Patent Publication Number: US-2021162649-A1

Title: Container forming apparatus, container forming method, container, and instant food packaging method using container

Description:
TECHNICAL FIELD 
     The present invention relates to a container forming apparatus, a container forming method, a container, and an instant food packaging method using a container, and more particularly, to a container forming apparatus, a container forming method, a container, and an instant food packaging method using a container with improved poor mold release. 
     BACKGROUND ART 
     In general, plastic forming methods are largely classified into a blow method, an injection method, and a thermoforming method. Among them, the thermoforming method is a method of making a cooling formed product by heating and softening a plastic sheet of a thermoplastic resin to deform the plastic sheet by an external force. 
     The thermoforming method includes pressure forming using compressed air, vacuum forming using vacuum air, and pressure vacuum forming using both compressed air and vacuum air. Recently, in order to increase the precision of forming, pressure vacuum forming using both pressure and vacuum has been generally used. 
     In the pressure vacuum forming, the plastic sheet is cut while forming and taken out from a mold and the forming s is performed at a high speed. Accordingly, a pressure vacuum forming apparatus needs to be made in a structure that is easily released from the mold, and cooling is important. In particular, in the case of forming a thin sheet, since there may be a problem such as crushing when taking out, a structure that is easily taken out is required. 
     Conventionally, a knock-out apparatus for discharging a container, which is a formed product, from a mold for thermoforming is manufactured in a small size on a surface where the bottom of the container contacts. However, according to the conventional method, it is not easy to take out the container during continuous production, and there is a problem that poor mold release occurs, such as a lot of crushing of the bottom surface of the container. 
     DISCLOSURE 
     Technical Problem 
     The present invention is derived to solve the above-described problems, and an object of the present invention is to provide a container forming apparatus, a container forming method, a container, and an instant food packaging method using a container capable of facilitating taking-out by pressing a side portion of the container to be included at the time of taking out, and improving poor mold release such as crushing of the bottom surface of the container. 
     Another object of the present invention is to provide a container forming apparatus, a container forming method, a container, and an instant food packaging method using a container capable of minimizing product defects due to contractional deformation of the container by increasing the strength of the side portion of the container. 
     Technical Solution 
     To achieve the object, according to the present invention, a container forming apparatus for forming the container by thermoforming includes a first mold part which includes a bottom forming part for forming a bottom portion of the container and a side forming part for extending to be inclined upward from the bottom forming part and forming a part of the side portion of the container and is lifted upward to separate and take out the container in which the forming is completed to press the container, and a second mold part which is disposed outside the first mold part and forms the remaining portion except for the part of the side portion. 
     Further, according to the present invention, a container forming method includes a heating step of heating a sheet to be formed into a container, a thermoforming step of press-fitting the heated sheet in a first mold part forming a part of a bottom portion and a side portion of the container and a second mold part provided outside the first mold part and forming the remaining portion except for the part of the side portion and coming into close contact with the first mold part and the second mold part by injection of compressed air and vacuum suction to form the bottom portion and the side portion, and a taking-out step of separating and taking out the container in which the forming is completed from the second mold part by lifting the first mold part upwardly. 
     Meanwhile, according to the present invention, a container includes a bottom portion, a side portion which is formed to be inclined upward from the bottom portion and includes a stepped portion protruding stepwise along a circumferential direction of an outer peripheral surface thereof, and an upper end portion which is provided at an upper side of the side portion and provided with a flange. 
     Meanwhile, according to the present invention, an instant food packaging method includes preparing a container, putting instant food into the container, sealing the container, and cooling the container, wherein the container includes a bottom portion, a side portion which is formed to be inclined upward from the bottom portion and includes a stepped portion protruding stepwise along a circumferential direction of an outer peripheral surface thereof, and an upper end portion which is provided at an upper side of the side portion and provided with a flange. 
     Advantageous Effects 
     According to the present invention, in the container forming apparatus and the container forming method, the first mold part serving as a knock-out has a structure formed by including not only the bottom portion of the container but also the side portion of the container to press the side portion of the container to be included when taking out. Accordingly, when the container is taken out, it is possible to facilitate the taking-out by further increasing a pressing force and improve poor mold release such as crushing of the bottom surface of the container. 
     Further, according to the present invention, since the stepped portion protrudes from the side portion of the container, the strength of the side portion of the container is reinforced, thereby minimizing product defects due to contractional deformation of the container. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       According to the present invention, in the container forming apparatus and the container forming method, the first mold part serving as a knock-out has a structure formed by including not only the bottom portion of the container but also the side portion of the container to press the side portion of the container to be included when taking out. Accordingly, when the container is taken out, it is possible to facilitate the taking-out by further increasing a pressing force and improve poor mold release such as crushing of the bottom surface of the container. 
