Materialkern

Materialkern is a term used in materials science and engineering to describe the central layer or phase of a composite or sandwich structure that provides most of the material's thickness and contributes to its out-of-plane properties. In sandwich panels, the materialkern lies between two facing skins and is primarily responsible for reducing density while maintaining bending stiffness and shear strength. The kernel is typically a lightweight, low-density material chosen for properties such as compressive strength, shear modulus, thermal insulation, and impact resistance, as well as compatibility with the bonding process used to join it to the skins.

Common kernel materials include closed-cell foams (such as PVC or polyurethane foams), paper or aramid honeycombs, and wood- or foam-core composites. The specific choice depends on the application, required stiffness, operating temperature, moisture exposure, and manufacturing method (adhesive bonding, riveting, or welding in some cases). The interface between the kernel and the skins is critical; effective bonding and barrier properties are needed to prevent delamination under load, impact, or environmental exposure.

Applications for materialkern-containing structures include aerospace interior panels, automotive and rail components, building façades, wind turbine blades, and sporting goods. The term's precise meaning can vary by industry, but it generally denotes the core material that imparts lightweight, thickness, and shear performance to the composite system.

See also: sandwich panel, core material, honeycomb core, foam core, composite material.