Container precursor and method for producing the same, closed container and method for producing the same

Abstract

The present invention relates to a container precursor and a method for preparing the same, a closed container and a method for preparing the same. In one aspect, a method for preparing a container precursor is described, comprising the steps of: a. providing a sheet-like composite material having a first longitudinal edge portion and a second longitudinal edge portion; b. heating one or both of a first surface of the first longitudinal edge portion and a second surface of the second longitudinal edge portion by means of a heater; c. bringing the first longitudinal edge portion into contact with the second longitudinal edge portion and joining the first longitudinal edge portion with the second longitudinal edge portion to form a longitudinal seam, thereby producing a container precursor. In the produced container precursor there is a longitudinally extending activation zone adjacent to the longitudinal seam which has been heated to a predetermined temperature. In the method, the heating operation is controlled to control the width of the activation zone, thereby ensuring the sealing effect at the longitudinal seam to avoid leakage of the beverage.

Description

Technical Field

[0001] This invention relates to the field of packaging, and particularly to a method for preparing a container precursor, a container precursor, a method for preparing a sealed container for holding food, and a sealed container. Background Technology

[0002] The content in this section only provides background information related to this invention and does not necessarily constitute prior art.

[0003] This invention primarily relates to packaging containers for holding beverages or liquid foods. These packaging containers are typically made of sheet-like composite materials. Sheet-like composite materials generally include a carrier layer and a barrier layer, with the barrier layer typically being a metal layer (e.g., aluminum foil). When metal foil materials such as aluminum foil are used as the barrier layer, after the packaging container is manufactured and used, there is a lack of appropriate waste disposal methods, making recycling difficult and causing environmental damage. Therefore, packaging containers can be manufactured using barrier layers that do not contain metal foil materials such as aluminum foil, thus facilitating recycling and being environmentally friendly.

[0004] However, for sheet composite materials that do not contain metal foils such as aluminum foil (e.g., sheet composite materials without a barrier layer or sheet composite materials with a barrier layer without aluminum foil), directly using the production process of sheet composite materials containing aluminum foil presents new challenges in terms of reliable sealing. For example, if traditional sealing methods for sheet composite materials containing metal foils such as aluminum foil are adopted, the sealing effect at the longitudinal joints may be unsatisfactory. Therefore, it is necessary to improve the sealing methods in the existing technology to at least partially solve the problems existing in the existing technology. Summary of the Invention

[0005] During the manufacturing of packaging containers, the end areas of composite materials are typically heated to seal them, forming a longitudinal seam. If the heating temperature is too high, blistering can occur in the relevant material layers at the end areas, affecting the sealing effect. Since this longitudinal seam includes the joint of the sheet composite material, moisture and other substances can penetrate through this joint into the layered structure of the sheet composite material, particularly into the carrier layer, which is usually composed of pallets or cardboard, causing beverages or liquid foods to leak through the longitudinal seam. Therefore, ensuring a good seal at the end areas of the sheet composite material is crucial.

[0006] One object of the present invention is to ensure a good sealing effect at the end regions of the sheet composite material, thereby preventing beverages or liquid foods from leaking through the longitudinal seams.

[0007] Another objective of this invention is to improve the sealing effect of sheet composite materials that do not contain aluminum foil by controlling the heating operation, thereby preventing beverages or liquid foods from leaking through longitudinal seams.

[0008] In a first aspect of the invention, a method for preparing a container precursor is provided. The method includes the following steps:

[0009] a. Providing a sheet composite material having a first surface and a second surface and having a first longitudinal edge portion and a second longitudinal edge portion opposite to the first longitudinal edge portion, wherein, after the container precursor is manufactured, the first surface will face the interior of the container precursor and the second surface will face the exterior of the container precursor;

[0010] b. Heating one or both of the first surface of the first longitudinal edge portion and the second surface of the second longitudinal edge portion using a heater;

[0011] c. The first surface of the first longitudinal edge portion is brought into contact with the second surface of the second longitudinal edge portion, and the first longitudinal edge portion and the second longitudinal edge portion are joined to form a longitudinal seam, thereby producing the container precursor.

[0012] The manufactured container precursor has a longitudinally extending activated region adjacent to the longitudinal seam, which is heated to a predetermined temperature.

[0013] In this method, the heating operation is controlled to control the width of the activation region.

[0014] Preferably, when the sheet-like composite material contains aluminum foil, the heating operation is controlled so that the width of the activated region is in the range of 2 mm to 3 mm.

[0015] Preferably, when the sheet composite material does not contain aluminum foil, the heating operation is controlled so that the width of the activated region is reduced compared to when the sheet composite material contains aluminum foil.

[0016] Preferably, when the sheet-like composite material does not contain aluminum foil, the heating operation is controlled so that the width of the activated region is in the range of 0.1 mm to 1.5 mm.

[0017] Preferably, when the sheet-like composite material does not contain aluminum foil, the heating operation is controlled so that the width of the activated region is in the range of 0.2 mm to 1 mm.

[0018] Preferably, when the sheet-like composite material does not contain aluminum foil, the heating operation is controlled so that the width of the activated region is 0.5 mm.

[0019] Preferably, controlling the heating operation includes:

[0020] Controlling the temperature of the heater; and / or

[0021] Controlling the lateral position of the heater relative to the sheet-like composite material; and / or controlling the hot gas injection velocity of the heater; and / or

[0022] Controlling the distance between the heater and the sheet-like composite material; and / or

[0023] The relative movement speed between the sheet-like composite material and the heater in the longitudinal direction is controlled.

