Industry ・ Environment
In 1949, after the post-war confusion had settled down, NGK SPARK PLUG moved forward in earnest with diversifying its product lineup in parallel with the production of plugs.
In the mid 1950's, we used the development of ceramic products that formed the "NTK brand" as a new point of departure, and started developing industry- and environment-related products. Above all, piezoelectric ceramics utilized the functional properties of ceramics, such as the generation of voltage by the application of pressure and the generation of sound waves by the application of voltage.
From then on, the NTK brand came to be widely used as new ceramics in addition to plug-related products.
Examples of the various industry- and environment-related products we made by using the characteristics of ceramics initially included evaporation trays, combustion crucibles, spinning yarn routes, beakers, protective tubes, and combustion tubes, to mention but a few.
In 1963, we concluded a technical assistance contract with an American corporation, and acquired patent rights for lead zirconate titanate ceramics and electric filters that applied these ceramics. In this way, we proceeded with the development of piezoelectric ceramic products.
Piezoelectric ceramic products differ from conventional ceramics whose passive properties were utilized. That is, the active properties of generating voltage by the application of voltage on piezoelectric ceramic and generating sound waves by the application of voltage are utilized.
In 1965, we developed piezoelectric devices and the "piezo igniter" which incorporated these piezoelectric devices and sold these devices through a gas apparatus manufacturer.
Since neither matches nor batteries were no longer required, use of piezo igniters spread widely for use in home table gas stoves, gas baths, gas stoves, and instantaneous water heaters. And, in 1971, they were officially incorporated into standards by gas companies.
The development of oscillators that applied the principles of piezoelectric ceramics to generate ultrasonic waves began in 1967.
Although sound waves are generated by a vibrating sound source, the frequency of ultrasonic waves is high and beyond the hearing range of humans. So, a special method is required to generate ultrasonic waves.
Ultrasonic waves and voltage can be generated by inserting piezoelectric ceramic between two electrodes and applying voltage to the electrodes. This causes the oscillators to expand and contract and, in turn, oscillate.
This principle was applied to PZT ceramic single body oscillators and bolt tightening langevin-type oscillators, which were sold for cleaning applications. In 1973, we developed ultrasonic bridging devices for the production of ultra high-voltage power line cables.
And, in 1975, we put onto the market ultrasonic transducers for fish detection.
Presently, they are used in a wide range of fields including industrial equipment for processing machines, washing machines and bonder devices, and in treatment systems such as dentistry scalers, surgical scalpels and for the destruction of calculus.
In 1979, we started sales of ceramic heaters that applied IC package laminating technology for auto chokes.
An auto choke uses the system of automatically enriching the air-fuel ratio when the engine is cold, and a thermostat is used for automatically actuating or stopping the choke or starter.
Our ceramic heaters were used for operating these thermostats.
From then on, ceramic heaters came to be used in other applications including warm water toilet seats, 24-hour baths and semiconductor production equipment.
Our ceramic heaters are sintered integrally with wiring embedded inside the ceramic. They have excellent acid and alkali resistance, and feature little wire breakage and changes over time and a fast temperature rise rate.
Currently, they are incorporated into various equipment including electrical heating apparatus, and are being put to use in DNA analyzers, heating of perm solutions and vaporization in kerosene fan heaters.
This high-performance ceramic, silicon nitride material, is being given attention as a structural material for improving the combustion temperature of automobile engines, for example.
We have continued research with the focus on new sintering technology, and this has made highly reliable gas pressure sintered silicon nitride bodies a reality.
In 1984, NGK Spark Plug's basic technological expertise was recognized, and we were commissioned to develop "a production technology for silicon nitride sintered bodies by a gas-pressure sintering method" from the former Research Development Corporation of Japan. The results of this were applied in bearings and cutting tools, for example, in addition to automobile engine parts such as ceramic rotors for turbochargers.
In 1999, sales of silicon nitride bearing balls were closely linked to the recovery of the semiconductor industry and increased rapidly.
At present, they are used, for example, in machine tool spindles and other high-speed rotation applications and in special environments like in high-temperature liquid chemicals, that had been difficult with metal bearings.