This research proposes a technique to recycle carbon-fiber-reinforced polypropylene thermoplastics based on a pelletization process followed by injection molding. Experiments were designed with different process conditions to evaluate the efficient performance of the recyclates. In this study, the properties of the recyclates with various fiber contents were compared with those of conventional virgin products. The study confirmed that the recycled composite is as usable for injection molding as virgin conventional materials in terms of flowability and mechanical properties. The recycled composite is suggested to have better interfacial adhesion between the fiber and the resin than conventional materials because of the good impregnation of the carbon fibers in the carbon-fiber-reinforced-thermoplastic waste. In conclusion, the recycling of carbon-fiber-reinforced-thermoplastic prepreg waste using the proposed method is simple, effective and it would be economical.

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In the press and injection hybrid molding of CFRTP, short or long fiber-reinforced thermoplastics are injected on the continuous fiber-reinforced thermoplastics, which are used for the outer shell material. Since its fracture often occurs at a rib root portion, which is the interface of the injected materials and the continuous fiber-reinforced thermoplastics, the rib root portion has to be strengthened. By using slit material having high formability for the outer shell material, the penetration height of the outer shell material into the rib becomes higher, therefore, improvement of the strength of rib root portion can be expected. In this study, to clarify the effect of penetration height of slit materials on the mechanical properties of the rib root portion of the press and injection hybrid molding, slit materials were used for the outer shell material, and tensile tests of the surface layer and bonding strength at rib root were conducted. Experimental results reveal that the press and injection hybrid molding using slit materials in half of the continuous fiber-reinforced thermoplastics prepreg possesses the good combination of high bonding strength of rib root portion and high tensile strength of the surface layer.

The surface features of an untreated 70/30 cotton/polyester fabric and of the same fabric treated with the flame retar dants APO-THPC, THPC-MM-urea, or THPOH-NH3 were compared by scanning electron microscopy. Little, if any, sign of the finish was observed on the APO-THPC-treated fabric. However, the presence of finish was evident along the sides of cotton fibers in the THPC-MM-urea finished fabric, and in the THPOH-NH3-treated material the finish could be seen on the entire surface. All fabrics were also examined after they had been burned. Marked differ ences were noted in the products obtained from the burning. Particles were seen on charred APO-THPC-finished fabric and on charred THPC-MM-urea-finished fabric, with the latter material containing a markedly greater number of particles than the former. In contrast, the charred THPOH-NH3-finished fabric contained no particles, and the surface was characterized by the presence of matter in the form of bubbies.

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