CN113581646A

CN113581646A - Packaging container and using method thereof

Info

Publication number: CN113581646A
Application number: CN202110939254.XA
Authority: CN
Inventors: 蔡沧洋
Original assignee: Meiyang Plastic Metals Products Co ltd Quanzhou
Current assignee: Meiyang Plastic Metals Products Co ltd Quanzhou
Priority date: 2021-08-16
Filing date: 2021-08-16
Publication date: 2021-11-02

Abstract

The invention provides a packaging container and a using method thereof. The case body has an accommodation chamber opened upward, and an upwardly projecting boss portion and a seal groove provided on an outer peripheral side of the boss portion are provided on an outer peripheral side of the opening. The middle part of lid is provided with first bulge, and first bulge is upwards protruding and forms accommodation space in the inboard, and a plane is injectd on its top, and the periphery side of lid is provided with the second bulge that upwards is protruding and be less than first bulge, forms the backcut, forms the recess between second bulge and the first bulge, and the lateral wall downwardly extending of second bulge surpasss the inside wall, and the bottom of lateral wall is formed with the turn-ups. According to the invention, the first bulge of the cover body has a certain volume and can be used as a dinner plate. The grooves can accommodate fingers when used as dinner plates, and the end-taking stability is improved. The defect that an ultrathin material forming flat product is easy to deform can be overcome by the common action of the flanging and the reverse groove, a thumb can be conveniently placed, and the phenomenon that the edge is too sharp to cause injury is avoided.

Description

Packaging container and using method thereof

Technical Field

The invention relates to a packaging container and a using method thereof.

Background

With the rise of modern logistics, the distribution demand of food, fresh food, take-away fast food and the like is more and more. Taking a takeaway snack as an example, most people are used to get a plurality of meals to be enjoyed at the same time. In order to avoid mixing different meal products, the number of the packaging boxes corresponding to the number of the meal products is often required to respectively contain different meal products when the meal products are eaten. Moreover, most packages are disposable. Such a use causes a great deal of waste of the packing box.

In addition, higher and higher requirements are being made on the packaging box in terms of deformation resistance, damage resistance, food sanitation safety and the like. Most thin-wall snack boxes on the market have poor sealing performance. The risk of food spilling and breakage of the meal box can occur when squeezed or otherwise transported carelessly.

Accordingly, there is a need to provide a packaging container and method of use thereof that at least partially address the above-mentioned problems.

Disclosure of Invention

The invention aims to provide a packaging container comprising a box body and a cover body and a using method thereof. The cover body of the packaging container can be used as a dinner plate while providing a covering function, has good deformation resistance, can provide a good sealing function, can ensure the safety and the sanitation of dining, and can greatly reduce the cost.

According to one aspect of the invention, the packaging container comprises:

a box body having an accommodation chamber opened upward, a boss portion projected upward being provided on an outer peripheral side of the opening, and a seal groove being provided on an outer peripheral side of the boss portion, a top of the seal groove being lower than a top wall of the boss portion; and

at least one cover body, wherein the middle part of the cover body is provided with a first bulge part which is upwards bulged and forms an accommodating space at the inner side of the cover body, the top end of the first bulge part limits a plane, and the middle of the top wall of the first projecting portion has a first recessed portion recessed toward the inner side of the lid body, the outer peripheral side of the cover body is provided with a second bulge part which is opened downwards and is in an inverted U shape, the second bulge part is bulged upwards and is lower than the first bulge part in height to form a reverse groove, the second convex part is provided with an inner side wall extending vertically, the tail end of the inner side wall is connected with the top wall of the first convex part through an arc-shaped wall recessed towards the inner side of the cover body to form a groove, the outer side wall of the second protruding part extends downwards to exceed the inner side wall of the second protruding part, and a flange is formed at the edge of the outer side wall;

wherein, under the state that the box body is closed to the lid, the boss portion imbeds in the second bulge, and the turn-ups imbeds in the sealed recess.

