Paper container and paper blank plate

Abstract

The utility model discloses a paper container and a paper blank plate. The paper container comprises a bottom plate, a surrounding plate unit, an extending unit and an adhesive film, each coaming unit comprises two first coamings, two second coamings and four partition plates, wherein each first coaming is provided with two first connecting edges, and each second coaming is provided with two second connecting edges. Each partition plate is provided with a broken line section, and each broken line section divides the corresponding partition plate into a first folded piece area and a second folded piece area. A first included angle is formed between each broken line section and the adjacent first connecting edge, and a second included angle smaller than the first included angle is formed between each broken line section and the adjacent second connecting edge. Due to the fact that the first included angle is larger than the second included angle, when each first folding piece area is overlapped with the adjacent second folding piece area, the first folding piece area can completely wrap the second folding piece area, and the effect of improving the leakage-proof effect is achieved.

Description

[0001] This application claims priority to a Taiwan patent filed on May 3, 2024, with application number 113116578, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This utility model relates to a container for holding food, and more particularly to a paper container and a paperboard. Background Technology

[0003] To facilitate takeout and for hygiene reasons, many restaurants use disposable food containers. One existing food container structure, disclosed in Taiwan Patent No. TWM618144U, is made of a single-piece molded paper container and includes a base plate, four side plates connected to the periphery of the base plate, four triangular connecting plates connecting the side plates in a triangular shape, and four top plates connected to the top edges of the side plates. Each triangular connecting plate has an inward fold line along the edge of an adjacent side plate, and a bifold line is formed at the center of each triangular connecting plate. By folding the triangular connecting plates inward along the inward fold lines and bifold lines, adjacent side plates can be joined together to achieve the function of packaging the food container.

[0004] However, the sealing effect achieved by the triangular connecting plate is limited. When the triangular connecting plate is folded, gaps still exist between the adjacent side plates and the top plate, resulting in a poor seal of the lunchbox. Therefore, if the lunchbox is tilted, food may spill out, which needs to be improved. Utility Model Content

[0005] The purpose of this invention is to provide a paper container that can improve the leak-proof effect.

[0006] The paper container of this utility model includes a base plate, a surrounding plate unit, an extension unit, and an adhesive film.

[0007] The base plate has multiple edges and corners.

[0008] The enclosure unit extends outward from the outer periphery of the base plate and includes two first enclosures spaced apart along a first direction, two second enclosures spaced apart along a second direction perpendicular to the first direction, and four spacers connecting adjacent first and second enclosures. Each first enclosure has two first connecting edges respectively connected to adjacent spacers. Each second enclosure has two second connecting edges respectively connected to adjacent spacers. Each spacer has a mating end and a zigzag segment defined between the mating end and the corresponding corner. Each zigzag segment divides the corresponding spacer into a first folded area and a second folded area. Each zigzag segment forms a first angle with the adjacent first connecting edge and a second angle with the adjacent second connecting edge that is smaller than the first angle.

[0009] The extension unit, the base plate, and the surrounding plate are integrally formed from paper. The extension unit extends around the edge of the surrounding plate and in a direction opposite to that of the base plate.

[0010] The adhesive film is formed on the inner and outer surfaces of the base plate, the enclosure unit, and the extension unit.

[0011] The paperboard of this utility model includes two first extension plates respectively connected to the first surrounding plate, two second extension plates respectively connected to the second surrounding plate, two first reverse folding plates respectively connected to the first extension plates, and two second reverse folding plates respectively connected to the second extension plates. Each first reverse folding plate can be stacked inward along the first direction on its respective first extension plate and defines a tangent edge away from the bottom plate with its respective first extension plate. Each second reverse folding plate can be stacked inward along the second direction on its respective second extension plate and defines another tangent edge away from the bottom plate with its respective second extension plate.

[0012] In the paperboard of this utility model, each of the first extension plates further has two first overlapping portions formed at two opposite ends and protruding from their respective first folded plates, and each of the second folded plates further has two second overlapping portions formed at two opposite ends and protruding from their respective second extension plates. Each of the first overlapping portions can be attached to its respective second overlapping portion in a third direction perpendicular to the first direction and the second direction.

