Method of processing a synthetic resin tube, and tubular container

摘要

The technical problem of this invention is to establish a method of processing a synthetic resin tube, in which the shape of a part of the tube wall is changed to form easily an attractively hollowed and/or raised portion in a fairly wide area of the tube wall. The object of this invention is to provide a tubular container having excellent decorativeness, appearance, or functionality that has never been found before. A method of processing a synthetic resin tube comprises utilizing a mandrel having a mold portion, which has at least a shape selected from a hollowed shape, a raised shape, and a hollowed and raised shape formed in a part of outer surface of the mandrel, and which is also provided with small through-holes in this mold portion; inserting a bottomed cylindrical mandrel into a synthetic resin tube, while bringing the inner wall of the tube in contact with the mandrel; heating and softening the tube in the portion facing the mold portion; deaerating the tube via a central opening and the through-holes to mold the softened portion of the tube in a manner similar to vacuum molding; and forming in the tube wall at least one of the portions selected from a hollowed portion, a raised portion, and a hollowed and raised portion.