Packaging paper bag manufacturing method based on partial film coating process of sealing strip and packaging paper bag

Abstract

This invention discloses a method for manufacturing packaging paper bags based on a partial sealing strip coating process. The method includes adding a long strip-shaped sealing strip to the inner side of the bag paper, the sealing strip extending along the conveying direction; coating the sealing strip with thermoplastic material from a nozzle, the nozzle having a nozzle at its outlet, the nozzle defining a coating area on the bag paper, the sealing strip being located within the coating area; coating the non-sealing strip area within the coating area to form a reinforced sealing zone; applying heat-sealing adhesive to pre-set adhesive areas on the sides of each packaging paper bag on double-layered bag paper, the double-layered bag paper being folded in half with a transparent paper liner attached, so that the reinforced sealing zones overlap and adhere to each other, the transparent paper being sandwiched between the double-layered bag paper; and heating the double-layered bag paper to seal the sides and sealing strip of the packaging paper bag. This invention can improve the load-bearing capacity, sealing performance, and durability of packaging paper bags through the reinforcement and sealing of the sealing strip.

Description

Technical Field

[0001] This invention relates to the technical field of packaging paper bags, and in particular to a method for manufacturing packaging paper bags based on a partial coating process for sealing strips, and a packaging paper bag thereof. Background Technology

[0002] In the packaging industry, to enhance product appeal and meet consumer demand, paper bags with display windows are increasingly being used, allowing consumers to visually see the product inside before purchasing. However, current paper bag manufacturing technologies often employ relatively simple sealing strip designs and processes, insufficient to meet the demands of high-intensity usage environments. This makes paper bags prone to damage and leakage during transportation, storage, or use, impacting product safety and the consumer experience. Summary of the Invention

[0003] This invention provides a packaging paper bag and its manufacturing method, aiming to solve the problem of poor load-bearing capacity of the sealed end of the packaging paper bag in the prior art.

[0004] In a first aspect, embodiments of the present invention provide a method for manufacturing packaging paper bags based on a partial coating process using a sealing strip. The method includes: opening at least one display window on a continuously conveyed bag paper, the display window being either continuous along the conveying direction or partially closed; applying heat-sealing adhesive at fixed points on the bag paper around the display window; attaching transparent paper to the display window and heating it to ensure a tight bond between the transparent paper and the bag paper; adding a long strip-shaped sealing strip to the inner side of the continuously conveyed double-layer bag paper, the sealing strip being continuous along the conveying direction; the double-layer bag paper being obtained by folding the bag paper with the transparent paper attached or by overlapping two corresponding bag papers; and uniformly coating the sealing strip with film material by squeezing plastic from a nozzle. A nozzle is installed at the nozzle outlet. Plastic inside the nozzle is squeezed and evenly coated onto the sealing strip. The nozzle outlet of the nozzle outputs heated plastic to form an adhesive film within a defined coating area on the bag paper. The sealing strip is located within the coating area. Non-sealing areas within the coating area are sealed by the adhesive film to form a reinforced sealing zone. Heat-sealing adhesive is applied to pre-set adhesive points on the sides of each packaging bag on the double-layer bag paper to overlap and bond the reinforced sealing zones together. Transparent paper is sandwiched between the double-layer bag paper. The double-layer bag paper is heated to seal the sides and sealing strip of the packaging bag. The sealed double-layer bag paper is then cut to obtain individual packaging bags.

[0005] Secondly, embodiments of the present invention also provide a packaging paper bag, which is manufactured by the manufacturing method of the first aspect described above. The packaging paper bag includes a first bag and a second bag that are arranged opposite to each other, overlap, and are bonded together. A sealing strip is disposed between the first and second bags. A display window is provided on the first and / or second bags, and a transparent sheet is attached to each display window. The transparent sheet is sandwiched between the two layers of bags and tightly adheres to the periphery of the display window. The sealing strip includes a strip-shaped groove and a strip-shaped protrusion on the first bag. A reinforced sealing area is provided on the first bag, and the strip-shaped groove is disposed within the reinforced sealing area. The strip-shaped groove and the strip-shaped protrusion are arranged opposite to each other and are both located at the opening of the packaging paper bag. Sealing edges are provided on the non-opening sides of the packaging paper bag, and the sealing edges are obtained by bonding the sides of the first and second bags together.