[0024] Preferably, controlling the temperature of the heater includes: when the sheet composite material does not contain aluminum foil, controlling the temperature of the heater in the range of 400°C to 800°C, and / or, controlling the temperature of the heater such that the temperature is reduced by 50°C to 80°C compared to the case where the sheet composite material contains aluminum foil.

[0025] Preferably, the temperature of the heater is controlled within the range of 480°C to 690°C.

[0026] Preferably, the heating operation is controlled such that the ratio of the width of the activated area to the width of the longitudinal joint is in the range of 0.01 to 0.19.

[0027] Preferably, the heater is a plurality of heaters, which heat the first surface of the first longitudinal edge portion and the second surface of the second longitudinal edge portion respectively and can be controlled independently of each other.

[0028] Preferably, the first surface of the first longitudinal edge portion and the second surface of the second longitudinal edge portion are both heated, so that the manufactured container precursor has a first activation region located on the first surface of the sheet composite material and a second activation region located on the second surface of the sheet composite material, wherein the first activation region is preferentially controlled and monitored.

[0029] Preferably, engaging the first longitudinal edge portion with the second longitudinal edge portion includes pressing the contact portion between the first longitudinal edge portion and the second longitudinal edge portion.

[0030] Preferably, before heating one or both of the first surface of the first longitudinal edge portion and the second surface of the second longitudinal edge portion by the heater, the edge of the second longitudinal edge portion is folded so that the second surface of the second longitudinal edge portion has a folded step portion.

[0031] Preferably, after the container precursor is made, the width of the activated region is measured, and if the width of the activated region deviates from a predetermined range, the heating operation is adjusted.

[0032] In a second aspect of the invention, a container precursor is provided. The container precursor is obtained by the method described in the first aspect of the invention.

[0033] In a third aspect of the invention, a method for preparing a sealed container for holding food is provided. The method includes the following steps:

[0034] a. Providing a container precursor according to a second aspect of the invention;

[0035] b. The bottom region of the container precursor is formed by folding the bottom portion of the sheet-like composite material;

[0036] c. Close the bottom region;

[0037] d. Filling the container precursor with food; and

[0038] e. The head region of the container precursor is formed by folding the head portion of the sheet-like composite material, and the head region is closed to form the sealed container.

[0039] In a fourth aspect of the invention, a sealed container is provided. The sealed container is obtained by a method for preparing a sealed container for holding food according to a third aspect of the invention.

[0040] In a fifth aspect of the invention, a container precursor is provided. The container precursor is manufactured by folding a sheet-like composite material, and the container precursor includes sidewalls.

[0041] The sidewall includes a longitudinal joint, which is formed by heating at least one of the two longitudinal edge portions of the sheet composite material and joining the two longitudinal edge portions together.

[0042] The sidewall also includes a longitudinally extending activation region adjacent to the longitudinal joint, which is heated to a predetermined temperature. The width of the activation region is controlled to have a predetermined value by controlling the heating operation.

[0043] Preferably, the sheet-like composite material comprises aluminum foil, and the width of the activated region is in the range of 2 mm to 3 mm.

[0044] Preferably, the sheet-like composite material does not contain aluminum foil, and the predetermined value of the width of the activated region is in the range of 0.1 mm to 1.5 mm.

[0045] Preferably, the width of the activated region is in the range of 0.2 mm to 1 mm.

[0046] Preferably, the width of the activated region is a predetermined value of 0.5 mm.

[0047] Preferably, the sheet-like composite material includes a barrier layer, the barrier layer comprising:

[0048] A matrix layer, the matrix layer primarily comprising a matrix layer mixture, the matrix layer mixture comprising at least two matrix layer polymers; and

[0049] A barrier layer, which is stacked with the substrate layer and includes a metal oxide,

[0050] The at least two matrix layer polymers include a first matrix layer polymer and a second matrix layer polymer, wherein the first matrix layer polymer and the second matrix layer polymer are different, such that the barrier layer has at least two melting point peaks.

[0051] Preferably, the matrix layer mixture further includes a third matrix layer polymer, which is different from the first and second matrix layer polymers, such that the barrier layer has at least three melting point peaks.

[0052] Preferably, the barrier layer further includes an additional barrier layer located between the substrate layer and the barrier layer, wherein the additional barrier layer comprises polyvinyl alcohol.

[0053] Preferably, the sheet-like composite material includes a barrier layer, the barrier layer comprising:

[0054] The matrix layer, which mainly comprises a polyolefin material or a biodegradable polymer; and

[0055] An additional layer, which is stacked on top of the substrate layer and mainly comprises at least one of a metal oxide and a non-metal oxide, as well as polyvinyl alcohol.

[0056] Preferably, the additional layer includes:

[0057] A first layer, the first layer being located on the substrate layer; and

[0058] The second layer is located on the side of the first layer away from the substrate layer, and the material of the second layer is different from that of the first layer.

[0059] The first layer comprises the polyvinyl alcohol, and the second layer comprises at least one of the metal oxide and the non-metal oxide.

[0060] Preferably, the sheet-like composite material includes a barrier layer, an outer cover layer, and an inner cover layer, with the barrier layer disposed between the outer cover layer and the inner cover layer.

