Kraft paper-tin foil composite material for packaging bags and production process thereof

Abstract

The present application relates to a kraft paper-tin foil composite material for packaging bags, and relates to the technical field of composite packaging bags, which comprises a color developing layer, an adhesive layer, a kraft paper layer and a tin foil layer arranged in sequence, wherein the color developing layer is a zinc silicate fluorescent brightener, and the adhesive layer is a starch adhesive layer. The present application has the effect of facilitating the improvement of the printing performance of the packaging bag while improving the thermal insulation performance and strength of the packaging bag.

Description

Technical Field

[0001] The present application relates to the technical field of packaging bags, and in particular to a kraft paper-tin foil composite material for packaging bags. Background Art

[0002] Packaging bags refer to bags used to package various items, making it easy to transport and store goods during production and circulation. Therefore, packaging bags are used in daily life and industrial production. At present, food packaging bags usually abandon plastic bags in order to consider food safety. Common food packaging bags include kraft paper bags and tin foil bags.

[0003] Kraft paper bags have strong wear resistance and tear resistance, can withstand a certain amount of weight and pressure, and have good air permeability, which helps to maintain the freshness and ventilation of items inside, and are particularly suitable for packaging items that require ventilation.

[0004] Tin foil packaging bags have good sealing properties and can effectively prevent the intrusion of external factors such as oxygen, moisture, and odor, thereby extending the shelf life of food. And because tin foil is made of high-purity aluminum, it has good thermal conductivity and electrical conductivity, and can conduct heat quickly and evenly, ensuring the insulation performance of food at a certain temperature.

[0005] With regard to the above-mentioned related technologies, when used as packaging bags, kraft paper bags often have poor moisture resistance and are prone to rupture in rainy weather. In addition, the surface of kraft paper bags is relatively rough. When printing on the surface of kraft paper bags, the ink is easily uneven when printed on the surface. Therefore, when printing colorful patterns, the effect is not as good as white cardboard packaging bags and plastic bags. When tin foil is used as a packaging bag, the cost is high, and although the tin foil packaging bag has good thermal insulation performance, the strength is poor. Therefore, improvements are needed when using kraft paper and tin foil alone as packaging bags. Summary of the invention

[0006] In order to improve the printing performance of packaging bags while improving the thermal insulation performance and strength of packaging bags, the present application provides a kraft paper-tin foil composite material for packaging bags.

[0007] The present application provides a kraft paper-tin foil composite material for packaging bags using the following technical solution:

[0008] A kraft paper-tin foil composite material for packaging bags comprises a color developing layer, an adhesive layer, a kraft paper layer and a tin foil layer which are arranged in sequence, wherein the color developing layer is a zinc silicate fluorescent brightener, and the adhesive layer is a starch adhesive layer.

[0009] By adopting the above technical solution, the starch adhesive layer is used as the adhesive of the packaging bag. When the starch adhesive layer is used to adhere the kraft paper layer and the tinfoil layer, the starch as a large molecule is not easy to pass through the atomic gaps of the tinfoil, and the starch adhesive is non-toxic compared to other adhesives, thereby further improving the safety performance of the food packaging bag.

[0010] By coating a fluorescent brightener on the surface of the kraft paper layer, the coloring performance of the kraft paper layer is improved, so that when the kraft paper-tin foil composite material is used as a packaging bag, the coloring degree when printing on the surface of the kraft paper layer is improved, thereby improving the aesthetics of the packaging bag.

[0011] The present application also provides a production process of a kraft paper-tin foil composite material for packaging bags, comprising the following steps: S1, firstly unrolling and flattening the tin foil and the kraft paper layer, coating the surface of the tin foil with starch glue through a composite device, so that the starch glue is evenly coated on the surface of the tin foil layer;

[0012] S2, then the surface of the kraft paper layer is coated with a fluorescent brightener by a composite device, and the fluorescent brightener is evenly applied to the surface of the kraft paper layer to improve the color rendering performance of the kraft paper surface;

[0013] S3, extruding and laminating the kraft paper layer and the tinfoil paper layer through a laminating device, so that the kraft paper layer and the tinfoil paper layer are adhesively laminated, and the adhesive layer between the kraft paper layer and the tinfoil paper layer is adsorbed and dried through the laminating device, so as to achieve rapid lamination and drying of the kraft paper layer and the tinfoil paper layer, and form a kraft paper-tinfoil paper composite material;

[0014] S4, using a composite device to detect the surface of the kraft paper layer-tin foil composite material, judging whether the kraft paper layer is damaged by the color reaction produced by the starch glue and the zinc silicate fluorescent brightener, and marking the damaged position, and subsequently cutting the damaged position to reduce the hygienic problems caused by the entry of chemicals into the packaging bag;

[0015] S5, again coating the tin foil of the kraft paper layer-tin foil composite material formed in S4 with starch glue through the composite equipment, and composite the new kraft paper layer with one side of the tin foil layer to form a kraft paper-tin foil-kraft paper three-layer composite material.

[0016] The starch glue is coated on the interlayer of kraft paper and tinfoil through the composite equipment, and the moisture is adsorbed from the starch glue on the tinfoil layer through the composite equipment. Since the starch glue mainly plays a bonding role, starch, gelatinizer, oxidant, etc., water is used as a solution in the adhesive to improve the fluidity of the adhesive. Since the moisture content cannot be too low in order to coat the entire surface of the tinfoil at this time, in order to improve the overall bonding and coating properties, after the adhesive is coated on the surface of the tinfoil through the composite equipment, when the composite material is rolled and adsorbed on the outside of the kraft paper, starch, gelatinizer, etc. are not easy to pass through the kraft paper, and moisture is easy to pass through the kraft paper, when adsorbing on one side of the kraft paper, moisture is easy to float to the outer surface of the kraft paper through the kraft paper, thereby facilitating the curing and drying of the adhesive layer, thereby improving the composite efficiency and composite properties of the composite material.

