Interlamination

Interlamination is the practice of inserting an additional layer between laminations or plies within a laminated structure to alter its properties. It is used across several engineering disciplines, including composite materials, electrical engineering, and wood products, and the exact meaning depends on the context.

In composites, interlamination (often called interleaving) involves placing thin layers, films, or fabric between laminae in a laminate. The goal is to improve interlaminar fracture toughness, delamination resistance, damage tolerance, impact performance, or thermal management. Common interleaves include thin polymer films, toughened resins, carbon or glass fabric, or ceramic particles. Interleaving can be introduced by inserting pre-cut films during layup, by resin infusion with interleaves, or by co-curing.

In electrical engineering, interlamination refers to insulation between the laminations of magnetic cores such as transformers and motors. The insulating layer minimizes eddy currents and stray losses and may be made from varnish, mica, paper, or polymer coatings. Proper interlamination reduces heat buildup and improves efficiency but must withstand thermal cycling and mechanical stresses.

In wood and veneered materials, interlamination describes the use of intermediate layers between veneers to adjust acoustic, thermal, or strength properties, or to cure mismatches in thickness or orientation. The technique can affect stiffness, damping, and moisture resistance.

Limitations include added cost, weight, and potential processing complexity, as well as possible adverse interactions between the interleave and surrounding plies if compatibility is poor. When designed appropriately, interlamination offers a practical route to improved damage tolerance, insulation performance, or functional properties in laminated systems.