[0061] Preferably, the sheet-like composite material further includes a carrier layer, which is disposed between the outer cover layer and the barrier layer.

[0062] In a sixth aspect of the invention, a sealed container is provided. The sealed container is manufactured using a container precursor as described in a fifth aspect of the invention.

[0063] According to the technical solution of the present invention, on the one hand, by controlling the heating operation, the width of the activated region is controlled within a predetermined range, thereby ensuring a good sealing effect on the two longitudinal edges of the sheet composite material and preventing leakage of beverages or liquid foods through the longitudinal seams. On the other hand, when the sheet composite material does not contain aluminum foil, the heating operation is adjusted compared to the case where the sheet composite material contains aluminum foil, so that the width of the activated region is within a predetermined range, thereby achieving a good sealing effect and preventing leakage of beverages or liquid foods through the longitudinal seams. Attached Figure Description

[0064] Embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings. In the drawings, the same features or parts are indicated by the same reference numerals, and the drawings are not necessarily drawn to scale. In the drawings:

[0065] Figure 1 A schematic diagram is shown of a heater heating a sheet-like composite material, wherein the edge of the second longitudinal edge portion of the sheet-like composite material is folded over;

[0066] Figure 2 A three-dimensional schematic diagram of a heater heating a sheet-like composite material is shown.

[0067] Figure 3 A schematic diagram of a container precursor according to the present invention is shown, wherein a longitudinal seam and a second activation region are shown;

[0068] Figure 4 A schematic diagram of the container precursor is shown from another angle, showing the longitudinal seam and the first activation region;

[0069] Figure 5 A cross-sectional view of a portion of the sidewall of the container precursor according to the present invention is shown;

[0070] Figure 6 A flowchart of a method for preparing a container precursor according to the present invention is shown; and

[0071] Figure 7 A schematic diagram of a sealed container according to the present invention is shown. Detailed Implementation

[0072] Exemplary embodiments of the invention will now be described more fully with reference to the accompanying drawings.

[0073] This document provides exemplary embodiments to make the invention exhaustive and to convey the scope more fully to those skilled in the art. Numerous specific details, such as examples of specific components, apparatuses, and methods, are set forth to provide a thorough understanding of various embodiments of the invention, and these specific details should not be construed as limiting the scope of the invention. It will be apparent to those skilled in the art that exemplary embodiments may be implemented in many different forms, not limited to the specific details disclosed. In some exemplary embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.

[0074] In this document, if used, the directional terms associated with "upper," "lower," "top," and "bottom," etc., are determined, for example, by the positions shown in the accompanying drawings. The use of these directional terms is intended for ease of description and not for limiting the invention.

[0075] The following will combine Figures 1 to 7 The subject matter of the present invention will be described in detail. Figure 1 A schematic diagram is shown of heater 20 heating sheet composite material, wherein the edge of the second longitudinal edge portion 14 of sheet composite material is folded. Figure 2 A three-dimensional schematic diagram of heater 20 heating sheet-like composite material is shown. Figure 3 A schematic diagram of a container precursor 100 according to the present invention is shown, wherein a longitudinal seam 30 and a second activation region 42 are shown. Figure 4 A schematic diagram of the container precursor 100 as viewed from another angle is shown, in which the longitudinal seam 30 and the first activation region 41 are shown. Figure 5 A cross-sectional view of a portion of the sidewall 10 of the container front 100 according to the present invention is shown. Figure 6 A flowchart of a method for preparing a container precursor 100 according to the present invention is shown. Figure 7 A schematic diagram of a sealed container 200 according to the present invention is shown.

[0076] In a first aspect of the invention, a method for preparing a container precursor 100 is provided.

[0077] like Figures 1 to 6 As shown, the method for preparing the container precursor 100 includes:

[0078] Step S610: As Figure 1 As shown, a sheet composite material is provided having a first surface 11 and a second surface 12 and having a first longitudinal edge portion 13 and a second longitudinal edge portion 14 opposite to the first longitudinal edge portion 13, wherein, after the container front 100 is made, the first surface 11 will face the interior 101 of the container front 100 and the second surface 12 will face the exterior of the container front 100.

[0079] Step S620: As Figure 1 and Figure 2 As shown, the heater 20 heats one or both of the first surface of the first longitudinal edge portion 13 and the second surface of the second longitudinal edge portion 14.

[0080] Preferably, there are multiple heaters 20, which heat the first surface of the first longitudinal edge portion 13 and the second surface of the second longitudinal edge portion 14, respectively, and can be controlled independently of each other. The heaters 20 may include any one or a combination of at least two of the following: radiant heaters, ultrasonic heaters, thermal contact heaters, and hot gas jet heaters. Figure 2 As shown, in an embodiment of the present invention, there are two heaters 20, which are hot air jet heaters. Each heater 20 includes a plurality of hot air nozzles (not shown) disposed in a protective cover. A plurality of holes are provided on the surface of the protective cover facing the sheet composite material. The hot air nozzles of the two heaters 20 guide hot air through the holes to the first surface 11 and the second surface 12 of the sheet composite material, thereby heating the first surface 11 and the second surface 12 of the sheet composite material. Although two hot air jet heaters are used in this embodiment of the present invention, it is conceivable that any suitable number and type of heaters can be provided.