[0013] The paperboard of this utility model has two first overlapping portions formed at two opposite ends in each first extension plate, two first overlapping portions formed at two opposite ends in each first fold plate, and two second overlapping portions formed at two opposite ends and protruding from their respective second extension plates in each second fold plate. Each first overlapping portion can be attached to its respective first overlapping portion and its respective second overlapping portion in a third direction perpendicular to the first direction and the second direction.

[0014] The paperboard of this invention has a flange extending toward the end edge of the adjacent first folded area in each of the first overlapping portions, and the flanges can respectively abut against the bottom side of the second extension plate.

[0015] The paperboard of this utility model has two first overlapping portions formed at two opposite ends in each first extension plate, two second overlapping portions formed at two opposite ends in each second extension plate, two first folded plates with two first overlapping portions formed at two opposite ends in each first folded plate, and two second folded plates with two second overlapping portions formed at two opposite ends in each second folded plate. Each first overlapping portion can be attached to its respective first overlapping portion, its respective second overlapping portion and its respective second overlapping portion in a third direction perpendicular to the first direction and the second direction.

[0016] The paperboard of this utility model has two second reinforcing portions extending from the second overlapping portion toward the adjacent second folded area, and each second reinforcing portion can fit into the inner surface of the corresponding first enclosure.

[0017] The beneficial effects of this utility model are as follows: Since the first included angle is greater than the second included angle, when each of the first folded areas overlaps with the adjacent second folded areas, the first folded area can completely cover the second folded area, so that the gap between the corresponding first enclosure 31 and the adjacent second enclosure 32 is filled and the tightness is high, thereby improving the leak-proof effect. Attached Figure Description

[0018] Other features and effects of this utility model will be clearly presented in the embodiments with reference to the accompanying drawings, wherein:

[0019] Figure 1 This is a top view illustrating the first embodiment of the paperboard board of this utility model;

[0020] Figure 2 This is a perspective view illustrating the paper container formed by the first embodiment;

[0021] Figure 3 yes Figure 2 A bottom view;

[0022] Figure 4 yes Figure 2 Side view;

[0023] Figure 5 It is along Figure 2 A cross-sectional view taken by the central line VV;

[0024] Figure 6 It is along Figure 4 A cross-sectional view taken along line VI-VI;

[0025] Figure 7 This is an incomplete partial cross-sectional view illustrating the extension unit of the first embodiment;

[0026] Figure 8 This is a top view illustrating the second embodiment of the paperboard board of this utility model;

[0027] Figure 9 This is a perspective view illustrating another paper container formed by the second embodiment;

[0028] Figure 10 yes Figure 9 A bottom view;

[0029] Figure 11 This is an incomplete partial sectional view illustrating the extension unit of the second embodiment;

[0030] Figure 12 This is a top view illustrating the third embodiment of the paperboard board of this utility model;

[0031] Figure 13 This is a perspective view illustrating another paper container formed by the third embodiment described above;

[0032] Figure 14 It is similar Figure 11 A cross-sectional view illustrating the extension unit of the third embodiment;

[0033] Figure 15 This is a top view illustrating the fourth embodiment of the paperboard board of this utility model;

[0034] Figure 16 This is a perspective view illustrating another paper container formed by the fourth embodiment described above;

[0035] Figure 17 yes Figure 16 A bottom view. Detailed Implementation

[0036] See Figures 1 to 3A first embodiment of the paperboard blank of this utility model is suitable for forming a paper container. The paperboard blank includes a base plate 2, a surrounding plate unit 3, an extension unit 4, and an adhesive film 5 (see...). Figure 5 ).

[0037] The base plate 2 is generally rectangular in shape and has four corners 21.

[0038] The enclosure unit 3 extends outward from the outer periphery of the base plate 2 and includes two first enclosures 31 that are spaced apart along a first direction L1 and are generally rectangular, two second enclosures 32 that are spaced apart along a second direction L2 that are perpendicular to the first direction L1 and are generally rectangular, and four partition plates 33 connecting adjacent first enclosures 31 and second enclosures 32.

