Monodzukuri Nippon Grand Award HOMEJapanese
Documentation of Award Winners’ Enthusiasm
search by keyword search by region play video see cartoon version
Professionals Who Create the World’s Leading EdgeProfessionals Who Succeed Tradition and Keep Progressing
Kagawa aquarium acryl panel screen
Miki Town, Kagawa Prefecture
Nippura Co., Ltd.
Chujo, Toshifumi (57)
Director, Factory General Manager Miki Town, Kagawa Prefecture
Nippura Co., Ltd.
Chujo, Toshifumi (57)
Director, Factory General Manager
Acrylic Panel Manufacturing Technology that Changed the Concept of Aquariums
Acrylic is softer than glass, yet safe and strong. Nippura possesses cutting-edge technology for manufacturing and processing products made of acrylic materials. For the viewing window of a gigantic water tank (“Sea of Black Current”) at the Churaumi Aquarium in Okinawa, the company manufactured and installed a single acrylic panel measuring 8.2 m in height, 22.5 m in width, and 60 cm in thickness. Employed therein are an adhesion technology for layering panels, a heat treatment technology for enhancing strength during the curing of adhesives, and a construction technology for combining the seven 20-ton panels onsite and installing them in the tank frame. Nippura’s original know-how was generously utilized to produce a huge window capable of withstanding water pressure of 7,500 tons without even a single pillar. The Guinness Book of World Records has certified this viewing window as the world’s largest, single acrylic panel, as well as the largest aquarium window in the world.
The desire to create an atmosphere where visitors can feel as if immersed in the sea was crystallized into the world's largest acrylic panel window.
play video(56KB)play video(1MB)read prize-winner’s documents
Company Profile
Nippura Co., Ltd.
http://www.nippura.com/en/
After being established in 1969, the company supplied the world’s first acrylic aquarium for the Yashima Aquarium the following year. While engaging in the manufacturing and processing of various acrylic products, Nippura earned worldwide recognition for its acrylic window installed at the Monterey Bay Aquarium, thus becoming a leading manufacturer in this field. Nippura’s products have been commercially introduced in over 40 countries worldwide. In Japan, such products are known at the Osaka Aquarium Kaiyukan, the Polar Bear house at the Asahiyama Zoo, and other facilities.
Extra large-scale panels with polished surfaces: as the adhesives applied between panels become transparent, only the front and back faces of the layered panels need polishing.
Extra large-scale panels with polished surfaces: as the adhesives applied between panels become transparent, only the front and back faces of the layered panels need polishing.
Because there are at least seven major methods of producing metal powder, the factory has various plants that employ each of these methods. On the other hand, the laboratory for developing new products is small and simple.
Because there are at least seven major methods of producing metal powder, the factory has various plants that employ each of these methods. On the other hand, the laboratory for developing new products is small and simple.
The cross section indicates a multi-layered structure, which cannot be recognized when viewed from the front
The cross section indicates a multi-layered structure, which cannot be recognized when viewed from the front
Huge circular saw for cutting thickly laminated panels, and chip materials cut out will be shipped overseas for recycling.
Huge circular saw for cutting thickly laminated panels, and chip materials cut out will be shipped overseas for recycling.
From a live fish tank at a sushi bar to the Monterey Bay Aquarium
In the midst of the third aquarium boom nowadays, the windows of aquariums are becoming increasingly larger and more diversified in shape, made possible by the remarkable advances made in manufacturing/processing technology related to transparent acrylic panels. In response to the aquarium boom, general Japanese contractors engaged in the construction of aquariums decided to take overseas tours of the world’s major aquariums. They naturally asked the staff of the facilities, “Which manufacturer supplied this gigantic acrylic window for you?” The answer was, “A manufacturer called ‘Nippura,’ from your own country.”
Mr. Chujo is the general manager of this manufacturer, “Nippura.”
“When I joined the company, it was the time when acryl and other resin materials were starting to become popular. In time, the demand for live fish tanks like the ones in sushi bars created a boom. Our technology was related to the assembly of acrylic panels without using frames, and we offered the service of delivering as well as installing such tanks in the sushi bars.”
Their main sales in those days, however, derived from acrylic lampshades, the production of which was subcontracted by major manufacturers. Then came the oil crisis. The demand decreased as the price of acryl soared, but as a subcontractor, Nippura could hardly increase the product prices.
“Under such circumstances, the president decided to discontinue this unpromising subcontracting business, and we started sales activities to receive orders for tanks in aquariums on our own. However, no one in Japan wanted to do business with a small-sized enterprise based in Kagawa. Consequently, we took the courageous step of going abroad to seek business opportunities.”
