A packaging and filling device for forming a paper container, the paper container comprising a cylindrical body having a substantially square cross section, four sidewalls, a top, and a bottom,
- wherein the paper container is formed of a blank prepared by cutting a band-shaped packaging material including an outermost thermoplastic layer, a paper layer, and an innermost thermoplastic layer, the blank further comprising:
- a first panel and a third panel, the first and third panels being configured to form a first pair of opposing sidewalls of the container;
- a second panel and a fourth panel, the second panel and fourth panels being configured to form a second pair of opposing sidewalls of the container;
- a first bottom panel and a third bottom panel, the first and third bottom panels extending from the respective lower sides of the first panel and the third panel;
- a second bottom panel and a fourth bottom panel, the second and fourth bottom panels extending from the respective lower sides of the second panel and the fourth panel;
- and
- a plurality of top panels corresponding to the top of the paper container;
- wherein:
- the third bottom panel comprises a sixth panel partially extended from a center of the lower side of the third bottom panel;
- and
- a width of the sixth panel is 15-65% of a total length of the lower side of the third bottom panel;
- wherein the bottom of the paper container is formed by:
- bending the sixth panel outward;
- bending the second bottom panel and the fourth panel into triangular flaps with the lower side surfaces of the second and the fourth bottom panels facing outward, and bending the second and the fourth bottom panels inward;
- stacking the first bottom panel and the third bottom panel on the outsides of the second bottom panel and the fourth bottom panel with the first bottom panel positioned outside of the third bottom panel;
- and
- pressing from the inside and the outside of the paper container;
- and
- heat-sealing to form a seal;
- the packaging and filling device further comprising:
- a loading unit configured to extract a selected blank from a bundle of a plurality of vertically sealed and flattened blanks;
- a bottom forming unit configured to form the bottom of a cylindrical blank to form the container having a top opening and the bottom;
- a filling unit configured to fill liquid food through the top opening;
- and
- a top sealing unit configured to heat-seal the top opening;
- wherein the loading unit further comprises:
- an extracting unit configured to extract the blank, the extracting unit including a bendable unit which bends the sixth panel outward to make the sixth panel bendable;
- an erecting unit configured to erect the flattened blank into the cylindrical blank;
- and
- an infeeder which inserts a mandrel of the bottom forming unit into the cylindrical blank with the sixth panel made bendable,
- wherein:
- the bendable unit is a sector piece provided on a shaft of a rotary roller which receives and transfers the extracted blank, the sector piece being provided at a position corresponding to the sixth panel;
- and
- the infeeder comprises:
- a carrier which moves together with the sixth panel of the cylindrical blank;
- and
- a prior bending block fixed to a position immediately before the mandrel;
- wherein as the carrier is moved downward, the sixth panel follows the carrier to be bent with the corners of the forward end of the prior bending block;
- wherein the bottom forming unit comprises:
- a heating station configured to heat the container bottom, the heating station comprising:
- a nozzle surface for heating the container bottom;
- and
- bending claws provided on the nozzle surface for heating an inside surface of the third bottom panel, the bending claws including two pointed claws erected toward the third bottom panel;
- and
- a press station configured to press the container bottom from the outside and the inside of the container by a forward side surface of the mandrel and a press surface, the press station comprising a triangular emboss provided on the forward side surface of the mandrel at a position corresponding to the sixth panel and abutting a position where the third bottom panel is exposed on the inside surface of the container, whereby the sixth panel is bent, and the container bottom is formed.