[0039] Each of the first enclosure panels 31 extends along the second direction L2 and has two first connecting edges 311 located on opposite sides and respectively connected to the adjacent partition panels 33. Each of the second enclosure panels 32 extends along the first direction L1 and has two second connecting edges 321 located at opposite ends and respectively connected to the adjacent partition panels 33. Each partition panel 33 has a fitting end 331, a zigzag segment 332 defined between the fitting end 331 and the corresponding corner 21, and a protrusion 333 near the corresponding first connecting edge 311.

[0040] Each of the broken line segments 332 divides the corresponding spacer plate 33 into a first folded area 334 and a second folded area 335. Each broken line segment 332 forms a first angle θ1 with the adjacent first connecting edge 311 and a second angle θ2 with the adjacent second connecting edge 321, which is smaller than the first angle θ1.

[0041] Each of the tabs 333 extends from the edge of the corresponding first folded area 334 toward the extension unit 4. In this first embodiment, each tab 333 is generally triangular.

[0042] The extension unit 4, the base plate 2, and the surrounding plate unit 3 are integrally formed from paper. The extension unit 4 extends around the edge of the surrounding plate unit 3 and in a direction opposite to that of the base plate 2, and includes two first extension plates 41 respectively connected to the first surrounding plate 31, two first reverse folding plates 42 respectively connected to the first extension plates 41, two first reverse folding segments 43 respectively formed between the first extension plates 41 and the first reverse folding plates 42, two second extension plates 44 respectively connected to the second surrounding plate 32, two second reverse folding plates 45 respectively connected to the second extension plates 44, and two second reverse folding segments 46 respectively formed between the second extension plates 44 and the second reverse folding segments 45.

[0043] Each of the first extension plates 41 has a first bottom surface 411, and each of the first folded plates 42 has a first top surface 421 opposite to the first bottom surface 411. Each of the second extension plates 44 has a second bottom surface 441, and each of the second folded plates 45 has a second top surface 451 opposite to the second bottom surface 441. In this first embodiment, the first bottom surface 411, the first top surface 421, the second bottom surface 441, and the second top surface 451 are embossed. The embossing is, for example, a three-dimensional structure made by techniques such as embossing or stamping. Since those skilled in the art can deduce the details of the embossing from the above description, they will not be repeated here.

[0044] See Figure 1 and Figure 4 Each of the first extension plates 41 further has two first overlapping portions 412 formed at two opposite ends and protruding from the respective first folding plates 42, and each of the second folding plates 45 further has two second overlapping portions 452 formed at two opposite ends and protruding from the respective second extension plates 44.

[0045] See Figure 1 , Figure 2 and Figure 5 The adhesive film 5 is formed on the inner and outer surfaces of the base plate 2, the surrounding plate unit 3, and the extension unit 4. In this first embodiment, the adhesive film 5 is, for example, a plastic film made of polyethylene (PE) or polypropylene (PP), which has good high-temperature resistance and grease resistance, and is commonly used in paper lunch boxes or coffee cups for holding hot food.

[0046] In this first embodiment, each of the first folding plates 42 can be stacked inward along the first direction L1 onto its respective first extension plate 41, and defines a tangent edge 40a, which is away from the base plate 2 and formed in the first folding segment 43, with its respective first extension plate 41. Each of the second folding plates 45 can be stacked inward along the second direction L2 onto its respective second extension plate 44, and defines another tangent edge 40b, which is away from the base plate 2 and formed in the second folding segment 46, with its respective second extension plate 44. The tangent edges 40a and 40b divide the adhesive film 5 into an outer adhesive layer 51 and an inner adhesive layer 52.

[0047] Therefore, when the manufacturer applies a sealing film (not shown) to the adhesive film 5, the embossing on the extension unit 4 reduces the contact area between the sealing film and the adhesive film 5. Thus, even if the adhesive film 5 applied to the extension unit 4 tears or breaks during the process of the sealing film being torn off the extension unit 4, these tears or breaks will be blocked at the junction and turning points of the three-dimensional embossing and the extension unit 4, and will be limited to a small area, preventing them from extending to the inner and outer surfaces of the enclosure unit 3.