[0081] Step S630: As Figure 3 and Figure 4 As shown, the first surface of the first longitudinal edge portion 13 is brought into contact with the second surface of the second longitudinal edge portion 14, and the first longitudinal edge portion 13 and the second longitudinal edge portion 14 are joined to form a longitudinal seam 30, thereby producing the container precursor 100. Step S630 is the step of sealing the two longitudinal edge portions of the sheet composite material.

[0082] Preferably, such as Figure 1As shown, before heating one or both of the first surface of the first longitudinal edge portion 13 and the second surface of the second longitudinal edge portion 14 by the heater 20, the edge of the second longitudinal edge portion 14 is folded so that the second surface of the second longitudinal edge portion 14 has a folded step portion 141.

[0083] Preferably, joining the first longitudinal edge portion 13 and the second longitudinal edge portion 14 includes pressing the contact portion of the first longitudinal edge portion 13 and the second longitudinal edge portion 14 to make the two longitudinal edge portions more firmly joined, thereby improving the sealing effect of the two longitudinal edge portions of the sheet composite material.

[0084] like Figures 3 to 5 As shown, after the container precursor 100 is manufactured, i.e., after the sealing step is completed, the manufactured container precursor 100 has a longitudinally extending activated region adjacent to the longitudinal seam 30, heated to a predetermined temperature. The activated region can be understood as a special region with a visual difference (e.g., a slightly whitish area, or an area with different light reflection than other locations) that can be observed externally after the sheet-like composite material is heated to a predetermined temperature (above the Vicat softening temperature of the heated area material) and cooled. The activated region can also be more easily observed near the longitudinal seam 30 of the container precursor 100 using a polarizing filter, thereby allowing for the measurement of the width of the activated region. The size of the activated region's width can be used to measure and determine whether the heating operation was appropriate. Specifically, as... Figure 2As shown, region 22 is the entire heating area 22 in which the heater 20 heats the first surface 11 of the sheet composite material. Since the sealing position of the sheet composite material is fixed for a fixed product during the actual manufacturing process of the container precursor 100, the width of the area of ​​the entire heating area 22 sealed within the longitudinal joint 30 is fixed. Therefore, after the sealing step, the heated area not covered by the longitudinal joint 30 is the activated area. The width of the activated area can be used to measure the width of the entire heating area 22, thus helping to determine whether the heating operation is appropriate. The inventors have discovered that when the width of the activated area is within a predetermined range, the heating operation is appropriate and a good sealing effect can be achieved. Therefore, by controlling the heating operation to control the width of the activated area, thereby controlling the width of the activated area within a predetermined range, it is helpful to obtain a good sealing effect. Furthermore, as will be further described below, the inventors have also discovered that after the container precursor 100 is formed (i.e., after the longitudinal seam 30 is formed), the width of the activated region can be measured. If the width of the activated region deviates from the predetermined range, it indicates that the heating operation is inappropriate and needs to be adjusted so that the width of the activated region is within the predetermined range, thereby ensuring a good sealing effect of the two longitudinal edge portions of the sheet composite material, thus preventing beverages or liquid foods from leaking through the longitudinal seam.

[0085] Because different sheet composite materials have different structures or contain different materials, the heating parameters (such as heating temperature) for these materials will vary. If the heating operation is inappropriate, a good seal between the two longitudinal edges of the sheet composite material cannot be ensured, leading to leakage of beverages or liquid foods through the longitudinal seams. For example, if the heating temperature is too high, bubbling may occur in the material layers at the two longitudinal edges, affecting the seal and potentially causing leakage. Conversely, if the heating temperature is too low, the material layers at the two longitudinal edges will not melt, also affecting the seal and potentially causing leakage.

[0086] In this invention, the width of the entire heating zone 22 is measured by the width of the activated region, which facilitates measurement and helps determine whether the heating operation is appropriate. If the width of the activated region deviates from a predetermined range, it indicates that the heating operation is inappropriate, and the heating operation is adjusted to bring the width of the activated region within the predetermined range. This allows for the selection of appropriate heating operations for different sheet-like composite materials, thereby ensuring a good sealing effect on the two longitudinal edges of the sheet-like composite material and preventing beverages or liquid foods from leaking through the longitudinal seams.

[0087] Preferably, the first surface of the first longitudinal edge portion 13 and the second surface of the second longitudinal edge portion 14 are both heated, so that a first activation region 41 located on the first surface of the sheet composite material is formed in the manufactured container precursor 100 (e.g., Figure 4 and Figure 5 (as shown) and the second activation region 42 located on the second surface of the sheet-like composite material (as shown) Figure 3 and Figure 5 As shown), the first activation region 41 is located inside the container precursor 100 101, adjacent to... Figure 5 As shown at joint A, moisture may penetrate into the layered structure of the sheet composite material, particularly the carrier layer typically composed of stencils or cardboard, potentially causing beverage leakage. Therefore, prioritizing the control and monitoring of the more critical first activation region 41, while appropriately neglecting the second activation region 42, simplifies the related procedures while ensuring a good seal.

[0088] Preferably, the sheet-like composite material and the heater 20 are movable relative to each other in the longitudinal direction, thus eliminating the need for a long heater.

[0089] Preferably, controlling the heating operation includes controlling at least one of the following: (1) controlling the temperature of the heater 20; (2) controlling the lateral position of the heater 20 relative to the sheet composite material (i.e., along the lateral direction X of the sheet composite material). Figure 1 (3) Control the hot gas injection speed of heater 20; (4) Control the distance between heater 20 and sheet composite material; and (5) Control the relative movement speed between sheet composite material and heater 20 in the longitudinal direction.

