Kazufumi Yokoyama

Title: Kazufumi Yokoyama: Innovator in Rigid Polyurethane Foam Technology

Introduction

Kazufumi Yokoyama, an innovative inventor based in Yokosuka, Japan, has made significant contributions to the field of polyurethane foams. With two patents to his name, Yokoyama’s work focuses on methods that enhance the manufacturing of rigid polyurethane foam, commonly utilized in various applications such as energy absorbent pads.

Latest Patents

Yokoyama's latest patents exhibit his ingenuity in foam technology. The first patent details a method for making and then removing a molded article of rigid polyurethane foam. This process involves using a separable mold with upper and lower sections to define a cavity. The method incorporates a pre-formed polypropylene film that is secured within the cavity. A rigid polyurethane foam-forming raw material is introduced, causing it to foam and expand in place. Once the molding is complete, the article is lifted along with the film using pneumatic pressure or an ejector pin. Remarkably, this method allows for the molded article to be stripped from the film without removing the entire film from the mold, making it a more efficient production process.

The second patent focuses on a method for manufacturing a rigid polyurethane foam molding specifically designed for energy absorption. In this process, a rigid polyurethane foam raw material, which consists primarily of a polyhydroxy compound and a polyisocyanate compound, is introduced into the mold cavity. The unique aspect of this innovation lies in the pack ratio of the core portion, which ranges from 0.5 to less than 1.2. This careful calibration allows the foam molding to achieve energy absorption characteristics comparable to traditional rigid polyurethane foam slab stock.

Career Highlights

Kazufumi Yokoyama is currently employed at Bridgestone Corporation, where he utilizes his expertise in polymer chemistry and materials science to advance the company’s innovations in foam technology. His commitment to research and development has positioned him as a valuable asset in the field of material sciences.

Collaborations

Throughout his career, Yokoyama has collaborated with notable colleagues such as Keiichiro Tabata and Yoichi Nabeshima. These partnerships have enriched his research endeavors and contributed to the successful development of his patented methodologies.

Conclusion

Kazufumi Yokoyama stands out in the realm of polyurethane foam innovation, with a particular focus on manufacturing processes that enhance energy absorption capabilities. Through his patents and collaborative efforts at Bridgestone Corporation, Yokoyama continues to drive advancements in this critical field, showcasing the importance of innovation in materials technology.