According to the scheme, the first bulge of the cover body of the packaging container protrudes upwards to form the accommodating space on the inner side of the cover body, so that the cover body has a certain volume, and the cover body can be used as a dinner plate for accommodating food. The groove is formed between the first protruding portion and the second protruding portion, so that the first protruding portion and the second protruding portion can be conveniently gripped when being used as a cover, fingers can be accommodated when being used as a dinner plate, and the holding stability is improved. The easy deformable defect of fashioned platykurtic goods of ultra-thin material can be overcome to the turn-ups of lid periphery side and reverse recess combined action, avoids producing sharp edge simultaneously, and the thumb is placed in the convenience when holding and getting, avoids being injured. In addition, when the cover body covers the box body, the flanging can also play a role in sealing.

In one embodiment, the ratio of the width of the groove to the maximum peripheral dimension of the cover is 3 to 25, preferably 5 to 20.

According to the scheme, the ratio range can avoid the phenomenon that the width of the groove is too large and occupies more transverse size, so that the volume of the cover body when the cover body is used as a dinner plate is reduced, and the structural strength of the cover body is enhanced.

In one embodiment, the ratio of the height difference between the top wall of the first projection and the bottom end of the inner side wall of the second projection to the maximum peripheral dimension of the cover body is 5 to 20.

According to the scheme, the cover body manufactured according to the proportion not only can keep a relatively flat shape and play a role of covering the box body without wasting materials, but also can have enough depth and deformation resistance so as to be conveniently used as a dinner plate. Tests prove that the proportion is the optimal proportion, so that the shape of the cover body can be balanced between two purposes, and the influence of over inclination of one purpose on the use of the other purpose is avoided.

In one embodiment, the radial dimension of the cap is 10-40 cm. According to this scheme, the lid size can satisfy and use the size demand as the dinner plate and as the lid.

In one embodiment, the cuff extends outwardly from a bottom end of the outer side wall of the second projection and then bends upwardly.

According to this scheme, the turn-ups that so sets up can further strengthen the structural strength of lid.

In one embodiment, the top wall of the first projecting portion further has a second recessed portion recessed toward the inner side of the lid body, the second recessed portion being configured as an annular groove surrounding the first recessed portion.

According to this scheme, the structural strength of lid can further be strengthened to the second depressed part.

In one embodiment, the bottom wall of the first recess is flush with the bottom wall of the second recess and is higher than the bottom wall of the recess.

According to the scheme, the cover body can be ensured to have enough volume by the arrangement, and the cover body is convenient to use as a dinner plate.

In one embodiment, the ratio of the maximum peripheral dimension to the wall thickness of the cover is 300-700. Preferably, the wall thickness of the cover is not more than 0.6mm, which is particularly advantageous in terms of cost and environmental protection.

According to the scheme, the corresponding wall thickness can be set according to the difference of the transverse size of the cover body, so that the strength of the cover body is ensured, and meanwhile, the ultrathin wall allows a large amount of materials to be saved on the basis of ensuring enough structural strength.

In one embodiment, the radial width of the top wall of the first projection is greater than two-thirds of the diameter of the cap.

According to this aspect, the cover can have a sufficient volume.

In one embodiment, the side wall of the box is provided with a parting line around a circumference dividing the side wall in the up-down direction into an upper side wall and a lower side wall staggered inside and outside, the lower side wall being offset to the inside with respect to the upper side wall.

In one embodiment, the parting line is configured in three or more undulations or curves, with at least three peak to valley variations.

According to each scheme, the parting line can play a role in positioning when a plurality of box bodies are stacked, and the structural strength of the box bodies can be increased.

In one embodiment, in a state where the cover covers the box body, the boss portion of the box body abuts against and contacts with an inner side surface of the second protruding portion of the cover body to form a seal.

According to the scheme, the boss part and the second protruding part are abutted, contacted and matched to form the mutually staggered rotary type matching structure, sealing can be achieved, good stability and deformation resistance can be achieved, when the nested structure is extruded or twisted by external force, the nested structure is mutually locked and prevented from being disengaged, the extrusion or twisting of the external force can be effectively overcome, and high matching strength is achieved. According to another aspect of the present invention, there is also provided a method of using the packaging container as described above, wherein one of the at least one cover and the box can be closed together to serve as a packaging container for food, and wherein at least one of the at least one cover serves as a dinner plate during dinner.

