EPP (Expanded Polypropylene), EPP has been intensively used in the RC hobby model planes and children toys industry and well known as its lightweight physical property, excellent resistance to impact and abrasion.
EPP is well proven as a highly durable material for R/C aircraft.
EPP is lightweight yet capable of flexing and returning to its given shape.Squeeze it,punch it and you will not dent it.
EPP has very good impact characteristics due to its low stiffness; this allows EPP to resume its shape after impacts.
EPP is extensively used in model aircraft and other radio controlled vehicles by hobbyists. This is mainly due to its ability to absorb impacts, making this an ideal material for RC aircraft for beginners and amateurs. EPP foam is able to absorb kinetic impacts very well without breaking, retains its original shape, and exhibits memory form characteristics which allow it to return to its original shape in a short amount of time
In consequence, a radio-control model whose wings and fuselage are constructed from EPP foam is extremely resilient, and able to absorb impacts that would result in complete destruction of models made from lighter traditional materials, such as balsa or even EPS foams.