[0048] Furthermore, by dividing the adhesive film 5 into the outer adhesive layer 51 and the inner adhesive layer 52 through the cut edges 40a and 40b, when the sealing film is torn off from the surface of the extension unit 4, since the outer adhesive layer 51 is not connected to the inner adhesive layer 52, the sealing film attached to the inner adhesive layer 52 can be prevented from tearing off the outer adhesive layer 51 along with it, thereby preventing the outer surface of the enclosure unit 3 from being torn open and cracked.

[0049] See Figure 7 It is worth mentioning that, since each of the first folding plates 42 is inwardly stacked on its respective first extension plate 41, and each of the second folding plates 45 is inwardly stacked on its respective second extension plate 44, when the user tears the sealing film inward, the step difference between the first folding plate 42 and the second folding plate 45 on a third direction L3 perpendicular to the first direction L1 and the second direction L2 can further prevent the inner surface of the enclosure unit 3 from being torn off along with the torn sealing film.

[0050] See Figure 1 , Figure 5 and Figure 6 The first embodiment is formed into a paper container (e.g. Figure 2The process is described as follows: First, the surrounding panel unit 3 is bent upwards along the outer periphery of the base plate 2, so that the surrounding panel unit 3 and the base plate 2 define a chamber 30. Next, the second folded areas 335 are respectively overlapped with the outer surfaces of their respective first folded areas 334 and their respective second surrounding panels 32 in the direction of the second surrounding panel 32. Then, each of the first overlapping portions 412 is attached to its respective second overlapping portion 452 along the third direction L3, and the protrusions 333 are respectively attached to the bottom side of the second extension plate 44 of the extension unit 4 (see...). Figure 3 Finally, the tip of a cutting die (not shown) is heated and comes into contact with the first folded section 43 and the second folded section 46 to form the cut edges 40a and 40b.

[0051] Since the first included angle θ1 is greater than the second included angle θ2, when each of the first folded areas 334 overlaps with the adjacent second folded area 335, the first folded area 334 can completely cover the second folded area 335, thereby improving the leak-proof effect and increasing the structural strength. Furthermore, the structural design of each protrusion 333 being adjacent to the connection point between its respective first enclosure 31 and second enclosure 32 further enhances the overlapping strength at the interface of the panels.

[0052] It should be noted that each of the first overlapping portions 412 protrudes from its respective first folded plate 42, and each of the second overlapping portions 452 protrudes from its respective second extension plate 44. Therefore, when each of the first overlapping portions 412 overlaps with its respective second overlapping portion 452 along the third direction L3, the first top surface 421 of each of the first folded plates 42 and the second top surface 451 of the adjacent second folded plates 45 are flush with each other without any step difference, which is beneficial for the manufacturer to seal the upper surface of the extension unit 4.

[0053] See Figures 8 to 11 This is a second embodiment of the paperboard blank of this utility model, suitable for forming another paper container. This second embodiment is similar to the first embodiment, also including the base plate 2, the surrounding plate unit 3, the extension unit 4, and the adhesive film 5 (see...). Figure 5 The difference is:

[0054] Each of the spacers 33 omits the tab 333. Each of the first overlapping portions 412 has a generally triangular flange 413 extending toward the end edge of the adjacent first folded area 334. Each of the first reverse folding plates 42 also has two first overlapping portions 422 formed at two opposite ends and aligned with the first overlapping portions 412 along the first direction L1. Each of the first overlapping portions 422 has a first inclined edge 423 extending obliquely away from the base plate 2, and each of the second extension plates 44 also has two second inclined edges 442 formed at two opposite ends and tapering toward the base plate 2.

[0055] In the paper container of this second embodiment, each of the first overlapping portions 412 is attached to the respective first overlapping portion 422 and the respective second overlapping portion 452 along the third direction L3, each of the first inclined edges 423 faces the respective second inclined edges 442, and each of the flanges 413 abuts against the second bottom surface 441 of the respective second extension plate 44.

