Title:
PAPER BAG OF SIMPLIFIED STRUCTURE ADAPTED TO BE RETAINED IN EACH OF THE OPENED AND THE FOLDED CONFIGURATIONS
United States Patent 3578236
Abstract:
A paper bag having a substantially rectangular cross section and made of a single tough but cheap paper material and provided with a flexible and tough reinforcement wire or band lined along the entire open top edges and also with intermediate vertical folding lines in the side panels, at least one horizontal folding line extending around the vertical panels in the lower portions of these panels, inclined folding lines extending inwardly from the corners of the bottom side edges to join the point of intersection of said intermediate vertical folding line and said horizontal folding line, and at least one longitudinal central folding line in the bottom panel, whereby said paper bag may be retained in each of the opened and the closed configurations by virtue of said reinforcement means.
US Patent References:
Bag with closing strip, a blank of paper, cardboard, or other sheet material for such bags, and a method of manufacturing bags from such blanks
Simonsen - October 1958 - 2855137
Bag closure
Wellman - September 1964 - 3150813
Carrying bag
Budd - February 1932 - 1846542
Closing and clamping device
Gerendas - January 1944 - 2338927
Foldable receptacle
Frazier - May 1964 - 3132794
Bag with closing strip, a blank of paper, cardboard, or other sheet material for such bags, and a method of manufacturing bags from such blanks
Simonsen - October 1958 - 2855137
Bag closure
Wellman - September 1964 - 3150813
Carrying bag
Budd - February 1932 - 1846542
Closing and clamping device
Gerendas - January 1944 - 2338927
Foldable receptacle
Frazier - May 1964 - 3132794
Application Number:
04/809291
Publication Date:
05/11/1971
Filing Date:
03/21/1969
View Patent Images:
Export Citation:
Assignee:
Lyric Kabushiki Kaisha (Tokyo, JA)
Primary Class:
Other Classes:
383/98, 383/905
International Classes:
B65D33/00; B65D33/02; B65D33/30; B65D33/16; B65D33/02
Field of Search:
229/55,57,60,54,65
Primary Examiner:
Bockenek, David M.
Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention 2,
The present invention is concerned with paper bags, and more particularly, it relates to a paper bag having a substantially rectangular cross section and made of a single tough but cheap paper material and provided with a flexible and tough reinforcement wire or band lined along the entire open top edges and also with folding lines formed in all of the panels, whereby said bag may be retained in each of its opened configuration for putting things therein and its folded or closed configuration after things have been placed therein for the convenience of being carried along.
2. Description of the Prior Art
A conventional paper bag was made with a single sheet of paper and it was provided with folding lines in the panels of said bag so that this paper bag was folded or bent along said folding lines into a mere hollow bag shape having either a rectangular cross section or a square cross section, and the bottom panel had folded flaps which were adhered to the bottom panel to form a closed bottom. A paper bag of the prior art thus formed was used in putting things in it. However, when it was intended to be used this paper bag of the prior art as a waste bag in place of a waste box, there was encountered an inconvenience such that the open top edges of the paper bag easily yielded because these edges were not of sufficient strength due to lack of a reinforcement means whenever a slight amount of external force was applied to the edge portions, or that the bag as a whole tended to collapse easily from its opened configuration. For this reason, the paper bag of the prior art presented a great deal of inconvenience and difficulty in keeping it in its opened state when it was intended to put things therein or in closing the open top edges when it was intended to carry the bag filled with things from one place to the destination.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to eliminate the foregoing inconvenience and difficulty of the paper bags of the prior art and to provide a paper bag which is simple in structure and is of a markedly increased strength along the open top edge portions.
Another object of the present invention is to provide a paper bag which is capable of retaining its folded configuration and its opened configuration without causing spontaneous deformation or collapsing.
Still another object of the present invention is to provide a paper bag which is capable of retaining its configuration as a bag and which provides a great deal of convenience in the transportation, storing and carrying along of the bag.
Yet another object of the present invention is to provide a paper bag which is made of a cheap but tough paper material and which is simple in structure and which, accordingly, will not give any mentionable burden from economical aspect when the paper bags are used as consumer goods which are destined to be discarded after use.
The paper bag of the present invention will hereunder be described in connection with one which is to be used as a trash bag for containing trash. It should be understood, however, that the use of the paper bag of the present invention is not limited only thereto and that it can be utilized for many other purposes as a matter of course.
