Production process of a hexagonal honeycomb structure

A production process of a hexagonal honeycomb structure in which a large number of hexagonal cells are provided surrounded by partitions in the form of a hexagonal matrix comprising:

• an extrusion step for obtaining a molding in which partitions surrounding a large number of hexagonal cells are provided in the form of a hexagonal matrix by extrusion molding of a mixed raw material using a horizontal extruder having an extrusion die provided with slits in the form of a hexagonal matrix and in which the direction of extruding is substantially a horizontal direction parallel to a horizontal plane,
• a drying step for drying said molding, and
• a baking step for baking said molding,
• wherein two partitions of each hexagonal cell are substantially vertical to the horizontal plane and parallel to an axis during the extruding step, and the orientation of the two partitions differ by 60-120° from the orientation of the two partitions in the case of placing said molding horizontally in at least one of either of said drying step or said baking step so that the lengthwise direction of said molding is maintained substantially in the horizontal direction.