[0090] It is conceivable that if the width of the activated area is within a predetermined range, there is no need to adjust the heating operation.

[0091] It is conceivable that if the width of the activation region exceeds a predetermined range, i.e., the width of the activation region is too large, the heating operation can be adjusted as follows: reduce the temperature of the heater 20, and / or move the heater 20 away from the sheet composite material in the transverse direction X, and / or reduce the hot gas injection speed of the heater 20, and / or increase the distance between the heater 20 and the sheet composite material (i.e., move the heater 20 upward), and / or reduce the relative movement speed between the sheet composite material and the heater 20 in the longitudinal direction.

[0092] It is conceivable that if the width of the activation region is less than a predetermined range, i.e., the width of the activation region is too small, the heating operation can be adjusted as follows: increase the temperature of the heater 20, and / or move the heater 20 in the transverse direction X toward the sheet composite material, and / or increase the hot gas injection speed of the heater 20, and / or reduce the distance between the heater 20 and the sheet composite material (i.e., move the heater 20 downward), and / or increase the relative movement speed between the sheet composite material and the heater 20 in the longitudinal direction.

[0093] Sheet composite materials used to manufacture container precursors typically include a carrier layer and a barrier layer. The barrier layer can include metal foil materials such as aluminum foil. "Aluminum foil" refers to a metal layer with a thickness greater than 1 μm. When the barrier layer includes aluminum foil, it has excellent barrier properties, preventing the passage of oxygen and water, and also provides light-blocking characteristics. However, a problem with metal foils such as aluminum foil is that after use as packaging containers, there is a lack of appropriate waste disposal methods, making recycling difficult and causing environmental damage. Therefore, sheet composite materials that do not include metal foils such as aluminum foil (such as sheet composite materials without a barrier layer or sheet composite materials including a barrier layer without aluminum foil) can be used to manufacture packaging containers, which facilitates recycling and is environmentally friendly.

[0094] The inventors discovered that when the sheet composite material contains aluminum foil, the sheet composite material has good heat dissipation effect due to the presence of aluminum foil, and is less likely to cause blistering at the longitudinal joints. Therefore, the heating operation can be controlled to keep the width of the activated area within a larger value, preferably within the range of 2 mm to 3 mm.

[0095] The inventors also discovered that when the sheet composite material does not contain aluminum foil, i.e., when the sheet composite material does not contain a barrier layer or contains a barrier layer without aluminum foil, the heat dissipation effect of the sheet composite material is poor, easily causing blistering at the longitudinal joints. Therefore, it is necessary to control the heating operation to reduce the width of the activation region compared to the case where the sheet composite material contains aluminum foil. In particular, through a series of repeated experiments, the inventors found that making the width of the activation region within the range of 0.1 mm to 1.5 mm, preferably within the range of 0.2 mm to 1 mm, more preferably 0.5 mm or about 0.5 mm, enables proper heating (i.e., avoiding underheating or overheating) to achieve effective sealing of the sheet composite material without aluminum foil. The inventors have discovered that when the sheet composite material does not contain aluminum foil, and the width of the activation region is within the above range, the sealing part of the sheet composite material (especially...) Figure 5The joint position A shown in the figure is less prone to bubbling, thus achieving a good sealing effect and preventing beverages or liquid foods from leaking through the longitudinal seam.

[0096] Preferably, the width of the longitudinal joint 30 can be in the range of 7 mm to 10 mm, so the ratio of the width of the activated area to the width of the longitudinal joint 30 can be in the range of 0.01 to 0.22. More preferably, the width of the longitudinal joint can be in the range of 7.9 mm to 9.5 mm, so the ratio of the width of the activated area to the width of the longitudinal joint 30 can be in the range of 0.01 to 0.19.

[0097] When the sheet composite material does not contain aluminum foil, the heating operation is controlled to reduce the width of the activated region compared to when the sheet composite material contains aluminum foil. As described above, to reduce the width of the activated region, the heating operation can be adjusted as follows: reducing the temperature of heater 20, and / or moving heater 20 away from the sheet composite material in the transverse direction X, and / or reducing the hot gas injection velocity of heater 20, and / or increasing the distance between heater 20 and the sheet composite material (i.e., moving heater 20 upwards), and / or reducing the relative movement speed between the sheet composite material and heater 20 in the longitudinal direction.

[0098] Preferably, when the sheet composite material does not contain aluminum foil, the temperature of the heater 20 is controlled such that the temperature is reduced by 50°C to 80°C compared to the case where the sheet composite material contains aluminum foil. More preferably, the temperature of the heater 20 is controlled in the range of 400°C to 800°C. More preferably, the temperature of the heater 20 is controlled in the range of 480°C to 690°C.

[0099] In a second aspect of the invention, a container precursor 100 is provided, which is obtained by the method for preparing the container precursor 100 described above.

[0100] In a third aspect of the present invention, a method for preparing a sealed container 200 for holding food 300 is provided, the method comprising the following steps:

[0101] a. Providing the container precursor 100 as described in the second aspect of the present invention;

[0102] b. The bottom region of the container precursor 100 is formed by folding the bottom portion 103 of the sheet-like composite material;

[0103] c. Close the bottom area;

[0104] d. Fill the container precursor with 300g of food; and

[0105] e. The head region of the container precursor 100 is formed by folding the head portion 102 of the sheet-like composite material, and the head region is closed, thereby forming a sealed container 200.

