Attendance at Electric & Hybrid Vehicle Tech Expo proves growing interest in this technology area

by Jim Greig, Global Sales and Marketing Manager Electronic Materials, LORD Corporation

Jim Greig, Global Sales and Marketing Manager Electronic Materials, LORD Corporation-photo

Jim Greig


 

The attendance at the recent Electric & Hybrid Vehicle Tech Expo held in Novi, Michigan proved that the interest in this technology continues to grow.

The show organizers noted that regulatory and environmental policies, consumer demands as well as technology advancements are forcing automotive OEMs, utility companies and the battery supply chain to address a number of challenges.

According to the show’s website, “…the entire supply chain is under immense pressure to improve efficiency, drive down cost and thereby make environmentally friendly, sustainable vehicle, power and battery choices a viable option for consumers and businesses. But meeting market demands at a price that makes sense for suppliers is no easy task, and calls for an understanding of issues impacting the entire supply chain.”

I couldn’t agree more. The change in drivetrains for automobiles is comingELECTRIC-CAR_INTERACTIVE-red3 and it is time for our industry to embrace it, as well as work together to bring this technology shift to the public in an efficient and economic manner.

One of the key focuses of discussion at the show was research showing that a potting or encapsulation process using high thermal conductivity material can dramatically decrease the operating temperature of an electric motors at a given load, resulting in higher output power, better reliability and a longer life system.

A recent feature in Charged EV magazine highlights this potential as well as outlines some new options for improving performance in electric motors using thermal potting solutions. The article highlights research conducted by a doctoral candidate related to the use of thermal management materials and their efficiency on electric motors.

Based on this research and the market need, it is likely that new developments in battery technology very well may continue to help with range anxiety.

LORD recently participated in a webinar detailing how to improve motor power density with thermally conductive materials. We invite you to watch this webcast or contact LORD for additional information

How can you protect your fragile electrical/electronic encapsulating applications?

by Jim Greig, Global Sales and Marketing Manager Electronic Materials, LORD Corporation

Jim Greig, Global Sales and Marketing Manager Electronic Materials, LORD Corporation-photo

Jim Greig

Protecting your electrical/electronic encapsulating applications can be a challenge. Electrical overstress (EOS) is caused by thermally-induced damage that may occur when an electronic device is subjected to harsh conditions that go beyond the specified limitations of a device. LORD Corporation’s Thermoset SC-300M Silicone Encapsulant – a two-component system – was designed for encapsulation of delicate electronic components to solve this problem.

SC300M ImageThermoset SC-300M encapsulant system cures to an extremely soft, gel-like consistency using either room temperature or heat cure. This encapsulant system offers a selection of hardeners, providing a choice in working life and cure schedule.

Here are a few other features and benefits you can expect With Thermoset SC-300M, you can expect low stress, excellent adhesion, durability and an insulative solution.

Want to learn more?

State-of-the-art RTI Index, extend your reliability performance

by Jim Greig, Global Sales and Marketing Manager Electronic Materials, LORD Corporation

Jim Greig, Global Sales and Marketing Manager Electronic Materials, LORD Corporation-photo

Jim Greig

Do you need an excellent thermally conductive solution for your electrical/electronic encapsulating applications? LORD Corporation’s Thermoset SC-303 Thermally Conductive Silicone Encapsulant – a two-component system – was designed to solve this problem, while retaining desirable properties associated with silicones.

LORD Corporation Thermoset SC-303The SC-303 has achieved state-of-the-art RTI (relative temperature index) results at 180 Celsius. This allows components potted with this material to maintain their performance characteristics at higher temperatures.

Here are a few other features and benefits you can expect with Thermoset SC-303:

  • Low-stress durability – composed of an addition-curing polydimethyl siloxane polymer; won’t depolymerize when heated in confined spaces
  • Low viscosity
  • Environmentally resistant broad temperature range (-40 to 200°Celsius)

For more information, visit LORD.com/electronicmaterials or contact LORD Corporation at +1 877 ASK LORD (275 5673).

Improving electric motor performance up to 55 percent

by Jim Greig, Global Sales and Marketing Manager Electronic Materials, LORD Corporation

Jim Greig, Global Sales and Marketing Manager Electronic Materials, LORD Corporation-photo

Jim Greig

LORD Corporation’s Thermoset SC-320 Thermally Conductive Potting Material was recently cited as a solution for improving electric motor performance in a third-party study.

The research, conducted by Shafigh Nategh while a graduate student at KTH in Stockholm, Sweden, dealt with thermal management aspects of electric machinery used in high-performance applications with particular focus put on electric motors designed for hybrid electric vehicle applications. The research can be viewed here: “Thermal Analysis and Management of High-Performance Electrical Machines.”

MotorPhoto-small-1

LORD Thermoset SC-320- a relatively soft, high-thermal conductivity material (3.2 W/m-K) with sufficiently low viscosity to be used in vacuum potting – was evaluated in Nategh’s research. Nategh’s research notes that hot spot temperatures can be reduced by 35-50 percent using this material as compared to an un-potted motor, compared to improvements of only 20-30 percent using typical epoxy potting materials. According to Dan Barber, Ph.D., a staff scientist in LORD Corporation’s Open Technology Innovation group, this material may provide significant improvements in power density of electric motors.

