A microwaveable PP coated paper container and its processing technology

Abstract

The present application relates to a microwaveable PP coated paper container and its processing technology. The paper container comprises a container wall and a container bottom. The container bottom is connected to the lower side of the container wall. The upper end of the container wall forms a container opening. The inner wall of the container wall and the container bottom are both provided with a PP coated layer. The container wall and the container bottom are both bonded by the PP coated layer. The internal connection between the container wall and the container bottom is also provided with a PP reinforcing layer. The top opening of the container wall is provided with a first curling edge. The processing technology comprises: PP coating and die-cutting of base paper to obtain container wall-shaped paper and container bottom, heating the edge of the container wall-shaped paper, rolling to obtain the container wall, loading the container bottom, heating and bonding to obtain a preformed container; spraying PP coating liquid into the inner cavity of the preformed container and heating to form a PP reinforcing layer; curling the top of the container wall to obtain a PP coated paper container. The paper container of the present application has the effect of being easy to carry out microwave heating; the processing technology has the effect of improving processing efficiency and quality.

Description

Technical Field

[0001] The present application relates to the field of paper containers, and in particular to a microwaveable PP coated paper container and a processing technology thereof. Background Art

[0002] Paper containers such as paper cups and paper bowls are very commonly used in people's lives, especially in food packaging, they are often used to hold water, beverages, and various edible liquids or foods. However, the thermal insulation and heat resistance of the commonly used single-layer paper containers are still far from meeting people's usage requirements, which brings inconvenience to people's daily use.

[0003] The Chinese utility model patent with application number 201621179515.3 discloses a high-heat-sealable and high-strength paper container, including a cup body and a cup bottom. The cup body is connected to the cup bottom, and an outer film layer, a heat insulation layer, a barrier layer and an inner film layer are sequentially arranged from the outside to the inside. The outer film layer is formed by bonding the two ends of a fan-shaped paper, the heat insulation layer is composed of a plurality of equidistant edges, and the middle of the edge is hollow. The barrier layer is an aluminum-plated layer, and the inner film layer is formed by bonding the two ends of a complete fan-shaped white cardboard, and a PE coating layer is arranged on the inner side of the fan-shaped white cardboard.

[0004] Regarding the above-mentioned related technologies, the inventors believe that since the PE coating layer arranged on the inner side of the fan-shaped white cardboard has a low melting point, the PE coating layer will melt when heated in a microwave oven, resulting in a decrease in the stiffness and barrier properties of the paper container, and there is a defect that it is not convenient for microwave heating. Summary of the invention

[0005] In order to facilitate microwave heating of paper containers, the present application provides a microwaveable PP coated paper container and a processing technology thereof.

[0006] In the first aspect, the present application provides a microwaveable PP coated paper container, which adopts the following technical solution:

[0007] The present application provides a microwaveable PP coated paper container adopting the following technical solution:

[0008] A microwaveable PP coated paper container comprises a container wall and a container bottom, wherein the container bottom is connected to the lower side of the container wall, a container opening is formed at the upper end of the container wall, a PP coated layer is provided on the inner wall of the container wall and the container bottom, the container wall is formed by gluing paper sheets together, and the container wall and the container wall and the container bottom are bonded together by the PP coated layer, a PP reinforcing layer is further provided at the internal connection between the container wall and the container bottom, and a first curling edge is provided at the top opening of the container wall.