[0106] It should be noted here that the final locations formed by the "bottom area of ​​the container front 100" and the "head area of ​​the container front 100" differ depending on the shape of the packaging container. For packaging containers such as square-shaped paper packages and brick-shaped paper packages, the "bottom area of ​​the container front 100" ultimately forms the bottom of the sealed container, and the "head area of ​​the container front 100" ultimately forms the top of the sealed container. However, for packaging containers such as eye-catching bottles (paper bottle-shaped packaging containers), since these packaging containers are filled upside down, the "bottom area of ​​the container front 100" ultimately forms the top of the sealed container, and the "head area of ​​the container front 100" ultimately forms the bottom of the sealed container.

[0107] In a fourth aspect of the invention, a sealed container 200 is provided, which is obtained by a method for preparing a sealed container for holding food according to a third aspect of the invention.

[0108] In a fifth aspect of the invention, a container precursor is provided, which can be obtained by the method for preparing a container precursor according to the first aspect of the invention or by other suitable preparation methods. The container precursor is formed by folding a sheet-like composite material. The container precursor includes sidewalls. The sidewalls include a longitudinal seam formed by heating at least one of two longitudinal edge portions of the sheet-like composite material and joining the two longitudinal edge portions together. The sidewalls also include a longitudinally extending activated region adjacent to the longitudinal seam, heated to a predetermined temperature, the width of which is controlled to have a predetermined value by controlling the heating operation.

[0109] In this invention, the width of the entire heating zone is measured by the width of the activated region, which helps determine whether the heating operation is appropriate. If the width of the activated region deviates from a predetermined range, it indicates that the heating operation is inappropriate, and the heating operation is adjusted to bring the width of the activated region within the predetermined range. This allows for the selection of appropriate heating operations for different sheet-like composite materials, thereby ensuring a good sealing effect on the two longitudinal edges of the sheet-like composite material and preventing beverages or liquid foods from leaking through the longitudinal seams.

[0110] Preferably, both longitudinal edge portions of the sheet-like composite material are heated, such that the sidewall of the container precursor includes a first activation region facing the interior of the container precursor and a second activation region facing the exterior of the container precursor.

[0111] The features regarding the width of the activated region (including the first activated region and the second activated region) described in the method for preparing the container precursor in the first aspect of the present invention above also apply to the width of the activated region of the container precursor in the fifth aspect of the present invention, and therefore will not be repeated here.

[0112] In some embodiments, the sheet-like composite material comprises aluminum foil, and the width of the activated region is predetermined to be in the range of 2 mm to 3 mm.

[0113] In some embodiments, the sheet composite material does not contain aluminum foil, that is, the sheet composite material does not include a barrier layer or includes a barrier layer without aluminum foil, and the predetermined value of the width of the activation region is in the range of 0.1 mm to 1.5 mm, preferably in the range of 0.2 mm to 1 mm, and more preferably 0.5 mm.

[0114] In one embodiment of the invention, when the sheet composite material does not contain a barrier layer and therefore does not contain aluminum foil, the sheet composite material can be one of the following three examples.

[0115] Example 1: A sheet composite material comprises the following layers in sequence, from the outside of the sheet composite material to the inside of the sheet composite material: low-density polyethylene (LDPE), a paperboard layer, an adhesive layer, PA6, an adhesive layer, low-density polyethylene (LDPE), and mPE / LDPE.

[0116] Example 2: The sheet composite material comprises the following layers in a layer sequence in the direction from the outside of the sheet composite material to the inside of the sheet composite material: low-density polyethylene (LDPE), paperboard layer, adhesive layer, high-density polyethylene (HDPE) and mPE / LDPE.

[0117] Example 3: The sheet composite material comprises the following layers in a layer sequence in the direction from the outside of the sheet composite material to the inside of the sheet composite material: low-density polyethylene (LDPE), paperboard layer, low-density polyethylene (LDPE).

[0118] In other embodiments of the invention, the sheet composite material may include a barrier layer. The barrier layer may be a barrier layer containing aluminum foil or a barrier layer without aluminum foil. It is contemplated that the sheet composite material may have any suitable structure and / or include any suitable material.

[0119] Preferably, the sheet-like composite material includes a barrier layer, an outer cover layer, and an inner cover layer, with the barrier layer disposed between the outer cover layer and the inner cover layer.

[0120] Preferably, the sheet-like composite material further includes a carrier layer, which is placed between the outer cover layer and the barrier layer.

[0121] In one embodiment of the invention, when the sheet-like composite material includes a barrier layer, the barrier layer comprises a matrix layer and a barrier layer. The matrix layer mainly comprises a matrix layer mixture, which includes at least two matrix layer polymers. The barrier layer is laminated with the matrix layer and includes a metal oxide. The at least two matrix layer polymers include a first matrix layer polymer and a second matrix layer polymer, which are different, such that the barrier layer has at least two melting point peaks. Because the barrier layer for packaging has at least two different first and second matrix layer polymers, it has at least two melting point peaks. One advantage of this is that when the packaging container is sealed, due to the difference in melting point peaks, one of the first and second matrix layer polymers enters the molten state first, and the other enters the molten state later. That is, as the temperature increases during sealing, the matrix layer polymer with the lower melting point peak enters the molten state first, and the matrix layer polymer with the higher melting point peak enters the molten state later. By ensuring that the barrier layer for packaging has at least two melting point peaks, the layer structure of the barrier layer is prevented from undergoing rapid deformation due to temperature changes. This avoids bubbling of the barrier layer under high-temperature heating conditions, thus ensuring that the packaging material with this barrier layer can complete the heat sealing process within a wider temperature window (i.e., a wider temperature range) during filling and sealing.

