JP6496768B2 - Microwave oven food container - Google Patents

Description

  The present invention relates to a microwave heated food container, and more particularly to a container that enables efficient exhaust of water vapor from a lid.

  When cooking cooked foods at a retail store such as a convenience store or cooking them after taking them home, a container for packaging these foods consists of a combination of a container body and a lid. In particular, since it is a single-use container that is used only once for display, sales, etc., it has a simplified structure as much as possible. Therefore, at present, molded products of synthetic resin sheets are the mainstream of containers.

  A microwave oven (microwave irradiation) is usually used for cooking and reheating food. Therefore, the food containers are provided after being put in a microwave oven and heated as they are. Focusing on foods that are actually sold, foods with a high water content such as soups and foods with a low water content per weight such as fried foods are present, and the types of foods are very common. The problem here is that water vapor is generated from the food in the container when the food is cooked by the microwave oven.

  If the fitting between the container main body and the lid is loosened, the internally generated water vapor can be easily exhausted. However, when the fitting on the lid side is loose, there is a concern that foreign matter may be mixed due to problems such as the lid body being easily detached at an intermediate stage of manufacture, shipment, and display. For this reason, the reputation from the purchaser of food is not good. In view of this, a lid having a hole for exhausting internally generated water vapor to the outside of the container has been proposed (see Patent Documents 1 and 2, etc.). According to the container lid represented by Patent Documents 1 and 2, a tongue-shaped opening formed by a U-shaped or V-shaped cut is formed in the lid. The water vapor passes through the tongue-shaped opening and is released to the outside of the container.

  The exhaust efficiency of the tongue-shaped opening due to the U-shaped or V-shaped cut is good. However, the good exhaust of water vapor increases the risk of foreign matter intrusion from the tongue-shaped opening. Therefore, in this case, a sealing tape that closes the tongue-shaped opening may be applied. Furthermore, a film member for covering the tongue-shaped opening is additionally covered as necessary. For example, when a film member is covered, a wall portion surrounding the periphery of the tongue-shaped opening is provided on the lid side, and a gap is formed around the tongue-shaped opening. Further, the structure of the wall is complicated, for example, a passage for water vapor is formed on the wall. Moreover, when the tongue piece due to the cut breaks and falls into the container, there is a problem that foreign matter is mixed in itself.

  As described above, a container that employs an existing structure for exhausting water vapor requires materials other than those necessary only for the original food packaging, and the cost increase cannot be denied. In addition, the shape of the tongue-like opening due to the cut is uniform, and there are many restrictions on the peripheral structure.

JP 2012-50672 A Utility Model Registration No. 3056026

  From a series of circumstances, the inventor has sought a new exhaust structure that replaces the exhaust of steam using a tongue-shaped opening formed by a U-shaped or V-shaped cut. Among them, it has been found that a structure in which fine long holes are provided in the lid of the container is effective. And since it was a fine long hole, it turned out that the tolerance with respect to a failure | damage and a foreign material mixing is also favorable.

  The present invention has been made in view of the above points, and proposes a new exhaust structure that replaces the exhaust of water vapor using a tongue-shaped opening by a conventional U-shaped or V-shaped cut, By intensively studying the location, it is possible to improve the sealing performance and suppress the mixing of foreign substances, and it is advantageous for reducing the material cost. To do.

  That is, the invention of claim 1 is a food container for heating a microwave oven that includes a container main body and a lid that fits into the opening of the container main body, and stores food in the container main body. The lid surface portion of the lid body portion is provided with a lid ridge portion protruding upward from the lid surface portion, and the lid ridge portion is provided with the food contained in the container main body portion during microwave heating. It is characterized in that it is provided with an exhaust hole having a width of 0.15 to 1 mm, which is formed so as to straddle the lid ridge portion in the width direction by laser beam irradiation. It relates to a container for microwave heated food.

  A second aspect of the present invention relates to the microwave oven heated food container according to the first aspect, wherein the exhaust elongated holes are arranged in a comb shape on the lid protrusion.

  Invention of Claim 3 concerns on the container for microwave oven heated food of Claim 1 or 2 in which the surrounding wall part is formed by the said lid protrusion part.

  A fourth aspect of the present invention relates to the microwave oven heated food container according to the third aspect, wherein the enclosing wall portion is provided with a concave groove portion.

  According to a fifth aspect of the present invention, a lid recess is formed inside the enclosing wall, and the bottom surface of the lid recess is dug down to the container inner side of the container main body than the lid surface plate of the lid surface. The microwave oven heated food container according to claim 3 or 4.

  The invention of claim 6 is the microwave oven food container according to any one of claims 1 to 5, wherein a lid convex portion protruding upward is provided on the lid surface portion in the vicinity of the exhaust hole. Related.

  The invention of claim 7 relates to the microwave oven food container according to any one of claims 1 to 6, wherein the lid portion is formed of a synthetic resin sheet.