Barber noted the decrease in hot-spot temperature, depending on current, may provide: 1). Increase in achievable power/ torque for a given motor size, 2). Decrease in motor size for a required power/ torque, and 3). Longer operation of motor before reaching temperature limit.

Want to learn more? Read the full article here in the October 2013 Electric & Hybrid Vehicle Technology Expo newsletter.

What type of material should I use: epoxy, urethane or silicone?

by Jim Greig, Global Sales and Marketing Manager Electronic Materials, LORD Corporation

Jim Greig, Global Sales and Marketing Manager Electronic Materials, LORD Corporation-photo

Jim Greig

This is the question that most people consider first when planning to pot an electrical or electronic device. The answer depends on the specific application and the requirements of the device in its intended working surroundings. Typically most epoxy, urethane or silicone systems provide the environmental and electrical protection needed at ambient conditions. The real differentiation comes into play when you evaluate the operating conditions of your device and the specific additional requirements you want from your potting compound besides ambient protection.

The physical and electrical properties of the resin systems do vary within a chemistry family such as epoxy, urethane and silicone. A range of hardness, chemical resistance, adhesion and electrical insulation can be achieved in any of these groups. Normally, there are some differences in the handling properties and cured properties of the materials that can be used to give an overview of each potting compound family.

Epoxy compounds:

In typical formulations, epoxy compounds have better adhesion, chemical resistance and high temperature physical properties. Epoxy systems are usually more rigid and have a higher modulus and tensile strength. They work well for a wide range of applications because of their adhesion to a wide range of substrates without the use of primers. Most epoxies have excellent moisture resistance so they can be used in outdoor applications. Further, their ability to provide electrical insulation makes them ideal for potting transformers and switches.

The epoxy systems are usually divided into three categories: 1) room-temperature cure two-component materials (these are usually amine curatives), 2) heat-curing two-component materials (these are usually either anhydride or aromatic amine curatives), and 3) heat-curing one-component materials (these are usually catalytic curatives that disassociate or solubilize at higher temperatures).

Urethanes:

In general, the urethanes have better flexibility, elongation and abrasion resistance. These properties give urethanes an advantage in devices where there are large stresses due to mismatch of component composition or dimensions. Many urethanes have very low Tgs so they can easily protect components in the normal consumer electronics operating range of -40C to 105C. Some urethanes can be used down to -70C and some up to 130C.

Urethane formulations can be adjusted easily to have very fast gel times at room temperature or very slow gel times with very low exotherms. They can be formulated to a range of hardness from soft gels to high Shore D.

The urethane chemistry is usually a two-component system with one side being a polyol and the other side being an isocyanate. The isocyanate is sensitive to reaction with moisture in the air, so it is recommended to protect any unused material by putting a layer of nitrogen gas in the container to purge any air out of the container.

Silicone:

The silicone potting compounds are similar to the urethanes in flexibility and elongation. But, unlike the urethanes, the standard silicones do not have a high enough strength to withstand abrasion.  There are high-strength silicone potting compounds, but they usually are too high in viscosity for most applications.

Silicones offer the widest range of operating temperatures for a potting compound. Specialty silicone polymers can stay soft to below -100C and some formulated silicone materials can handle 200C operating temperatures.  The silicone material stays soft throughout these temperature ranges and provides protection for components with the minimum amount of stress.

Silicones are the safest of these three types of potting compounds from a health and environmental aspect. They are usually easy to mix two-component systems with convenient mix ratios. One-component heat cure systems are also produced.

Chemically, there are two types of silicone systems used for potting compounds. One is the vinyl polymer-based material that is platinum catalyzed. This platinum can be neutralized by sulfur, amine and tin salts, leaving a potting compound with areas of cured material where the contamination is located.  The other silicone chemistry is the condensation type, which uses tin salts as catalysts. These formulations usually offer better adhesion but are not good for potting very large masses due to unevenness of cure.

Following is a table of generic uncured and cured properties for epoxy, urethane and silicone potting compounds.

EPOXY URETHANE SILICONE
Uncured Properties
Cost of Material Medium Low to Medium High
Ease of Handling Good Good Excellent
Uncured Moisture Sensitivity Low to Medium High Low
Speed of Cure Slow to Fast Slow to Fast Slow to Fast
Exotherm Low to High Medium Low
Shrinkage Low to High Low to Medium Low
Cured Properties
Hardness (stiffness) Medium to Hard Soft to Medium Soft
Adhesion Excellent Very Good Fair
Chemical Resistance Excellent Average Poor
Moisture Resistance Excellent Good Good
Expansion Rate Low to Medium Medium to High High
Tensile Strength Medium to High Medium Low
Tear Strength High Medium to High Low
Elongation Low Medium to High High
Component Stress Poor to Fair Good Excellent
Thermal Shock/ Thermal Cycling Fair to Good Good Good
High Temperature Operation Good Poor Excellent
Electrical Insulation Excellent Fair Excellent