[0122] Preferably, the matrix layer mixture further includes a third matrix layer polymer, which is different from the first and second matrix layer polymers, such that the barrier layer has at least three melting point peaks.

[0123] Preferably, the barrier layer further includes an additional barrier layer located between the substrate layer and the barrier layer, and the additional barrier layer includes polyvinyl alcohol.

[0124] In another embodiment of the present invention, when the sheet-like composite material includes a barrier layer, the barrier layer comprises a matrix layer and an additional layer. The matrix layer mainly comprises a polyolefin material or a biodegradable polymer. The additional layer is laminated with the matrix layer and mainly comprises at least one of a metal oxide and a non-metal oxide, as well as polyvinyl alcohol. On the one hand, since the polyolefin material or biodegradable polymer of the matrix layer has good water-blocking properties, it plays a good water-blocking role for the contents in the packaging container; on the other hand, since at least one of a metal oxide and a non-metal oxide is added to the polyvinyl alcohol, the gas-barrier properties of the polyvinyl alcohol are improved, preventing gases such as oxygen and water vapor from seeping into the interior of the packaging container from the outside and affecting the quality of the contents, thereby improving the overall water and oxygen barrier properties of the barrier layer.

[0125] Preferably, the additional layer comprises a first layer and a second layer. The first layer is located on the substrate layer, and the second layer is located on the side of the first layer away from the substrate layer. The material of the second layer is different from that of the first layer. The first layer comprises polyvinyl alcohol, and the second layer comprises at least one of a metal oxide and a non-metal oxide.

[0126] In a sixth aspect of the invention, a sealed container is provided. This sealed container is manufactured using a container precursor as described in a fifth aspect of the invention.

[0127] Although various embodiments of the invention have been described in detail herein, it should be understood that the invention is not limited to the specific embodiments described and shown herein, and other modifications and variations can be made by those skilled in the art without departing from the spirit and scope of the invention. All such modifications and variations fall within the scope of the invention. Moreover, all components described herein can be replaced by other technically equivalent components.

Claims

1. A method for producing a container precursor, the method comprising the steps of: a. providing a sheet-like composite material having a first surface and a second surface and having a first longitudinal edge portion and a second longitudinal edge portion opposite the first longitudinal edge portion, wherein the first surface will face towards the interior of the container precursor and the second surface will face towards the exterior of the container precursor after the container precursor has been made; b. heating one or both of the first surface of the first longitudinal edge portion and the second surface of the second longitudinal edge portion by means of a heater; c. bringing the first surface of the first longitudinal edge portion into contact with the second surface of the second longitudinal edge portion and joining the first longitudinal edge portion to the second longitudinal edge portion to form a longitudinal seam, thereby making the container precursor, wherein in the container precursor that has been made there is a longitudinally extending activation zone adjacent to the longitudinal seam that has been heated to a predetermined temperature, characterized in that in the method the heating operation is controlled to control the width of the activation zone, when the sheet-like composite material comprises an aluminium foil, the heating operation is controlled so that the width of the activation zone is in the range of 2 mm to 3 mm, when the sheet-like composite material does not comprise an aluminium foil, the heating operation is controlled so that the width of the activation zone is reduced compared to the case where the sheet-like composite material comprises an aluminium foil, and when the width of the longitudinal seam is in the range of 7.9 mm to 9.5 mm, so that the ratio of the width of the activation zone to the width of the longitudinal seam is in the range of 0.01 to 0.

19.

2. The method of claim 1, wherein, when the sheet-like composite material does not comprise an aluminium foil, the heating operation is controlled so that the width of the activation zone is in the range of 0.1 mm to 1.5 mm.

3. The method of claim 1, wherein, when the sheet-like composite material does not comprise an aluminium foil, the heating operation is controlled so that the width of the activation zone is in the range of 0.2 mm to 1 mm.

4. The method of claim 1, wherein, when the sheet-like composite material does not comprise an aluminium foil, the heating operation is controlled so that the width of the activation zone is 0.5 mm.

5. The method according to any one of claims 1 to 4, characterized in that, controlling the heating operation comprises: controlling the temperature of the heater; and / or controlling the transverse position of the heater relative to the sheet-like composite material; and / or controlling the hot gas injection speed of the heater; and / or controlling the distance of the heater from the sheet-like composite material; and / or controlling the relative speed of the sheet-like composite material and the heater in the longitudinal direction.

6. The method of claim 5, wherein, controlling the temperature of the heater comprises controlling the temperature of the heater so that the temperature is reduced by 50 °C to 80 °C compared to the case where the sheet-like composite material comprises an aluminium foil, when the sheet-like composite material does not comprise an aluminium foil.

7. The method of claim 6, wherein, controlling the temperature of the heater in the range of 400 °C to 800 °C.

8. The method of claim 7, wherein, controlling the temperature of the heater in the range of 480 °C to 690 °C.

9. The method according to any one of claims 1 to 4, characterized in that, The heater is a plurality of heaters, each of the plurality of heaters heating a first surface of the first longitudinal edge portion and a second surface of the second longitudinal edge portion and being independently controllable from one another.

