure materials, the longer the working life, the longer the cure time (at room temperature) usually. Single-part UV-cured materials can be cured quickly, and the working life doesn’t apply.
  6. Configuration: The dimensions of the parts and how they fit together are very important to determining the best material. Larger parts and thicker bond gaps may require a slower cure to reduce shrinkage. Certain adhesives are designed to work best with thinner gaps.
  7. Required Performance: Some factors that should be understood before selecting an adhesive:
  • Does the adhesive need to form a structural bond?

Ideally, a structural bonding material will create a finished part that is as strong as the substrates. As stated earlier, knowledge of the composition of the substrates helps decide the best adhesive and preparation to accomplish an ultimate bond. Also, understanding the configuration of the parts to be bonded will determine the types of adhesives for use. With most adhesives the larger the surface area of the mated parts, the stronger the bond.

The bond gap is also critical. Various adhesive chemistries work best with certain gaps. In general, cyanoacrylates and anaerobics need the thinnest bond line whereas epoxies and urethanes are better with thicker gaps. Every chemistry can vary, depending upon how they were formulated, but these are general rules.

  • How much mechanical stress will there be on the bond during use?

This may seem obvious, but the forces on the adhesive joint and the direction of those forces have a major impact on the adhesive to be used. Some chemistries may have excellent tensile strength (strength in a horizontal direction) and very little shear strength (strength in a vertical direction). Other considerations would be whether there are any compressive forces or torsion on the joint. Adhesives may be formulated to be more flexible or with fillers to compensate for these stresses.

  • Will stresses be consistent or intermittent?

Some adhesives can take extreme stresses for very short periods but not withstand the stress over longer periods. Others may hold up to long consistent stress as long as it is not brought on suddenly.

Other types of stresses may also be of concern. For example, autoclaving is a standard practice in many industries. Many adhesives cannot withstand autoclaving. It is important to consider all stresses when selecting adhesives.

  • What are the temperature requirements during processing and use?

This can be an extremely important parameter. Materials with low-temperature cures may not withstand high temperatures during use. Adhesives designed for high-temperature uses might only cure with heat, so the adhesive will have to be exposed to dry heat (an oven or a heat element).

The exposure temperatures during use are critical. Also consider whether the parts will be temperature cycled. Many materials that will withstand high temperatures will crack when cycled to low temperatures, and low-temperature materials might lose their strength at high temperatures.

  • What optical properties (if any) are important?

Optical properties may be important for certain applications. If light transmission is important, we must know the wavelength being transmitted and the duration. You may also want to consider the refractive index of the substrates. Certain chemistries will not remain clear over long exposure to UV radiation.

  • Does the cosmetic appearance matter?

Some adhesive chemistries can be easily colored but others cannot. Some chemistries will have lot-to-lot variations, so the final appearance can change. In applications requiring specific colors (especially for consumer products), it may be necessary to ensure that lots can be color-matched.

These are some of the more important issues, although for any specific application, there can be other considerations before selecting the right candidate. It is not often feasible to know all required parameters before choosing, but it is important to have as much information as possible to make an educated decision. There is no substitute for sampling and evaluating a product. Testing often reveals previously unconsidered parameters.

Considerations for application

 

When evaluating adhesives and potting materials, it also important not only to make sure it works on a performance level but also on a production level. How will material be applied? It is a common occurrence that engineers or project managers approve a product that works perfectly for the application only to find out later that processing it on the production floor is either inefficient and wasteful or just not possible. Considering dispensing, mixing, applying concepts early can save a lot of time and money down the line and avoid production or launch delays.

 

Mix Ratio:

One of the biggest issues facing production lines while using 2 part polymer systems are the mix ratios. Mix ratios vary from product to product and unfortunately not as simple as 1:1 by weight and volume. Some mix ratios are also less critical allowing for higher degrees of tolerance. Alternatively, slight changes in a mix can result in changes in the physical characteristics of the product. For instance, polyamide based epoxy systems are very forgiving in mix ratios. If the product calls for a 100:80 mix ratio by weight and the actually mix ratio is off by even 10%, the finished polymer and the characteristics are not drastically different nor should it affect its performance. A tin catalyzed silicone is very vulnerable to changes in mix ratio. A 10% increase in catalyst can accelerate the polymerization process and decrease work life not allowing operators enough time to pot or encapsulate the part leading to waste material.

 

Amine and imidazole cured epoxies, (as well as many urethane systems) with an incorrect ratio, will result in a finished adhesive with diminished properties. If a ratio specific material is the best choice, ensure that manufacturing processes are set up accordingly to produce the best and consistent results.

 

While uneven mix ratios should not deter one from choosing a product, many prefer even ratios to reduce risk of mistakes. There are several options for high efficiency application of adhesive systems. Many products that have even volumetric mix ratios (1:1. 2:1, 4:1) are also available in dual barrel cartridges. These types of cartridges come different sizes and are convenient because there is no risk of weighing and/or mixing mistakes. These dual barrel cartridges can be dispensed via applicator guns which can operated either manually (like a caulking gun) or pneumatically for higher efficiency.