[0009] By adopting the above technical scheme, the PP coating layer is designed, and the possibility of the coating layer of the paper container being melted and damaged during the microwave heating process is reduced by utilizing the characteristic that the melting point of the PP coating layer is higher than the temperature required for heating food, that is, the paper container can still maintain good insulation and strength during the microwave heating process; and because the container wall and the bonding between the container wall and the container bottom are both bonded through the PP coating layer, the adhesion performance can still be maintained under the high temperature condition of microwave heating, so that the paper container can still maintain structural stability under the microwave heating environment; the bonding part of the container wall and the container bottom is structurally strengthened by the PP reinforcement layer to overcome the disadvantage that the bonding part of the container wall and the container bottom of the paper container is prone to leakage, so that the paper container as a whole has good insulation performance. The designed PP coating layer and PP reinforcement layer reduce the infiltration of moisture in the food into the container wall and bottom, so that the paper container can maintain stiffness and insulation properties even in the high temperature environment of microwave heating, which facilitates microwave heating of the paper container and improves the practicality of the paper container; the designed first curled edge strengthens the structural strength of the container opening, making it easy to move the microwave-heated paper container by applying force to the first curled edge, reducing the possibility of deformation of the paper container when force is applied to the paper container, and facilitating microwave heating of the paper container.

[0010] Optionally, a thickened wall is provided at one end of the container wall close to the container bottom, and the thickness of the thickened wall is greater than the thickness of the container wall.

[0011] By adopting the above technical solution, the designed thickened wall strengthens the bottom strength of the paper container, so that when the heated paper container is moved, it can be supported from the bottom without contacting the container wall with a higher temperature; and it is also possible to hold the paper container for a long time by applying force to the first curled edge and the thickened wall at the same time, which facilitates the removal and placement of the paper container during microwave heating and its use after heating is completed.

[0012] Optionally, a printing layer is provided on the outer side of the container wall, a PP coating layer is also provided on the outer wall of the printing layer, and a second curling edge is provided on the bottom of the printing layer.

[0013] By adopting the above technical scheme, the printed layer is blocked by the PP coating layer, which limits the movement and dispersion of dye molecules on the printed layer after microwave heating, reduces the contact between users and dye molecules, and improves the safety of paper containers. It can also replace the varnish of the printed layer, so that after the printed layer is printed, there is no need to spray varnish for brightening, which facilitates processing. At the same time, the PP coating layer can also provide waterproof protection for the printed layer to maintain the stiffness of the paper container and reduce the impact and restrictions of the external environment on the use of the paper container. The designed second curling edge further strengthens the bottom strength of the paper container.

[0014] Optionally, the distance from the second curled edge to the bottom end of the container wall is smaller than the distance from the container bottom to the bottom end of the container wall.

[0015] By adopting the above technical solution, the second curled edge can serve as a preparatory measure for erosion and damage to the bottom of the container wall. Once the bottom of the container wall is soaked and softened by external moisture, the second curled edge can support the paper container, extend the time required for the bottom of the container to be further soaked, and improve the practicality of the paper container.

[0016] Optionally, a sealing assembly is provided on the outer wall of the printing layer, and the sealing assembly includes a tear strip and a double ring buckle, the tear strip is provided on the printing layer and can be torn away from the printing layer from one end of the tear strip, the double ring buckle is adhered to the printing layer, and the free end of the tear strip after being torn can bypass the container opening and pass through the double ring buckle for fixation.

[0017] By adopting the above technical scheme, when a paper container containing food is heated in a microwave oven, in order to reduce the dirt inside the microwave oven caused by liquid splashing, a top cover is usually installed on the paper container and the top cover is temporarily fixed. When fixing, the tear strip is torn off, and the tear strip is passed through the top cover covering the opening of the container, and the free end of the tear strip is passed through the double ring buckle, and then the tension of the tear strip is adjusted to complete the fixing of the top cover and put it in the microwave oven for heating. The designed sealing assembly has a simple structure and can simply fix the top cover. The fixed top cover can not only prevent liquid splashing, but also avoid the top cover from expanding due to a large pressure difference between the inside and outside of the paper container during heating due to over-tightening, and is highly practical.