       Further, according to the present invention, since the stepped portion protrudes from the side portion of the container, the strength of the side portion of the container is reinforced, thereby minimizing product defects due to contractional deformation of the container. 
     
    
    
     MODE FOR INVENTION 
     Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
     First, embodiments to be described below are examples suitable for understanding technical features of a container forming apparatus, a container forming method, a container, and an instant food packaging method using a container according to the present invention. However, the present invention is not restricted and applied to the embodiments to be described below, or the technical features of the present invention are not limited by the embodiments to be described, and various modifications are possible within the technical scope of the present invention. 
       FIGS. 1 and 2  illustrate a container  10  formed by a container forming apparatus  100  according to the present invention and a method thereof,  FIGS. 3 to 6  illustrates the container forming apparatus  100  according to the present invention, and  FIG. 7  illustrates Comparative Example of the container forming apparatus  100  according to the present invention.  FIG. 8  illustrates a flowchart of a container forming method according to the present invention. 
     Referring to  FIGS. 1 and 2 , the container  10  according to the present invention includes a bottom portion  20 , a side portion  30 , and an upper end portion  40 . 
     The bottom portion  20  may be formed in various shapes as long as it may be seated on the ground. When the container  10  is placed on the ground, a portion in contact with the ground may be defined as a bottom surface of the bottom portion  20 . In addition, an inclined portion may be formed on the inside and/or outside of the bottom surface in contact with the ground, but such an inclined portion may be included in the bottom portion  20  when the inclined portion is distinguished from a slope of the side portion  30 . For example, the bottom portion  20  may include a finely inclined portion at a portion to which the bottom surface and the side portion  30  are connected, but this portion is in contrast to the slope of the side portion  30  and is configured as a part of the bottom portion  20 . 
     The side portion  30  is formed to be inclined upward from the bottom portion  20  and includes a stepped portion  33  protruding stepwise along a circumferential direction thereof. Specifically, the side portion  30  may be a side wall which is connected to the bottom portion  20  to form an accommodation space in which the contents are accommodated. The side portion  30  may be formed to be inclined, and the stepped portion  33  may protrude in a strip shape along an outer circumferential surface of the side portion  30 . Here, the stepped portion  33  may be formed adjacent to the bottom portion  20 . The stepped portion  33  protrudes from the side portion  30  to reinforce the rigidity of the side portion  30  of the container  10 . 
     The upper end portion  40  is provided on the upper side of the side portion  30  and provided with a flange  41 . 
     Specifically, the upper end portion  40  may include a skirt  42  extending upward from the side portion  30  and a flange  41  connected to the skirt  42 . If an angle of the skirt  42  is larger than that of the side portion  30  with respect to the bottom surface, the angle thereof is not limited. For example, the skirt  42  may be 90° or more, particularly 94° to 99°, and more particularly 96° to 97° from an extension line formed by extending the bottom surface in an outer direction of the container. 
     Here, the side portion  30  may include a first side surface  31  and a second side surface  35  provided in a vertical direction. The first side surface  31  extends to be inclined upward from the bottom portion  20 , inclined at a first slope based on the bottom surface of the bottom portion  20 , and formed with a stepped portion  33 . The second side surface  35  extends to be inclined upward from the first side surface  31  and may be inclined at a second slope greater than the first slope with respect to the bottom surface. 
     The container  10  may be a container manufactured by thermoforming, and specifically, may be a container manufactured by pressure and/or vacuum. For example, the container  10  may be a container manufactured using the container forming apparatus  100  to be described below. 
     Referring to  FIGS. 3 to 6 , the container forming apparatus  100  according to the present invention is based on forming the container  10  by thermoforming, and includes a first mold part  200  and a second mold part  300 . 
     Specifically, the container forming apparatus  100  according to the present invention may manufacture a container by thermoforming, and more specifically, may form a container by pressure vacuum forming. That is, a sheet may be formed by being in close contact with the first and second mold parts  200  and  300  by injection of compressed air and vacuum suction. However, the thermoforming method to be applied to the present invention is not limited thereto, and may be formed by, for example, at least one of injection of compressed air and vacuum suction. 
     The first mold part  200  includes a bottom forming part  210  for forming the bottom portion  20  of the container  10 , and a side forming part  230  for extending to be inclined upward from the bottom forming part  210  and forming a part of the side portion  30  of the container  10 . The first mold part  200  is lifted upward to separate and take out the container  10  in which the forming is completed to press the container  10 . 