The foregoing as well as the other objects and the attendant advantages of the present invention will become apparent by reading the following detailed description in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view, showing the paper bag representing a preferred embodiment while in the state of being used;
FIG. 2 is a vertical cross-sectional view, in an enlarged scale, taken along the line A-A in FIG. 1;
FIG. 3 is a bottom view of the paper bag shown in FIG. 1;
FIG. 4 is a perspective view, showing one example of the manner in which the paper bag of FIG. 1 is folded;
FIG. 5 is a perspective representation as viewed from the bottom side of the paper bag in the state shown in FIG. 4;
FIG. 6 is a perspective representation similar to FIG. 5 but showing the state of the paper bag in its final closed state;
FIG. 7 is a perspective view, showing another example of the manner in which the paper bag is finally folded;
FIG. 8 is a perspective view of the paper bag, representing another embodiment while in the state of being used;
FIG. 9 is a perspective view showing the state in which the folded paper bag of said another embodiment is about to be opened from its closed state; and
FIG. 10 is a plan view of the same.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the present invention will hereunder be described by referring to FIGS. 1 through 7 of the drawing.
In the drawing, reference numeral 1 represents a paper bag intended for being used as trash bag for containing trash. This paper bag is made of a relatively thick but cheap and tough paper material and is formed in a generally rectangular hollow boxlike configuration having peripheral panels 1a, 1b, 1c and 1d and a bottom panel 1e which is formed by folding the flaps at said bottom side and bending the open top edges along the four vertical side corners. The marginal edge portions adjacent the open top edges of the paper bag 1 are folded inwardly and the free end edges of the folded marginal edge portions are made to adhere to the inner sides of the side, front and rear panels by the use of a known adhesive or starch. In the spaces formed between said inwardly folded four marginal edge portions and said four peripheral panels 2a,1b, 1c and 1d along the resulting folded upper edges of the paper bag 1 is inserted a piece of flexible but tough reinforcement member 6 which may be made of a wire or a band of either a metal or an appropriate plastic or like material which can be bent or straightened manually into a shape corresponding to the substantially rectangular open top configuration of the paper bag. When it is intended to fold or collapse the paper bag 1 in its open state to form a collapsed rectangular paper bag, it is only necessary to fold the paper bag 1 along the vertical folding lines 2, 3, 4 and 5 which represent the four corners of the paper bag 1 where the side, front and rear panels join each other. Intermediate vertical folding lines 7 and 8 are provided along the vertical center lines of the side panels 1c and 1d, respectively, so as to extend from the open top edge to the bottom edges of these side panels at which the latter panels join the bottom panel of the paper bag 1. Horizontal folding lines 8a, 9a, 8b and 9b are provided in the vertical panels 1a, 1b, 1c and 1d. These horizontal folding lines are formed in these four vertical panels in a relatively lower portion thereof so as to be aligned to each other and spaced from the bottom edges thereof and in parallel with the bottom edges as best seen in FIGS. 1 and 5. In the side panels 1c and 1d, inclined folding lines 10a, 10b and 10c, 10d extend inwardly from the bottom corners of these two side panels, respectively, in such a way that those extending from the corners of the same side edge join each other at a point located on the horizontal folding line 8a or 8b at which said horizontal folding line intercepted by the aforesaid intermediate vertical folding line 7 or 8. In the bottom panel 1e, a longitudinal folding line 11 is formed to run in the center of the panel 1e and it extends in opposite directions up to the side edges on the opposite sides of this panel to form two extension folding lines 11a and 11b which are equal in length. From the four corners of this panel 1e, extend inwardly inclined folding lines 12, 13 and 14, 15 of an equal length in such a way that the inclined folding lines 12 and 13 join each other at a point of juncture of the longitudinal folding line 11 and its extension folding line 11a, and that the inclined folding lines 14 and 15 join each other at a point of juncture of the longitudinal folding line 11 and its extension folding line 11b and also that these four inclined folding lines from symmetrically disposed two triangles extending inwardly from the opposite side edges as best seen in FIGS. 3 and 5. Although not illustrated in the drawing of the paper bag, the external surfaces of the bag are provided with decorative patterns, such as colorful flower patterns or like designs as desired, which are printed on said surfaces to impart a decorative effect to the paper bag as a shole.