[0017] At the same time, after the moisture is adsorbed on one side of the kraft paper, the fluorescent brightener is coated on the other side of the kraft paper. Since the zinc silicate fluorescent brightener is also water-soluble, the adhesion performance of the zinc silicate fluorescent brightener to the surface of the kraft paper is improved, thereby reducing the moisture content in the fluorescent brightener and improving the subsequent drying and curing efficiency of the fluorescent brightener.

[0018] If the kraft paper is torn, when it is used as a packaging bag as a composite material, there is only tin foil as support at the torn part, which is not strong enough and is easy to break, thus affecting the storage period of the items in the packaging bag when it is used as a packaging bag. In addition, since the fluorescent brightener is a non-edible agent, it is easy to affect the packaging bag while passing through the rolling and adsorption of the composite equipment. When the kraft paper is torn, it is easy for the starch adhesive to pass through the torn part through the adsorption of the composite equipment. At this time, the starch adhesive reacts with the zinc silicate fluorescent brightener to produce a green-yellow reaction, which makes it easy to visually observe whether there is a crack.

[0019] If the kraft paper is not broken, large molecules such as starch and gelatinizers are not easy to pass through the kraft paper, and color reaction is not easy to occur at this time. Only water can easily pass through the kraft paper, which is convenient for the adhesion of fluorescent brighteners and improves the colorability of kraft paper. The fluorescent brightener is not easy to enter the inside of the packaging bag, thereby improving the safety performance when used as a food packaging bag.

[0020] By finally forming a composite material of a three-layer structure of kraft paper-tinfoil paper-kraft paper, the tear resistance of the entire packaging bag is further improved after it is made into a packaging bag, and the packaging bag has both the printing performance of kraft paper and the thermal insulation performance of tinfoil paper, while also improving the safety performance when used as a packaging bag.

[0021] Optionally, the composite equipment described in steps S1-S4 includes a frame, a rolling assembly arranged on the frame, a detection assembly arranged on the frame, and a coating assembly arranged on the frame;

[0022] The rolling assembly comprises a flattening roller rotatably arranged on the frame and a rotating member for driving the flattening roller to rotate. Two flattening rollers are provided, and the two flattening rollers are arranged opposite to each other, and a gap is left between the two flattening rollers for kraft paper and tin foil to pass through;

[0023] The detection assembly includes an optical camera assembly arranged on the frame, a marking member movably arranged on the frame, and a driving member for movably driving the marking member, and the optical camera assembly is electrically connected to the driving member;

[0024] The coating assembly includes a glue coating roller arranged on the frame, a coating rod arranged on the frame and a rotating part for driving the glue coating roller to rotate, the glue coating roller is located on the side of the flattening roller close to the input direction, the glue coating roller extends into the gap between the kraft paper and the tinfoil paper, the glue coating roller and the side of the tinfoil paper close to the kraft paper are in contact with each other, the coating rod is located on the side of the flattening roller away from the input direction, a plurality of coating holes are provided on the coating rod, and the plurality of coating holes are arranged at intervals along the length direction of the coating rod, a coating box is provided on the frame, zinc silicate brightener is stored in the coating box, the coating box is communicated with the coating rod, a glue box is provided in the glue coating roller, starch adhesive is stored in the glue box, the glue box is fixed to the frame, the glue box is communicated with the coating rod, and an extrusion piece for periodically extruding the adhesive in the glue box is also provided in the glue coating roller.

[0025] By adopting the above technical scheme, when producing composite materials, the technicians unwind the kraft paper and the tinfoil, and then convey the kraft paper and the tinfoil toward between two flattening rollers. During the conveying process, the starch adhesive in the glue box is squeezed into the flattening roller through the extruder, and then squeezed to the surface of the tinfoil through the connecting hole. The starch adhesive is periodically extruded by the set extruder, thereby reducing the waste caused by continuous extrusion of the starch adhesive. At the same time, since the conveying of the entire kraft paper and the tinfoil is periodic, the adhesive is periodically coated on the surface of the tinfoil according to the entire conveying rhythm through the periodic extrusion of the extruder.

[0026] At the same time, after the adhesive is coated on the surface of the tinfoil, the kraft paper and the tinfoil are composited and rolled by flattening rollers to form a kraft paper-tinfoil composite material. After the rolling is completed, the fluorescent brightener is coated on the surface of the kraft paper by a coating rod. At this time, the composite material is not completely dry before the fluorescent brightener is coated, which reduces the drying steps in the two processes of compounding and colorant coating, thereby improving the compounding efficiency of the entire composite material, and at the same time improving the coloring performance of the composite material as a packaging material.

[0027] When the colorant is applied, since the composite material is not completely dried, the moisture in the adhesive acts as a solvent for the colorant, thereby improving the adhesion of the colorant to the surface of the kraft paper.

[0028] Optionally, the extrusion component includes a connecting tube provided on the glue box and a sealing block provided on the sealing tube for sliding movement, the connecting tube is communicated with the glue box, the glue coating roller is hollow, and a plurality of groups of connecting holes are evenly spaced along the circumference direction of the glue coating roller, the outer peripheral side of the glue coating roller is covered with a sponge pad, and the sponge pad is in contact with the surface of the tin foil, a sealing hole is provided on the outer peripheral wall of the connecting tube, and the sealing block is slidably provided in the sealing hole, two sealing blocks are provided, and the two sealing blocks are arranged relative to each other, and the two sealing blocks are movably fitted on the sides close to each other, and when the two sealing blocks are in contact with each other, the connecting tube is blocked by the sealing block, and an adjusting member for slidingly adjusting the sealing block is also provided in the glue coating roller.