     Specifically, referring to  FIGS. 3 and 6 , the first mold part  200  may include the bottom molding part  210  and the side molding part  230 . The bottom molding part  210  may form the bottom portion  20  of the container  10  and may be provided to correspond to the shape of the bottom portion  20  of the container  10  to be formed. 
     The side molding part  230  may form a lower portion which is a part of the side portion  30  of the container  10 , and may extend to be inclined upward from the bottom molding part  210 . That is, the first mold part  200  may form a part of the lower portion of the bottom portion  20  and the side portion  30  of the container  10 . 
     In addition, referring to  FIG. 4 , the first mold part  200  may be provided to be lifted upwardly. Specifically, when the forming of the container  10  is completed, the first mold part  200  is lifted upwardly to press the container  10 , thereby separating and taking out the container  10  from the second mold part  300 . That is, the first mold part  200  may serve as a knockout for ejecting a formed product in which the forming is completed. 
     The second mold part  300  is disposed outside the first mold part  200  and forms the remaining portion except for the part of the side portion  30 . Here, the second mold part  300  may be a cavity mold together with the first mold part  200 . 
     Specifically, the second mold part  300  may be disposed around the outer circumference of the first mold part  200  to form the side portion  30  of the container  10 . That is, the second mold part  300  may form the side portion  30  of the container  10  together with the side forming part  230  of the first mold part  200 . More specifically, the upper portion of the side portion  30 , which is a portion excluding a part of the lower portion of the side portion  30  formed by the side forming part  230 , may be formed. In  FIG. 3 , H 1  and H 2  (not illustrated) are vacuum air holes for vacuum suction for bringing the sheet into close contact with the first mold part  200  and the second mold part  300 . 
     As described above, in the container forming apparatus  100  according to the present invention, the first mold part  200  serving as a knock-out has a structure formed to include not only the bottom portion  20  of the container  10  but also the side portion  30  of the container  10  to press the side portion  30  of the container  10  to be included when taking out. Accordingly, when the container  10  is taken out, it is possible to facilitate the taking-out by further increasing a pressing force and improve poor mold release such as crushing of the bottom surface of the container  10 . 
     Specifically, as Comparative Example illustrated in  FIG. 7 , when the first mold part  200  is provided to press only the bottom portion  20  of the container  10 , an appropriate pressing force is not applied to the container  10 , so that it may be difficult to be taken out and crushing of the bottom surface of the container  10  may occur. In particular, in the case of forming a thin sheet, when pressing a narrow surface of the bottom of the container  10 , the bottom of the container  10  may be crushed. Accordingly, it may be advantageous to press the side portion  30  that may receive a relatively larger force. Accordingly, according to the present invention, the first mold part  200  presses the side portion  30  of the container  10  to be included, thereby improving such poor mold release. 
     In addition, according to the present invention, when taking out, the first mold part  200  and the second mold part  300  are separated from the side portion  30  of the container  10 , so that a parting line P (see the stepped portion  33  of  FIGS. 1 and 2 ) may be formed on the side portion  30  of the container  10 . In the parting line P formed on the side portion  30  of the container  10 , the stepped portion  33  in the form of a rib protruding finely is formed to reinforce the strength of the side portion  30  of the container  10 . 
     Accordingly, it is possible to minimize the contractional deformation of the container  10  in the product packaging and distribution process of the container  10 . 
     Specifically, the container  10  packaging foods such as aseptic cooked rice and the like is sealed and packaged in a hot state, and may be naturally or forcibly subjected to a cooling process. At this time, as the hot air is cooled, air contraction occurs, so that the pressure inside the container  10  may become a negative pressure state that is lower than that of the outside. As such, when the negative pressure is applied, a thin portion or a portion subjected to excessive force of the container  10  may be easily contracted and deformed, and particularly, the side portion  30  of the container  10  is frequently contracted and deformed. Accordingly, in the container  10  according to the present invention, a rib (stepped portion) by the parting line P is formed on the side portion  30  of the container  10  to reinforce the strength of the side portion  30  of the container  10 , thereby minimizing product defects due to such contractional deformation. 
     In addition, according to the present invention, the side portion  30  of the container  10  is pressed to be included when taking out, thereby minimizing defects occurring on the bottom portion  20  of the container  10  by the angle of the skirt  42  when taking out. Specifically, the skirt  42  is configured at the angle as described above and is a portion having an inverted tapered structure, and a lot of force is applied to the when taking out, and in particular, in the case of molding using a thin sheet such as a container for instant food, the deformation rate of the bottom portion is high when pressing the bottom portion  20 . 
