Abstract: A creased-plastic-sheet manufacturing apparatus which can warm a plastic sheet to uniform temperature, and can form smooth creasing lines on the sheet is provided. The creased-plastic-sheet manufacturing apparatus includes a punching apparatus for manufacturing a plastic sheet having creasing lines, which is folded into a container or the like, the creased-plastic-sheet manufacturing apparatus being characterized in that the punching apparatus includes: (1) a flat platen to which a cutting die is secured, the cutting die carrying cutting blades, including a creasing-line forming blade, embedded into the cutting die; and (2) a temperature-maintaining platen disposed in opposition to the flat platen and equipped with a temperature-maintaining mechanism including a flow passage formed within the temperature-maintaining platen, the flow passage being formed of fine channels through which a temperature-maintaining liquid can be passed.

Abstract: A plastic sheet has a plurality of creasing lines. Each creasing line includes a main groove having a narrow bottom surface and a pair of opposed side surfaces each slanting at a certain angle; and a plurality of slant grooves disposed at a certain pitch in the longitudinal direction of the main groove. Each slant groove is formed by means of two or more curved projections to have at least one narrow bottom surface extending along an inclined direction with respect to the longitudinal direction of the main groove.

Abstract: A plastic sheet has a plurality of creasing lines. Each creasing line includes a main groove having a narrow bottom surface and a pair of opposed side surfaces each slanting at a certain angle; and a plurality of slant grooves disposed at a certain pitch in the longitudinal direction of the main groove. Each slant groove is formed by means of two or more curved projections to have at least one narrow bottom surface extending along an inclined direction with respect to the longitudinal direction of the main groove.

Abstract: A plastic sheet processing apparatus for cutting into a predetermined shape an elongated plastic sheet unwound from a roll includes a heating unit for heating the plastic sheet; an embossing unit for uniformly forming depressions on the heated plastic sheet at predetermined intervals; an antistatic agent application unit for applying an antistatic agent onto the embossed plastic sheet; and a sliding enhancing agent application unit for applying a sliding enhancing agent onto the embossed plastic sheet.

Abstract: In a plastic sheet having a plurality of creasing lines, each creasing line is formed of a groove having a narrow bottom surface and a pair of opposed side surfaces each slanting at a certain angle; and a plurality of transverse grooves are disposed at a certain pitch in the longitudinal direction of the groove. Each transverse groove is formed by two or more curved projections to have at least one narrow bottom surface extending in a direction substantially perpendicular to the longitudinal direction of the groove.

Abstract: A plastic sheet having a plurality of creasing lines. Each creasing line is formed of a groove having a bottom surface and a pair of opposed side surfaces each slanting at a certain angle. A plurality of substantially semi-cylindrical ribs are formed on the bottom surface at substantially equal intervals along the longitudinal direction such that the ribs connect the opposed side surfaces. The area of a portion of the bottom surface not occupied by the ribs accounts for about 90% to about 95% the entire area of the bottom surface as measured when the ribs are not present.