[0029] By adopting the above technical solution, when the glue coating roller rotates, the sealing block is slidably adjusted by the arranged adjusting member, and when the glue coating roller rotates to the position corresponding to the connecting tube and the connecting hole, the adjusting member drives the sealing block to slide to a state of being separated from each other, so that the connecting tube is stably opened at this time, and the starch adhesive is stably applied. When the glue coating roller rotates to the position where the connecting tube and the connecting hole are separated, the sealing block is adjusted by the adjusting member to a position where it fits together, and the connecting tube is sealed. This is one cycle, and through this cycle, the starch adhesive can be periodically extruded.

[0030] At the same time, the sponge pad is set to reduce the scratches caused by the connecting holes opened on the glue coating roller when the kraft paper is attached, which affects the surface quality of the kraft paper. The adsorption and coating of the sponge pad further reduce the waste of starch adhesive and improve the uniformity of adhesive coating on tin foil.

[0031] Optionally, the adjusting member is slidably sleeved on the connecting sleeve on the connecting tube, one end of the sealing block is movably protruding from the connecting tube, the inner circumferential wall of the connecting sleeve and the sealing block are movably fitted and pressed against one end of the connecting tube, the sealing block is elastically arranged in the connecting tube, one end of the connecting sleeve is movably protruding from the connecting tube, a pressing block is provided on the inner circumferential wall of the rubber coating roller, the pressing block is movably fitted and pressed against the connecting sleeve, and the end of the pressing block fitted with the connecting sleeve is in an inclined shape.

[0032] By adopting the above technical solution, when the glue coating roller rotates, the inclined side of the pressing block and the end side of the connecting sleeve are movably fitted and pressed against each other, so that during the rotation of the glue coating roller, the pressing connecting sleeve slides, thereby causing the connecting sleeve to slide on the connecting pipe;

[0033] When the glue coating roller rotates to the position corresponding to the connecting tube and the connecting hole, the pressing block presses against the connecting sleeve and slides upward. At this time, the connecting sleeve and the sealing block are separated, so that the sealing blocks are separated from each other under the elastic force of the reset part, and the connecting tube is opened. At this time, the starch adhesive drips from the connecting tube to the connecting hole under the action of gravity, and is smeared on the surface of the tin foil through the sponge pad.

[0034] When the glue coating roller rotates until the connecting pipe and the connecting hole are offset, the pressing block separates from the connecting sleeve, causing the connecting sleeve to move away from the glue box. At this time, the connecting sleeve presses against the sealing block, so that the sealing blocks are close to each other and pressed tightly to achieve sealing of the connecting pipe, thereby reducing leakage of adhesive and achieving periodic dripping coating of the adhesive.

[0035] Optionally, the flattening roller located on the top side is provided with a plurality of groups of negative pressure holes, and the plurality of groups of negative pressure holes are evenly spaced along the circumference direction of the flattening roller. A negative pressure box is provided in the flattening roller, and a negative pressure member for generating negative pressure in the negative pressure box is provided on the frame. A negative pressure tube is provided on the negative pressure box, and the negative pressure tube corresponds to one of the plurality of groups of negative pressure holes, and a switching member for making the negative pressure tube correspond to one of the negative pressure holes is provided in the flattening roller.

[0036] By adopting the above technical scheme, after the tin foil is coated with adhesive, when it is rolled by two flattening rollers, the negative pressure part works to generate negative pressure in the negative pressure box, and the switching part is set to make the negative pressure tube correspond to one of the multiple groups of negative pressure holes when the flattening roller rotates, so that negative pressure is generated at the negative pressure holes where the flattening roller and the kraft paper are in contact, and the negative pressure of the negative pressure holes is used to absorb the moisture in the adhesive between the kraft paper and the tin foil, so as to facilitate the subsequent coating and adhesion of the fluorescent brightener. Since the flattening roller is hollow, negative pressure will also be generated at other negative pressure holes at this time, so as to properly dry the moisture in the composite material during transportation, improve the stability during transportation, and reduce transportation tearing caused by excessive moisture.

[0037] At the same time, by setting negative pressure in the flattening roller, when cracks appear on the kraft paper, the negative pressure member will suck the adhesive out of the cracks, thereby facilitating the subsequent detection of the cracks when the fluorescent brightener is colored.

[0038] Optionally, the switching member includes a switching plate arranged in the flattening roller, the switching plate is rotatably arranged in the flattening roller, the switching plates are provided with a plurality of groups, the plurality of groups of switching plates are arranged at intervals along the inner circumferential wall of the flattening roller, the negative pressure hole is located between two adjacent groups of switching plates, the switching plate movably blocks the negative pressure hole, a clamping rod is provided on the negative pressure box, the clamping rod is movably fitted with the switching plate, a return member is provided at the rotating shaft of the switching plate, the clamping rod is slidably arranged on the negative pressure box, and a sliding member for slidingly adjusting the clamping rod is also provided on the negative pressure box.

[0039] By adopting the above technical solution, the moisture content of the added starch adhesive is inconsistent according to the components and thickness of different kraft papers. Therefore, the negative pressure strength required during rolling is also inconsistent for adhesives with different moisture contents. When the output power of the negative pressure piece is adjusted, the drying speed of the final composite material is affected. In order to change the negative pressure strength during rolling without affecting the overall drying speed of the composite material.