  According to the microwave-heated food container according to the invention of claim 1, the microwave oven includes a container main body part and a lid part that fits into the opening of the container main body part, and stores the food in the container main body part. A container for food for heating, the lid surface portion of the lid body portion being provided with a lid ridge portion protruding upward from the lid surface portion, and the container in the microwave oven heating in the lid ridge portion Exhaust holes with a width of 0.15 to 1 mm provided to exhaust water vapor generated from food contained in the main body to the outside and to penetrate the lid ridge in the width direction by laser beam irradiation Therefore, by proposing a new exhaust structure that replaces the exhaust of water vapor using a tongue-shaped opening with a conventional U-shaped or V-shaped cut, and by studying its position repeatedly , Improved sealing performance, contamination Realized braking is advantageous in reducing material costs, moreover, can be bored easily and quickly exhaust slot.

  According to the microwave oven food container according to the invention of claim 2, in the invention of claim 1, the exhaust elongated holes are arranged in a comb-teeth shape on the lid protrusion, so that the water vapor pressure during heating is reduced. In response, the lid protrusion can be deformed with flexibility.

  According to the microwave oven food container according to the invention of claim 3, in the invention of claim 1 or 2, since the surrounding wall portion is formed by the lid protrusion, the water vapor ejected from the exhaust long hole is liquefied. Then, when it becomes a water droplet, the water droplet can be kept.

  According to the microwave oven food container according to the invention of claim 4, in the invention of claim 3, since the enclosing wall portion is provided with a recessed groove portion, water vapor staying inside the enclosing wall portion passes through the recessed groove portion. Easier to get out.

  According to the microwave oven food container according to the invention of claim 5, in the invention of claim 3 or 4, a lid recess is formed inside the surrounding wall portion, and the bottom surface of the lid recess is the lid Since it is dug down to the container inside side of the container main body part rather than the lid surface plate part of the surface part, it becomes a part that presses the material directly under the lid recess part by the step between the lid surface plate part and the recess bottom part.

  According to the microwave oven food container according to the invention of claim 6, in the invention of any one of claims 1 to 5, a lid convex portion protruding upward is provided on the lid surface portion in the vicinity of the exhaust long hole. Therefore, the upper part of the upper surface of the ridge of the lid ridge is opened, and the external diffusion of water vapor ejected from the exhaust long hole becomes easy.

  According to the microwave oven food container according to the invention of claim 7, in the invention of any one of claims 1 to 6, since the lid portion is formed from a synthetic resin sheet, mass production is inexpensive and simple. Can be manufactured and used as a single-use container.

It is a whole longitudinal cross-sectional view of the isolation | separation state of the container for microwave oven heated food which concerns on embodiment of this invention. It is a whole top view of the cover part of FIG. It is a schematic diagram of the exhaust long hole at the time of steam exhaust. It is a perspective view of the lid ridge part and exhaust long hole concerning other examples. It is a partial enlarged plan view of a surrounding wall part. It is the schematic which shows the effect | action of a cover convex part. It is a photograph of the lid part which employ | adopted the exhaust long hole of embodiment of this invention. It is a photograph of the lid part which adopted the exhaust long hole of other embodiments.

  The food container 1 according to the embodiment of the present invention includes a container main body 100 and a lid 10 that fits into the opening 101 of the container main body 100 as shown in the entire longitudinal sectional view of FIG. Composed of a combination. The food C is contained in the container interior 103 of the container main body 100, and is heated or heated by microwave irradiation in a microwave oven with the lid 10 covered (cooking). Therefore, the food container 1 is a “microwave heated food container”.

  Food containers 1 (combination of container body 100 and lid 10) are sold mainly at convenience stores, supermarkets, department stores, restaurants, delicatessens, coffee shops, service areas, and other stores. Used for packaging foods including bento, side dishes, noodle dishes, soup dishes, and other beverages such as coffee, cocoa, black tea, green tea, medicinal herbs, etc. It is. The food container 1 is a single-use container (disposable container) for one-time use that is mainly referred to as one-way or disposable. By using a single-use container, it is convenient for food hygiene management.

  Since it is used as a single-use container, the lid 10 of the food container 1 is formed from a synthetic resin sheet (plastic resin sheet) that can be mass-produced and manufactured at low cost. Specifically, the lid 10 is made of a thermoplastic resin sheet (synthetic resin sheet) such as polyethylene, polypropylene, polystyrene, or polyethylene terephthalate (PET resin), or a biodegradable thermoplastic resin such as polylactic acid. It is a sheet. Although the thickness of the synthetic resin sheet is appropriate, it is approximately 1 mm or less, and is usually 200 to 700 μm. The synthetic resin sheet is formed by vacuum forming. When a synthetic resin sheet is used as a raw material, vacuum molding is simple and optimal in consideration of mass productivity at the time of molding, processing accuracy, and the like. In addition, as will be described later, processing by laser beam irradiation is also considered.

