Carbon fiber reinforced plastic (CFRP) is increasingly used in aerospace, automobile, and other industries. With the improvement of carbon fiber reinforced thermoplastic molding technology using thermoplastic resin, it is expected that the applications of CFRP will be expand further. Because of the following issues, CFRP is known as a difficult-to-cut material. i) Machining CFRP is difficult. ii) Its finished surface deteriorates due to delamination and uncut fiber. iii) It has a shortened tool life due to severe tool wear. In addition to these issues, we has been problem presentation of fine cutting chips generated by machining. Because these fine cutting chips may scatter in the atmosphere and adversely affect the human body and machine tools, we have established a chip disposal technology that suppresses these issues to improve the processing environment. A previous study reported that shape of the tool edge is responsible in suppressing the generation of fine cutting chips. Here, we experimentally investigated the effects of tool edge shapes on the chip collection rate and tool life. An attempt was made to determine whether the same effect can be obtained by using the outside dust-collection method which is known that the dust collection efficiency is low. We revealed that the chip collection rate increases if a tool that suppresses the generation of fine cutting chips is used instead of a conventional tool; furthermore, the tool life is insensitive to coating. In contrast, a comparison of our results with previous findings indicates that the tool with a sharpened cutting edge has a longer tool life than the conventional twist drill with honing. A high cutting chip collection rate was obtained, even with the outside dust-collection method, which led to an improvement in the working environment.

1. [1] T. Inoue, M. Hagino, M. Matsui, and L. W. Gu, “Cutting Characteristics of CFRP Materials with End Milling,” J. of the Key Engineering Materials, Vol.407-408, pp. 710-713, 2009.
2. [2] Y. Sawada, “New Introduction to Carbon Material 2.2,” Carbon Fiber Society of Japan, pp. 91-98, 1996.
3. [3] N. Shimizu, “Development Status of Carbon Fiber Reinforced Plastics,” Laser Review, Vol.38, No.8, pp. 603-608, 2010.
4. [4] M. Kaizuka, T. Tachibana, T. Kosaka, S. Doki, and Y. Ota, “Latest technological trends for electrification of automobile technologies,” IEEJ Trans. on Industry Applications, Vol.139, pp. 535-542, 2019.
5. [5] T. Yoneyama, D. Tatsuno, K. Kawamoto, and M. Okamoto, “Effect of Press Slide Speed and Stroke on Cup Forming Using a Plain-Woven Carbon Fiber Thermoplastic Composite Sheet,” Int. J. Automation Technol., Vol.10, No.3, pp. 381-391, 2016.
6. [6] K. Sakuma, Y. Yokoo, and M. Seto, “Study on Drilling of Reinforced Plastics (GFRP and CFRP) Relation Between Tool Material and Wear Behavior,” J. of Japan Society of Mechanical Engineering, Series C, Vol.49, No.446, pp. 1799-1807, 1983.
7. [7] K. Sakuma, M. Seto, M, Taniguchi, and Y. Yokoo, “Tool Wear in Cutting Carbon-Fiber-Reinforced-Plastics the Effect of Physical Properties of Tool Materials,” J. of Japanese Society of Mechanical engineering, Vol.30, No.13, pp. 656-666, 1985.
8. [8] S. Tamura and T. Matsumura, “Cutting Force Prediction in Drilling of Unidirectional Carbon Fiber Reinforced Plastics,” Int. J. Automation Technol., Vol.9, No.1, pp. 59-66, 2015.
9. [9] H. Hocheng and C. C. Tsao, “Comprehensive analysis of delamination in drilling of composite materials with various drill bits,” J. of Materials Processing Technology, Vol.140, pp. 335-339, 2003.
10. [10] J. Fujiwara, R. Nagaura, and T. Tashiro, “Drilling of CFRP/Ti6Al4V Stack Board,” Int. J. Automation Technol., Vol.7, No.4, pp. 426-432, 2013.
