Interest in natural fiber composites is increasing as manufacturers pursue sustainable production. Compared with carbon or glass fibers, natural fibers are bio-based and can contribute to carbon neutrality depending on material selection.

Kawamura Kikai Co., Ltd. is developing composites that combine CFRTP with natural fibers such as cacao husk, flax/hemp, and coconut fiber. Prototyping and evaluation are being conducted to explore the potential of natural fiber composites and their applications.

【Significance of Utilizing Natural Fibers】
Natural fibers are lightweight, provide moderate stiffness, and support environmentally conscious design. Although less rigid than carbon fiber, adequate performance can be achieved through optimized structural design and resin selection. Their natural texture and color also offer advantages for aesthetic-oriented applications.

【Material and Resin Combinations】
Through collaboration with industrial technology support institutions, prepregs impregnated with resin and natural fibers have been successfully developed.

Target materials include:
・Cacao husk: Fiber derived from food waste. Suitable for design applications due to its unique appearance.
・Flax (Flax/Hemp): Used in woven form. Bending rigidity can be enhanced when combined with rib structures.
・Coconut fiber: Currently under condition exploration due to variability in fiber length and moisture content.

As matrix resins, bio-based PA11 and hemicellulose-based materials are selected to promote effective use of biomass resources.

【Molding Methods and Evaluation】
Both hot press and cold press processes are evaluated. Hot press improves impregnation and surface quality, while cold press enables shorter cycle times and deeper geometries. Prototyping uses an A4 flat mold to test 0.5–5.0 mm thickness. Mechanical properties are assessed mainly by tensile and flexural tests, quantifying the effects of fiber orientation and resin type.

【Path Toward Practical Application】
Natural fiber composites are expected to serve as new materials that combine aesthetic value with environmental performance. They are particularly suitable for lightweight panels and exterior components where both performance and visual differentiation are important. Through collaboration with partner institutions and companies, development progresses step by step from flat prototypes to actual product geometries, with future mass production in view.

【Equipment and System】
Press equipment supports capacities up to 200t and molding temperatures up to approximately 400°C. Mold sizes are approximately 1200×1500mm, with product sizes up to approximately 500×500mm. Inspection is conducted using 3D coordinate measuring machines and image dimension measuring systems to verify dimensional accuracy and surface quality. Secondary processing is not handled in-house; however, machining, drilling, and assembly processes can be supported in cooperation with partner companies.

【Summary】
CFRTP combined with natural fibers holds significant potential for environmentally conscious product development. By integrating materials such as cacao husk, flax/hemp, and coconut fiber with bio-based resins, sustainable and differentiated composites can be realized. Further verification and evaluation are expected to expand applications that balance aesthetic appeal and structural performance.

【Contact Information】
Kawamura Kikai Co., Ltd.
Head Office: 2-4 Shimizu-cho, Itabashi-ku, Tokyo 【Composite Division】
Hanazono Factory: 10 Kitane, Fukaya-shi, Saitama 【Metal Press Division】
Website: https://www.kawamura-kikai.co.jp
Inquiry / Quotation: https://www.kawamura-kikai.co.jp/contact/
Please mention that you saw us on “Emidas” when making your inquiry.