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#048 Purasu Industrial Co.,ltd2016/07/19

Exploring New Genres for Paper Products Using Technologies for Manufacturing Paper Speaker Cones (Shizuoka Pochi / Gakraft)

Pursuing Three-Dimensional Molding Technologies in a Commitment to Sound Quality Excellence

In an area near the Abe River that flows through the city of Shizuoka, there is a company using the three-dimensional paper molding technology that it has built up over many years to venture into completely new fields. That company is Purasu Industrial Co.,ltd, and it is developing new paper products such as “Shizuoka Pochi,” a completely new concept of paper zakka goods, and a paper art material called “Gakraft.” Purasu Industrial designs and manufactures paper cones, the diaphragms that control the sound quality of audio speakers. Its extensive product line-up ranges from large cones for professional equipment to small cones for portable speakers. The types of speakers that contain Purasu Industrial cones include audio systems, car audio, game consoles and smartphones. Although many of us have seen these dome-shaped cones, few would know that they are made by molding paper into three-dimensional shapes.

Purasu Industrial’s President, Tsukasa Osuga, succeeded his father, who founded the company in 1975 after working at a major audio equipment manufacturer. Today, as the second president, he is taking on the challenge of new projects.

“The paper cone is actually an extremely important component of a speaker, which has a major impact on the sound quality of the audio equipment. Paper is one of the lightest materials in existence and has very low density, two of the most important characteristics required of speaker diaphragms. Since we were first founded in 1975, we have devoted our efforts to the research and development of paper materials and the improvement of technologies for the three-dimensional molding of that paper, with the aim of producing excellent quality of sound,” explains Tsukasa Osuga, President of Purasu Industrial.

Paper speaker cones that meet the needs of users seeking high sound quality

Purasu Industrial was established here because the location offered good-quality, soft water, the kind used to make Japanese sake, from the subsurface water flow of the Abe River. This soft water, which is peculiar to Japan, can be used to make superior paper that would be impossible to make with the hard water of other countries.

The “beater,” a machine that pounds the raw material and separates the fibers. It was designed and built exclusively for Purasu Industrial by expert craftspersons.

Where once Japan had as many as 30 paper cone manufacturers, today there are just two. Like many industrial products, offshore production in Asian countries has become the norm, and times are tough for manufacturers of all-Japanese products.

Japan’s soft water is suited to making paper from pulp, the raw material. It is often said that, where there is a paper production region, there will always be a high-quality sake producer as well. That is how closely good-quality water and paper are related.

Taking on the Challenge of the Ultimate High-End Speaker

As if to deliberately make waves in this market environment, the concept that Mr. Osuga embarked on in 2011 was an “all-Japanese speaker.” He launched “sui,” a high-end speaker made entirely of materials and components that were made in Japan.

Even the machining of the speaker frames was done in-house at Purasu, adapting the company’s technologies for machining paper cone press molds. In this way, Purasu Industrial mobilized its own technologies for the finest of details of the product.

In circumstances where even high-end European-made speakers contain components that are manufactured in Asia, making a speaker with an insistence on 100% Japan-made even for the raw materials was an industry first. Made with traditional Japanese materials, namely mitsumata, a raw material of Japanese washi paper, the soft water of Abe River, sand, and lacquer, Purasu Industrial’s product resonated in an acoustic environment of high quality, rich with atmosphere, in a compact body, and quickly became a hot topic in the industry.

The lacquer coating on the body of the all-Japan-made high-end speaker, “sui,” was the work of Toba Shitsugei, a producer of Suruga Lacquerware, a traditional folk craft of Shizuoka Prefecture. Sand from the Abe River and lacquer are applied in a coating of about 8 mm, creating a hard finish for the body.

Venturing into New Genres Through Collaborations with Designers and a Planning Company

Wanting to take a giant step outside the realm of manufacturing paper cones as speaker components, Purasu Industrial took part in Tsunagu Design Shizuoka, a project to assist local manufacturers organized by the Shizuoka Industry Promotion Association. The company worked with a designer living in Shizuoka on the creation of “sui,” the speaker that Purasu Industrial made from scratch. The following year, it joined hands with Shizugen Co., Ltd., a Shizuoka company that plans and sells local specialty products and gifts, and the Shizuoka Industry Promotion Association matched them with a local furniture designer. In collaboration with the planning company and the designer, Purasu Industrial began the challenge of venturing into further new frontiers.