11. [11] M. Sato, H. Tanaka, and K. Yamamoto, “Temperature Variations in Drilling of CFRP/Aluminum and CFRP/Titanium Stacks,” Int. J. Automation Technol., Vol.10, No.3, pp. 348-355, 2016.
12. [12] T. Kaneeda and M. Takahashi, “The Effects of Fiber Angle and Tool Rake Angle on Unidirectional CFRP Cutting Mechanism,” Bulletin of the Okayama University of Science, A, Natural Science, Vol.22, pp. 143-153, 1987.
13. [13] T. Kaneeda and M. Takahashi, “CFRP Cutting Mechanism (1st Report) Surface Generation Mechanism at Very Low Cutting Speeds,” J. of the Japan Society for Precision Engineering, Vol.55, pp. 1456-1461, 1989.
14. [14] T. Kaneeda and M. Takahashi, “CFRP Cutting Mechanism (2nd Report) Analysis of Depth of Reluctant Uncut and Deformed Part,” J. of the Japan Society for Precision Engineering, Vol.56, pp. 1058-1063, 1990.
15. [15] T. Kaneeda, “CFRP Cutting Mechanism (3rd Report) Effects of Tool Edge Roundness and Relief Angle on Cutting Phenomena,” J. of the Japan Society for Precision Engineering, Vol.57, pp. 491-496, 1991.
16. [16] T. Inoue and M. Hagino, “Cutting Characteristics of CFRP Materials with Carbon Fiber Distribution,” Int. J. Automation Technol., Vol.7, No.3, pp. 285-291, 2013.
17. [17] A. Koplev, A. Lystrup, and T. Vorm, “The cutting process, chips, and cutting forces in machining CFRP,” J. of Composites, Vol.14, pp. 371-376, 1983.
18. [18] M. Hagino, T. Inoue, A. G. Olabi, W. Aoki, and F. Matsumoto, “New Machine Tool on Collecting Cutting Chips of CFRP for Working Environment Improvement,” J. of Advanced Materials Research, Vol.816-817, pp. 211-215, 2013.
19. [19] M. Hagino, D. Haga, T. Inoue, W. Aoki, and F. Matsumoto, “Worker’s Environment Improvement of CFRP Material by Hollow Type Drill,” Proc. of the 5th Int. Conf. on Sustainable Energy and Environmental Protection, Part 2, pp. 314-319, 2012.
20. [20] M. Hagino, D. Haga, T. Inoue, W. Aoki, and F. Matsumoto, “Effectiveness of Chip Collection and Characteristics of Drilling CFRP Materials Using Hollow-Type Drill,” Proc. of the 10th Int. Conf. on Progress of Machining Technology, pp. 93-96, 2012.
21. [21] M. Hagino, T. Inoue, M. Mizoguchi, W. Aoki, and F. Matsumoto, “Dust Collection Validity and Effect of Hole Shape Accuracy of CFRP with Developed Hollow-Type Drill and Dust Collector,” Int. J. Automation Technol., Vol.10, No.3, pp. 324-333, 2016.
22. [22] M. Hagino, T. Inoue, T. Fujita, and H. Usuki, “Effects of Tool Edge Form during the Drilling of CFRP,” J. of the Key Engineering Materials, Vol.749, pp. 141-147, 2017.
23. [23] M. Hagino and T. Inoue, “Effect of Carbon Fiber Orientation and Helix Angle on CFRP Cutting Characteristics by End-milling,” Int. J. Automation Technol., Vol.7, No.3, pp. 292-299, 2013.
24. [24] S. Maegawa, Y. Morikawa, S. Hayakawa, F. Itoigawa, and T. Nakamura, “Effects of Fiber Orientation Direction on Tool-Wear Processes in Down-Milling of Carbon Fiber-Reinforced Plastic Laminates,” Int. J. Automation Technol., Vol.9, No.4, pp. 356-364, 2015.