     However, when a small area of the bottom portion  20  of the container  10  is pressed when taking out, the stress may be concentrated to increase a defect rate. Accordingly, according to the present invention, since a large area of the bottom portion is pressed when taking out and the side portion  30  including an inclined surface is pressed, the force applied to the bottom portion  20  may be distributed over a large area. As a result, even in the case of forming the container having the skirt  42  having an inverted tapered structure using the thin sheet according to the present invention, it is possible to minimize the deformation of the bottom portion  20 . 
     Meanwhile, as described above, the side portion  30  of the container  10  may include a first side surface  31  which extends to be inclined upward from the bottom portion  20  and has a first slope with respect to the bottom surface of the bottom portion  20 , and a second side surface  35  which extends to be inclined upward from the first side surface  31  and has a second slope with respect to the bottom surface. In addition, the side forming part  230  provided in the first mold part  200  may be formed to be inclined with the first slope. 
     Here, the first slope and the second slope may be the same as or different from each other, and more specifically, the first slope may be provided more gently than the second slope. Accordingly, the first mold part  200  presses a portion of the side portion  30  of the container  10  with a gentle slope at the bottom. Accordingly, even if the first mold part  200  presses the side surface of the container  10 , there is an advantage that the upper end portion  40  of the container  10  is not broken. 
     In addition, the inclination angle of the side portion  30  of the container  10  is not limited, and may be provided at, for example, about 15° or more with respect to the bottom surface. However, the present invention is not limited thereto, and the inclination angle may be modified at various angles if the damage to the upper end portion  40  may be prevented when the first mold part  200  presses the container  10 . 
     Meanwhile, referring to  FIGS. 3 and 4 , the second mold part  300  may include a first inclined surface  310  and a second inclined surface  320 . 
     The first inclined surface  310  is inclined at the first slope with respect to the reference surface of the bottom forming part  210  at the same angle as the bottom surface, and may form a first side surface  31  together with the side forming part  230 . In addition, the second inclined surface  320  may extend from the first inclined surface  310 , inclined at the second slope with respect to the reference surface, and form a second side surface  35 . 
     Referring to  FIG. 2 , the first side surface  31  provided on the side portion  30  of the container  10  may include a first region  31   a  and a second region  31   b . The first region  31   a  is a region that continues from the bottom part  20 , and the second region  31   b  may be located above the first region  31   a . In addition, on a cross section perpendicular to the bottom portion  20  (see  FIG. 2 ), the length of the first region  31   a  may be shorter than the length of the second region  31   b.    
     In addition, the side forming part  230  of the first mold part  200  forms the first region  31   a , and the first inclined surface  310  of the second mold part  300  may form the second region  31   b . Accordingly, the first mold part  200  and the second mold part  300  may be separated between the first region  31   a  and the second region  31   b  when taking out. 
     More specifically, the side portion  30  further includes a stepped portion  33 , and the stepped portion  33  is located between the first region  31   a  and the second region  31   b  and may protrude stepwise along a circumferential direction on an outer circumferential surface of the first side surface  31 . That is, the stepped portion  33  may be formed on the parting line P where the first mold part  200  and the second mold part  300  are separated. Here, since the length of the first region  31   a  is shorter than the length of the second region  31   b , the stepped portion  33  may be formed adjacent to the bottom portion  20 . 
     Meanwhile, the second mold part  300  may be spaced apart at a predetermined interval from the first mold part  200  to the outside. More specifically, the first inclined surface  310  may be spaced apart at a predetermined interval from the side forming part  230  (see d of  FIG. 5 ). 
     As such, since the first mold part  200  and the second mold part  300  are provided to be spaced apart from each other, it is possible to prevent abrasion due to the lifting operation of the first mold part  200  when taking out. In addition, since the size of the stepped portion  33  formed on the parting line may be further increased by a distance d between the first mold part  200  and the second mold part  300 , the strength of the side portion  30  of the container  10  may be further reinforced. 
     Here, the distance d between the first mold part  200  and the second mold part  300  may be variously applied, and may be provided with, for example, about 0.3 mm. However, the distance d between the first mold part  200  and the second mold part  300  is not limited thereto, and may be modified in various sizes if the distance may prevent abrasion due to the lifting operation. 
     Meanwhile, the present invention may further include a driving part (not illustrated) and a guide part  500 . 
     The driving part may drive the first mold part  200  upward. As long as the driving part may drive the first mold part  200  upward, the type thereof is not limited. For example, the first mold part  200  may be driven by a cam member or air pressure, but the present invention is not limited thereto. 
     The guide part  500  may guide the vertical movement of the first mold part  200 . The guide part  500  may be provided in the form of a guide shaft like the illustrated example, but is not limited thereto. 