[0040] Through the setting of the switching plate, when the flattening roller rotates to the position corresponding to the negative pressure tube and the negative pressure hole, the clamping rod fits with the switching plate. Since the switching plate is rotatably arranged in the flattening roller, during the rotation of the flattening roller, the clamping rod successively fits with the switching plate located close to the surface of the kraft paper, thereby driving the switching plate to rotate, so that the effective width of the corresponding negative pressure hole changes. The greater the rotation angle of the switching plate, the smaller the negative pressure at the corresponding negative pressure hole, and the greater the negative pressure at the corresponding remaining negative pressure holes, thereby reducing the damage to the kraft paper surface when the moisture content of the adhesive is high while improving the drying efficiency of the composite material.

[0041] When the moisture content of the adhesive is low, the position of the clamping rod is adjusted to reduce the rotation angle of the switching plate, thereby increasing the negative pressure on the surface of the kraft paper and improving the efficiency of moisture transfer to the surface of the kraft paper. At this time, the negative pressure at the remaining negative pressure holes is small, which can also help dry the composite material.

[0042] Optionally, the sliding member includes a sliding rack slidably set on the negative pressure box and connected to the clamping rod, a sliding gear is rotatably connected to the collection box, the sliding gear is meshed with the sliding rack, and the frame is also provided with a rotating handle fixed to the rotating shaft of the sliding gear.

[0043] By adopting the above technical solution, when it is necessary to adjust the rotation angle of the switching plate under different humidity, the technician rotates the rotating handle to drive the sliding gear to rotate, thereby driving the sliding rack to rise and fall. When the sliding rack drives the abutment rod to rise and fall, the abutment length between the abutment rod and the switching plate is adjusted, thereby achieving the purpose of adjusting the rotation angle of the switching plate.

[0044] Optionally, a coating rod is provided with a coating plate on the side away from the flattening roller, and the coating plate is in contact with the surface of the kraft paper. The frame is provided with a clamping wheel that rotates on the bottom side of the coating rod, and the clamping wheel is provided on the bottom side of the coating plate, and the clamping wheel is movably in contact with the bottom side of the tin foil. The coating rod is also provided with a coloring part that periodically extrude the silicate brightener.

[0045] By adopting the above technical scheme, a coating plate is provided to scrape the surface of the kraft paper evenly after the fluorescent brightener is applied to the surface of the kraft paper, thereby improving the uniformity of the coating of the fluorescent brightener on the surface of the kraft paper, thereby making the coloring performance and color rendering performance of the kraft paper surface uniform, and because the fluorescent brightener is a water-soluble agent, the fluorescent brightener is periodically squeezed out through the provided coloring parts, thereby reducing the waste of the fluorescent brightener and improving the uniformity of coloring on the kraft paper surface.

[0046] Optionally, the coloring member includes a sealing plate slidably disposed on the paint rod, the sealing plate movably seals the paint hole, the end side of the clamping wheel is rotatably connected to a connecting rod, and the end of the connecting rod away from the clamping wheel is rotatably connected to the sealing plate.

[0047] By adopting the above technical solution, when the pressing wheel rotates to press and convey the composite material, it drives the connecting rod to rotate, and the connecting rod drives the sealing plate to slide, thereby intermittently sealing the paint hole of the paint rod, thereby realizing the periodic dropping of the fluorescent brightener.

[0048] In summary, the present application includes at least one of the following beneficial technical effects:

[0049] 1. Through the provided glue coating roller, extrusion piece and multiple groups of connecting holes on the glue coating roller, when the kraft paper and tin foil are laminated, the extrusion piece periodically squeezes the adhesive out of the connecting holes to achieve the coating of the adhesive on the surface of the tin foil, reducing the waste of the adhesive and facilitating the adjustment of the adhesive coating time according to the conveying cycle without manual intervention;

[0050] 2. Through the flattening roller and the negative pressure holes on the flattening roller, negative pressure is generated when the composite material is rolled, and the moisture in the adhesive is adsorbed by negative pressure, so that the moisture in the adhesive floats to the surface of the kraft paper, which is convenient for the subsequent attachment of the fluorescent brightener and the detection of cracks;

[0051] 3. Through the sealing block slidably arranged in the connecting pipe, the connecting sleeve slidably arranged on the connecting pipe and the pressing block arranged in the glue coating roller, when the glue coating roller rotates, the glue coating roller drives the pressing block to rotate periodically, thereby performing periodic sliding adjustment on the connecting sleeve, thereby achieving stable coating of the tin foil adhesive. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present application;

[0053] Figure 2 It is a schematic diagram of the connection structure of the glue coating roller and the frame;

[0054] Figure 3 is a schematic diagram of the connection structure of the flattening roller;

[0055] Figure 4 It is a schematic diagram of the connection structure of the paint rod.

[0056] Figure numerals: 1, frame; 11, unwinder; 12, kraft paper; 13, tin foil; 14, winder; 2, rolling assembly; 21, flattening roller; 22, rotating member; 23, negative pressure hole; 24, negative pressure tube; 25, switching member; 251, switching plate; 252, clamping rod; 253, clamping torsion spring; 26, negative pressure box; 27, negative pressure member; 28, sliding member; 281, sliding rack; 282, sliding gear; 283, rotating handle; 3, detection assembly; 31, optical camera ; 32. Marking part; 33. Driving part; 4. Coating assembly; 41. Coating rod; 411. Coating hole; 42. Coating box; 43. Glue roller; 431. Connecting hole; 432. Glue box; 433. Sponge pad; 44. Extrusion part; 441. Connecting pipe; 442. Sealing block; 443. Sealing spring; 45. Adjusting part; 451. Connecting sleeve; 452. Clamping block; 46. Coating plate; 47. Clamping wheel; 48. Coloring part; 481. Sealing plate; 482. Connecting rod. DETAILED DESCRIPTION

[0057] The following is combined with Figure 1-4 This application is described in further detail.