In case it is intended to use the paper bag described above from its closed state, it is only necessary to expand this paper bag 1 along the respective vertical as well as the horizontal and inclined folding lines formed in the panels of this bag, and this operation may be effected by simply expanding or opening the open top edges lined with the reinforcement wire or band 6. Thereafter, these open top edges are bent at four corners of the edges which are determined by the points at which the four vertical folding lines 2, 3, 4 and 5 join the open top edges of the paper bags 1. As a result, there is obtained a paper bag 1 as a whole in a substantially rectangular hollow configuration, and the resulting paper bag 1 is retained in its open state as will be seen in FIG. 1. When it is intended to fold or collapse this paper bag 1 starting at the opened configuration, this can be effected in either of the following two kinds of procedures. One such example is represented by the procedure which consists of pressing inwardly the side panels 1c and 1d along the intermediate vertical folding lines 7 and 8 formed in the opposite side panels 1c and 1d to inwardly fold these two side panels. It should be understood that the open top edges lined with the reinforcement wire or band 6 are also folded inwardly at the points at which these intermediate vertical folding lines 7 and 8 terminate as is best viewed in FIG. 4. The aforesaid folding operation of these side panels 1c and 1d is continued till the inner surfaces of the folded side panels 1c and 1d are brought into contact with the inner surfaces of the front and the rear panels 1a and 1b of the paper bag 1, with the result that the portions of the bottom panel are folded along the folding lines 11, 11a, 11b and 12, 13, 14, 15 accordingly spontaneously in inward directions as is seen in FIG. 5 to produce a completely collapsed flat state of the paper bag 1 as seen in FIG. 6. By folding the paper bag 1 in this way which is quite simple in procedure, there is obtained a folded compact paper bag 1 which retains its folded shape by virtue of the folded reinforcement wire or band 6.
Another example of folding the opened paper bag 1 is in the procedure which consists of inwardly folding the bottom panel 1e along the folding lines 11, 11a and 11b which are formed therein till the outer surfaces of the bottom panel thus folded along the aforesaid folding lines are brought into contact with each other, followed by folding the paper bag 1 along the vertical folding lines 2, 3, 4 and 5 which are formed at the four vertical corners of the paper bag 1, while continuing this folding till the inner surfaces of the folded side panels 1c and 1d are brought into contact with the inner surfaces of the front and the rear panels of the paper bag 1. As a result, there is obtained a folded flat paper bag 1 as shown in FIG. 7.
Description will hereunder be directed to another embodiment of the paper bag of the present invention by referring to FIGS. 8 and 9. The paper bag of this second embodiment is identical with the paper bag of the preceding embodiment with the exception of the additional folding lines provided in some of the panels. Therefore, like parts and like folding lines as are contained in the preceding embodiment are indicated by like reference numerals and their explanation is omitted since they have been already described in connection with the preceding embodiment. The paper bag 1 of this second embodiment is provided, in addition to the respective folding lines which are formed on the paper bag of the preceding embodiment, with additional folding lines which consist of aligned horizontal folding lines 16a, 17a and 16b, 17b which are formed in the four side, front and rear panels 1c, 1a, 1b and 1d at an appropriate distance above the horizontal folding lines 8a, 9a, 8b and 9b and at an appropriate distance from the open top edges of the paper bag 1 and in parallel relationship with the horizontal lines 8a, 9a, 8b and 9b, and also consist of inclined folding lines 18a, 18b which extend inwardly from the corners of the open top edge of the side panel 1c to join the point of intersection of the horizontal folding line 16a and the intermediate vertical folding line 7 both of which are formed in said side panel 1c, and further consist of inclined folding lines 18c and 18d which extend inwardly from the corners of the open top edge of the side panel 1d to join the point of intersection of the horizontal folding line 16b and the intermediate vertical folding line 8 which are both formed in said side panel 1d.