[0056] Therefore, the first overlapping portion 412 of each first extension plate 41, the first overlapping portion 422 of each first folding plate 42, and the second overlapping portion 452 of each second folding plate 45 form a three-layer structure along the third direction L3, thereby improving the structural strength of the extension unit 4 in this second embodiment. Simultaneously, the flanges 413 abut against the bottom side of the second extension plate 44, thus enhancing the leak-proof effect.

[0057] See Figures 12 to 14 This is a third embodiment of the paperboard blank of this utility model, suitable for forming another paper container. This third embodiment is similar to the first embodiment, also including the base plate 2, the surrounding plate unit 3, the extension unit 4, and the adhesive film 5 (see...). Figure 5 The difference is:

[0058] Each of the first folding plates 42 further has two first overlapping portions 424 formed at two opposite ends and aligned with the first overlapping portion 412 along the first direction L1. Each of the second extension plates 44 further has two second overlapping portions 443 formed at two opposite ends and aligned with the second overlapping portion 452 along the second direction L2, respectively.

[0059] In the paper container of this third embodiment, each of the first overlap portions 412 is attached to its respective first overlap portion 424, its respective second overlap portion 443 and its respective second overlap portion 452 along the third direction L3.

[0060] In this way, the first overlapping portion 412 of each first extension plate 41, the first overlapping portion 424 of each first folding plate 42, the second overlapping portion 443 of each second extension plate 44, and the second overlapping portion 452 of each second folding plate 45 form a four-layer structure along the third direction L3, thereby improving the structural strength of the extension unit 4 of this third embodiment.

[0061] See Figures 15 to 17 This is a fourth embodiment of the paperboard blank of this utility model, suitable for forming another paper container. This fourth embodiment is similar to the third embodiment, also including the base plate 2, the surrounding plate unit 3, the extension unit 4, and the adhesive film 5 (see...). Figure 5 The difference is:

[0062] Each of the spacers 33 omits the tab 333. Each of the first flap regions 334 has an edge 336 close to the adjacent first extension plate 41. Each of the second extension plates 44 also has two second reinforcing portions 444 extending from the second overlapping portion 443 toward the adjacent second flap region 335.

[0063] In the paper container of this fourth embodiment, each of the end edges 336 is attached to the second bottom surface 441 of its respective second extension plate 44, and each of the second reinforcing portions 444 is attached to the inner surface of the corresponding first enclosure plate 31. Since each of the second reinforcing portions 444 and each of the end edges 336 is adjacent to the junction of their respective first enclosure plate 31 and second enclosure plate 32, the leak-proof effect can be further improved.

[0064] Based on the above explanation, the advantages of the aforementioned embodiments can be summarized as follows:

[0065] 1. Since the first included angle θ1 is greater than the second included angle θ2, when each of the first folded areas 334 overlaps with the adjacent second folded areas 335, the first folded area 334 can completely cover the second folded area 335, so that the gap between the corresponding first enclosure 31 and the adjacent second enclosure 32 is filled and the tightness is high. Therefore, this utility model can indeed achieve the effect of improving the leak-proof effect and increasing the structural strength.

[0066] 2. The adhesive film 5 is divided into the outer adhesive layer 51 and the inner adhesive layer 52 by the cutting edges 40a and 40b. In this way, when the sealing film is torn off from the surface of the extension unit 4, the sealing film attached to the inner adhesive layer 52 can be prevented from tearing off the outer adhesive layer 51 along with it, and the outer surface of the enclosure unit 3 can be prevented from being torn off and cracked.

[0067] 3. Through the structural design of the first anti-folding plate 42 being stacked inward on its respective first extension plate 41 and the second anti-folding plate 45 being stacked inward on its respective second extension plate 44, when the user tears the sealing film inward, the first anti-folding plate 42 and the second anti-folding plate 45 can provide a step difference on the third direction L3, so as to prevent the inner surface of the enclosure unit 3 from being torn off along with the torn sealing film.

[0068] 4. The embossing formed on the first bottom surface 411, the second bottom surface 441, the first top surface 421, and the second top surface 451 reduces the contact area between the sealing film and the outer adhesive layer 51 and the inner adhesive layer 52, making it easier to remove.