[0058] The present application embodiment discloses a kraft paper-tin foil composite material for packaging bags. Figure 1 A kraft paper-tin foil composite material for packaging bags includes a color development layer, an adhesive layer, 12 layers of kraft paper and 13 layers of tin foil arranged in sequence. The color development layer is formed after the zinc silicate fluorescent brightener is cured, and the adhesive layer is formed after the starch glue is cured.

[0059] The present application also discloses a production process of a kraft paper-tin foil composite material for packaging bags, comprising the following steps:

[0060] S1, firstly, unrolling and flattening the tin foil 13 and the kraft paper 12, and coating the surface of the tin foil 13 with starch glue by a composite device, so that the starch glue is evenly coated on the surface of the tin foil 13;

[0061] S2, then the surface of the kraft paper 12 layer is coated with a fluorescent brightener by a composite device, and the fluorescent brightener is evenly applied to the surface of the kraft paper 12 layer to improve the color rendering performance of the surface of the kraft paper 12;

[0062] S3, extruding and laminating the kraft paper 12 layer and the tinfoil paper 13 layer through a laminating device, so that the kraft paper 12 layer and the tinfoil paper 13 layer are adhesively laminated, and the adhesive layer between the kraft paper 12 layer and the tinfoil paper 13 layer is adsorbed and dried through the laminating device, so as to achieve rapid lamination and drying of the kraft paper 12 layer and the tinfoil paper 13 layer, and form a kraft paper 12-tinfoil paper 13 composite material;

[0063] S4, the surface of the composite material of kraft paper 12 layers and tin foil paper 13 is inspected by composite equipment, and the color reaction produced by starch glue and zinc silicate fluorescent brightener is used to determine whether the kraft paper 12 layers are damaged, and the damaged position is marked, and the damaged position is subsequently cut to reduce the hygiene problems caused by chemical agents entering the packaging bag.

[0064] S5, again coating the tin foil of the kraft paper layer-tin foil composite material formed in S4 with starch glue through the composite equipment, and composite the new kraft paper layer with one side of the tin foil layer to form a kraft paper-tin foil-kraft paper three-layer composite material.

[0065] According to the above process, the present application also proposes a composite device, including a frame 1 fixed to the ground, the frame 1 is arranged horizontally, and the extension direction of the frame 1 is consistent with the conveying direction of kraft paper 12 and tinfoil 13. The frame 1 is provided with an uncoiler 11 along the conveying direction, a coating component 4 for adhesive coating and fluorescent brightener coating, a rolling component 2 for roll-compounding the kraft paper 12 and the tinfoil 13, a detection component 3 for detecting cracks, and a winding machine 14 for the finally formed composite material. The uncoiler 11 is provided with two groups, and the two groups of uncoilers 11 are arranged relative to each other in the height direction. The uncoiler 11 on the top side is used to unwind the kraft paper 12, and the uncoiler 11 on the bottom side is used to unwind the tinfoil 13.

[0066] Reference Figure 1 and Figure 2The coating assembly 4 includes a coating roller 43 disposed on the side of the rolling assembly 2 close to the unwinder 11 and a coating rod 41 close to the side of the winder 14. The coating roller 43 is disposed between the kraft paper 12 and the tin foil 13, and the coating roller 43 is in contact with the surface of the tin foil 13. The coating roller 43 is rotatably disposed on the frame 1, and the coating roller 43 is hollow. A glue box 432 is disposed in the coating roller 43, and starch adhesive is stored in the glue box 432. A connecting pipe is disposed on the bottom side of the glue box 432. A plurality of connecting holes 431 are provided on the coating roller 43. The plurality of connecting holes 432 are provided on the coating roller 43. The connecting holes 431 are evenly spaced along the circumference direction of the glue coating roller 43, and the outer peripheral wall of the glue coating roller 43 is covered with a sponge pad 433 to reduce the scratching of the tin foil 13 during the gluing process and improve the uniformity of the adhesive coating. Each group of connecting holes 431 includes a plurality of connecting holes 431 evenly spaced along the axial direction of the glue coating roller 43, and a plurality of connecting pipes are also provided. The plurality of connecting pipes correspond to the plurality of connecting holes 431 in each group one by one and are movably connected. In order to periodically extrude the adhesive when the glue coating roller 43 rotates, an extrusion piece 44 is also provided in the glue coating roller 43.

[0067] Reference Figure 1 and Figure 2 The extrusion piece 44 includes a blocking block 442 slidably arranged on the connecting pipe, and the sliding direction of the blocking block 442 is perpendicular to the length direction of the connecting pipe. There are two blocking blocks 442 on each connecting pipe, and the two blocking blocks 442 are arranged relatively to each other. The two blocking blocks 442 are movably fitted together, and a blocking spring 443 is fixedly connected between the two blocking blocks 442. When the two blocking blocks 442 are fitted together, the connecting pipe is completely blocked. When the two blocking blocks 442 are separated, the connecting pipe is opened.

