Slot Insulation of Nomex® Helps Darby Electric Ensure Quality

Founded in 1948 as a two-man shop specializing in armature rewinding, Darby Electric Company has grown into a competitive company that offers everything from analysis and repair of large DC motors to the repair and reconditioning of AC induction and synchronous motors, squirrel-cage rotors and servo motors.  The company relies on DuPont™ Nomex® brand paper and Nomex® based laminates for slot insulation and other critical insulating applications to ensure quality for the unique and demanding needs of its customers.

Application Description

Whether it’s motor repair, rotor rebuilding, replacement laminations or stator restacking, providing excellent quality of workmanship has become synonymous with the Darby Electric Company name. 

“We’ve been using Nomex® since 1992 and it has proven to be a major advantage for us,” said Mike Darby, president of Darby Electric Company.  “We use it primarily for slot liners in our random-wound, low-voltage applications.  The laminated material provides excellent mechanical strength at the end of the slot, reducing the tendency to split at the opening.”

Darby Electric Company specializes in bringing high-level service that keeps critical motors running in the paper, plastics, wood products, cement and chemical industries.  In every one of those markets, the Darby name means quality and the reliability of Nomex® as slot insulation and other critical insulating applications contributes to that reputation.

Benefits Gained

Reliability:   The excellent mechanical strength and electrical properties of Nomex® insulation help Darby Electric Company ensure the reliability and dependability of their design and enable their customers to achieve superior performance in their motors.  


Increased productivity:  Darby Electric Company uses Nomex® primarily as slot insulation.   “The electrical properties of Nomex® allow us to use thinner material as a separator in the slot,” said Darby.  “This means reduced time in the rewind procedure.”

Design flexibility:   Nomex® insulation is available in a number of types and thicknesses.  This allows Darby Electric Company’s engineers to adapt the materials to specific products, as well as to a customer’s one-of-a-kind specifications.


Materials Selected and Why

Darby Electric Company uses Nomex® paper and Nomex® based laminates for slot insulation and other critical insulating applications because the reliability of these advanced insulation materials contributes to the company’s reputation for outstanding quality.  In addition, Darby Electric Company looks to DuPont for superior customized solutions and technical support.  “Thanks to DuPont’s efforts, Darby Electric has benefited greatly,” said Ben Hamilton, vice president of Darby Electric Company.  “Our working relationship with DuPont is excellent.”

Nomex® Brand Paper Helps Darby Electric Company Exceed Customer Expectations Every Day