[0006] This invention provides a method for manufacturing packaging paper bags based on a partial sealing strip coating process, and the packaging paper bag itself. The manufacturing method includes: opening at least one display window on a continuously conveyed bag paper, the display window being either continuous along the conveying direction or partially closed; applying heat-sealing adhesive at fixed points around the display window on the bag paper; attaching transparent paper to the display window and heating it to ensure a tight bond between the transparent paper and the bag paper; adding a long strip sealing strip to the inner side of the continuously conveyed double-layer bag paper, the sealing strip being continuous along the conveying direction; the double-layer bag paper is obtained by folding the bag paper with the transparent paper attached or by overlapping two corresponding bag papers; and applying the adhesive through a pressure nozzle... The material is evenly coated onto the sealing strip. A nozzle is installed at the nozzle of the spray head. The spray head outputs heated plastic to form an adhesive film within a defined coating area on the bag paper. The sealing strip is located within the coating area, and the non-sealing strip area within the coating area passes through the adhesive film to form a reinforced sealing zone. Heat-sealing adhesive is applied to pre-set adhesive points on the sides of each packaging bag on the double-layer bag paper to overlap and bond the reinforced sealing zones together. Transparent paper is sandwiched between the double-layer bag paper. The double-layer bag paper is heated to seal the sides and sealing strip of the packaging bag. The sealed double-layer bag paper is then cut to obtain individual packaging bags.

[0007] The aforementioned method for manufacturing packaging paper bags can enhance their load-bearing capacity, sealing performance, durability, and reusability by reinforcing the sealing strip. This provides a more efficient and reliable solution for the packaging paper bag industry, demonstrating significant advantages, especially in applications requiring high sealing standards and strong load-bearing capacity. Attached Figure Description

[0008] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a flowchart of a method for producing packaging paper bags based on a local coating process for sealing strips, provided in an embodiment of the present invention.

[0010] Figure 2 This is a manufacturing state diagram of the packaging paper bag provided in an embodiment of the present invention;

[0011] Figure 3 This is another manufacturing state diagram of the packaging paper bag provided in an embodiment of the present invention;

[0012] Figure 4 Another manufacturing state diagram of the packaging paper bag provided in an embodiment of the present invention;

[0013] Figure 5 A schematic diagram illustrating the manufacturing process of the packaging paper bag provided in an embodiment of the present invention;

[0014] Figure 6 Another manufacturing state diagram of the packaging paper bag provided in an embodiment of the present invention;

[0015] Figure 7 Another manufacturing state diagram of the packaging paper bag provided in an embodiment of the present invention;

[0016] Figure 8 A diagram illustrating a further manufacturing process of the packaging paper bag provided in an embodiment of the present invention;

[0017] Figure 9 A diagram showing the final manufacturing state of the packaging paper bag provided in an embodiment of the present invention;

[0018] Figure 10 Another manufacturing state diagram of the packaging paper bag provided in an embodiment of the present invention;

[0019] Figure 11 This is a subsequent manufacturing state diagram of the packaging paper bag provided in an embodiment of the present invention;

[0020] Figure 12 A diagram illustrating the subsequent manufacturing process of the packaging paper bag provided in an embodiment of the present invention;

[0021] Figure 13 A diagram illustrating the latter manufacturing state of the packaging paper bag provided in an embodiment of the present invention;

[0022] Figure 14 A diagram showing the next manufacturing state of the packaging paper bag provided in an embodiment of the present invention;

[0023] Figure 15 Another manufacturing state diagram of the packaging paper bag provided in the embodiment of the present invention.

[0024] Figure 16 This is a structural diagram of a packaging paper bag provided in an embodiment of the present invention;

[0025] Figure 17 Another structural diagram of the packaging paper bag provided in an embodiment of the present invention;

[0026] Figure 18 Another structural diagram of the packaging paper bag provided in an embodiment of the present invention;

[0027] Figure 19 Another structural diagram of the packaging paper bag provided in an embodiment of the present invention;

[0028] Figure 20 This is a cross-sectional structural diagram of a packaging paper bag provided in an embodiment of the present invention.

