Bonded construction is an insulation design where layers like glass braid and nylon jacket are permanently fused into a single protective covering.
In bonded construction, two or more insulation layers are chemically or mechanically joined during manufacturing, rather than applied as separate, loose layers. This process creates a unified insulation system that enhances abrasion resistance, durability, and environmental protection. For example, certain MIL-DTL-5086 Type II wires feature a glass braid and nylon jacket bonded together to function as one. The design reduces fraying, delamination, and moisture penetration while maintaining flexibility and electrical integrity. In commercial and industrial environments, bonded construction extends cable service life and improves performance in demanding conditions.
Bonded construction is specified in military and aerospace standards such as MIL-DTL. It may also be evaluated under UL (Underwriters Laboratories) and ASTM (American Society for Testing and Materials) methods for adhesion, flame resistance, and durability.
Bonded construction was developed in the mid-20th century to meet military and aerospace requirements for wires that could withstand vibration, extreme temperatures, and chemical exposure. Over time, the technique expanded into commercial and industrial applications where enhanced insulation reliability and service life were essential.