  In the combination of the container main body part 100 and the lid part 10, the raw material resin of the synthetic resin sheet may be the same or different. In particular, since the food container 1 supports heating by a microwave oven, the container main body side can be made of expanded polystyrene or paper in consideration of heat conduction. The type of resin to be used is appropriately selected depending on the application, contents, and packaging target. In the subsequent embodiment disclosed in FIG. 2 and the like, the lid 10 is made of polystyrene, and the container body 100 is made of expanded polystyrene.

  The container main body 100 is composed of an opening 101, a trunk 104, and a bottom 105 from above, and is a bowl-shaped or bowl-shaped container having an internal capacity that sufficiently corresponds to the amount of food. In the opening 101 of the container main body 100, an outer edge flange 107, an opening peripheral wall 106, and a fitting recess 109 are formed at the lower end thereof. The U-shaped peripheral wall portion 15 of the lid body portion 10 is formed from the lid contact wall portion 16, the circumferential groove bottom portion 17, and the inner wall portion 18, and the fitting convex portion 19 is formed on the lid contact wall portion 16. Is done. A lid flange portion 14 is formed on the outer edge of the peripheral wall portion 15. The cross-sectional shapes of the container main body 100 and the lid body 10 are appropriate, and are circular in the illustrated embodiment. A cross-sectional shape such as a polygon or an ellipse is also possible.

  The fitting between the container body 100 and the lid body 10 shown in the figure is a form called an inner fitting, and the periphery of the lid body part 10 is fitted into the opening 101 of the container body 100. Around the lid part 10, a peripheral wall part 15 having a U-shape in sectional view for fitting inside the opening 101 of the container main body part 100 is provided. The peripheral wall 15 of the lid 10 is received inside the opening 101 of the container body 100 and can be fitted. Although not shown in the drawings, when the lid is closely attached to the opening peripheral wall portion 106 during fitting, the container body portion 100 and the lid body portion 10 are firmly adhered to each other. In addition, the fitting convex part 19 of the lid body part 10 and the fitting concave part 109 of the container main body part 100 are closely attached. Therefore, the lid 10 is not easily detached from the container body 100. In addition to the inner fitting shown in the figure, the fitting form may be an outer fitting in which, for example, the edge of the lid body covers the opening of the container main body from the outside.

  As understood from the plan view of the lid body portion of FIG. 2 in addition to the longitudinal sectional view of FIG. 1, the lid body portion 10 is provided with a lid ridge portion 20 protruding upward from the lid surface portion 11. . In the illustrated embodiment, a flat hexagonal surrounding wall portion 21 is formed by a combination of the lid ridge portions 20. And in the cover protrusion part 20, the exhaust long hole 40 is formed so that the width direction (protrusion upper surface part 22) may be straddled. The illustrated exhaust oblong hole 40 is formed not only in a straight line on the upper surface portion 22 of the ridge which is the width direction of the lid ridge portion 20 but also in the vertical direction of the lid ridge portion 20. . Specifically, the exhaust long hole 40 is a three-dimensional slit groove having a “Π” shape in a longitudinal sectional view (see FIGS. 3 and 4). In addition, a plurality of exhaust holes 40 are arranged in a “comb-tooth shape” on the lid protrusion 20. The comb-tooth shape means an arrangement in which a plurality of exhaust holes are arranged in the same direction at equal intervals.

  The exhaust oblong hole 40, when heating the food of the contents together with the food container 1 with a microwave oven, generates water vapor generated from the food C (see FIG. 1) contained in the container main body 100 (the container interior 103). This is a part for exhausting to the outside of the food container 1. As described above, in the inner fitting structure of the combination of the container main body 100 and the lid 10 in the food container 1, the mutual fitting and close contact at the opening 101 are strong. Therefore, the internally generated water vapor hardly escapes from the opening 101 to the outside, and there is a possibility that the lid 10 may be inadvertently removed when heating the microwave oven unless a portion for exhausting any water vapor is provided. Therefore, by providing the exhaust long hole 40 on the lid 10 side, the internally generated water vapor can be efficiently exhausted.

  As a method of forming the exhaust long hole 40, a laser beam is applied to the lid protrusion 20 (enclosure wall 21). Therefore, a thin slit-like exhaust hole 40 is formed in the lid protrusion 20. In forming the exhaust long hole 40, for example, in the case of a physical processing method such as a needle stick, a drill, or a cutter, in addition to requiring a lot of time, sufficient processing accuracy cannot be obtained. Moreover, when forming the holes, the problem of the generation of fine powder cannot be eliminated, and the subsequent cleaning work is also required. Therefore, irradiation with a laser beam is used from the viewpoint that an exhaust long hole can be formed in the lid ridge portion 20 simply and quickly. In particular, the laser beam irradiation is preferable because a plurality of exhaust long holes 40 are formed in a comb-like shape in the lid protrusion 20 so that the processing accuracy is good and the processing time can be shortened.