[0029] Reference numerals: 10, paper bag; 101, first paper bag; 102, second paper bag; 11, display window; 12, heat sealant; 13, transparent paper; 14, edge sealing; 15, hanging opening; 20, sealing strip; 21, strip groove; 22, strip protrusion; 23, connecting film; 24, reinforced sealing area; 3, nozzle; 31, nozzle; 321, outlet edge; 33, glue storage chamber. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0032] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0033] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0034] In this embodiment, please refer to Figure 1 As shown in the figure, this embodiment of the invention provides a method for manufacturing packaging paper bags based on a partial coating process for sealing strips, wherein the method includes steps S110 to S180.

[0035] S110. At least one display window 11 is opened on the continuously conveyed bag paper 10, and the display window 11 is either continuous along the conveying direction or partially closed.

[0036] The paper bag 10 is continuously conveyed by mechanical equipment, such as rollers on both sides of the paper bag 10. By rotating the rollers, the paper bag 10 is continuously conveyed horizontally. Figure 2 As shown, at least one display window 11 is opened on the continuously conveyed bag paper 10, and the display window 11 is either continuous along the conveying direction or partially closed.

[0037] Specifically, the display window 11 opened on the single-layer paper bag 10 can be as follows: Figure 3 or Figure 4 As shown, the display window 11 extends through the conveying direction. The specific manufacturing process for creating this display window 11 is as follows: Figure 5 As shown, two side-by-side cutters can be used to cut the continuously conveyed paper bag 10, thus removing the portion of the paper bag 10 between the two cutters, thereby obtaining a display window 11 extending along the conveying direction. The display window 11 opened on a single layer of paper bag 10 can also be as follows... Figure 7 As shown, the display window 11 forms a partially closed structure.

[0038] The bag paper 10 can be continuously conveyed in a single layer and the display window 11 can be opened in a double layer. For cutting one of the single layers of the double-layer bag paper 10 to form a partially closed display window 11, refer to the applicant's previously filed patent "Bag Material Cutting Device and Bag Manufacturing Method," patent application number "202410392756.9". For cutting one of the single layers of the double-layer bag paper 10 to form a display window 11 extending along the conveying direction, refer to the applicant's previously filed patent "Dustproof Bag Production Device for Continuous Production," patent application number "202311521727.X" (this patent uses a single-blade cutter; two parallel cutters can be used for cutting).

[0039] S120. Apply heat-sealing adhesive to the perimeter of the display window on the bag 10 at specific points.

[0040] Heat-sealing adhesive 12 is applied to the periphery of the display window 11 on the bag paper 10. The structure of the side of the bag paper 10 coated with heat-sealing adhesive 12 is as follows: Figure 6 and Figure 7 As shown, where Figure 6 Correspondingly, a display window 11 is opened on the paper bag 10, running through the conveying direction. Figure 7 A partially enclosed display window 11 is provided on the paper bag 10. A heat-sealing adhesive 12 is applied to the perimeter of the display window 11. For a single-layer paper bag 10, the heat-sealing adhesive 12 can be applied directly. For a double-layer paper bag 10, the heat-sealing adhesive 12 needs to be applied to the side of the paper bag 10 with the display window 11 facing the other paper bag 10. The heat-sealing adhesive 12 spreads rapidly upon heating and adheres and seals the paper bag 10. In a more specific embodiment, the heat-sealing adhesive 12 is a solvent-based adhesive film. Using a solvent-based adhesive film increases the bonding effect on the paper bag 10, thereby increasing the sealing performance of the bonded paper bag 10.

[0041] S130. Cover the display window 11 with transparent paper 13 and heat it to make the transparent paper 13 adhere tightly to the bag paper 10.

