U.S. Military Specification MIL-P-26514

MIL-P-26514 is a U.S. military specification intended to control the quality and performance of prefoamed (fabricated) and foam-in-place polyurethane foams procured for use in military packaging. Specifically, it:

• classifies foams according to type, class, and grade
• outlines instructions for inspecting, sampling, and testing materials and methods during foam manufacturing
• outlines instructions for packing foams (in rolls, drums, sheets or fabricated form) for transport to the fabricator or the packaging site
• specifies required material properties and characteristics for various types and classes of foam

Type I materials are prefoamed products (such as flexible bunstock); Type II products are foam-in-place. The two classes under each type are rigid (Class 1) and flexible (Class 2). The three grades under each class are distinguished by their performance according to standard dynamic cushioning curves included as part of the specification. The material properties covered under the specification include compressive strength, creep, dimensions, water absorption, flammability, density and shelf life.