 

Conclusion:

While evaluating and ultimately choosing an adhesive or encapsulating compound can be an exhausting effort, it can be made easier by considering some of the elements discussed in this article. The more information you have on the application helps to tremendously eliminate a majority of options and makes it easier in filtering the variety of products available. Contacting the experts is also a major step in choosing the right product. Adhesive suppliers tend to have a vast amount of knowledge to know only their products but where they are used. Ultimately, evaluating adhesives comes down to choosing one (or a few) and testing them in your application before deciding. As mentioned before, there is no substitute for sampling and testing products on your own.

EPOXYSET SOLUTIONS: PREMIXED AND FROZEN ADHESIVES

View More: http://kieraslyephotography.pass.us/epoxyset

Epoxyset saves you time and money with Premixed & Frozen Materials

Epoxyset supplies a complete line of premixed and frozen adhesives, sealants, and potting compounds using a specialized proprietary process that delivers quality results. Epoxyset can take nearly any one of its products and supply it as a premixed and frozen system. The process consists of weighing the reactive compounds at the precise mix ratio, mixing until a homogenous mixture is made, degassing to eliminate entrapped air, packaging into pre-portioned syringes, and freezing to suspend the reaction. All of the desirable properties of the compound are maintained using this process. All of our products are strictly tested by our quality control laboratory to assure the finished product meets specifications.

Epoxyset premixed and frozen products assure quality, saves time and money, reduces waste, improves safety and increases productivity. Our frozen systems allow our customers to focus on manufacturing and eliminate the need to spend valuable time processing adhesives which can be messy, difficult and inconsistent.

Delivering a Quality Product

The use of Epoxyset frozen products guarantees the product is weighed and mixed properly so you don’t have to. Our fully equipped Quality Control lab tests for important factors including work life, bond strength, viscosity, density, and hardness. We can also test to our customer’s individual specifications.

Epoxyset frozen adhesives are tightly controlled using batch manufacturing which allows important aspects of the system to be tightly controlled. We limit our batches depending on the particular product to ensure quality and to deliver each lot of material with consistency. We offer our premixed and frozen adhesives in a variety of sizes from 1mL graduated syringes up to 55mL syringes. We also package products in 6oz, 10oz, 12oz, and even 32oz cartridges on specialty products.

Electronics part with syringes

How to save money using Epoxyset Premixed and Frozen Adhesives

Epoxyset premixed and frozen systems REDUCE WASTE!. Our precise mixing and packaging allows our customers to simply remove syringes from the freezer, let them thaw, and use immediately. There is no more time wasted on mixing a large batch only to use a portion of it and discard the rest. Trying to get every drop out of a bucket or bottle is next to impossible when weighing and mixing yourself. Dispensing a syringe of adhesives guarantees much less waste and more material can be used in the production line.

Reduced Rejects

All Epoxyset frozen adhesives are tested for complete quality assurance. Component manufacturers can have rejected parts due to improper weighing and/or mixing of the adhesive or encapsulant. Our processing of premixed and frozen guarantees that the resin to hardener mix ratio is always accurate and homogeneously mixed. Epoxyset premixed and frozen products eliminates a large portion of the risk.

Safety

In premixed and frozen systems, the handler has a significantly lower possibility of chemical exposure. This results in a greatly reduced potential for contact dermatitis or other exposure hazards. Using premixed and frozen system also reduces the risk of spills and contamination of the work area which can cause harm to others.

Short Lead time

Epoxyset has very short lead times compared to its competitors. Our standard lead time for premixed and frozen adhesives is less than 7 days and all products are shipped priority for the shortest transit time. Our experience in processing, packaging, and logistics both domestically and internationally allows Epoxyset to decrease lead time.

Handling

Frozen products are kept frozen at -80ºC at our facility and shipped in dry ice using specially insulated boxes. All premixed and frozen products are sent via next day shipment and are to be stored in a commercial freezer at -40ºC (or below) upon receipt.

Additional Capabilities

Epoxyset frozen adhesives meet the demanding needs of the aerospace, medical device, electronics, and other high tech industries. Almost all Epoxyset products are available in premixed and frozen packaging including epoxies, silicones, and polyurethanes. In addition to our own products Epoxyset also offers the packaging service for other products in these industries. We can supply premixed and frozen systems of products manufactured by Henkel Loctite, Huntsman, LORD Corporation, 3M and many others.

Technical Service

Epoxyset chemists and engineers specialize in all the uses of engineered polymers including bonding, sealing, coating, and encapsulating. We are commonly asked for solutions to novel, demanding applications and we take pride in accepting these challenges. Many companies who offer premixed and frozen services are not manufacturers or do not have the technical experience to offer anything beyond the service. Also, many companies that offer premixed and frozen packaging do not do it themselves and are not comfortable with the operations. We are both manufacturer and packager to assure the best results.
Contact Epoxyset for product and application assistance and find out whether premixed and frozen adhesives are the right fit for your application. Epoxyset also supplies products in standard 2-part containers as well as side by side cartridges and bi-packs.