[0042] Transparent paper 13 is attached to the display window 11. The structure of the display window 11 after attaching transparent paper 13 is as follows. Figure 8 As shown; heating is performed to ensure that the transparent paper 13 and the bag paper 10 are tightly bonded together. At this time, the structure of the bag paper 10 on the side opposite to the transparent paper 13 is as follows. Figure 9 As shown. Furthermore, transparent paper 13 can be pasted inside the display window 11, so that for the double-layered bag paper 10, transparent paper 13 is located between the two layers of bag paper 10. Specifically, transparent paper 13 is transparent fiber paper; bag paper 10 is non-transparent fiber paper. Transparent paper 13 can be set as transparent fiber paper, and bag paper 10 can be set as non-transparent fiber paper. The transparent fiber paper portion allows light to pass through and displays the product inside the packaging bag, and the fiber paper can increase the overall structural strength of the packaging bag.

[0043] Specifically, the display window 11 is a long strip window running along the conveying direction, with a width of 1-10cm. The transparent paper 13 is also a long strip of transparent paper running along the conveying direction. The width of the long strip display window 11 running along the conveying direction can be set to 1-10cm. In this case, the transparent paper 13 also needs to be set to a long strip of transparent paper running along the conveying direction, with the width of the long strip of transparent paper 13 slightly larger than the width of the display window 11. For example, the width of the long strip of transparent paper 13 can be set to 1.15-1.4 times the width of the display window 11.

[0044] Alternatively, the display window 11 may be a partially enclosed window, and may be circular, elliptical, rectangular, polygonal, or rounded rectangular. The transparent paper 13 may be a long strip of transparent paper extending along the conveying direction or a non-through transparent paper 13 that independently covers the display window 11. For the case where the display window 11 is partially enclosed, the transparent paper 13 can be a long strip of transparent paper extending along the conveying direction, thus partially covering the display window 11; alternatively, the transparent paper 13 can be a non-through transparent paper that independently covers the display window 11, thus covering only one display window 11. For example, for a circular display window 11, a corresponding circular non-through transparent paper 13 can be used to cover the display window 11.

[0045] Specifically, the heating temperature is 150-350℃, and the heating time is 0.5-5.5 seconds. During the heating process, the pressure applied to the paper bag is 8-25 kg / dm². 2 .

[0046] To achieve bonding of the transparent paper 13 and the bag paper 10 using the heat-sealing adhesive 12, the bonding area of ​​the transparent paper 13 and the bag paper 10 can be heated. The specific heating temperature is 150-350℃, and the heating time is 0.5-5.5 seconds. After heating, the heat-sealing adhesive 12 diffuses into the transparent paper 13 and the bag paper 10, achieving a tight bond. Furthermore, to improve the bonding effect of the transparent paper 13 and the bag paper 10, the transparent paper 13 and the bag paper 10 can be pressed together while heating, with an applied pressure of 8-25 kg / dm². 2 .

[0047] S140. A long strip sealing strip 20 is added to the inner side of the continuously conveyed double-layer bag paper 10, and the sealing strip 20 runs through the conveying direction; the double-layer bag paper 10 is obtained by folding the bag paper 10 with the transparent paper attached or by overlapping the two bags paper accordingly.

[0048] A long strip sealing strip 20 is added to the inside of the continuously conveyed double-layer bag paper 10. The double-layer bag paper 10 is formed by covering another bag paper 10 on top of the bag paper 10 with the transparent paper 13, or by folding the bag paper 10 with the transparent paper 13 in half; the transparent paper 13 is sandwiched between the double-layer bag paper 10.

[0049] Steps S110 to S130 can involve processing and manufacturing a single-layer bag paper 10 separately, or processing and manufacturing one of the single-layer bag paper 10s in a double-layer bag paper 10. If the single-layer bag paper 10 is processed and manufactured separately, another bag paper 10 can be placed on top of the bag paper 10 with the transparent paper 13 to form a double-layer bag paper 10. Alternatively, the bag paper 10 with the transparent paper 13 can be folded in half (e.g., folded in half). Figure 4The shown bag paper 10 is folded along the horizontal center line to form a double-layer bag paper 10. Steps S110 to S130 can also be used to process one of the single-layer bag papers 10 in the double-layer bag paper 10, that is, to first fold the bag paper 10 or to first overlap and glue two bags paper 10 together to form a double-layer bag paper 10, and then perform steps S110 to S130.