[0018] In the second aspect, the present application provides a processing technology for a microwaveable PP coated paper container, which adopts the following technical solution:

[0019] A processing technology for a microwaveable PP coated paper container comprises the following steps:

[0020] Step 1: PP coated paper production, PP coating is applied to base paper to obtain PP coated paper;

[0021] Step 2: Making the container wall and the container bottom, die-cutting the obtained PP coated paper to obtain container wall paper and container bottom, heating the edge of the obtained container wall paper to be overlapped, and then rolling it to obtain the container wall;

[0022] Step 3: Initially forming the container, inserting the container bottom into the container wall, heating and bonding, and obtaining an initially formed container;

[0023] Step 4: PP reinforcement layer processing, spraying atomized PP coating liquid into the inner cavity of the primary formed container, heating the bottom part of the container, so that a PP reinforcement layer is formed at the internal connection between the container wall and the container bottom;

[0024] Step 5: Curling: curl the top of the container wall to obtain a PP coated paper container.

[0025] By adopting the above technical scheme, the entire processing process has strong flow, which is conducive to the realization of assembly line operation and helps to improve the production efficiency of paper containers. Moreover, no additional adhesive is required in the overall processing process. The bonding and forming can be achieved only by hot melting the PP coating layer. The obtained paper container has high quality stability and good heat resistance. It can be used under conventional microwave heating conditions and is highly practical.

[0026] Optionally, in step three, the container bottom is pushed into the container wall from the bottom of the container wall.

[0027] By adopting the above technical solution, the curling edge during the installation of the container bottom is located on the side away from the container opening, so that a joint seam is formed at the internal connection between the container wall and the container bottom, which facilitates the PP coating liquid in the subsequent step four to converge to the internal connection between the container wall and the container bottom, which helps to improve the anti-seepage effect of the PP reinforcement layer.

[0028] Optionally, after the heating and bonding in step three, a portion of the container wall at the container bottom away from the container opening is extruded so that the thickness of the extruded portion of the container wall is increased to form a thickened wall.

[0029] By adopting the above technical solution, the thickened wall is formed by extrusion, the process is simple, and the formed thickened wall has high strength, which is convenient and practical.

[0030] Optionally, step four also includes: preparing a printing paper tube, printing a pattern on one side of the base paper, and performing PP lamination, and then die-cutting to obtain printed paper, and heating the edges of the printed paper to be overlapped, and then rolling the printed paper to obtain a printing paper tube, and curling the bottom of the printing paper tube; sleeve the printing paper tube, sleeve the printing paper tube on the initially formed container, and bond the printing paper tube and the initially formed container.

[0031] By adopting the above technical solution, the production of the printing paper tube can be carried out simultaneously with the initial forming of the container, and then assembled centrally, which helps to improve the processing efficiency and is convenient and practical.

[0032] Optionally, the step four also includes: engraving an easy-tear line on the printed paper when die-cutting the printed paper, and gluing a double ring buckle on the printed paper tube before sleeved.

[0033] By adopting the above technical solution, an easy-tear line is engraved on the printed paper, so that an easy-tear portion is formed on the obtained printed paper tube, which can be torn open to become a tear strip when needed, and cooperates with the double ring buckle, which is convenient and practical.

[0034] In summary, the present application includes at least one of the following beneficial technical effects:

[0035] 1. The designed PP coating layer and PP reinforcement layer reduce the infiltration of moisture in the food into the container wall and bottom, so that the paper container can maintain stiffness and insulation performance even in a high temperature environment of microwave heating, which facilitates microwave heating of the paper container and improves the practicality of the paper container;

[0036] 2. The designed cover assembly has a simple structure and can simply fix the top cover. The fixed top cover can prevent liquid splashing and also prevent the top cover from expanding due to the large pressure difference between the inside and outside of the paper container during heating caused by over-tight closure. It is highly practical.

[0037] 3. The designed processing technology has a strong flow throughout the entire processing process, which is conducive to assembly line operation and helps to improve the production efficiency of paper containers. Moreover, no additional adhesive is required during the overall processing process. The bonding and forming can be achieved only by hot melting the PP coating layer. The resulting paper container has high quality stability and good heat resistance. It can be used under conventional microwave heating conditions and is highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of the overall structure of the microwaveable PP coated paper container of an embodiment of the present application.