     Meanwhile, referring to  FIG. 3 , the present invention may further include a third mold part  400 . 
     The third mold part  400  may include a skirt forming part  420  and a flange forming part  410 . In addition, the third mold part  400  may further include a cutting part  430 . The skirt forming part  420  is provided on the upper side of the second mold part  300  to form the skirt  42  of the container  10 , and the flange forming part  410  may form a flange  41  of the container  10 . 
     In addition, the cutting part  430  may be provided outside the flange forming part  410  to cut the container  10  in which the forming is completed. 
     Hereinafter, as another aspect of the present invention, a container forming method will be described with reference to  FIGS. 3 to 6 and 8 . 
     The container forming method according to the present invention includes a heating step (S 110 ), a thermoforming step (S 130 ), and a taking-out step (S 170 ). In the heating step (S 110 ), a sheet to be formed into the container  10  is heated. 
     In the thermoforming step (S 130 ), the heated sheet is press-fitted in the first mold part  200  forming a part of the bottom portion  20  and the side portion  30  of the container  10  and the second mold part  300  provided outside the first mold part  200  and forming the remaining portion except for the part of the side portion  30  and comes into close contact with the first mold part  200  and the second mold part  300  by injection of compressed air and vacuum suction to form the bottom portion  20  and the side portion  30 . 
     Specifically, when the sheet having a predetermined thickness is heated at a temperature suitable for forming, the sheet may be first press-fitted into the first mold part  200  and the second mold part  300  using a plug. In addition, by injecting compressed air, the sheet may come into close contact with the first mold part  200  and the second mold part  300 . At this time, the sheet may be brought into close contact with the sheet by vacuuming the first mold part  200  and the second mold part  300  by vacuum suction. Accordingly, the bottom portion  20  and the side portion  30  of the container  10  may be formed. In the thermoforming step (S 130 ), the upper end portion  40  of the container  10  may be formed through the third mold part  400 . 
     In the cutting step (S 150 ), the container  10  in which the forming is completed may be cut. The cutting step (S 150 ) may be performed before or after the taking-out step (S 170 ). Hereinafter, a case in which the cutting step (S 150 ) is performed before the taking-out step (S 170 ) is described as an example, but is not limited thereto, and the cutting step (S 150 ) may be performed before or simultaneously with the taking-out step (S 170 ). 
     In the taking-out step (S 170 ), the first mold part  200  is lifted upwardly, and the container  10 , in which the forming is completed, is separated from the second mold part  300  and taken out. 
     Specifically, in the taking-out step (S 170 ), when the container  10 , in which the forming is completed, is cut, the container  10  may be taken out. Referring to  FIG. 4 , while the first mold part  200  is lifted upwardly, the container  10  may be separated from the second mold part  300 , and the separated container  10  may be taken out. A series of thermoforming steps including the heating step (S 110 ), the thermoforming step (S 130 ), the cutting step (S 150 ), and the taking-out step (S 170 ) may be performed at high speed in a short time. 
     Meanwhile, in the thermoforming step, the stepped portion  33  may protrude stepwise from the side portion  30  through a spaced gap between the first mold part  200  and the second mold part  300 . 
     Hereinafter, as yet another aspect of the present invention, an instant food packaging method using a container will be described. 
     The packaging method of instant food using a container according to the present invention includes preparing a container, putting instant food into the container, sealing the container, and cooling the container. 
     So long as the instant food applied to the present invention requires cooling in the packaging process, the type thereof is not limited, and for example, the instant food may include instant rice, instant soup, instant porridge, and the like, but is not limited thereto. 
     In the sealing of the container, the means and method for sealing the container are not limited, and various materials and methods may be applied. For example, the upper end of the container may be sealed by using a lead film. 
     In the cooling of the container, the cooling temperature may be applied without limitation as long as the temperature is a temperature lower than the temperature of the instant food in the putting of the instant food into the container. 
     According to the present invention, in the container forming apparatus and the container forming method, the first mold part serving as a knock-out has a structure formed to include not only the bottom portion of the container but also the side portion of the container to press the side portion of the container to be included when taking out. Accordingly, when the container is taken out, it is possible to facilitate the taking-out by further increasing a pressing force and improve poor mold release such as crushing of the bottom surface of the container. 
     Further, according to the present invention, since the stepped portion protrudes from the side portion of the container, the strength of the side portion of the container is reinforced, thereby minimizing product defects due to contractional deformation of the container. 
     While the specific embodiments of the present invention have been described above, the spirit and scope of the present invention are not limited to these specific embodiments, and various modifications and variations can be made without changing the subject matter of the present invention disclosed in the appended claims by a person with ordinary skill in the art to which the invention pertains.