  The laser beam is not particularly limited as long as it can obtain a processing output, processing accuracy, and the like, and various lasers such as a carbon dioxide laser, a YAG laser, a semiconductor laser, and an argon laser and their irradiation devices are used. As described above, when the material of the lid portion is formed of a synthetic resin sheet, the exhaust long hole is easily and quickly formed by laser beam irradiation. Particularly excellent in mass productivity.

  The width of each exhaust long hole 40 (the length on the short side when viewed as a rectangular shape) is 0.15 to 1 mm. The width of the exhaust long hole 40 is more preferably 0.3 to 0.5 mm. The lower limit of the width of the exhaust long hole 40 is to obtain an opening amount sufficient for exhausting water vapor generated during microwave heating. The lower limit of 0.15 mm is a value considering the current processing technique. When the width of the exhaust long hole 40 is less than 0.15 mm, the exhaust long hole becomes too narrow, and it is considered that the exhaust efficiency of water vapor from the exhaust long hole 40 decreases. As a result, the lid body portion 10 fitted to the container main body portion 100 is easily detached due to the internal pressure. It can also be considered as a lower limit on the accuracy of the laser beam irradiation apparatus.

  In addition, when the lid portion 10 formed from the synthetic resin sheet is irradiated with a laser beam, the resin sheet is dissolved and a hole is opened at the irradiated portion. However, when the setting range is too narrow, there is a possibility that the resin melted by the heat of the laser beam irradiation is bonded to each other when it is cooled and solidified. If it does so, a desired appropriate exhaust long hole will not be formed in an irradiation site | part, but sufficient water vapor | steam exhaustion will be impaired. For this reason, the lower limit of the width is set to 0.15 mm, preferably 0.3 mm, for the convenience of preventing inadvertent rejoining.

  This is because the upper limit of the width of the exhaust oblong hole 40 is set to a size for effectively suppressing contamination of foreign matter inside the food container 1. For example, in the case of a minute insect or the like that is generally recognized as a foreign object, invasion is prevented when the width is narrower than 1 mm. Furthermore, if the width is smaller than 0.5 mm, the effect of preventing entry into the container is greatly enhanced. Therefore, the upper limit of the width is 1 mm, and the more preferable upper limit of the width is 0.5 mm. Accordingly, the width of the exhaust long hole 40 is defined within the above-described range.

  The length of the exhaust long hole 40 (the sum of the length of the long side and the length of the bent portion when the exhaust long hole is regarded as a rectangular shape) is approximately 5 mm to 20 mm, although not particularly limited. If it is extremely short, the opening area of the exhaust long hole 40 itself cannot be obtained, which hinders desired steam exhaust. Further, if the length exceeds 20 mm, the strength of the portion where the exhaust long hole 40 is formed in the lid ridge portion 20 is liable to decrease, which is not preferable. Therefore, the length of the exhaust long hole 40 is defined in the above-described range.

  In the lid surface portion 11 of the lid body portion 10, the inside of the surrounding wall portion 21 configured by the combination of the lid protrusions 20 is a lid recess portion 25. Since the surrounding wall portion 21 has a portion where the exhaust long hole 40 is formed, the surrounding wall portion 21 becomes the exhaust surrounding wall portion 26. By providing the lid recess 25, when the water vapor ejected from the exhaust oblong hole 40 is liquefied into water droplets, the water droplets accumulate in the lid recess 25 and do not spread on the lid surface portion 11. Therefore, the part which the cover surface part 11 gets wet can be decreased.

  In addition, as can be understood from the embodiment of FIG. 2, the cover surface portion 11 is also provided with an auxiliary surrounding wall portion 31 configured by a combination of other cover protrusions 20. An inside of the auxiliary surrounding wall portion 31 is an auxiliary recess portion 35. Therefore, a sachet or the like (not shown) containing spices or seasonings for seasoning food in the container main body 100 is placed in the auxiliary recess 35 as necessary. In addition, an auxiliary concave groove portion 37 is provided in a part of the lid protrusion 20 of the auxiliary surrounding wall portion 31. As shown in FIG. 5 described later, a protective film F for packaging or the like is attached to the lid portion 10 (lid surface portion 11). In this case, water vapor ejected from the exhaust long hole 40 of the exhaust surrounding wall portion 26 may flow along the protective film and flow into the auxiliary surrounding wall portion 31 side. Thus, the water vapor escapes from the auxiliary recess 35 to the outside through the auxiliary concave groove portion 37. If it carries out like this, wetting of the small bag etc. which were mounted in the auxiliary | assistant hollow part 35 can be suppressed.