[0039] Figure 2 yes Figure 1 Cross-sectional view of the microwaveable PP coated paper container.

[0040] Figure 3 yes Figure 2 Enlarged schematic diagram of part A.

[0041] Figure 4 This is a diagram of the state of a microwaveable PP coated paper container when it is heated.

[0042] Figure 5 yes Figure 4 Schematic diagram of the structure of the double ring buckle.

[0043] Explanation of the reference numerals: 1. container wall; 11. first curling edge; 12. thickened wall; 2. container bottom; 3. PP coating layer; 4. PP reinforcement layer; 5. printing layer; 51. second curling edge; 6. capping assembly; 61. tear strip; 611. easy tear line; 62. double ring buckle; 621. top wall perforation; 622. side wall perforation; 7. top cover. DETAILED DESCRIPTION

[0044] The following is combined with Figure 1-5 This application is described in further detail.

[0045] The present application discloses a microwaveable PP coated paper container. Figure 1 and Figure 2The microwaveable PP coated paper container includes a container wall 1, a container bottom 2, a printing layer 5, a PP coated layer 3 and a capping assembly 6. The container bottom 2 is connected to the lower side of the container wall 1, the upper end of the container wall 1 forms a container opening, the printing layer 5 is sleeved outside the container wall 1, and the capping assembly 6 is arranged on the printing layer 5.

[0046] Reference Figure 2 and Figure 3 , the inner and outer walls of the container wall 1 and the container bottom 2 are sprayed with a PP coating layer 3, wherein the container wall 1 is formed by bending and bonding a fan-shaped double-sided PP coating paper sheet, and the adhesive used for bonding is a PP coating that is melted after heating the overlapping part of the double-sided PP coating paper sheet. The container wall 1 and the container wall 1 and the container bottom 2 are bonded by the melted PP coating layer 3, and the internal connection between the container wall 1 and the container bottom 2 is also sprayed with PP coating liquid, which becomes a PP reinforcement layer 4 after solidification. The PP coating liquid in this embodiment is made by PP particles melt-extruded by a screw extruder. A first curling edge 11 is integrally provided at the top opening of the container wall 1, and a thickened wall 12 is extruded and formed at one end of the container wall 1 close to the container bottom 2, and the thickness of the thickened wall 12 is greater than the thickness of the container wall 1. The outer side of the container wall 1 is sleeved with a cylindrical printing layer 5, the outer wall of the printing layer 5 is printed with a packaging pattern, and the PP coating layer 3 is also sprayed and formed. In other embodiments, the PP coating layer 3 can also be sprayed and formed on the inner wall of the printing layer 5 according to the use requirements. The bottom of the printing layer 5 is integrally provided with a second curling edge 51, and the distance from the second curling edge 51 to the bottom end of the container wall 1 is smaller than the distance from the container bottom 2 to the bottom end of the container wall 1. The printing layer 5 at the second curling edge 51 is also hot-melt bonded to the container wall 1 through the PP coating layer 3 on the outside of the container wall 1.

[0047] Reference Figure 4 and Figure 5The cover assembly 6 includes a tear strip 61 and a double ring buckle 62. The tear strip 61 is formed by three tear lines 611 engraved on the printing layer 5, wherein two tear lines 611 are arranged at intervals along the generatrix direction of the printing layer 5, and one end of the two tear lines 611 close to the second curling edge 51 is connected by another tear line 611, so that the tear strip 61 can be torn off from the peripheral printing layer 5 at the end close to the second curling edge 51, while the end close to the first curling edge 11 is still connected to the printing layer 5. The double ring buckle 62 is glued to the printing layer 5. In this embodiment, the top wall, bottom wall and side wall away from the printing layer 5 of the double ring buckle 62 are all provided with perforations, and the top wall perforations 621 and the side wall perforations 622 are connected and smoothly transitioned, and the bottom wall perforations are also connected and smoothly transitioned with the side wall perforations 622, wherein the bottom perforations are not shown in the figure. When fixing the tear strip 61, the free end of the tear strip 61 is inserted into the top wall perforation 621 of the double ring buckle 62, and then passed out from the side wall perforation 622, and then passed out from the bottom wall perforation to fix the tear strip 61. When the paper container is heated and a top cover 7 is provided on the paper container, the free end of the tear strip 61 after being torn can bypass the container opening and the top cover 7 and pass through the double ring buckle 62, so as to temporarily clamp and fix the top cover 7.