[0068] At the same time, in order to realize the sliding adjustment of the blocking block 442, an adjusting piece 45 is provided on the connecting pipe, and the adjusting piece 45 includes a connecting sleeve 451 slidably mounted on the connecting pipe 441, one end of the blocking block 442 is movably protruding from the connecting pipe 441, and the end of the blocking block 442 movably located outside the connecting pipe 441 is in an arc shape, the inner circumferential wall of the connecting sleeve 451 is movably fitted and tightly pressed against the end side of the blocking block 442, one end of the connecting sleeve 451 is protruding from the connecting pipe 441, and a plurality of groups of pressing blocks 452 are fixedly connected to the inner circumferential wall of the glue coating roller 43, each group of pressing blocks 452 includes a plurality of pressing blocks 452 corresponding to the connecting holes 431 one by one, the outer circumferential wall of the pressing block 452 is inclined, and the inclined side of the pressing block 452 is movably fitted and tightly pressed against the end side of the connecting sleeve 451 protruding from the connecting pipe 441.

[0069] Therefore, when the glue coating roller 43 rotates to the position corresponding to the connecting tube 441 and the connecting hole 431, the pressing block 452 presses against the connecting sleeve 451 and slides upward. At this time, the connecting sleeve 451 is separated from the blocking block 442, so that the blocking blocks 442 are separated from each other under the elastic force of the reset member, and the connecting tube 441 is opened. At this time, the starch adhesive drips from the connecting tube 441 to the connecting hole 431 under the action of gravity, and is smeared on the surface of the tin foil 13 through the sponge pad 433.

[0070] When the glue coating roller 43 rotates until the connecting tube 441 is offset from the connecting hole 431, the pressing block 452 is separated from the connecting sleeve 451, so that the connecting sleeve 451 moves in the direction away from the glue box 432. At this time, the connecting sleeve 451 presses against the sealing block 442, so that the sealing blocks 442 are pressed against each other to achieve the sealing of the connecting tube 441, thereby reducing the leakage of the adhesive and achieving the periodic dripping coating of the adhesive.

[0071] Further, after the adhesive is applied, the kraft paper 12 and the tin foil 13 need to be rolled and laminated. Figure 1 and Figure 3 The rolling assembly 2 includes two flattening rollers 21 arranged opposite to each other in the height direction, and a gap is left between the two flattening rollers 21 for the composite material to pass through. The frame 1 is provided with a rotating member 22 for rotating and driving the flattening rollers 21. In the present application, the rotating member 22 is a rotating motor fixedly connected to the rotating shaft of one of the flattening rollers 21. The rotating shafts of the two flattening rollers 21 are provided with rotating gears meshing with each other, and in order to apply the fluorescent brightener later, a negative pressure hole 23 is opened on the flattening roller 21. There are multiple negative pressure holes 23, and the multiple negative pressure holes 23 are evenly spaced along the circumference direction of the flattening roller 21, and the flattening roller 21 is also arranged in a hollow shape. A negative pressure box 26 is provided in the flattening roller 21, and a negative pressure part 27 for generating negative pressure in the negative pressure box 26 is provided on the frame 1. A negative pressure pipe 24 is fixedly connected to the bottom side of the negative pressure box 26, and the negative pressure pipe 24 corresponds to the negative pressure holes 23 one by one, and a switching part 25 for making the negative pressure pipe 24 correspond to the negative pressure holes 23 one by one is provided in the flattening roller 21.

[0072] Reference Figure 3 The switching member 25 includes a switching plate 251 rotatably connected to the top flattening roller 21. The switching plates 251 are provided with multiple groups. The rotation axis of the switching plates 251 is consistent with the rotation axis of the flattening roller 21, and the multiple groups of switching plates 251 correspond one by one to the multiple negative pressure holes 23. The switching plates 251 movably block the negative pressure holes 23, and a clamping rod 252 is slidably provided on the side wall of the negative pressure box 26, and the end side of the clamping rod 252 is tightly fitted with the switching plate 251.

[0073] In order to achieve coating and drying of adhesives with different moisture contents for different kraft papers 12, a sliding member 28 for slidingly adjusting the clamping rod 252 is provided in the flattening roller 21. The sliding member 28 includes a sliding rack 281 slidably set on the side wall of the negative pressure box 26. The sliding rack 281 is fixedly connected to the clamping rod 252. A sliding gear 282 is rotatably connected to the side wall of the negative pressure box 26. The rotating shaft of the sliding gear 282 is consistent with the rotating shaft of the flattening roller 21. The sliding gear 282 is meshed with the sliding rack 281. A rotating handle 283 coaxial with the sliding gear 282 is rotatably connected to the frame 1.

[0074] When the flattening roller 21 rotates to the position corresponding to the negative pressure tube 24 and the negative pressure hole 23, the clamping rod 252 fits with the switching plate 251. Since the switching plate 251 is rotatably arranged in the flattening roller 21, and a clamping torsion spring 253 is fixedly connected to the rotating shaft of the switching plate 251, during the rotation of the flattening roller 21, the clamping rod 252 fits with the switching plate 251 located close to the surface of the kraft paper 12 in turn, thereby driving the switching plate 251 to rotate, so that the effective width of the corresponding negative pressure hole 23 changes. The greater the rotation angle of the switching plate 251, the smaller the negative pressure at the corresponding negative pressure hole 23, and the greater the negative pressure at the corresponding remaining negative pressure holes 23, thereby reducing the damage to the surface of the kraft paper 12 when the moisture content of the adhesive is high while improving the drying efficiency of the composite material.

[0075] When the moisture content of the adhesive is low, the position of the clamping rod 252 is adjusted to reduce the rotation angle of the switching plate 251, thereby increasing the negative pressure on the surface of the kraft paper 12 and improving the efficiency of moisture reaching the surface of the kraft paper 12. At this time, the negative pressure at the remaining negative pressure hole 23 is small, which can also help dry the composite material.

