 More recently, pultrusion has been successfully used with thermoplastic matrices such as polybutylene terephthalate (PBT), polyethylene terephthalate (PET) either by powder impregnation of the glass fiber or by surrounding it with sheet material of the thermoplastic matrix, which is then heated.Ecological cleanness of manufactured products, in contrast to composites on thermosetting resins base, as well as practically unlimited possibilities of recycling (processing) after the resource depletion appear to be forcible arguments in favor of reinforced thermoplastics.For these reasons the industrial output and use of the given materials in highly industrialized countries have increased by 8–10% per year in recent decades.