[0048] This embodiment also discloses a processing technology of the microwaveable PP coated paper container, comprising the following steps:

[0049] Step 1: PP coated paper production, PP particles are coated on both sides of the base paper through a double-sided laminating machine to obtain double-sided coated PP coated paper.

[0050] Step 2: The container wall 1 and the container bottom 2 are produced. The PP coated paper is die-cut by a die-cutting machine to obtain a fan-shaped container wall paper and a circular container bottom 2. The edges of the obtained container wall paper to be overlapped are heated by an ultrasonic heater. The container wall 1 is then transported to a paper cup machine and rolled up by the rolling station of the paper cup machine to obtain the container wall 1.

[0051] Step 3: The container is initially formed, and the container bottom 2 is also sent to the paper cup machine. The paper cup machine pushes the container bottom 2 from the bottom of the container wall 1 into the container wall 1 at the assembly station, and transfers it to the heating station of the paper cup machine. The contact part of the container bottom 2 and the container wall 1 is heated from the bottom of the container wall 1 by using a heater, so that the PP coating layer 3 at the contact part of the container bottom 2 and the container wall 1 melts, and then the heating is stopped, and the PP coating layer 3 at the contact part of the container bottom 2 and the container wall 1 is re-solidified, and the container wall 1 and the container bottom 2 are bonded; after heating and bonding, the part of the container wall 1 on the side of the container bottom 2 away from the container opening is extruded at the extrusion and thickening station of the paper cup machine, so that the thickness of the extruded part of the container wall 1 increases, forming a thickened wall 12, and obtaining a initially formed container.

[0052] Step 4: Processing the PP reinforcing layer 4, using an atomizing spray gun to spray the atomized PP coating liquid into the inner cavity of the initially formed container, and heating the container bottom 2 at the heating station of the paper cup machine, so that the PP reinforcing layer 4 is formed at the internal connection between the container wall 1 and the container bottom 2;

[0053] Prepare a printing paper tube, use a printing machine to print a pattern on one side of the base paper, and use a laminating machine to perform PP laminating on the side with the printed pattern, and then use a die-cutting machine to die-cut into fan-shaped printed paper, and simultaneously die-cut an easy-tear line 611 on the printed paper, and then use an ultrasonic heater to heat the edge of the printed paper to be overlapped, and then use the roll-forming station of the paper cup machine to roll the printed paper to obtain a printing paper tube, use the paper cup machine to roll the bottom of the printing paper tube, and then use an ultrasonic heater to heat the position on the printing paper tube for gluing a double ring buckle 62, melt the PP laminating film on the outside of the printing paper tube, and glue the double ring buckle 62 on the melted PP laminating film on the outside of the printing paper tube;

[0054] Sleeve the printing paper tube, sleeve the printing paper tube on the preformed container, and then heat the printing paper tube and the preformed container together from the outer bottom of the printing paper tube, so that the PP coating layer 3 at the outer bottom of the container wall 1 melts and re-solidifies after being adhered to the printing paper tube, so as to bond the preformed container and the printing paper tube;

[0055] Step 5: curling: curling the top of the container wall 1 at the curling station of the paper cup machine to obtain a PP coated paper container.