10. The method according to any one of claims 1 to 4, characterized in that, The first surface of the first longitudinal edge portion and the second surface of the second longitudinal edge portion are heated such that the manufactured container precursor has a first activated area on the first surface of the sheet of composite material and a second activated area on the second surface of the sheet of composite material, wherein the first activated area is preferentially controlled and monitored.

11. The method according to any one of claims 1 to 4, characterized in that, The joining of the first longitudinal edge portion to the second longitudinal edge portion comprises pressing the contact portion of the first longitudinal edge portion to the second longitudinal edge portion.

12. The method according to any one of claims 1 to 4, characterized in that, The edge of the second longitudinal edge portion is crimped such that the second surface of the second longitudinal edge portion has a crimped step before heating one or both of the first surface of the first longitudinal edge portion and the second surface of the second longitudinal edge portion by the heater.

13. The method according to any one of claims 1 to 4, characterized in that, The width of the activated area is measured after the manufacture of the container precursor and the heating operation is adjusted if the width of the activated area deviates from a predetermined range.

14. A container precursor, characterized in that, The container precursor is obtained by the method according to any one of claims 1 to 13.

15. A method for the preparation of a closed container for the containment of food products, characterized in that, The method comprises the following steps: a. providing a container precursor according to claim 14; b. forming a bottom area of the container precursor by folding a bottom portion of the sheet of composite material; c. closing the bottom area; d. filling the container precursor with a food product; and e. forming a head area of the container precursor by folding a head portion of the sheet of composite material and closing the head area, thereby manufacturing the closed container.

16. A closed container characterized in that, The closed container is obtained by the method for manufacturing a closed container for containing a food product according to claim 15.

17. A container precursor manufactured by folding a sheet of composite material, the container precursor comprising a side wall, wherein, the side wall comprising a longitudinal seam formed by heating at least one of two longitudinal edge portions of the sheet of composite material and joining the two longitudinal edge portions to one another, characterized in that the side wall further comprises a longitudinally extending activated area adjacent to the longitudinal seam, the activated area being heated to a predetermined temperature, the width of the activated area being controlled to have a predetermined value by controlling the heating operation, wherein the sheet of composite material comprises a barrier layer, an outer cover layer and an inner cover layer, the barrier layer being interposed between the outer cover layer and the inner cover layer, when the sheet of composite material comprises an aluminum foil, the predetermined value of the width of the activated area is in the range of 2 mm to 3 mm, when the sheet of composite material does not comprise an aluminum foil, the predetermined value of the width of the activated area is in the range of 0.1 mm to 1.5 mm, The sheet composite includes a barrier layer, the barrier layer including:

18. The container precursor of claim 17, wherein, a base layer including primarily a base layer mixture, the base layer mixture including at least two base layer polymers; 19. The container precursor of claim 17, wherein, wherein the at least two base layer polymers include a first base layer polymer and a second base layer polymer, the first base layer polymer and the second base layer polymer being different, such that the barrier layer has at least two melting point peaks.

20. The container precursor of claim 17, wherein, When the sheet composite does not include an aluminum foil, the predetermined value of the width of the activated area is in the range of 0.2 mm to 1 mm. When the sheet composite does not include an aluminum foil, the predetermined value of the width of the activated area is 0.5 mm.

21. The container precursor of claim 17, wherein, The barrier layer further includes:

22. The container precursor of claim 20, wherein, a barrier layer stacked with the base layer and including a metal oxide.

23. The container precursor of claim 17, wherein, The base layer mixture further includes a third base layer polymer, the third base layer polymer being different from the first base layer polymer and the second base layer polymer, such that the barrier layer has at least three melting point peaks. The barrier layer further includes an additional barrier layer between the base layer and the barrier layer, wherein the additional barrier layer includes polyvinyl alcohol. wherein The sheet composite further includes a carrier layer between the outer cover layer and the barrier layer.

24. A container precursor made by folding a sheet composite, the container precursor including a side wall, the side wall including a longitudinal seam formed by heating and joining to each other at least one of two longitudinal edge portions of the sheet composite, characterized in that the side wall further includes a longitudinally extending activated area adjacent to the longitudinal seam, the activated area being heated to a predetermined temperature, the width of the activated area being controlled to have a predetermined value by controlling the heating operation, wherein the sheet composite includes a barrier layer, an outer cover layer, and an inner cover layer, the barrier layer being between the outer cover layer and the inner cover layer, When the sheet composite includes an aluminum foil, the predetermined value of the width of the activated area is in the range of 2 mm to 3 mm, When the sheet composite does not include an aluminum foil, the predetermined value of the width of the activated area is in the range of 0.1 mm to 1.5 mm, The sheet composite includes a barrier layer, the barrier layer including:

25. The container precursor of claim 24, wherein, a base layer including primarily a polyolefin material or a degradable polymer; and an additional layer stacked with the base layer and including primarily at least one of a metal oxide and a non-metal oxide and polyvinyl alcohol. The additional layer includes: a first layer on the base layer; and 26. A closed container characterized by a second layer on a side of the first layer distal from the base layer, the second layer having a material different from a material of the first layer, wherein the first layer includes the polyvinyl alcohol, and the second layer includes the at least one of the metal oxide and the non-metal oxide. The closed container is made by the container precursor according to any one of claims 17 to 25.

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