[0076] After the kraft paper 12 and the tin foil 13 are compounded, under the negative pressure of the flattening roller 21, the moisture in the adhesive floats on the surface of the kraft paper 12 due to the negative pressure. At this time, the coating of the fluorescent brightener can not only improve the adhesion but also reduce the moisture content in the fluorescent brightener, thereby improving the coloring performance of the surface of the kraft paper 12. Therefore, the coating component 4 includes a coating rod 41 fixed on the frame 1 and located on the side of the flattening roller 21 close to the winding roller. A coating hole 411 is opened on the bottom side of the coating rod 41. There are multiple coating holes 411, and the multiple coating holes 411 are evenly spaced along the length direction of the coating rod 41. A coating box 42 connected to the coating hole 411 is fixedly connected to the frame 1. Zinc silicate brightener is stored in the coating box 42. In order to achieve uniform coating of the fluorescent brightener on the surface of the kraft paper 12, a coating plate 46 is fixedly connected to the frame 1 on the side of the coating rod 41 away from the flattening roller 21. A clamping wheel 47 is rotatably connected to the bottom side of the coating plate 46. The clamping wheel 47 and the coating plate 46 are arranged opposite to each other, and the clamping wheel 47 is in contact with the bottom side of the composite material, and the coating plate 46 is in contact with the top side of the composite material.

[0077] Since the zinc silicate brightener is in the form of a solution, if the coating hole 411 is always opened, it is easy to cause waste of the zinc silicate brightener. Therefore, in order to solve this problem, a coloring member 48 for periodically extruding the zinc silicate brightener is provided on the coating stem. Figure 3 and Figure 4 The coloring member 48 includes a sealing plate 481 which is slidably arranged inside the coating rod 41, and the sealing plate 481 movably seals the coating hole 411. A connecting rod 482 is rotatably connected to the end side of the pressing wheel 47 away from the axis, and the rotation axis of the connecting rod 482 is parallel to the rotation axis of the pressing wheel 47. The end of the connecting rod 482 away from the pressing wheel 47 is rotatably connected to the sealing plate 481; when the pressing wheel 47 rotates to convey the composite material, the connecting rod 482 is driven to rotate, and the connecting rod 482 drives the sealing plate 481 to slide, thereby intermittently sealing the coating hole 411 of the coating rod 41, thereby realizing the periodic dropping of the fluorescent brightener.

[0078] Also refer to Figure 1 and Figure 4 The detection component 3 includes an optical camera 31 fixed on the frame 1, the optical camera 31 is located between the coating rod 41 and the winding roller, and the optical camera 31 is arranged toward the surface of the kraft paper 12. A marking member 32 is slidably provided on the frame 1. In this application, the marking member 32 is in the form of a marking pen, and the sliding direction of the marking member 32 is consistent with the height direction of the frame 1. A driving member 33 for lifting and sliding the marking member 32 is provided on the frame 1. In this application, the driving member 33 is an electric push rod electrically connected to the optical camera 31.

[0079] The implementation principle of the kraft paper-tinfoil composite material for packaging bags in an embodiment of the present application is as follows: when producing the composite material, the technician unwinds the kraft paper 12 and the tinfoil 13, and then conveys the kraft paper 12 and the tinfoil 13 toward between two flattening rollers 21. During the conveying process, the starch adhesive in the glue box 432 is squeezed into the flattening roller 21 through the extrusion piece 44, and is squeezed onto the surface of the tinfoil 13 through the connecting hole 431.

[0080] At the same time, after the adhesive is coated on the surface of the tinfoil 13, the kraft paper 12 and the tinfoil 13 are composited and rolled by the flattening roller 21 to form a kraft paper 12-tinfoil 13 composite material. After the rolling is completed, the surface of the kraft paper 12 is coated with a fluorescent brightener by the provided coating rod 41. At this time, the fluorescent brightener is coated when the composite material is not completely dry, thereby reducing the drying steps in the two processes of compounding and colorant coating.

[0081] After the tin foil 13 is coated with adhesive, when it is rolled by two flattening rollers 21, the negative pressure member 27 works to generate negative pressure in the negative pressure box 26. The switching member 25 is set so that when the flattening roller 21 rotates, the negative pressure tube 24 is selected to correspond to one of the multiple groups of negative pressure holes 23, so that negative pressure is generated at the negative pressure holes 23 where the flattening roller 21 and the kraft paper 12 are in contact. The negative pressure of the negative pressure holes 23 is used to absorb the moisture in the adhesive between the kraft paper 12 and the tin foil 13, so as to facilitate the subsequent coating and adhesion of the fluorescent brightener.

[0082] When the pressing wheel 47 rotates to press and convey the composite material, it drives the connecting rod 482 to rotate, and the connecting rod 482 drives the blocking plate 481 to slide, thereby intermittently blocking the coating hole 411 of the coating rod 41, thereby achieving periodic dropping of the fluorescent brightener.

