Norinaka Hirokawa

Title: Norinaka Hirokawa: Innovations in Fiber Surface Fasteners.

Introduction

Norinaka Hirokawa is an inventor based in Toyama, Japan, whose work focuses on improving the durability, flexibility, and manufacturing of fiber surface fasteners. He is associated with YKK Corporation and is credited with 3 patents.

Latest Patents

Hirokawa’s patent, “Fiber Surface Fastener and Method for Finishing Same,” describes a finishing process designed to firmly secure engaging elements to a foundation cloth while preserving the fastener’s softness. The method applies powdered hot-melt adhesive to the fastener, heats it to melt the adhesive between the engaging elements and the cloth, and then cools the material. Applying the adhesive separately from the protruding surfaces helps prevent it from coating or solidifying on the engaging elements.

His “Surface Fastener” patent addresses how engaging-element yarns can be firmly attached to a woven foundation fabric. The design uses cross-woven warps to secure the yarns around their loop portions. In one implementation, thermal-melting yarns are used as the cross-woven warps and melted to weld the engaging-element yarns to the foundation fabric. The approach aims to produce a durable fastener with good flexibility and feel.

Career Highlights

Hirokawa’s patented work centers on practical improvements to fiber fastening products, including stronger attachment of engaging elements and finishing methods that support softness and reliable production. His inventions explore how weaving structures, yarns, and heat-activated adhesives can improve the performance of surface fasteners.

Collaborations

Hirokawa is associated with YKK Corporation. His listed coworkers include Mitsuhisa Okawa and Masashi Doi.

Conclusion

Norinaka Hirokawa’s patents reflect a focused contribution to surface-fastener technology, combining manufacturing methods and fabric structures to improve strength, flexibility, and softness.