According to the invention, one box body can be matched with a plurality of cover bodies for use, and the cover bodies can be used as plates at the same time due to the design of the cover bodies, so that the box is particularly suitable for occasions of eating different meals or multi-person meal and the like at the same time, and is clean and sanitary. Meanwhile, a plurality of lunch boxes do not need to be purchased, and a plurality of cover bodies can be stacked, so that the cost is saved, and the space is saved. Particularly for tableware formed by ultra-thin process technology, the invention provides a dual-purpose anti-deformation sealed food functional packaging container which cannot be realized in the prior art. In the process of packaging and transporting, each box body and each cover body can be independently packaged, one cover body or a plurality of cover bodies can be independently packaged, one box body and one cover body can be packaged together as a set, or one box body and a plurality of cover bodies can be packaged together as a set. Therefore, the fast food box is particularly convenient and sanitary to transport and distribute, and breaks the limitation of single use and one-to-one matching of the traditional fast food box.

Drawings

For a better understanding of the above and other objects, features, advantages and functions of the present invention, reference should be made to the preferred embodiments illustrated in the accompanying drawings. Like reference numerals in the drawings refer to like parts. It will be appreciated by persons skilled in the art that the drawings are intended to illustrate preferred embodiments of the invention without any limiting effect on the scope of the invention, and that the various components in the drawings are not drawn to scale.

Fig. 1 is a perspective view of a cap body of a packaging container according to a preferred embodiment of the present invention;

FIG. 2 is a vertical cut-away view of the cover shown in FIG. 1;

fig. 3 is a vertical sectional view of a cover body of a packing container according to another embodiment of the present invention;

FIG. 4 is a schematic view of the cover of FIG. 1 in use as a serving tray;

fig. 5 is a perspective view of a box body of a packaging container according to the present invention;

FIG. 6 is a vertical cut-away view of the cassette shown in FIG. 5;

FIG. 7 is a schematic view of the cover and the box of the packaging container according to the present invention; and

fig. 8 a-8 d are schematic views of the top and bottom of the packaging container according to the present invention.

Description of reference numerals:

100/200 cover body

11 first projection

101 accommodating space

111 top wall of the first projection

12 second projection

121 outer side wall of second projection

122 inner side wall of the second projection

13 groove

131 arc wall

14 turnup

141 lateral extension

142 vertical extension

15 first recess

16 second recess

300 case

301 holding cavity

21 side wall

211 upper side wall

212 lower side wall

22 sealing groove

23 boss part

231 outer side wall of boss part

232 inner side wall of boss part

24 parting line

201 convex rib

202 arc part

Detailed Description

Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings. What has been described herein is merely a preferred embodiment in accordance with the present invention and other ways of practicing the invention will occur to those skilled in the art and are within the scope of the invention.

The present invention provides a dual-purpose ultra-thin sealed deformation-resistant series of packaging containers which can be used as food containers. The packaging container may include a case having an opening and a cover. The lid body may be closed on the case body to form a closed space therebetween, whereby liquid or solid food or the like may be contained in the packaging container. Of course, the packaging container is not limited to holding food, and may be a container holding any article. According to the present invention, the cover and the box can be made of elastic materials, such as ultra-thin injection molding materials, thicker plastics, etc., and in addition, materials such as metal or plastic can be used. The packaging container according to the invention will be described in detail below with reference to the accompanying drawings. In which directional terms such as "inside", "outside", "upward", "downward", "lateral", and the like are used hereinafter based on the state of the lid body when it is used as a lid and is normally placed.

Fig. 1 and 2 show a disc-shaped cover body 100 according to a preferred embodiment, which is provided at the middle thereof with a first protrusion 11 protruding upward. The protrusion of the first projection 11 forms a concave receiving space 101 at the inner side of the cover body 100. Thus, when the cover body 100 is turned over and placed with the first protruding portion 11 facing downward, the cover body 100 can be used as a dinner plate for holding food and the like in the holding space 101. Fig. 4 shows the cover 100 in use as a dinner tray.

