4055 Mesh of φ0.25 and Our World-class Technological Strength
As proof of Nunobiki Manufacturing’s technological strength, its factory was designated a Rationalization Model Factory by the Small and Medium Enterprise Agency in 1966. It retained the designation each year until the program ended in April 1996, when it received a certificate of appreciation in recognition of its achievements that contributed to management rationalization promotion for many years.
The picture of 4055 Mesh used on the cover of
Nunobiki Manufacturing’s catalogue
In 1972, Nunobiki Manufacturing channeled its perforated screen technology into the challenge of producing a screen with the smallest holes and the highest precision. At that time, a German manufacturer had produced a screen with around 3,500 holes of φ0.25 per square inch. Nunobiki Manufacturing succeeded in punching 4,032 holes of φ0.25 per square inch in a 90º straight pattern and 4,055 holes of φ0.25 per square inch in a 60° staggered pattern. Thus, it realized micro-holed, high-precision, perforated screens with an open area of 30.7 percent. Dies for these screens had more than 500 punches within a width of 200mm, and expert technicians steadily drilled each hole. The upper and lower dies must be assembled with a subtle clearance of all the pins less than one hundredth of a millimeter, without losing any precision. This is not a skill that can be attained overnight. The process required perseverance and endurance. Only artisans who dedicate the long period required to attain the skill are able to produce dies to meet customer needs.
Even today, Nunobiki Manufacturing prides itself on possessing a world-class, technological level for manufacturing screens with 4,055 holes (=0.25φ) per square inch.