To deal with environmental issues, the gasoline mileage of passenger cars can be improved by reduction of the car weight. The use of car components made of Carbon Fiber Reinforced Plastics (CFRP) is increasing because of its superior mechanical properties and relatively low density. Many vehicle structural parts are pipe-shaped, such as suspension arms, torsion beams, door guard bars and impact beams. A reduction of the car weight is expected by using CFRP for these parts. Especially, when considering the recyclability and ease of production, Carbon Fiber Reinforced Thermoplastics are a prime candidate. On the other hand, the moulding process of CFRTP pipes for mass production has not been well established yet. For this pipe moulding process an induction heating method has been investigated already, however, this method requires a complicated coil system. To reduce the production cost, another system without such complicated equipment is to be developed. In this study, the pipe moulding process of CFRTP using direct resistance heating was developed. This heating method heats up the mould by Joule heating using skin effect of high-frequency current. The direct resistance heating method is desirable from a cost perspective, because this method can heat the mould directly without using any coils. Formerly developed Non-woven Stitched Multi-axial Cloth (NSMC) was used as semi-product material. NSMC is very suitable for the lamination process due to the fact that non-crimp stitched carbon fiber of [0°/+45°/90°/-45°] and polyamide 6 non-woven fabric are stitched to one sheet, resulting in a short production cycle time. The use of the pipe moulding process with the direct resistance heating method in combination with the NSMC, has resulted in the successful moulding of a CFRTP pipe of 300 mm in length, 40 mm in diameter and 2 mm in thickness.

Carbon Fibre Reinforced Plastics (CFRP) with thermo-setting resin are usually used in aerospace applications and racing cars. However, considering moulding time and recyclability, it is desirable to use thermoplastics resin for the matrix. In our previous study, Non-woven Stitched Multi-axial Cloth (NSMC) was developed as moulding semi-product of Carbon Fibre Reinforced Thermoplastics (CFRTP). In this study, the rapid pipe moulding process of CFRTP components by means of high-frequency direct resistance heating, in combination with NSMC, was invented. This method allows heating of the mould surface rapidly by using high-frequency direct resistance heating. NSMC makes the lamination process easy, due to the fact that the non-crimp fabric of carbon fibre and the non-woven fabric of thermoplastics resin are stitched to one sheet, so production cycle time can be reduced. The invented high-speed moulding technique is expected to apply to CFRTP pipes. This moulding method can also reduce production cycle times, and therefore the cost to manufacture composite parts can also be reduced. CFRTP pipe had been successfully moulded in the size of 300 mm in length, 47 mm in diameter and 3 mm in thickness by this moulding method.

No abstract

No abstract