Because the cover body can be used for two purposes, a user can only select one packaging container to hold under the condition of selecting various food, and a plurality of cover bodies are selected at the same time. That is, one case can be used in cooperation with a plurality of covers. When eating, the cover body can be used for respectively containing different meal items, or the cover body can be used for multiple people to have meals. Therefore, a plurality of lunch boxes do not need to be purchased, the using amount of tableware can be reduced to a great extent, and a plurality of cover bodies can be stacked, so that the cost is saved, and the space is saved.

The top end of the first projection 11 defines a plane so that it can be stably placed on a support surface (e.g., a table top) by the first projection 11 when the cover 100 is used as a dinner tray. In the illustrated embodiment, the first projecting portion 11 includes a top wall 111 forming a flat surface. Preferably, the first protrusion 11 has an overall lateral dimension greater than two-thirds of the maximum peripheral dimension of the cover body 100, ensuring that the receiving space 101 has a sufficient volume to contain food.

It will be appreciated that in other embodiments, the top of the first protrusion 11 may also be formed with a rib-like protrusion or a bump, the top of which is in the same plane, so long as the cover 100 can be stably placed when used as a dinner plate.

The cover body 100 also has a second projecting portion 12 on the outer peripheral side. The second projection 12 is disposed around the first projection 11 with a groove 13 formed therebetween. The provision of the second projecting portion 12 on the one hand makes it possible to increase the structural strength of the cover body 100, which is advantageous in particular in the case of cover bodies 100 which are formed by ultra-thin process techniques using plastic materials. On the other hand, a groove 13 is formed between the second projecting portion 12 and the first projecting portion 11. When the cover body 100 is used as a cover body, the cover body 100 can be easily grasped through the groove 13. When the cover 100 is used as a dinner plate, the fingers of the hand can be just placed in the grooves 13, so that the stability of taking the dinner plate from the end can be improved.

With continued reference to fig. 2, the second projection 12 is substantially of a downwardly opening inverted U-shaped configuration, i.e., the second projection 12 forms a reverse channel opposite the opening of the recess 13, having opposed outer and

inner side walls

121 and 122. Preferably, the outer sidewall 121 of the second projection 12 extends downwardly beyond the inner sidewall 122. When the cover 100 is used as a tray, the outer side wall 121 of the second projections 12 forms the outer edge of the tray, as shown in figure 4. This arrangement allows the tray to have a higher edge, further increasing the volume of the tray, which is advantageous when holding food containing soup.

Preferably, the height difference H between the bottom end of the inner side wall 122 of the second projection 12 and the top wall 111 of the first projection 11 (i.e., the projection height of the first projection 11) is 12-20 mm. In various embodiments, the height H may be set to 13mm, 15mm, 18mm, or any value within the above range. This allows the cover body 100 to have a certain volume while maintaining a flat shape, thereby satisfying both the use requirements as a dish and as a lid.

Preferably, the inner side wall 122 of the second projecting portion 12 is configured as a vertically extending straight wall. The end of the inner side wall 122 is connected to the top wall 111 of the first protruding part 11 via an arc wall 131 that is concave toward the inner side of the cover body 100. In this way the recess 13 is formed. The provision of the arc-shaped wall 131 may further enhance the structural strength of the cover body 100. And in the process of injection molding, the arc-shaped wall 131 can also be conveniently demoulded. In addition, referring to fig. 4, the arc-shaped wall 131 and the top wall 111 of the first protrusion 11 have a larger space therebetween, so that a dead space can be avoided, and the cover 100 can be easily cleaned after being used as a dinner plate.

Preferably, the ratio of the width D of the recess 13 to the maximum peripheral dimension D of the cover 100 is 3-25, preferably 5-20. This ratio range prevents the groove 13 from having an excessively large width and occupying a large lateral dimension, which reduces the volume of the cover 100 when used as a dinner plate, and also contributes to the structural strength of the cover 100. In particular, the width d of the groove 13 may be set to 10-15mm to accommodate the finger to be inserted therein. In different embodiments, the width d of the groove 13 may be set to 12mm, 13mm, 14mm or any value within the above range. In the illustrated embodiment, the width d is defined as the distance between the intersection line of the plane of the top surface of the second projecting portion 12 and the arc-shaped wall 131 to the inner side wall 122 of the second projecting portion 12 in the transverse direction. It will be appreciated that when the recess 13 is formed by two vertically extending walls, its width may be defined by the transverse dimension between the two vertically extending walls.