  Further, the lid surface portion 11 in the vicinity of the exhaust long hole 40 is provided with a lid convex portion 50 that projects to the opposite side of the container main body portion 100. In particular, the cover convex portion 50 of the lid body portion 10 of the embodiment includes two pieces between the cover ridge portion 20 that constitutes the exhaust surrounding wall portion 26 and the exhaust long hole 40 is formed, and the auxiliary surrounding wall portion 31. Provided. The operation of the lid protrusion 50 will be described with reference to FIG. In the lid surface portion 11 of the embodiment, lid inclined portions 60 and 60 are provided on the outer peripheral side of the exhaust surrounding wall portion 26 and the outer peripheral side of the auxiliary surrounding wall portion 31, and the handle portion 61 is provided on the outer peripheral side of the lid surface portion 11. 61 is also provided. The protective film is easily attached to the lid body portion 10 (lid surface portion 11) through the lid inclined portions 60 and 60. The food container 1 is easily held by the handle portions 61 and 61.

  The state of water vapor exhaust in the lid portion 10 of the embodiment will be described using the schematic diagram of FIG. It is the top view (FIG. 3 (a)) and side view (same (b)) of the lid protrusion part 20 and the exhaust long hole 40 before a heating with a microwave oven. The exhaust long holes 40 are formed in the upper surface portion 22 of the ridge portion 20 of the lid ridge portion 20 in a comb-like shape with a constant interval, and the pierced portion straddles the lid ridge portion 20 in the width direction. The ridge side surface portion 23 of the ridge portion 20 is also digged into. As understood from the drawing, the long hole side end portion 41 of the exhaust long hole 40 is a short “I” -shaped cut portion.

  A state during heating by the microwave oven is a plan view (FIG. 3C) and a side view (FIG. 3D) of the lid protrusion 20 and the exhaust long hole 40. The internal pressure of the food container 1 increases with water vapor generated from the contents (food) in the container main body 100 by heating. Then, the lid 10 receives the pressure of water vapor, and the lid ridge 20 is also bent and bent. At this time, the ridge upper surface portion 22 also expands due to the pressure of water vapor. Then, the shape of the exhaust long hole 40 slightly swells from the rectangular shape in plan view ((b)) before heating to a spindle shape ((d)).

  Further, the elongated hole side end 41 of the exhaust elongated hole 40 is expanded from the original “I” shape to the “V” shape in response to the curved deformation of the lid protruding portion 20 so that the projected upper surface portion 22 side is expanded. The shape is deformed. In other words, this is because the amount of expansion increases toward the ridge upper surface portion 22 side of the longitudinal notch of the long hole side end portion 41. In particular, since the exhaust long holes 40 are arranged in a comb shape, the lid protrusion 20 can be expanded and deformed in a bellows shape (accordion shape). The lid protrusion 20 can be flexibly deformed in conjunction with the expansion of the lid 10, thereby further increasing the opening area of the exhaust long hole 40 ((d)). That is, although the deformation amount at the time of expansion is small due to the structural rigidity of the lid ridge portion 20 alone, the three-dimensional exhaust elongated holes 40 arranged in a comb-teeth shape are combined with the lid ridge portion 20, so that flexibility is achieved. Deformation with the property is realized.

  The partial perspective view of FIG. 4 is a disclosure of a modified example of the lid protrusion. FIG. 4A is an example of a combination of the lid ridge 20 and the exhaust elongated hole 40 disclosed in FIGS. 1 to 3, and straddles the lid ridge 20 in a vertical cross-sectional view (laterally U-shaped). In this way, the exhaust long hole 40 is formed, and long hole side end portions 41 are formed at both ends thereof. In FIG.4 (b), the shape of the lid protrusion part 20 is the same as that of the same (a). However, the long hole side end 41 is formed only on one side of the exhaust long hole 40b. Even in this case, expansion deformation on one side of the lid protrusion 20 is possible, and the same effect as described above is expected.

  Further, the lid protrusion 20c in FIG. 4 (c) has a Λ shape (letter shape) in a longitudinal sectional view, and an exhaust long hole 40c is formed so as to straddle the lid protrusion 20c. The lid protrusion 20d in FIG. 4 (d) has a semicircular shape in a longitudinal sectional view, and an exhaust long hole 40d is formed so as to straddle the arc portion of the lid protrusion 20c. Even in the case of the lid ridges 20c and 20d, the respective lid ridges can be deformed by receiving an expansion pressure, and the water vapor exhaust efficiency desired by the present invention is enhanced. As shown in the figure, the degree of freedom in designing the shape of the lid protrusion and the exhaust long hole is high, and the design is also enhanced.

