NITTAI Co., Ltd.

How to Create

Tile manufacturing method

Quality and aesthetic value produced by skilled people, technical abilities and state-of-the-art equipment

NITTAI products are recognized for their high quality, subtle toning and the reassuring texture of ceramics. These products are slowly fired over a long time in tunnel kilns 40 to 70 meters long, while controlling the humidity and furnace atmosphere.
This requires subtle adjustments according to human sensibilities, backed by high-level equipment and technical ability.
Also, in regard to quality control, quality is checked at every step, including raw materials, equipment, work process, inspections and tests.
For inspection of completed products, having set company standards above the administrative standards of JIS A5209, we conduct water absorption tests, friction tests, bending tests, dimensional measurement, warpage measurement, etc., and rigorously gather detailed data through extensive use of computer systems.
The skilled work that only highly-experienced craftsmen can produce is adjusted with state-of-the-art equipment and cutting-edge technology, and only then do NITTAI tiles go out into the world as products.

Manufacturing process

1.Raw materials
High-quality clays and feldspars are brought in from quarries in places such as Seto and Tajimi.
Raw materials
2.Processing of raw materials
The clay and rocks are ground and mixed to form the base material of the tiles. The base material is then kneaded with aggregates (sand, stone dust, etc.) and water and is left to sit for a couple of days.
Processing of raw materials
The prepared clay is vacuumized and then shaped by an extruder (wet process). At this point, tiles exceeding size allowance are removed.
The tiles are dried over several days in a drying room. Sample inspections are performed to check the shape of the tiles. Some tiles are then glazed, as required.
The tile pieces are lined up and loaded onto kiln carts, with adjustments made for height, etc.
The tiles are fired inside the tunnel kiln under controlled temperature for approximately a day and a half.
7.Selection and inspection
A sorting machine removes significantly warped tiles and performs inspection for chips and scrapes.
Selection and inspection
The tiles are packaged on a fully automated operation line and are shipped out to locations all over Japan.