Combining the ideas of Shizugen President, Hidemi Yanagisawa, with her insistence on products that typify Shizuoka, and Purasu Industrial’s development and technological capabilities, the collaborators pursued the development of products that would be distinctive and competitive in the marketplace.

Shizugen President, Ms. Hidemi Yanagisawa, admitted, “Purasu Industrial’s three-dimensional paper molding technology is something unique that no other company possesses, so I had had my eye on them for some time, thinking that we could work together to develop some distinctive, typically Shizuoka zakka goods made of paper.”

Using Purasu Industrial’ s three-dimensional paper molding technology, the two companies and the designer embarked on a process of repeated prototyping to produce press molds with motifs that distinctively represented Shizuoka.

After much trial and error, they finally arrived at a three-dimensional petite case that conveys the warm feel of paper. Given the name “Shizuoka Pochi,” this little case puts a smile on the face of both the giver and recipient. It is a new kind of paper zakka item that stirs up expectations and imagination about what might be inside. It comes in three auspicious motifs, kinmedai (splendid alfonsino) and sakuraebi (cherry shrimp), both seafoods for which Shizuoka is famous, and the World Heritage-listed Mt. Fuji. The popularity of these cute little cases is growing, as people give themselves free rein to use them for a variety of purposes. Examples of use include as gifts given at celebratory occasions or in the New Year’s season, or for keeping them on one’s desk to store stationery, SD cards and other small items.

The 3D petite case, Shizuoka Pochi Case, can be used to give money or small non-monetary gifts on occasions such as New Year’s, when adult relatives traditionally give gifts of money to children, as tips, and as gestures of appreciation.

As Ms. Yanagisawa describes, “One thing I learned from participating in the regional assistance project was that, by collaborating with designers, we were able to create new value in unprecedented genres,” the freedom of ideas that came from not being tied to one’s conventional areas of expertise allowed these two companies to expand their potential enormously.

Revolutionary Paper Art Material, Offering New Value to the Art World

The year after venturing out from the audio industry into the new field of paper zakka, the Purasu Industrial-Shizugen team rode the wave of the favorable reaction to their Shizuoka Pochi case and embarked on another new project. This time, they set a new challenge for themselves. Whereas Shizuoka Pochi had a very seasonable element to it, they wanted to create a paper product that could be sold all year round. Moreover, the item would need to be able to use the three-dimensional molding technology and take advantage of the characteristic features of paper, the material it would be made from. They set to work, considering a wide variety of items.

To achieve the desired whiteness in the art paper, the pulp was exposed until it turned white, before being press-molded.

This time, the designer they collaborated with was an industrial designer with whom Purasu Industrial had a long association in the development and manufacture of audio cones. The product that emerged from meetings between the three parties was a completely new concept in paper art material, which they called “Gakraft,” which is a blend of the Japanese word for frame, gaku, and the English word, craft. Because the surface for drawing or painting is integrated with the frame, the paper will not warp, making it suitable for a range of paint types, such as watercolors and oil paints. The product has received high praise for combining this versatility with durability and resistance to deterioration over time, realizing excellent functionality as an art paper.


Gakraft is an art paper that comes with its own frame. As well as the paper, the frame itself can also be drawn and painted on. Combined with the product’s strong resistance to deterioration over time, it has greatly expanded the possibilities for the art scene. The collaborators wanted to recreate the feel of canvas, so the painting surface has been given a textured finish.

The ability to incorporate the frame into the painting to create an original work of art offers artists a high degree of creativity, and this has been extremely well received. It has actually prompted a new art movement, with Gakraft exhibitions being held in various regions, and elementary schools including it in their art education supplies.

Five years have passed since the company embarked on their new challenges. They have since had their new products exhibited at trade fairs organized by Rin crossing, attracting the attention of other industries, and at the same time, they are apparently receiving a renewed wave of inquiries for diaphragms, the company’s original line of business.

“Being able to build networks with people from other industries and buyers at the trade events is a major benefit of registering with Rin crossing. That is something that we have never had until now, while we were focused solely on the audio industry. We’ve seen a sudden broadening of our sales channels as a result. I see myself more as a maker than a manager. While holding onto the basics of our three-dimensional molding technologies, which we have built up over the years, I hope to continue with our efforts to develop new products going forward. As long as we can get the basics of “usefulness” and “practicability” right in manufacturing, then I don’t think we can go wrong. We also look forward to going global with the help of Rin crossing,” enthused Mr. Osuga. The company’s next venture into new product development is already underway.

Purasu Industrial Co.,ltd

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