  FIG. 5 is a plan view and a side view of the exhaust surrounding wall portion 26. Usually, a protective film F for packaging the lid body portion 10 (lid surface portion 11) is attached to the upper portion of the exhaust surrounding wall portion 26. Therefore, the lid protrusion 20 and the exhaust long hole 40 are protected during distribution. When the food container is heated by the microwave oven, the internally generated water vapor is sufficiently exhausted through the exhaust long hole 40 as described above. However, depending on the attachment state such as the size and position of the protective film F, the vicinity of the exhaust long hole 40 of the exhaust surrounding wall 26 may be blocked by the protective film F, and the exhaust efficiency may be lowered. As a countermeasure, a concave groove portion 27 is provided in a part of the exhaust surrounding wall portion 26 (the surrounding wall portion 21). Therefore, water vapor staying in the cover recess 25 inside the exhaust surrounding wall 26 (enclosure wall 21) escapes from the inside of the cover recess 25 through the recessed groove 27.

  FIG. 6 is an enlarged cross-sectional view of the vicinity of the lid convex portion 50 of the lid body portion 10. As shown in the figure, the lid convex portion 50 is a portion protruding upward from the lid surface portion 11. For example, when the protective film F is attached to the exhaust surrounding wall portion 26 (enclosure wall portion 21) formed on the lid body portion 10, the upper surface portion 22 of the ridge portion 20 of the lid ridge portion 20 is covered with the protective film F. It is also assumed that As can be understood from the shape of the exhaust long hole 40, the water vapor can be exhausted from the ridge side surface portion 23 of the lid ridge portion 20. However, since the largest opening portion of the exhaust long hole is the ridge upper surface portion 22, the amount of water vapor exhausted from the exhaust long hole 40 is suppressed by the protective film F. If heating continues as it is, the originally assumed steam exhaust capability may not be exhibited, and the lid 10 may be detached from the container body 100 due to the internally generated steam pressure, and the microwave oven may be soiled.

  Therefore, as shown in FIG. 6, by forming the lid convex portion 50, the position of the protective film F is raised by the top portion 51 of the lid convex portion 50, and the exhaust surrounding wall portion 26 (the surrounding wall portion 21). The ridge upper surface portion 22 of the side lid ridge portion 20 does not directly contact the protective film F. Then, a gap H is formed between the upper surface 22 of the ridge and the protective film F, and water vapor (arrow Vp in the figure) ejected from the exhaust long hole 40 can be diffused to the outside via the gap H. In this way, a passage for internally generated water vapor is secured and smooth exhaust is realized.

  Further, as can be seen from FIG. 6, in the lid body portion 10 of the embodiment, the inner side of the surrounding wall portion 21 configured by the combination of the lid protrusions 20 is a lid recess portion 25, and the recess of the lid recess portion 25. The bottom surface portion 28 is dug down to the container interior 103 side of the container main body portion 100 rather than the lid surface plate portion 13 of the lid surface portion 11. That is, the lid recess 25 is positioned below the lid plate 13.

  For example, when the food of the contents is udon or the like, fried chicken may be placed as the ingredient G. As a characteristic of ingredients such as fried chicken, it is flat and has a large area. When food containing such ingredients is heated, the ingredients may rise due to internally generated water vapor. There may also be an expansion of the fried food itself. Then, the lid surface portion 11 of the lid ridge portion 20 directly under the exhaust long hole 40 may be blocked by the material G. For this reason, the internally generated water vapor cannot reach the lid protrusion 20 and the exhaust from the exhaust long hole 40 is easily hindered. Therefore, a step between the lid surface portion 11 (the lid surface plate portion 13) and the lid recess portion 25 (the recess bottom surface portion 28) is used, and the lid recess portion 25 also functions as a pressing portion for the ingredient G.

  As described so far, taking into account the width of the exhaust oblong hole in the food container (microwave-heated food container) of the present invention, the entry of foreign matter such as insects can be effectively suppressed since it is extremely fine. Therefore, the food container of the present invention does not require the trouble of opening the tongue-shaped opening when heating or heating a microwave oven, and simplifies service and work. In particular, the food container of the present invention can be easily selected and processed for the exhaust oblong holes. Therefore, the food container of the present invention is a very suitable packaging material that can cope with the amount of water vapor generated from various types of food.

[Preparation of microwave heated food containers]
The microwave oven food container was an article composed of a combination of a container body and a lid. The “preparation of microwave-heated food container” assumed packaging of a large amount of food. A heat resistant biaxially stretched polystyrene (heat resistant OPS) resin sheet material was used for the lid. This was processed into a disk-shaped lid by vacuum forming (see the photographs in FIGS. 7 and 8). The maximum diameter of the lid portion was about 175 mm, and the maximum diameter of the lid surface portion was about 135 mm. The material thickness of the lid part was 0.3 mm. The shape of the lid portion of the example was a common shape as shown in the photograph because of the need for performance comparison with the comparative example.

  A sheet material made of heat-resistant foamed polystyrene (polypropylene film adhering product) was used for the container main body combined with the lid. This was processed into a bowl-shaped (basket-shaped or bowl-shaped) container body portion having a circular cross section by vacuum forming. The opening diameter (inner diameter) of the container main body was about 160 mm, the depth was 70 mm, and the inner volume of the container main body (capacity for accommodating food) was about 800 mL.

