Process and equipment for manufacturing a plastic hollow body from two sheets

Equipment for manufacturing a plastic hollow body by molding two sheets of molten plastic, comprising:

• an extrusion die configured to extrude a continuous stream of sheets of molten plastic;
• a mold having two cavities;
• and
• two moveable blades and two cooling bars that are also moveable, the blades being configured to move toward each other, the blades and the bars having a geometry configured, respectively, to transversely cut a stream of the sheets of molten plastic, and to cool the lower portion of the two sheets before, during, or after the transverse cutting operation,
• wherein the two moveable blades have a cutting surface that finishes in a substantially horizontal tip, use being made of two blades per sheet, which have a width substantially equal to that of the sheets and a size, position, and movement such that tips of their cutting surfaces substantially meet at a center of the stream of the sheets of the molten plastic.

A process for manufacturing a plastic hollow body by molding two sheets of molten plastic in a mold including two cavities, the process comprising:

• a) manufacturing two molten plastic sheets by extrusion of at least one stream of molten plastic;
• b) introducing the two sheets between the mold cavities;
• c) closing the mold, transverse cutting the two sheets of molten plastic while the mold is closed and manufacturing the hollow body by conforming the two sheets to the mold cavities;
• d) removing the hollow body thus obtained from the mold;
• and
• e) repeating all of operations a) to d) to manufacture another hollow body from two new sheets,
• wherein before, during, or after the transverse cutting operation, a lower portion of the two new sheets is cooled using a specific cooling device that makes possible a local cooling of the sheets in the lower portion,
• wherein a movement of the cooling device is independent from a movement of the mold, and
• wherein the transverse cutting operation is carried out using blades that have a cutting surface that finishes in a substantially horizontal tip, use being made of two blades per sheet, which have a width substantially equal to that of the sheets and a size, position, and movement such that tips of their cutting surfaces substantially meet at a center of the stream of molten plastic.

Equipment for manufacturing a plastic hollow body by molding two sheets of molten plastic, comprising:

• a mold having two cavities;
• and
• two moveable blades and two cooling bars that are moveable with respect to the mold, the blades and the bars having a geometry configured, respectively, to transversely cut a stream of molten plastic, and to cool the lower portion of the two sheets before, during, or after the transverse cutting operation,
• wherein the two moveable blades have a cutting surface that finishes in a substantially horizontal tip, use being made of two blades per sheet, which have a width substantially equal to that of the sheets and a size, position, and movement such that tips of their cutting surfaces substantially meet at a center of the stream of the sheets of the molten plastic.