Cost Evaluation of Fiber Reinforced Thermoplastics for Mass Produced Cars

Transcription

1 THE SCIENCE AND ENGINEERING REVIEW OF DOSHISHA UNIVERSITY, VOL. 5, NO. 4 January 21 Cost Evaluation of Reinforced Thermoplastics for Mass Produced Cars Kazuto TANAKA*, Toshiki UEMURA** and Tsutao KATAYAMA*** (Received October 19, 29) The utilization of plastic materials in automotive products is increasing because of environmental requirement on the automotive industry to produce light weight fuel efficient cars. Reinforced Plastics (FRP) have superior advantages of high-specific strength and high-specific modulus. For automotive products, however, FRP are not really used for mass-produced cars well due to its high cost. The utilization of FRP in automotive applications requires specific focus on manufacturing and cost constraints. High speed continuous Reinforced Thermoplastics (FRTP) process using electromagnetic induction heating system in combination with Non-woven Stitched Multi-axial Cloth (NSMC) was developed. This system can reduce production cycle times and the cost of manufacturing composite applications. This study presents the cost evaluation of FRTP manufactured by the high speed compression molding process. The evaluation takes into a count the material cost and the production cost. The cost of FRTP was compared with the costs of FRP made from prepreg and. fiber reinforced plastics, cost evaluation, thermoplastic resin, non-woven stitched multi-axial cloth (NSMC), electromagnetic induction heating (NSMC) CO 2 1 ( Reinforced Plastics: FRP) FRP FRP FRP (Carbon Reinforced Plastics: RP) (Glass Reinforced Plastics: RP) RP FRP * Department of Biomedical Engineering, Doshisha University, Kyoto TEL&FAX: , ktanaka@mail.doshisha.ac.jp ** dmi124@mail4.doshisha.ac.jp *** tkatayam@mail.doshisha.ac.jp 13

2 172 RP RP RP (Glass Mat reinforced Thermoplastics) (Glass Reinforced Thermoplastics: RTP) RTP FRTP NSMC(Non-woven Stitched Multi-axial Cloth) FRTP 2) FRTP FRP FRP Fig. 1 3) Table 1 4) Table 2 Table 3 Table 1. Properties of reinforcement fibers 3). Tensile strength Tensile modulus Specific gravity Material cost (GPa) (GPa) (yen/kg) Carbon fiber () (3K35t) (12K24t) Glass fiber () Table 2. Properties of matrix resins 4). Bending strength Bending modulus Specific gravity Material cost (MPa) (MPa) (yen/kg) Epoxy (EP) Polyamide 6 (PA6) Polypropylene (PP)

3 173 FRP 125 FRP FRP FRP Table 4 FRP FRP Table 4 82 Multi-axial multi-ply fabric: MMF 12k 24t (Carbon )/PA6(Polyamide 6) (Glass )/PA6 /PP(polypropylene) FRTP (Glass )/PA6 /PP(polypropylene) NSMC N FRP Table 3. Cost of semi product. Cost of semi-product Prepleg (/EP) 5 Non-woven Stitched (yen/m 2 ) NSMC (/PA6) NSMC (/PA6) Multi-axial Cloth: NSMC, NSMC (/PP) 2 Fig. 2 Cost of semi-product (/PP) 5 Non-crimp stitched fabric: N, (yen/kg) Table 4. Condition values of cost evaluation. Working times (s) Prepleg 72 NSMC(/PA6) 32 NSMC(/PA6) 32 NSMC(/PP) 28 (a) semi products. 6 Employment cost (yen/h) 125 Mold cost (yen) 6 Number of molding times of one mold 23 (times) Molding system cost (yen) 5 (b) Molding process. Fig.1. Manufacturing process of FRP. Number of molding capacity of one system (times) 9 15

4 174 5) Fig. 3 3k 35t 13 /EP(Epoxy) (Glass Mat reinforced Thermoplastics) FRP Fig. 2. Fabricating process of NSMC. 7) Fig. 4 (PP) FRP Fig. 5 Cage System Roctool IH system IH system Fig C 12 Fig. 3. Fabricating process of prepreg. Fig. 4. Fabricating process of. 25mm4mm 2mm Table 4 2 NSMC Fig. 6 NSMC(/PA6) NSMC(/PA6) 25 9s NSMC(/PP) 23 9s 6s Table 5 Table 1,2 NSMC 16

5 175 IH system FRP JIS-K717 8, 9 (a) Mould with IH system. Electrical current Inductors Cold water Heated surface Fig. 7 NSMC 1kg NSMC 4% NSMC NSMC Fig. 8 NSMC 1kg NSMC PA6 PP NSMC Electrical current (b) Schematic drawing of IH system. Fig. 5. Mould and schematic drawing of IH system. 3 Fig NSMC 1 Temperature C Time s Table 5. Strength of FRP. Strength (MPa) volume fraction () orientation (/EP) 1414 (5) 5 /9 NSMC(/PA6) 82 5 /9 NSMC(/PA6) /9 (/PP) 63 (6) 35(4wt) Random Fig. 6. Temperature history of mould surface. 17

6 176 Fig. 1 NSMC RP NSMC 4 FRP 22 PP NSMC PA6 PP 5 NSMC NSMC Fig. 11 Fig. 12 Fig. 1 NSMC NSMC(/PA6) NSMC(/PA6) NSMC Cost of yen Cost of molded part yen Molding (/EP) NSMC (/PA6) (/EP) NSMC (/PA6) Fig. 7. Cost of semi-product using carbon fiber. Fig. 9. Cost of the molded part using carbon fiber. Cost of yen Cost of molded part yen Molding (/PA6) (/PP) (/PP) Fig. 8. Cost of semi-product using glass fiber. (/PA6) (/PP) (/PP) Fig. 1. Cost of the molded part using glass fiber. 18

7 177 NSMC IH system FRTP FRP (1) NSMC RP (2) NSMC x1 3 Specific strength m (EP) Fig. 11. Specific strength. (PA6) (PA6) (PP) 1) 63, No.1, 82-87, (29). 2) RTP 58, No.7, (29). 3) 24p ) 24 p.34,22,486. 5) 1989p ) Quadrant Plastic Composites Japan Ltd 7) No.44, (25). 8) M. Kawai, N. Maki, Fatigue strengths of cross-ply RP laminates at room andhigh temperatures and its phenomenological modeling, International Journal of Fatigue, 28, , (26). 9) F. Henning, H. Ernst and R. Brussel. LFTs for automotive applications, REINFORCEDplastics, 2, 24-33, ( 25). Cost of molded part per specific strength yen/(m x ) (EP) (PA6) (PA6) (PP) Fig. 12. Cost of molded part per specific strength. 19