[Formation of exhaust holes]
In forming the exhaust long hole group, a known carbon dioxide laser irradiation device generally used in the resin processing field was used. In Example 1 (see the photograph in FIG. 7), an exhaust long hole was bored so as to straddle the lid protrusion protruding from the lid surface in the width direction, and a lid body was produced. Five pieces were produced for performance evaluation. As shown in the photograph, there are two rows of lid projections with exhaust long holes, 34 exhaust long holes, the width of the exhaust long holes is about 0.35 mm, and the length is about 10 mm. The total opening area of the exhaust long holes is about 120 mm ² . The upper part of FIG. 7 is a photograph of the entire perspective view, and the lower part is a photograph of an enlarged perspective view of the exhaust long hole portion.

Further, Examples 2 and 3 in which the width of the exhaust long hole was changed were also produced. In Example 2, a lid having the same shape and dimensions as used in Example 1 was used, and 34 exhaust long holes were formed at the same position as in Example 1. The width of the formed exhaust long hole was about 0.7 mm and the length was about 10 mm. The total opening area of the exhaust long holes of Example 2 is about 240 mm ² . In Example 3, a lid body having the same shape and size as in Example 1 was used, and 34 exhaust long holes were formed at the same position in Example 1. The width of the formed exhaust long hole was about 0.9 mm and the length was about 10 mm. The total opening area of the exhaust long holes of Example 3 is about 310 mm ² .

On the other hand, in Comparative Example 1, exhaust long holes were formed side by side vertically and horizontally in the lid recess surrounded by the lid protrusion (see the photograph in FIG. 8). The comparative example 1 has 50 exhaust long holes, the width of the exhaust long hole is about 0.4 mm, and the length is about 3.3 mm. The total opening area of the exhaust long holes is about 65 mm ² . In Comparative Examples 2 and 3, exhaust long holes having the same size and shape as Comparative Example 1 were used, and only the number thereof was increased. The comparative example 2 has 60 exhaust long holes, and the total opening area of the exhaust long holes is about 78 mm ² . The comparative example 3 has 70 exhaust long holes, and the total opening area of the exhaust long holes is about 95 mm ² . The photographs for Comparative Examples 2 and 3 were omitted. The upper part of FIG. 8 is a photograph of an overall perspective view, and the lower part is a photograph of an enlarged perspective view of an exhaust long hole portion. For Comparative Examples 1, 2 and 3, 10 lid bodies were prepared for performance evaluation.

  The exhaust oblong holes of the examples and comparative examples were long rectangular shapes with rounded ends. In particular, the exhaust long hole of the embodiment has a structure that straddles the lid protrusion and has a long hole side end portion of the bent portion. On the other hand, each comparative example is a plane. In calculating the opening area, the shape of the rounded part at both ends was ignored, and it was simply regarded as a rectangular shape, and the product of “maximum width” and “maximum length” was used. Moreover, about the Example, it was set as the length also including the long hole side edge part.

[Measurement of mating strength]
The types of food that are actually sold are extremely diverse. Therefore, the inventor decided to evaluate the difficulty (fitting strength) of detachment of the lid portions of the examples and the comparative examples from the container main body assuming heating with a microwave oven and generation of water vapor. Specifically, a metal container provided with an opening that fits the lid body in a similar shape to the container body described above was prepared. A pressurizing pump, an air pressure meter, a flow meter, and piping were connected to the metal container, and processing was performed so that air could be supplied into the metal container through the pressurizing pump. And the lid part of an Example and each comparative example was fitted to the opening part of metal containers. After confirming the fitting, pressurized air was supplied into the metal container. Thereafter, the supply pressure (air pressure) (MPa) and the supply flow rate (L / min) at the time when the lid body part was removed from the metal container with the supply of pressurized air (increase in internal pressure) were read.

[Result of mating strength]
Tables 1 and 2 show the results of the pressure tests performed on the lid portions of Examples 1, 2, and 3 and Comparative Examples 1, 2, and 3, respectively. In the table, the number of exhaust long holes (number of holes) (number), opening area (mm ² ), supply pressure (MPa) and its standard deviation, supply flow rate (L / min) and its standard deviation are shown. Here, the opening area and the supply flow rate of Examples 1, 2, and 3 were a simple average of 5 pieces, and the opening area and the supply flow rate of Comparative Examples 1, 2, and 3 were a simple average of 10 pieces. However, in Examples 2 and 3, the lid portion did not come off even when the supply flow rate was increased. In addition, 500 L / min was the limit due to the performance of the apparatus used for the experiment, so the experiment was terminated with the same value or more.