[0050] A long strip sealing strip 20 is added to the inner side of the continuously conveyed double-layer paper bag 10. When the double-layer paper bags 10 are aligned and continuously conveyed, there is a gap between them. The long strip sealing strip 20 can be inserted into this gap, thus allowing the double-layer paper bags 10 and the long strip sealing strip 20 to overlap and combine. The process of inserting the long strip sealing strip 20 into the gap between the double-layer paper bags 10 is as follows: Figure 10 As shown, the structure of the double-layered bag paper 10 completely enclosed by the long strip sealing strip 20 is as follows: Figure 11 As shown.

[0051] S150. The plastic inside the nozzle is squeezed to uniformly coat the sealing strip. A nozzle is set at the nozzle opening. The nozzle outputs the heated plastic to form a film within the coating area defined on the bag paper. The sealing strip is located within the coating area. The non-sealing strip area within the coating area is coated with the film to form a reinforced sealing area.

[0052] The sealing strip 20 is located within the coating area. The plastic used for localized coating is preferably PE or PP material. Thermoplastic, formed when the plastic is heated, coats the non-sealing strip area within the coating area to form a reinforced sealing zone 24. In the packaging paper bag manufacturing process, the proper application of the nozzle 3 directly affects the uniform coating of the thermoplastic and the effective sealing of the sealing strip. The core of this uniform-speed nozzle 3 lies in the nozzle 31 installed at the nozzle opening. Its design fully considers the principles of fluid mechanics and the needs of practical applications. The nozzle diameter is precisely calculated to ensure that, under a certain pressure, the adhesive film can flow uniformly from the nozzle at a stable flow rate. This design avoids dripping or uneven coating caused by uneven flow rates, ensuring that every inch of the sealing strip receives precise adhesive coverage. The smooth surface of the nozzle further reduces turbulence, resulting in a continuous and smooth adhesive line when the thermoplastic leaves the nozzle. The working principle of the uniform-speed nozzle 3 is based on a precise control system that maintains a constant speed during the movement of the nozzle 3, thereby ensuring the consistency of the entire coating process. Both the coating speed and the colloid flow rate can be precisely controlled, creating a uniform coating area on the bag paper. Within this area, a long, narrow sealing strip is precisely positioned, acting as the center line of the coating area. The non-sealing areas on both sides are also covered with colloid, forming a reinforced sealing zone. The width of this reinforced sealing zone matches the width of the sealing strip, ensuring that both sides of the sealing strip are fully filled with colloid during the subsequent heat sealing process, resulting in a strong seal. The nozzle 31 of the printhead 3 is designed for ease of maintenance. Because the nozzle is less prone to clogging, downtime for cleaning is reduced during production, improving efficiency. Furthermore, the replaceability of the nozzle ensures quick replacement after wear, without affecting the operation of the entire production line. Figure 15 As shown, the heated plastic is evenly sprayed out through the nozzle 3 to form a film. The hot plastic is originally stored in the storage chamber 33 and coated onto the bag paper 10 through the nozzle. The outlet edge end 321 is provided on both sides of the outlet of the nozzle 31. The outlet edge end 321 on both sides forms the target area of ​​the coating process. The target area corresponds to the reinforced sealing area 24 formed on the bag paper 10 afterward. It is used to determine the area of ​​uniform coating and ensure that the coating process is completed uniformly and stably.

[0053] S160. Apply heat-sealing adhesive to the pre-set adhesive area on the side of each packaging paper bag on the double-layer bag paper 10 so that the reinforced sealing areas 24 overlap and adhere to each other.

[0054] The double-layered bag paper 10 is formed by folding the bag paper 10 with the transparent paper attached, so that the reinforced sealing area 24 overlaps and sticks to each other, and the transparent paper is sandwiched between the double-layered bag paper 10.

[0055] Heating the double-layer paper bag 10 seals the sides of the packaging paper bag and the sealing strip 20, thus forming the sealing edge 14.