Further, the bottom end of the outer side wall 121 of the second protruding portion 12 is provided with a flange 14, which together with the aforementioned reverse groove overcomes the defect that the flat product formed by the ultra-thin material is easy to deform. Referring to fig. 4, when the cover 100 is used as a dinner tray, the flange 14 forms the outer edge of the cover 100, and the thumb is just placed on the flange 14 when the person takes the cover 100 from the end. The flange 14 prevents sharp edges from being formed on the cover 100 and prevents injury. In the illustrated embodiment, the cuff 14 includes a lateral extension 141 extending laterally outward from the bottom end of the outer side wall 121 of the second projection 12 and a vertical extension 142 extending upward from the lateral extension 141. The flange 14 can further improve the structural strength of the lid body 100, and enhance the deformation resistance thereof. In addition, the flange 14 may also cooperate with the case to provide a seal, as will be described below.

Further, in order to enhance the structural strength and the deformation resistance of the cover body 100 at the middle portion, the middle portion of the top wall 111 of the first projecting portion 11 is provided with a first recessed portion 15 recessed toward the inside of the cover body 100. Wherein the bottom wall of the first recess 15 is higher than the bottom wall of the groove 13, which avoids the accommodation space 101 of the cover 100 from being excessively reduced while increasing the strength.

Further, the maximum peripheral dimension D of the cover body 100 may be set to 10-40 cm. In various embodiments, the maximum peripheral dimension D may be specifically set to 15cm, 20cm, 25cm, 30cm, 35cm or any value within the above range to accommodate cartridges of different sizes. Further preferably, the ratio of the height difference H between the bottom end of the inner side wall 122 of the second projection 12 and the top wall 111 of the first projection 11 to the maximum peripheral dimension D of the cover body 100 may be set to 5-20.

The wall thickness of the cover body 100 is set to be not more than 0.6 mm. On the premise of ensuring the structural strength, the material can be saved, and the production cost can be reduced. It will be appreciated that as the maximum peripheral dimension D increases, the wall thickness of the cap is correspondingly increased to ensure sufficient structural strength, while the wall thickness preferably remains of ultra-thin gauge. Preferably, the ratio of the maximum peripheral dimension D to the wall thickness is in the range of 300-700. In particular, the maximum peripheral dimension D may have the following correspondence with the wall thickness:

fig. 3 shows a cover 200 according to another embodiment, in which like structures are shown using like reference numerals. In the cover 200, the top wall 111 of the first projecting portion 11 is further provided with a second recessed portion 16 recessed toward the inside of the cover 100, differently from the cover 100. The second recess 16 forms an annular groove around the first recess 15, spaced apart therefrom. Preferably, the bottom wall of the second recess 16 is substantially flush with the bottom wall of the first recess 15, and both are higher than the bottom wall of the groove 13. When the cover 200 is closed on the box 300, which will be described in detail below, the annular groove formed by the second recess 16 can also cooperate with a downwardly protruding annular rib provided at the bottom of another box 300, that is, the annular rib of the box 300 is snapped into the annular groove of the cover 200, so as to achieve the positioning between two stacked packaging containers. In addition, the first recessed portion 15 and the second recessed portion 16 can also realize the positioning between two vertically adjacent covers 200 when the covers 200 are stacked, so that the stacked covers 200 are more tidy and compact, and are convenient to transport and store.

Fig. 5 to 6 show a cartridge 300 according to a preferred embodiment. The case 300 is substantially configured in an inverted truncated cone shape or a cylindrical shape having a receiving cavity 301 surrounded by a bottom wall and a side wall 21, and is opened at the top. When the cover covers the opening and is engaged with the case 300, a closed space is formed therebetween.