[0069] The above description is merely an embodiment of this utility model and should not be construed as limiting the scope of this utility model. Any simple equivalent changes and modifications made in accordance with the claims and description of this utility model shall still fall within the scope of this utility model.

Claims

1. A paper container comprising: a bottom panel having a plurality of corners; characterized in that the paper container further comprising: a surrounding panel unit extending upwardly from an outer periphery of the bottom panel and surrounding the bottom panel to define a container chamber, the surrounding panel unit including two first surrounding panels spaced apart in a first direction, two second surrounding panels spaced apart in a second direction perpendicular to the first direction, and four spacer panels connected between adjacent ones of the first surrounding panels and the second surrounding panels, each of the first surrounding panels having two first connecting edges connected to adjacent ones of the spacer panels, each of the second surrounding panels having two second connecting edges connected to adjacent ones of the spacer panels, each of the spacer panels having a tacking end and a fold line segment defined between the tacking end and a corresponding one of the corners, each of the fold line segments dividing a corresponding one of the spacer panels into a first flap region and a second flap region, each of the fold line segments making a first included angle with an adjacent one of the first connecting edges and making a second included angle with an adjacent one of the second connecting edges, the second included angle being smaller than the first included angle, each of the second flap regions being superposed on a respective one of the first flap regions and an outer surface of a respective one of the second surrounding panels; an extension unit integrally formed with the bottom panel and the surrounding panel unit from paper, the extension unit extending around edges of the surrounding panel unit and in a direction opposite to the container chamber, the extension unit including two first extension panels connected to the first surrounding panels, two second extension panels connected to the second surrounding panels, two first reverse fold panels connected to the first extension panels, and two second reverse fold panels connected to the second extension panels, each of the first extension panels having a first bottom surface, each of the second extension panels having a second bottom surface, the first bottom surface and the second bottom surface being formed with embossing, each of the first reverse fold panels being superposed inwardly on a respective one of the first extension panels in the first direction and defining a cut edge with the respective one of the first extension panels away from the container chamber, each of the second reverse fold panels being superposed inwardly on a respective one of the second extension panels in the second direction and defining another cut edge with the respective one of the second extension panels away from the container chamber; and a film formed on inner and outer surfaces of the bottom panel, the surrounding panel unit, and the extension unit.

2. The paper container of claim 1, wherein: Each of the spacer panels further has a tab extending from an edge of the corresponding first flap region in a direction of the extension unit, the tab being attached to an underside of the extension unit.

3. The paper container of claim 1, wherein: Each of the first reverse fold panels has a first top surface opposite to the first bottom surface, each of the second reverse fold panels has a second top surface opposite to the second bottom surface, the first top surface and the second top surface being formed with embossing.

4. The paper container of claim 1, wherein: Each of the first extension panels further has two first lap portions formed at two opposite ends and protruding from the respective first reverse fold panel, each of the second reverse fold panels further has two second lap portions formed at two opposite ends and protruding from the respective second extension panel, each of the first lap portions being attached to a respective one of the second lap portions in a third direction perpendicular to the first direction and the second direction.

5. The paper container of claim 1, wherein: Each of the first extension plates further has two first overlapping portions formed at two opposite ends thereof, each of the first reverse folding plates has two first overlapping portions formed at two opposite ends thereof, each of the second reverse folding plates has two second overlapping portions formed at two opposite ends thereof and protruding from the respective second extension plates, and each of the first overlapping portions is fitted to the respective first overlapping portions, the respective second overlapping portions and the respective second overlapping portions along a third direction perpendicular to the first direction and the second direction.

6. The paper container of claim 5, wherein: Each of the first overlapping portions has a flange extending toward an end edge of the adjacent first folding tab area, and the flange is respectively abutted against a bottom side of the second extension plate.

7. The paper container of claim 1, wherein: Each of the first extension plates further has two first overlapping portions formed at two opposite ends thereof, each of the second extension plates further has two second overlapping portions formed at two opposite ends thereof, each of the first reverse folding plates has two first overlapping portions formed at two opposite ends thereof, each of the second reverse folding plates has two second overlapping portions formed at two opposite ends thereof, and each of the first overlapping portions is fitted to the respective first overlapping portions, the respective second overlapping portions and the respective second overlapping portions along a third direction perpendicular to the first direction and the second direction.