Description will hereunder be made on the manner in which the open paper bag 1 of this second embodiment is folded and collapsed. To this end, the side panels 1c and 1d are pressed inwardly along the intermediate vertical folding lines 7 and 8, respectively, with the result that the side panels 1c and 1d will be folded inwardly in two, while being folded also spontaneously along the inclined folding lines 18a, 18d and 10a, 10d in such a way that these inclined folding lines in each pair will be brought closer to each other, respectively. It is needless to say that the open top edges lined with the reinforcement wire or band 6 are also folded inwardly, along with the folding operation of the side panels 1c and 1d. The folding operation of these side panels is continued until the inner surfaces of the folded side panels 1c and 1d are brought into contact with the inner surfaces of the front panel 1a and the rear panel 1b of the paper bag 1. Then the paper bag 1 is folded in opposite directions along the horizontal folding lines 17a, 17b and 9a, 9b in the manner as shown in FIG. 9. By folding the paper bag 1 in this way, the open top of the paper bag 1 is completely closed as will be noted from FIG. 10. When it is intended to open the paper bag in its state of being closed in the aforesaid manner, it is only necessary to apply slight external opening forces in opposite directions, as shown by the solid arrows in FIG. 9, to the folded portions which are located at opposite ends adjacent to the intermediate portion of the paper bag 1. Whereupon, the respective portions of the paper bag 1 which are folded along the aforesaid respective folding lines will be spontaneously caused to be displaced toward the unfolding directions which are opposite to the directions in which these portions were folded, to expand and open the folded paper bag 1, and thus, a waste paper bag 1 is formed as seen in FIG. 8.
The paper bags which are provided by incorporating the present invention are suitable for use in places such as bedroom where decorative element is required in all things installed therein.
1. Field of the Invention 2,
The present invention is concerned with paper bags, and more particularly, it relates to a paper bag having a substantially rectangular cross section and made of a single tough but cheap paper material and provided with a flexible and tough reinforcement wire or band lined along the entire open top edges and also with folding lines formed in all of the panels, whereby said bag may be retained in each of its opened configuration for putting things therein and its folded or closed configuration after things have been placed therein for the convenience of being carried along.
2. Description of the Prior Art
A conventional paper bag was made with a single sheet of paper and it was provided with folding lines in the panels of said bag so that this paper bag was folded or bent along said folding lines into a mere hollow bag shape having either a rectangular cross section or a square cross section, and the bottom panel had folded flaps which were adhered to the bottom panel to form a closed bottom. A paper bag of the prior art thus formed was used in putting things in it. However, when it was intended to be used this paper bag of the prior art as a waste bag in place of a waste box, there was encountered an inconvenience such that the open top edges of the paper bag easily yielded because these edges were not of sufficient strength due to lack of a reinforcement means whenever a slight amount of external force was applied to the edge portions, or that the bag as a whole tended to collapse easily from its opened configuration. For this reason, the paper bag of the prior art presented a great deal of inconvenience and difficulty in keeping it in its opened state when it was intended to put things therein or in closing the open top edges when it was intended to carry the bag filled with things from one place to the destination.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to eliminate the foregoing inconvenience and difficulty of the paper bags of the prior art and to provide a paper bag which is simple in structure and is of a markedly increased strength along the open top edge portions.
Another object of the present invention is to provide a paper bag which is capable of retaining its folded configuration and its opened configuration without causing spontaneous deformation or collapsing.
Still another object of the present invention is to provide a paper bag which is capable of retaining its configuration as a bag and which provides a great deal of convenience in the transportation, storing and carrying along of the bag.
Yet another object of the present invention is to provide a paper bag which is made of a cheap but tough paper material and which is simple in structure and which, accordingly, will not give any mentionable burden from economical aspect when the paper bags are used as consumer goods which are destined to be discarded after use.
The paper bag of the present invention will hereunder be described in connection with one which is to be used as a trash bag for containing trash. It should be understood, however, that the use of the paper bag of the present invention is not limited only thereto and that it can be utilized for many other purposes as a matter of course.
The foregoing as well as the other objects and the attendant advantages of the present invention will become apparent by reading the following detailed description in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view, showing the paper bag representing a preferred embodiment while in the state of being used;
FIG. 2 is a vertical cross-sectional view, in an enlarged scale, taken along the line A-A in FIG. 1;
FIG. 3 is a bottom view of the paper bag shown in FIG. 1;
FIG. 4 is a perspective view, showing one example of the manner in which the paper bag of FIG. 1 is folded;
FIG. 5 is a perspective representation as viewed from the bottom side of the paper bag in the state shown in FIG. 4;
FIG. 6 is a perspective representation similar to FIG. 5 but showing the state of the paper bag in its final closed state;
FIG. 7 is a perspective view, showing another example of the manner in which the paper bag is finally folded;
FIG. 8 is a perspective view of the paper bag, representing another embodiment while in the state of being used;
FIG. 9 is a perspective view showing the state in which the folded paper bag of said another embodiment is about to be opened from its closed state; and
FIG. 10 is a plan view of the same.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the present invention will hereunder be described by referring to FIGS. 1 through 7 of the drawing.