Like the cover, the case 300 may also be a structure molded by an ultra-thin process technique using a plastic material. The outer peripheral sides of the opening of the case 300 are provided with a boss portion 23 protruding upward, and a sealing groove 22 provided on the outer peripheral side of the boss portion 23, respectively. Wherein the top of the sealing groove 22 is lower than the top wall of the boss portion 23. Figure 7 shows a cover body 200 for use as a lid and another cover body 200 inverted for use as a tray, respectively. When the cover body 200 used as a lid is coupled with the case body 300, the boss portion 23 of the case body 300 is nested into the inverted U-shaped structure of the second projection 12 of the cover body 200, and the beading 14 of the cover body 200 is nested into the sealing groove 22. Further, the boss portion 23 and the side wall and the top wall of the second protruding portion 12, and the flange 14 and the side wall and the bottom wall of the sealing groove 22 are in abutting contact with each other, so that a mutually staggered rotary type matching structure is formed, and sealing is realized. The nested structure has good stability, and when the nested structure is extruded or twisted by external force, the nested structures are mutually locked and prevented from being separated, so that the extrusion or twisting of the external force is effectively overcome, and higher matching strength and good sealing performance are realized.

The specific form of the above-described abutting contact seal is shown in fig. 8 a-8 d.

As shown in fig. 8a, the top wall, the outer side wall 231 and the inner side wall 232 of the boss portion 23 respectively contact against the top wall, the outer side wall 121 and the inner side surface of the inner side wall 122 of the first protruding portion 12 in a surface contact manner, so that the boss portion 23 and the first protruding portion 12 are in interference fit.

Fig. 8b shows a sealing manner similar to that of fig. 8a, except that the opening angle of the second projecting portion 12 is larger than that of the boss portion 23, and therefore, the outer side wall 231 and the inner side wall 232 of the boss portion 23 are brought into abutting contact with the outer side wall 121 and the inner side wall 122 of the first projecting portion 12, respectively, in a line contact manner.

Fig. 8c differs from fig. 8a in that the outer side surface of the inner side wall 232 of the boss portion 23 is provided with a rib 201, and abuts against and contacts the inner side surface of the inner side wall 122 of the first projecting portion 12 through the rib 201. It is to be understood that in another embodiment, the ribs 201 may be provided on the inner side surface of the inner side wall 122 of the first projecting portion 12, or the ribs 201 may be provided on both the outer side surface of the inner side wall 232 of the boss portion 23 and the inner side surface of the inner side wall 122 of the first projecting portion 12, but it is to be noted that the two ribs 201 are vertically displaced. Of course, the bead 201 may be provided on at least one of the boss portion 23 and the outer side wall of the first projecting portion 12.

Fig. 8d differs from fig. 8a in that the inner side wall 122 of the first protruding portion 12 and the inner side wall 232 of the boss portion 23 are respectively provided with arc-shaped portions 202 that are recessed inward, and sealing is achieved by abutting contact engagement of the respective arc-shaped portions 202. It is to be understood that the arcuate portion 202 may also be provided so as to be outwardly convex, or the arcuate portion 202 may also be provided on the outer side walls of both the first projecting portion 12 and the boss portion 23.

In addition, as shown in fig. 5, the side wall 21 of the cartridge 300 is provided with a parting line 24. The parting line 24 extends circumferentially around the case 300 and divides the side wall 21 into an upper side wall 211 and a lower side wall 212 which are offset inward and outward in the vertical direction. Thus, the parting line 24 is configured to resemble a stepped surface. Wherein the lower sidewall 212 is offset inwardly with respect to the upper sidewall 211. When a plurality of cartridges 300 are stacked, the step surface of the parting line 24 may play a role in positioning between two adjacent cartridges 300. Preferably, the parting line 24 is configured in the form of a wavy line or a curved line in the circumferential direction, for example, a wavy line in which three or more peaks and valleys are provided in the circumferential direction, which can enhance the structural strength of the box body 300, and is advantageous particularly when the box body 300 is configured as a structure formed by ultra-thin process technology.

It will be appreciated that the shape of the lid depends on the shape of the opening of the box with which it is fitted. The cover is not limited to a disc shape. When the whole or only the opening of the box is configured as a square, rectangle, oval or any other possible shape, the cover may have a corresponding shape. In addition, the opening of the box is not limited to be provided on the top, and may be provided at any possible position, for example, a part opened on the top or a part opened on the side of the box. In addition, the maximum peripheral dimension and the wall thickness of the case may be set to be the same as those of the above-described lid body.