8. The paper container of claim 7, wherein: Each of the second extension plates further has two second reinforcing portions respectively extending from the second overlapping portions toward the adjacent second folding tab areas, and each of the second reinforcing portions is fitted to an inner surface of the corresponding first surrounding plate.

9. A blank for forming a paper container, the blank comprising: a bottom panel having a plurality of corners; characterized in that the blank further comprising: a surrounding plate unit extending outwardly from an outer periphery of the bottom panel and including two first surrounding plates spaced apart along a first direction, two second surrounding plates spaced apart along a second direction perpendicular to the first direction, and four spacer plates connected between adjacent ones of the first surrounding plates and the second surrounding plates, each of the first surrounding plates having two first connecting edges respectively connected to adjacent ones of the spacer plates, each of the second surrounding plates having two second connecting edges respectively connected to adjacent ones of the spacer plates, each of the spacer plates having an abutment end and a fold line segment defined between the abutment end and a corresponding one of the corners, each of the fold line segments dividing the corresponding spacer plate into a first folding tab area and a second folding tab area, each of the fold line segments making a first included angle with an adjacent one of the first connecting edges and making a second included angle with an adjacent one of the second connecting edges, the second included angle being smaller than the first included angle. an extension unit integrally formed with the bottom plate and the panel unit from paper, the extension unit extending around edges of the panel unit and in a direction opposite to the bottom plate, the extension unit comprising two first extension panels respectively connected to the first panel, two second extension panels respectively connected to the second panel, two first reverse folding panels respectively connected to the first extension panels, and two second reverse folding panels respectively connected to the second extension panels, each of the first reverse folding panels being foldable inwardly along the first direction to be overlapped with the respective first extension panel and defining a cut edge away from the bottom plate with the respective first extension panel, and each of the second reverse folding panels being foldable inwardly along the second direction to be overlapped with the respective second extension panel and defining another cut edge away from the bottom plate with the respective second extension panel; and a film formed on inner and outer surfaces of the bottom plate, the panel unit and the extension unit.

10. The paper web sheet of claim 9, wherein: Each of the spacer panels further has a tab extending from an edge of the corresponding first flap region in a direction of the extension unit, each of the tabs being proximate to the corresponding first connecting edge.

11. The paperboard of claim 9, wherein: Each of the first extension panels further has two first lapping portions formed at two opposite ends and protruding the respective first reverse folding panel, each of the second reverse folding panels further has two second lapping portions formed at two opposite ends and protruding the respective second extension panel, and each of the first lapping portions is foldable along a third direction perpendicular to the first direction and the second direction to be overlapped with the respective second lapping portion.

12. The paperboard of claim 9, wherein: Each of the first extension panels further has two first lapping portions formed at two opposite ends, each of the first reverse folding panels has two first overlapping portions formed at two opposite ends, each of the second reverse folding panels has two second lapping portions formed at two opposite ends and protruding the respective second extension panel, and each of the first lapping portions is foldable along a third direction perpendicular to the first direction and the second direction to be overlapped with the respective first overlapping portion and the respective second lapping portion.

13. The paperboard of claim 12, wherein: Each of the first lapping portions has a flange extending toward an end edge of the adjacent first flap region, the flange being abutable against a bottom side of the second extension panel, respectively.

14. The paperboard of claim 9, wherein: Each of the first extension panels further has two first lapping portions formed at two opposite ends, each of the second extension panels further has two second overlapping portions formed at two opposite ends, each of the first reverse folding panels has two first overlapping portions formed at two opposite ends, each of the second reverse folding panels has two second lapping portions formed at two opposite ends, and each of the first lapping portions is foldable along a third direction perpendicular to the first direction and the second direction to be overlapped with the respective first overlapping portion, the respective second overlapping portion and the respective second lapping portion.

15. The paperboard of claim 14, wherein: Each of the second extension panels further has two second reinforcing portions respectively extending from the second overlapping portion in a direction of the adjacent second flap region, each of the second reinforcing portions being abutable against an inner surface of the corresponding first panel.

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