laminate sheet composite laminate composite materials LAMINATE SHEET Decorative Laminates - Plastic laminate sheets composed of decorative papers, patterned fabrics and/or other ornamental cores or face laminate sheets (normally using thermosetting condensation resins as binder material, laminated at a minimum of 500 psi). Delamination - The separation of a laminate sheet along the plane of its layers. Also separation of bonded insulation within the adhesive layer or at the adhesive interface. Density - Weight per unit volume of a given substance.