[Consideration of mating strength]
It can be said that the higher the supply pressure and the supply flow rate, the more difficult it is to come off (higher fitting strength). Specifically, from the tendency of Comparative Examples 1, 2, and 3, the difficulty of detachment improved as the hole area increased. The number of exhaust long holes and the opening area were in a proportional relationship, and the supply pressure and the supply flow rate were also increased in proportion to the opening area. Between Comparative Examples 1 and 2, the opening area is about 1.2 times (78 mm ² ÷ 65 mm ² ), the supply pressure is about 1.3 times (0.13 MPa ÷ 0.01 MPa), and the supply flow rate is about 1 .25 times (214 L / min ÷ 171 L / min). Similarly, between Comparative Examples 1 and 3, the opening area is about 1.46 times (95 mm ² ÷ 65 mm ² ), the supply pressure is about 1.4 times (0.14 MPa ÷ 0.01 MPa), and the supply flow rate Was about 1.3 times (225 L / min ÷ 171 L / min).

Next, attention was paid to the opening area of the example and the opening area of each comparative example. For example, the aperture area of Comparative Example 1 is 65 mm ² , and the aperture area of Example 1 is 120 mm ² . That is, the area is increased 1.85 times. By simply applying the proportional tendency of the aperture area in the comparative example described above, the supply pressure on the embodiment side can be expected to be about 0.18 to 0.19 MPa, and the supply flow rate can be expected to be about 308 to 325 L / min. . However, as shown in the results of the examples in Table 1, the actually measured supply pressure was 0.30 MPa, the supply pressure was 401 L / min, about 1.6 times the expected supply pressure, and about 1.3 times the supply pressure. It has been found to improve twice. Examples 2 and 3 are examples in which the width of the long exhaust hole is further expanded as compared with Example 1, and the exhaust efficiency is further increased.

  The result of the increase in supply pressure and supply flow rate cannot be explained only by an increase in proportion to the aperture area. Furthermore, when the inventors observed the supply of pressurized air in the lid portion of the example, it was confirmed that the lid protrusion itself was curved and expanded as shown in FIG. That is, it is necessary to consider the opening area of the exhaust long hole in the embodiment in consideration of the curved deformation accompanying the expansion of the lid protrusion, not the apparent area. Then, as shown in FIG. 3, it can be said that the most probable reason is that the width of the exhaust long hole is also expanded when the lid body portion is expanded from the beginning of the fitting of the lid body portion. In addition, since the exhaust long holes of the embodiment are arranged in a comb-like shape and the shape bites into the side surface portion of the lid ridge portion, the lid ridge portion is deformed into a bellows shape (accordion shape). It can be said that it helps. From this also, it is possible to assume a smooth increase in the opening area of the exhaust long hole. Examples 2 and 3 are examples in which the width of the long exhaust hole is further expanded as compared with Example 1, and the exhaust efficiency is further increased.

  As described above, the microwave heated food container of the present invention includes a lid protrusion on the lid surface portion, and an exhaust long hole that is drilled so as to straddle the lid protrusion, Good water vapor exhaust can be realized, which is extremely effective as an alternative to a packaging container for a microwave oven having an existing slit structure.

1 Food containers (microwave-heated food containers)
DESCRIPTION OF SYMBOLS 10 Cover body part 11 Cover surface part 13 Cover surface board part 15 Peripheral wall part 20 Cover rib part 21 Enclosure wall part 22 Projection upper surface part 25 Cover recess part 26 Exhaust enclosure wall part 28 Indentation bottom part 31 Auxiliary enclosure wall part 35 37 Auxiliary groove 40 Exhaust long hole 41 Long hole side end 50 Lid convex part 60 Lid inclined part 61 Handle part 100 Container body part 101 Opening part 103 Inner part of container 104 Trunk part 105 Bottom part 106 Opening peripheral wall part C Food F Protective film H Gap G Material Vp Water vapor

Claims (7)

A container for food for microwave heating, comprising a container body and a lid that fits into the opening of the container body, and containing food in the container body,
A lid ridge protruding upward from the lid surface portion is provided on the lid surface portion of the lid body portion,
A width formed in the lid ridge so as to straddle the lid ridge in the width direction by irradiating the water vapor generated from the food stored in the container main body to the outside during microwave heating. A microwave oven heated food container, characterized in that it is provided with an exhaust long hole with a thickness of 0.15 to 1 mm.   The container for a microwave oven heated food according to claim 1, wherein the exhaust elongated holes are arranged in a comb shape on the lid protrusion.   The microwave oven food container according to claim 1 or 2, wherein a wall portion is formed by the lid protrusion.   The microwave oven food container according to claim 3, wherein the enclosing wall is provided with a concave groove.   5. A lid recess is formed inside the surrounding wall, and the bottom surface of the lid recess is dug deeper into the container inside of the container body than the lid surface plate of the lid surface. A container for food heated by a microwave oven as described in 1.   The container for food heated by a microwave oven according to any one of claims 1 to 5, wherein a lid convex portion projecting upward is provided on the lid surface portion in the vicinity of the exhaust long hole.   The microwave oven food container according to any one of claims 1 to 6, wherein the lid portion is formed of a synthetic resin sheet.

Images