[0056] Furthermore, before cutting the sealed double-layer paper bag 10 to obtain individual packaging paper bags, the process includes: creating a hanging opening 15 on the double-layer paper bag 10 above the sealing strip 20. The specific structure after creating the hanging opening 15 on the double-layer paper bag 10 above the sealing strip 20 is as follows... Figure 14 As shown, the hanging opening 15 can be used to hang the packaging paper bag on the horizontally set support rod, which facilitates the display and sale of the items inside the packaging paper bag.

[0057] S170. The double-layer paper bag 10 is heated to seal the sides and sealing strip of the packaging paper bag.

[0058] The sealed double-layer paper bag 10 is cut to obtain individual packaging paper bags. The sealed double-layer paper bag 10 is cut using a cutter perpendicular to the conveying direction. This cutter cuts the joint between adjacent packaging paper bags, thus separating them into individual packaging paper bags. The individual packaging paper bags obtained after cutting are shown below. Figure 16 and Figure 19 As shown. Among them, Figure 16 This refers to the case where two sheets of paper bag 10 are overlapped and glued together to form a double-layered paper bag 10. Figure 19 This refers to the case where the paper bag 10 is folded in half to form a double-layered paper bag 10.

[0059] Furthermore, during the cutting process of the sealed double-layer paper bag 10, the top corners of the packaging paper bag can also be rounded simultaneously to obtain, as shown in the figure. Figure 18 The bag structure shown. For cases where two sheets of bag paper 10 are overlapped and glued together to form a double-layer bag paper 10, the excess portion of the bag body at the bottom can be cut off to obtain the structure shown. Figure 17 The bag structure shown.

[0060] S180. Cut the sealed double-layer paper bag to obtain a single packaging paper bag.

[0061] Before performing step S180, a hanging opening is made on the double-layered paper bag above the sealing strip, and the hanging opening is set on the symmetrical center line of the packaging paper bag body.

[0062] Steps S110 to S180 are all performed during the continuous conveying of the paper bag 10, which means that packaging paper bags can be manufactured during continuous conveying, greatly improving the production efficiency of packaging paper bags.

[0063] This application also discloses a packaging paper bag, which is manufactured by the manufacturing method described in the above embodiments. The packaging paper bag includes a first bag 101 and a second bag 102 that are arranged opposite to each other, overlap and are glued to each other. A sealing strip 20 is disposed between the first bag 101 and the second bag 102. A display window 11 is opened on the first bag 101 and / or the second bag 102. A transparent paper 13 is attached to each display window 11, and the transparent paper 13 is sandwiched between the two layers of bag paper and is tightly attached to the periphery of the display window 11. The sealing strip 20 includes a strip-shaped groove 21 and a strip-shaped protrusion 22 disposed on the first bag 101. The strip-shaped groove 21 and the strip-shaped protrusion 22 are arranged opposite to each other and are both disposed at the opening of the packaging paper bag. The non-opening side of the packaging paper bag is provided with a sealing edge 14, which is obtained by bonding the side of the first bag 101 and the side of the second bag 102.

[0064] Please see Figure 20 As shown in the figure, the packaging paper bag includes a first paper bag 101 and a second paper bag 102 that are arranged opposite to each other, overlap, and are glued together. A sealing strip 20 is disposed between the first paper bag 101 and the second paper bag 102. The sealing strip 20 includes a strip-shaped groove 21 and a strip-shaped protrusion 22 disposed on the first paper bag 101. A reinforced sealing area 24 is provided on the first paper bag 101, and the strip-shaped groove 21 is disposed within the reinforced sealing area 24. The strip-shaped groove 21 and the strip-shaped protrusion 22 are arranged opposite to each other and are both disposed at the opening of the packaging paper bag. The non-opening side of the packaging paper bag is provided with a sealing edge 14, which is obtained by bonding the side of the first paper bag 101 and the side of the second paper bag 102 together.

[0065] Specifically, the sealing strip 20 includes a strip-shaped groove 21 and a strip-shaped protrusion 22. To improve the stability of the adhesion between the sealing strip 20 and the bag paper (first bag paper 101 or second bag paper 102), a wider connecting film 23 can be provided on the side of the sealing strip 20 closest to the bag paper. The width of the connecting film 23 is 3-10 times the width of the sealing strip 20. The connecting film 23 is bonded and fixed to the bag paper using heat-sealing adhesive 12, thereby achieving a stable fixation between the sealing strip 20 and the bag paper. By providing the connecting film 23, the area for bonding and fixing the sealing strip 20 to the hot air curtain on the bag paper can be increased, thereby improving the stability of the adhesion between the sealing strip 20 and the bag paper.