Those efforts were rewarded by an order from a prestigious American aquarium—the Monterey Bay Aquarium. The work of Nippura was highly regarded, and the Nippura name became known worldwide almost overnight.
Viewing window that immerses the visitors at Churaumi (Beautiful Sea) in Okinawa
It was in 2001 when we heard about the planned construction of the Churaumi Aquarium in Okinawa, particularly the main viewing window of its feature exhibit, “Sea of Black Current.” The drawings showed a colossal window unheard of in the world, with amazing dimensions of 8.2 m in height and 22.5 m in width. In the presence of dumbfounded Mr. Chujo and his staff, the president of Nippura said something even more astonishing.
“We want the visitors to be unaware of even the presence of the window. We will remove everything from their sight except the fish and water, so that they can feel as immersed right in the sea.”
This statement suggested the construction of a window through the adhesion of acrylic panels without using any reinforcing materials. Given this suggestion, the original design was adjusted for the concrete window frame to have higher strength. A number of acrylic panels measuring 8.5 m (H) x 3.5 m (W) x 4 cm (D) were delivered from a panel manufacturer to the Kagawa factory.
“Those were special order items which we call extra large-scale, and were rarely used by other manufacturers (laughing).” These delivered panels have surface irregularities and are therefore murky in appearance, a condition that requires fine polishing. Machines are initially used for polishing, followed by finishing by hand. Then, these panels are laminated using adhesives to gain thickness. The design panel thickness for the Churaumi Aquarium is 60 cm, which can only be achieved by laminating a dozen panels. The adhesive agent was also developed using the company’s original know-how. “We call this agent ‘syrup.’ After the laminating process, applying insufficient pressure causes the syrup to contract, while too much pressure causes it to crack, thus requiring delicate pressurizing. An excessively high temperature during the curing process causes bubbles to form, so a stable environment must be provided at all times. Yet, after the laminating process, we need to raise the temperature; otherwise, the adhesion planes become cloudy or lack sufficient strength. Before, when we were ignorant and unafraid of anything, we failed repeatedly, but through such a trial and error process, we accumulated reliable know-how. Young workers today perform their work carefree without realizing such a background, and that scares us at times (laughing).”
The panel surfaces with adhesives applied eventually become transparent without polishing. Therefore,only the front and back faces of the layered panels require finish polishing. Another advantage is that, when hardened, the layered panels exhibit the same characteristics and strength as those of the acryl itself. On the other hand, just one bubble or scratch made during the process can render the dozen-layered acrylic panel useless, which incurs an enormous loss equivalent to the cost of a few Mercedes cars.
The seven prepared acrylic panels were shipped to Okinawa, and final installation was conducted right inside the aquarium tank. By slinging these 20-ton panels one by one with a 50-ton rafter crane, the seven panels were eventually joined together vertically with the “syrup.”
“The layered, single transparent wall was now moved horizontally using jacks, and then fitted tightly to the outer frame.”
Then 7,500 tons of seawater was poured into the completed aquarium tank, in which three whale sharks coupled with countless species of fish were to swim in swarms as if in the Black Current Sea. The immensity of this aquarium even sent shivers down the spines of Mr. Chujo and his coworkers who built it.
The importance of never giving up and persevering; taking another step forward next time!
Upon receiving an order from the Monterey Bay Aquarium, the president was astounded by information about a 36% tariff on the acrylic panel. His quick contact with the Japanese ministerial agencies concerned was met with a cold-shouldering response of “there is nothing we can do about it.”
“Then, our president immediately visited the American Embassy, hoping for the possibility of negotiations. One sympathetic member of the embassy staff kindly introduced an official in Washington.
After realizing that, ‘this is simply a water wall, or aquatic wall,’ he decided to reduce the tariff to 2.7% in a matter of 20 minutes or so (laughing).”
The company’s culture of perseverance, never giving up, and taking the initiative in risk-taking is reflected in its technological capacity. The acrylic panel project ordered by a client in Dubai, a Middle Eastern country, involved a panel 75-cm thick and weighing 27 tons, which even exceeded the dimensions of the Churaumi viewing window. Even after gaining worldwide recognition, this small-sized enterprise in Japan continues its efforts to manufacture “something larger and better” in a secluded corner of Kagawa.
ƒy[ƒWTOP‚É–ß‚éPage Top
[Other prizewinners (in Japanese syllabic order)]
Seiji Inoue, Jirou Yamamoto, Masayoshi Yoshitake
About this site (C)2006 The Japan Machinery Federation
The contents are based on the information as of 2006/03/31. This project is subsidized by the Japan Keirin Association