The foregoing description of various embodiments of the invention is provided for the purpose of illustration to one of ordinary skill in the relevant art. It is not intended that the invention be limited to a single disclosed embodiment. As above, many alternatives and variations of the present invention will be apparent to those of ordinary skill in the art. Thus, while some alternative embodiments are specifically described, other embodiments will be apparent to, or relatively easily developed by, those of ordinary skill in the art. The present invention is intended to embrace all such alternatives, modifications and variances of the present invention described herein, as well as other embodiments that fall within the spirit and scope of the present invention as described above.

Claims

1. A packaging container, characterized in that it comprises:

a box body (300), wherein the box body (300) is provided with an accommodating cavity (301) which is opened upwards, the outer periphery of the opening is provided with a boss part (23) which protrudes upwards and a sealing groove (22) which is arranged on the outer periphery of the boss part (23), and the top of the sealing groove (22) is lower than the top wall of the boss part (23); and

at least one cover body (100), a first protruding part (11) is arranged at the middle part of the cover body (100), the first protruding part (11) protrudes upwards and forms a containing space (101) at the inner side of the cover body (100), the top end of the first protruding part (11) defines a plane, the middle part of the top wall (111) of the first protruding part (11) is provided with a first sunken part (15) sunken towards the inner side of the cover body (100), the outer peripheral side of the cover body (100) is provided with a second protruding part (12) of an inverted U shape opened downwards, the second protruding part (12) protrudes upwards and protrudes to a height lower than the first protruding part (11), the second protruding part (12) is provided with an inner side wall (122) extending vertically, the tail end of the inner side wall (122) is connected with the top wall (111) of the first protruding part (11) through an arc-shaped wall (131) sunken towards the inner side of the cover body to form a groove (13), the outer side wall (121) of the second protruding part (12) extends downwards to exceed the inner side wall (122) of the second protruding part (12), and a flanging (14) is formed at the bottom end of the outer side wall (121);

wherein the boss portion (23) is fitted into the second projection (12) and the burring (14) is fitted into the sealing groove (22) in a state where the lid body (100) closes the box body (300).

2. A packaging container according to claim 1, wherein the ratio of the width of said recess (13) to the maximum peripheral dimension of said cover is 3-25.

3. A packaging container according to claim 1, wherein the ratio of the height difference between the top wall (111) of the first projecting portion (11) and the bottom end of the inner side wall (122) of the second projecting portion (12) to the largest peripheral dimension of the cover body is 5-20.

4. A packaging container according to claim 3, wherein said cover (100) has a maximum peripheral dimension of 10-40 cm.

5. A packaging container according to claim 1, c h a r a c t e r i z e d in that said flange (14) extends outwardly from the bottom end of the outer side wall (121) of said second projection (12) and then is bent upwardly.

6. A packaging container according to claim 1, wherein the top wall (111) of the first projection (11) further has a second recess (16) recessed towards the inside of the lid (100), said second recess (16) being configured as an annular groove around the first recess (15).

7. A packaging container according to claim 6, wherein the bottom wall of the first recess (15) is flush with the bottom wall of the second recess (16) and is higher than the bottom wall of the recess (13).

8. The packaging container as claimed in claim 1, characterized in that the ratio of the maximum peripheral dimension to the wall thickness of the cover (100) is 300-700.

9. A packaging container according to claim 1, wherein the radial width of the top wall (111) of the first bulge (11) is larger than two thirds of the diameter of the lid.

10. The packaging container according to claim 1, wherein the side wall (21) of the box body (300) is provided with a parting line (24) around a circumference, the parting line (24) dividing the side wall (21) in an up-down direction into an upper side wall (211) and a lower side wall (212) which are staggered inside and outside, the lower side wall (212) being offset inwardly with respect to the upper side wall (211).

11. The packaging container as claimed in claim 10, characterized in that the parting line (24) is configured as a wave.

12. The packaging container according to claim 1, wherein the boss portion (23) of the box body (300) comes into abutting contact with an inner side surface of the second projecting portion (12) of the cover body (100) to form a seal in a state where the cover body (100) closes the box body (300).

13. The method of using the packaging container of claim 1, wherein one of the at least one cover and the box are adapted to be closed together for use as a packaging container for food, and wherein at least one of the at least one cover is adapted to be used as a serving tray during a meal.