[0066] To improve the tightness of the engagement between the strip-shaped groove 21 and the strip-shaped protrusion 22, a buckle is provided on the side of the strip-shaped protrusion 22 facing the strip-shaped groove 21, and the width of the outer opening of the strip-shaped groove 21 is smaller than the width of the bottom of the strip-shaped groove 21. The specific structure is as follows: Figure 20As shown, the above structure can greatly improve the tightness of the interlocking connection between the strip groove 21 and the strip protrusion 22, that is, improve the sealing performance of the sealing strip 20 in sealing the opening of the packaging paper bag.

[0067] Users can first tear off the sealing edge 14 above the sealing strip 20 (the sealing edge 14 formed by bonding the first bag body and the second bag body), and then use external force to disengage the strip groove 21 from the strip protrusion 22, thereby opening the packaging paper bag and taking out the contents from the opening of the packaging paper bag.

[0068] This invention provides a method for manufacturing packaging paper bags based on a partial coating process for sealing strips. The method includes: opening at least one display window 11 on a continuously conveyed bag paper 10, the display window 11 being continuous along the conveying direction or having a partially closed structure; coating an adhesive film on the area surrounding the display window 11 on the bag paper 10; covering the display window 11 with a transparent paper sticker 13 and heating it to make the transparent paper 13 tightly adhere to the bag paper 10; adding a long strip sealing strip 20 to the inside of the bag paper 10, the sealing strip 20 being continuous along the conveying direction; and applying the adhesive film to the sealing strip through a nozzle 3, the nozzle 3 having a nozzle 31 at its nozzle opening, the nozzle 3 defining the direction of application on the bag paper through the nozzle 31. In the coating area, nozzle 3 is either a circular nozzle or a flat nozzle. The long axis of the flat nozzle is perpendicular to the conveying direction of the bag paper 10. The sealing strip 20 is located in the coating area. The non-sealing strip area in the coating area is coated with adhesive film to form a reinforced sealing area 24. Heat-sealing adhesive is applied to the pre-set adhesive points on the sides of each packaging paper bag on the double-layer bag paper. The double-layer bag paper 10 is formed by folding the bag paper 10 with the transparent paper attached so that the reinforced sealing areas 24 overlap and stick to each other. The transparent paper is sandwiched between the double-layer bag paper 10. The double-layer bag paper 10 is heated to seal the sides and sealing strip of the packaging paper bag. The sealed double-layer bag paper is cut to obtain individual packaging paper bags. The aforementioned method for manufacturing packaging paper bags based on a partial coating process for the sealing strip achieves a highly efficient and reliable sealing effect. A display window 11 is created on the bag paper and extends along the conveying direction or forms a partially closed structure. Then, an adhesive film is applied to the area around the display window to ensure a tight fit between the transparent paper and the bag paper. This ensures the sealing strip plays a crucial role in the packaging paper bag manufacturing process. Precise application of the adhesive film through the spray head 3 and nozzle 31 provides heat-sealing reinforcement to the sealing strip area. The thickness of the sealed area formed after the reinforced sealing areas 24 overlap is 0.05-0.1 cm. The width of the sealed area formed after the reinforced sealing areas 24 overlap is 0.5-1 cm. The reinforced sealing areas 24 are divided into an upper sealing area and a lower sealing area according to the sealing strip 20. The upper and lower sealing areas are symmetrical along the center line of the reinforced sealing areas 24, significantly improving the sealing performance and durability of the packaging paper bag. This reinforced sealing area 24 design makes the packaging paper bag more stable during transportation and storage, effectively preventing leakage of contents and external contamination, ensuring the safety and integrity of the product. Furthermore, by folding the double-layered paper bag 10 in half and then heating it, the reinforced sealing areas 24 overlap and adhere to each other, further enhancing the sealing strength of the packaging paper bag and ensuring its reliability in long-term use. This method not only improves the production efficiency of packaging paper bags, which can be reused multiple times due to their durability and environmental friendliness, but also reduces rework and material waste caused by poor sealing, thereby improving the overall economic benefits of the packaging process.

