| abstract |
The invention relates to a reinforcing element (R), which includes a surface layer (C1, C2) having a degree of crystallinity Tc and an atomic percentage of an oxygen element Pc, as well as an inner layer (C3) having a degree of crystallinity Ti and an atomic percentage of an oxygen element Pi, such that Ti/Tc >= 1.10, and Pi/Pc < 1. Both the surface layer (C1, C2) and the inner layer (C3) is made of polyester. |