In the drawing, reference numeral 1 represents a paper bag intended for being used as trash bag for containing trash. This paper bag is made of a relatively thick but cheap and tough paper material and is formed in a generally rectangular hollow boxlike configuration having peripheral panels 1a, 1b, 1c and 1d and a bottom panel 1e which is formed by folding the flaps at said bottom side and bending the open top edges along the four vertical side corners. The marginal edge portions adjacent the open top edges of the paper bag 1 are folded inwardly and the free end edges of the folded marginal edge portions are made to adhere to the inner sides of the side, front and rear panels by the use of a known adhesive or starch. In the spaces formed between said inwardly folded four marginal edge portions and said four peripheral panels 2a,1b, 1c and 1d along the resulting folded upper edges of the paper bag 1 is inserted a piece of flexible but tough reinforcement member 6 which may be made of a wire or a band of either a metal or an appropriate plastic or like material which can be bent or straightened manually into a shape corresponding to the substantially rectangular open top configuration of the paper bag. When it is intended to fold or collapse the paper bag 1 in its open state to form a collapsed rectangular paper bag, it is only necessary to fold the paper bag 1 along the vertical folding lines 2, 3, 4 and 5 which represent the four corners of the paper bag 1 where the side, front and rear panels join each other. Intermediate vertical folding lines 7 and 8 are provided along the vertical center lines of the side panels 1c and 1d, respectively, so as to extend from the open top edge to the bottom edges of these side panels at which the latter panels join the bottom panel of the paper bag 1. Horizontal folding lines 8a, 9a, 8b and 9b are provided in the vertical panels 1a, 1b, 1c and 1d. These horizontal folding lines are formed in these four vertical panels in a relatively lower portion thereof so as to be aligned to each other and spaced from the bottom edges thereof and in parallel with the bottom edges as best seen in FIGS. 1 and 5. In the side panels 1c and 1d, inclined folding lines 10a, 10b and 10c, 10d extend inwardly from the bottom corners of these two side panels, respectively, in such a way that those extending from the corners of the same side edge join each other at a point located on the horizontal folding line 8a or 8b at which said horizontal folding line intercepted by the aforesaid intermediate vertical folding line 7 or 8. In the bottom panel 1e, a longitudinal folding line 11 is formed to run in the center of the panel 1e and it extends in opposite directions up to the side edges on the opposite sides of this panel to form two extension folding lines 11a and 11b which are equal in length. From the four corners of this panel 1e, extend inwardly inclined folding lines 12, 13 and 14, 15 of an equal length in such a way that the inclined folding lines 12 and 13 join each other at a point of juncture of the longitudinal folding line 11 and its extension folding line 11a, and that the inclined folding lines 14 and 15 join each other at a point of juncture of the longitudinal folding line 11 and its extension folding line 11b and also that these four inclined folding lines from symmetrically disposed two triangles extending inwardly from the opposite side edges as best seen in FIGS. 3 and 5. Although not illustrated in the drawing of the paper bag, the external surfaces of the bag are provided with decorative patterns, such as colorful flower patterns or like designs as desired, which are printed on said surfaces to impart a decorative effect to the paper bag as a shole.
In case it is intended to use the paper bag described above from its closed state, it is only necessary to expand this paper bag 1 along the respective vertical as well as the horizontal and inclined folding lines formed in the panels of this bag, and this operation may be effected by simply expanding or opening the open top edges lined with the reinforcement wire or band 6. Thereafter, these open top edges are bent at four corners of the edges which are determined by the points at which the four vertical folding lines 2, 3, 4 and 5 join the open top edges of the paper bags 1. As a result, there is obtained a paper bag 1 as a whole in a substantially rectangular hollow configuration, and the resulting paper bag 1 is retained in its open state as will be seen in FIG. 1. When it is intended to fold or collapse this paper bag 1 starting at the opened configuration, this can be effected in either of the following two kinds of procedures. One such example is represented by the procedure which consists of pressing inwardly the side panels 1c and 1d along the intermediate vertical folding lines 7 and 8 formed in the opposite side panels 1c and 1d to inwardly fold these two side panels. It should be understood that the open top edges lined with the reinforcement wire or band 6 are also folded inwardly at the points at which these intermediate vertical folding lines 7 and 8 terminate as is best viewed in FIG. 4. The aforesaid folding operation of these side panels 1c and 1d is continued till the inner surfaces of the folded side panels 1c and 1d are brought into contact with the inner surfaces of the front and the rear panels 1a and 1b of the paper bag 1, with the result that the portions of the bottom panel are folded along the folding lines 11, 11a, 11b and 12, 13, 14, 15 accordingly spontaneously in inward directions as is seen in FIG. 5 to produce a completely collapsed flat state of the paper bag 1 as seen in FIG. 6. By folding the paper bag 1 in this way which is quite simple in procedure, there is obtained a folded compact paper bag 1 which retains its folded shape by virtue of the folded reinforcement wire or band 6.