[0069] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for manufacturing packaging paper bags based on a partial coating process for sealing strips, characterized in that, The manufacturing method includes: At least one display window is provided on the continuously conveyed paper bag, and the display window is either continuous along the conveying direction or has a partially closed structure; Heat-sealing adhesive is applied at specific points on the bag paper in the area surrounding the display window; Transparent paper is attached to the display window and heated to ensure it adheres tightly to the bag paper. A long strip sealing strip is added to the inner side of the continuously conveyed double-layer bag paper, and the sealing strip runs through the conveying direction; the double-layer bag paper is obtained by folding the bag paper with the transparent paper attached in half or by overlapping two bags paper accordingly; The plastic inside the nozzle is squeezed to uniformly coat the sealing strip. The nozzle is provided with a nozzle at the nozzle opening. The nozzle outputs the heated plastic in the coating area defined on the bag paper to form an adhesive film. The sealing strip is located in the coating area. The non-sealing strip area in the coating area passes through the adhesive film to form a reinforced sealing area. Heat-sealing adhesive is applied to the pre-set adhesive areas on the sides of each packaging paper bag on the double-layered paper bag so that the reinforced sealing areas overlap and adhere to each other; the transparent paper is sandwiched between the double-layered paper bags; Heating the double-layered paper bag seals the sides and sealing strip of the packaging bag. The sealed double-layered paper bag is cut to obtain individual packaging paper bags.

2. The method for manufacturing packaging paper bags based on a partial coating process for sealing strips according to claim 1, characterized in that, The nozzle is a circular nozzle or a flat nozzle, and the long axis of the flat nozzle is perpendicular to the conveying direction of the paper bag.

3. The method for manufacturing packaging paper bags based on a partial coating process for sealing strips according to claim 2, characterized in that, The heating temperature is 150-350℃, and the heating time is 0.5-5.5 seconds.

4. The method for manufacturing packaging paper bags based on a partial coating process for sealing strips according to claim 3, characterized in that, The pressure applied to the paper bag during the heating process is 8-25 kg / dm. 2 .

5. A packaging paper bag, wherein the packaging paper bag is manufactured by the packaging paper bag manufacturing method based on the partial coating process of the sealing strip as described in any one of claims 1-4, characterized in that, The packaging paper bag includes a first paper bag and a second paper bag that are arranged opposite to each other, overlap each other, and are glued together, with a sealing strip disposed between the first paper bag and the second paper bag; A display window is provided on the first bag of paper and / or the second bag of paper. Each display window is covered with a transparent sheet, and the transparent sheet is sandwiched between the two layers of paper and is tightly attached to the periphery of the display window. The sealing strip includes a strip-shaped groove and a strip-shaped protrusion disposed on the first bag paper. A reinforced sealing area is provided on the first bag paper, and the strip-shaped groove is disposed within the reinforced sealing area. The strip-shaped groove and the strip-shaped protrusion are disposed opposite to each other and are both disposed at the opening of the packaging paper bag. The non-opening sides of the packaging paper bags are all sealed, and the sealing edges are obtained by bonding the sides of the first bag paper and the sides of the second bag paper together.

6. The packaging paper bag according to claim 5, characterized in that, The transparent paper is transparent fiber paper; the bag paper is non-transparent fiber paper.

7. The packaging paper bag according to any one of claims 5 or 6, characterized in that, The thickness of the sealing area formed by the overlapping of the reinforced sealing areas is 0.05-0.1cm.

8. The packaging paper bag according to any one of claims 5 or 6, characterized in that, The width of the sealing area formed by the overlapping of the reinforced sealing areas is 0.5-1cm.

9. The packaging paper bag according to claim 8, characterized in that, The reinforced sealing area is divided into an upper sealing area and a lower sealing area according to the sealing strip, and the upper sealing area and the lower sealing area are symmetrical about the center line of the reinforced sealing area.

Images