[0056] The above are all preferred embodiments of the present application, and the protection scope of the present application is not limited thereto. Therefore, any equivalent changes made according to the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A microwaveable PP coated paper container, comprising a container wall (1) and a container bottom (2), wherein the container bottom (2) is connected to the lower side of the container wall (1), and the upper end of the container wall (1) forms a container opening, characterized in that: The inner walls of the container wall (1) and the container bottom (2) are both provided with a PP coating layer (3); the container wall (1) is formed by gluing paper sheets together, and the container wall (1) and the container wall (1) and the container bottom (2) are both bonded together by the PP coating layer (3); a PP reinforcement layer (4) is also provided at the internal connection between the container wall (1) and the container bottom (2); and a first curling edge (11) is provided at the top opening of the container wall (1); A printing layer (5) is arranged on the outer side of the container wall (1), a PP coating layer (3) is also arranged on the outer wall of the printing layer (5), and a second curling edge (51) is arranged on the bottom of the printing layer (5); the distance between the second curling edge (51) and the bottom end of the container wall (1) is smaller than the distance between the container bottom (2) and the bottom end of the container wall (1); a sealing assembly (6) is arranged on the outer wall of the printing layer (5), and the sealing assembly (6) comprises a tear strip (61) and a double ring buckle (62), the tear strip (61) is arranged on the printing layer (5), and can be torn off from the printing layer (5) at one end of the tear strip (61), the double ring buckle (62) is adhered to the printing layer (5), and the free end of the tear strip (61) after being torn can bypass the container opening and pass through the double ring buckle (62) for fixation.

2. The microwaveable PP coated paper container according to claim 1, characterized in that: A thickened wall (12) is provided at one end of the container wall (1) close to the container bottom (2), and the thickness of the thickened wall (12) is greater than the thickness of the container wall (1).

3. The processing technology of the microwaveable PP coated paper container according to claim 1 is characterized in that: The steps include: Step 1: PP coated paper production, PP coating is applied to base paper to obtain PP coated paper; Step 2: manufacturing the container wall (1) and the container bottom (2), die-cutting the obtained PP coated paper to obtain container wall paper and container bottom (2), heating the edge of the obtained container wall paper to be overlapped, and then rolling it to obtain the container wall (1); Step 3: Initially forming the container, inserting the container bottom (2) into the container wall (1), heating and bonding, and obtaining an initially formed container; Step 4: Processing the PP reinforcing layer (4), spraying atomized PP coating liquid into the inner cavity of the initially formed container, heating the container bottom (2) portion, so that the PP reinforcing layer (4) is formed at the internal connection between the container wall (1) and the container bottom (2); Step 5: Curling: Curling the top of the container wall (1) to obtain a PP coated paper container.

4. The processing technology of the microwaveable PP coated paper container according to claim 3 is characterized in that: In step three, the container bottom (2) is pushed into the container wall (1) from the bottom of the container wall (1).

5. The processing technology of the microwaveable PP coated paper container according to claim 3 is characterized in that: The step three further comprises: after heating and bonding, extruding the portion of the container wall (1) at the container bottom (2) away from the container opening, so that the thickness of the extruded portion of the container wall (1) is increased to form a thickened wall (12).

6. The processing technology of the microwaveable PP coated paper container according to claim 3 is characterized in that: The step four also includes: preparing a printing paper tube, printing a pattern on one side of the base paper, performing PP lamination, and then performing die-cutting to obtain a printing paper, and heating the edge of the printing paper to be overlapped, and then rolling the printing paper to obtain a printing paper tube, and curling the bottom of the printing paper tube; sleeve the printing paper tube, sleeve the printing paper tube on the preformed container, and bond the printing paper tube and the preformed container.

7. The processing technology of the microwaveable PP coated paper container according to claim 6 is characterized in that: The step four also includes: engraving an easy-tear line (611) on the printed paper when die-cutting the printed paper, and gluing a double ring buckle (62) on the printed paper tube before sleeved on the printed paper tube.

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