Another example of folding the opened paper bag 1 is in the procedure which consists of inwardly folding the bottom panel 1e along the folding lines 11, 11a and 11b which are formed therein till the outer surfaces of the bottom panel thus folded along the aforesaid folding lines are brought into contact with each other, followed by folding the paper bag 1 along the vertical folding lines 2, 3, 4 and 5 which are formed at the four vertical corners of the paper bag 1, while continuing this folding till the inner surfaces of the folded side panels 1c and 1d are brought into contact with the inner surfaces of the front and the rear panels of the paper bag 1. As a result, there is obtained a folded flat paper bag 1 as shown in FIG. 7.
Description will hereunder be directed to another embodiment of the paper bag of the present invention by referring to FIGS. 8 and 9. The paper bag of this second embodiment is identical with the paper bag of the preceding embodiment with the exception of the additional folding lines provided in some of the panels. Therefore, like parts and like folding lines as are contained in the preceding embodiment are indicated by like reference numerals and their explanation is omitted since they have been already described in connection with the preceding embodiment. The paper bag 1 of this second embodiment is provided, in addition to the respective folding lines which are formed on the paper bag of the preceding embodiment, with additional folding lines which consist of aligned horizontal folding lines 16a, 17a and 16b, 17b which are formed in the four side, front and rear panels 1c, 1a, 1b and 1d at an appropriate distance above the horizontal folding lines 8a, 9a, 8b and 9b and at an appropriate distance from the open top edges of the paper bag 1 and in parallel relationship with the horizontal lines 8a, 9a, 8b and 9b, and also consist of inclined folding lines 18a, 18b which extend inwardly from the corners of the open top edge of the side panel 1c to join the point of intersection of the horizontal folding line 16a and the intermediate vertical folding line 7 both of which are formed in said side panel 1c, and further consist of inclined folding lines 18c and 18d which extend inwardly from the corners of the open top edge of the side panel 1d to join the point of intersection of the horizontal folding line 16b and the intermediate vertical folding line 8 which are both formed in said side panel 1d.
Description will hereunder be made on the manner in which the open paper bag 1 of this second embodiment is folded and collapsed. To this end, the side panels 1c and 1d are pressed inwardly along the intermediate vertical folding lines 7 and 8, respectively, with the result that the side panels 1c and 1d will be folded inwardly in two, while being folded also spontaneously along the inclined folding lines 18a, 18d and 10a, 10d in such a way that these inclined folding lines in each pair will be brought closer to each other, respectively. It is needless to say that the open top edges lined with the reinforcement wire or band 6 are also folded inwardly, along with the folding operation of the side panels 1c and 1d. The folding operation of these side panels is continued until the inner surfaces of the folded side panels 1c and 1d are brought into contact with the inner surfaces of the front panel 1a and the rear panel 1b of the paper bag 1. Then the paper bag 1 is folded in opposite directions along the horizontal folding lines 17a, 17b and 9a, 9b in the manner as shown in FIG. 9. By folding the paper bag 1 in this way, the open top of the paper bag 1 is completely closed as will be noted from FIG. 10. When it is intended to open the paper bag in its state of being closed in the aforesaid manner, it is only necessary to apply slight external opening forces in opposite directions, as shown by the solid arrows in FIG. 9, to the folded portions which are located at opposite ends adjacent to the intermediate portion of the paper bag 1. Whereupon, the respective portions of the paper bag 1 which are folded along the aforesaid respective folding lines will be spontaneously caused to be displaced toward the unfolding directions which are opposite to the directions in which these portions were folded, to expand and open the folded paper bag 1, and thus, a waste paper bag 1 is formed as seen in FIG. 8.
The paper bags which are provided by incorporating the present invention are suitable for use in places such as bedroom where decorative element is required in all things installed therein.