View all newsletters
Receive our newsletter - data, insights and analysis delivered to you
  1. Master Bond
16 August 2022

UL Certified Epoxy Encapsulant Resists Arcing Without Igniting

Master Bond EP21AC is a two-part epoxy with a non-halogenated filler that is formulated for applications where arc resistance and flame retardancy are required. Electrical arcing is a challenge for numerous electronic or electrical devices; this occurs when electricity jumps from one connection to another, resulting in an electrical breakdown. The air surrounding the current becomes ionized and arcs, which may lead to combustion and fire. EP21AC is designed primarily with the aim to prevent arcing-related issues.

“EP21AC withstood over 150 arcs without igniting and therefore was assigned the highest PLC (Performance Level Category) of 0 under the UL746A High Amp Arc Ignition test,” says Rohit Ramnath, Senior Product Engineer. “The compound is also flame retardant, as per the UL94HB standard for flammability testing. This combination of unique performance properties makes EP21AC suitable for encapsulating, potting or coating in many demanding applications.”

The system is toughened, with an elongation of 10% to 20%, and is capable of resisting thermo-mechanical stresses. It is an excellent electrical insulator with a volume resistivity greater than 1014 ohm-cm, and a dielectric constant of 4.7 at 75°F. Other noteworthy properties include a tensile strength of 5,000psi-6,000psi and a tensile modulus of 300,000psi-350,000psi at 75°F. It is serviceable over the temperature range of -60°C to +90°C (-75°F to +194°F).

EP21AC has a convenient to use one to one mix ratio by weight and cures at room temperature, or more rapidly with heat. It has good flow properties with a mixed viscosity of 30,000cps-50,000cps, and a relatively long working life of 75-120 minutes at room temperature. This compound bonds well to a variety of substrates, including metals, ceramics, composites and many plastics and rubbers. It is available for use in ounce kits, ½ pint, pint, quart and gallon container kits. Specialty packaging is also available in premixed and frozen syringes.

For more information, please contact Masterbond via the contact details on our profile.

Today, there is a great market demand for all sorts of advanced power and high-frequency communications electronics, including high-power semiconductors, diodes, converters, amplifiers, radio devices,...
A NASA publication documented the use of Master Bond EP65HT-1 for use in organic photovoltaic devices.
Scientists at CERN used EP79 to reduce the radiation length and connect electrically-conductive joints of the aluminium barrel and copper end caps of the Faraday...
NEWSLETTER Sign up Tick the boxes of the newsletters you would like to receive. The top stories of the day delivered to you every weekday. A weekly roundup of the latest news and analysis, sent every Wednesday. The power industry's most comprehensive news and information delivered every month.
I consent to GlobalData UK Limited collecting my details provided via this form in accordance with the Privacy Policy


Thank you for subscribing to Power Technology