[0083] 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 process for producing a kraft paper-tin foil composite material for packaging bags, used for producing a kraft paper-tin foil composite material for packaging bags, the composite material comprising a color developing layer, a kraft paper (12) layer, an adhesive layer, a tin foil (13) layer, an adhesive layer and a kraft paper layer arranged in sequence, the color developing layer being a color developing layer formed after curing a zinc silicate fluorescent brightener, the adhesive layer being an adhesive layer formed after curing a starch glue, characterized in that: The production process comprises the following steps: S1, firstly, unrolling and flattening the tin foil (13) and the kraft paper (12) layer, and coating the surface of the tin foil (13) with starch glue through a composite device, so that the starch glue is evenly coated on the surface of the tin foil (13); S2, then, by means of a composite device, the surface of the kraft paper (12) layer is coated with a fluorescent brightener, and the fluorescent brightener is evenly applied to the surface of the kraft paper (12) layer to improve the color rendering performance of the surface of the kraft paper (12); S3, extruding and laminating the kraft paper (12) layer and the tinfoil (13) layer through a laminating device, so that the kraft paper (12) layer and the tinfoil (13) layer are adhesively laminated, and the adhesive layer between the kraft paper (12) layer and the tinfoil (13) layer is adsorbed and dried through the laminating device, so as to achieve rapid lamination and drying of the kraft paper (12) layer and the tinfoil (13) layer, thereby forming a kraft paper (12)-tinfoil (13) composite material; S4, using a composite device to detect the surface of the composite material of the kraft paper (12) layer and the tin foil paper (13), judging whether the kraft paper (12) layer is damaged by the color reaction produced by the starch glue and the zinc silicate fluorescent brightener, marking the damaged position, and subsequently cutting the damaged position to reduce the hygienic problems caused by the entry of chemical agents into the packaging bag; S5, again coating the tin foil of the kraft paper layer-tin foil composite material formed in S4 with starch glue through the composite equipment, and composite the new kraft paper layer with one side of the tin foil layer to form a kraft paper-tin foil-kraft paper three-layer composite material.

2. The process for producing a kraft paper-tin foil composite material for packaging bags according to claim 1, characterized in that: The composite equipment described in steps S1-S4 comprises a frame (1), a rolling assembly (2) arranged on the frame (1), a detection assembly (3) arranged on the frame (1), and a coating assembly (4) arranged on the frame (1); The rolling assembly (2) comprises a flattening roller (21) rotatably arranged on the frame (1) and a rotating member (22) for driving the flattening roller (21) to rotate, wherein two flattening rollers (21) are provided, the two flattening rollers (21) are arranged opposite to each other, and a gap is left between the two flattening rollers (21) for the kraft paper (12) and the tin foil (13) to pass through; The detection component (3) comprises an optical camera component (31) arranged on the frame (1), a marking component (32) movably arranged on the frame (1), and a driving component (33) for movably driving the marking component (32), and the optical camera component is electrically connected to the driving component (33); The coating assembly (4) comprises a glue coating roller (43) arranged on the frame (1), a coating rod (41) arranged on the frame (1), and a rotating member (22) for rotating the glue coating roller (43), wherein the glue coating roller (43) is located on a side of the flattening roller (21) close to the input direction, the glue coating roller (43) extends into a gap between the kraft paper (12) and the tinfoil (13), the glue coating roller (43) is in contact with a side of the tinfoil (13) close to the kraft paper (12), the glue coating roller (43) is provided with a plurality of groups of connecting holes (431), the coating rod (41) is located on a side of the flattening roller (21) away from the input direction, and the coating rod (41) is provided with a plurality of connecting holes (431). A plurality of paint holes (411), wherein the plurality of paint holes (411) are arranged at intervals along the length direction of the paint rod (41); a paint box (42) is provided on the frame (1); a zinc silicate fluorescent brightener is stored in the paint box (42); the paint box (42) is connected to the paint rod (41); a glue box (432) is provided in the glue coating roller (43); a starch adhesive is stored in the glue box (432); the glue box (432) is fixed to the frame (1); the glue box (432) is connected to the paint rod (41); and an extrusion piece (44) for periodically extruding the adhesive in the glue box (432) is also provided in the glue coating roller (43).

3. The process for producing a kraft paper-tin foil composite material for packaging bags according to claim 2, characterized in that: The extrusion piece (44) comprises a connection pipe (441) arranged on the glue box (432) and a blocking block (442) slidably arranged on the connection pipe (441); the connection pipe (441) is connected to the glue box (432); the glue coating roller (43) is hollow; a plurality of groups of communication holes (431) are evenly spaced along the circumference direction of the glue coating roller (43); the outer circumference of the glue coating roller (43) is covered with a sponge pad (433); the sponge pad (433) is in contact with the surface of the tin foil (13). The connecting tube (441) is provided with a blocking hole on its outer wall, and the blocking block (442) is slidably arranged in the blocking hole. Two blocking blocks (442) are provided, and the two blocking blocks (442) are arranged opposite to each other. The two blocking blocks (442) are movably fitted together on their sides close to each other. When the two blocking blocks (442) are fitted together, the connecting tube (441) is blocked by the blocking block (442), and an adjusting member (45) for slidingly adjusting the blocking block (442) is also provided in the glue coating roller (43).

4. The process for producing a kraft paper-tin foil composite material for packaging bags according to claim 3, characterized in that: The adjusting member (45) is slidably sleeved on the connecting sleeve (451) on the connecting tube (441); one end of the blocking block (442) is movably protruded from the connecting tube (441); the inner peripheral wall of the connecting sleeve (451) and one end of the blocking block (442) located on the connecting tube (441) are movably fitted and pressed against each other; the blocking block (442) is elastically arranged in the connecting tube (441); one end of the connecting sleeve (451) is movably protruded from the connecting tube (441); a pressing block (452) is provided on the inner peripheral wall of the rubber coating roller (43); the pressing block (452) and the connecting sleeve (451) are movably fitted and pressed against each other; and one end of the pressing block (452) that is in contact with the connecting sleeve (451) is in an inclined shape.

5. The process for producing a kraft paper-tin foil composite material for packaging bags according to claim 4, characterized in that: The flattening roller (21) located on the top side is provided with a plurality of groups of negative pressure holes (23), and the plurality of groups of negative pressure holes (23) are evenly spaced along the circumference direction of the flattening roller (21). A negative pressure box (26) is provided in the flattening roller (21), and a negative pressure member (27) for generating negative pressure in the negative pressure box (26) is provided on the frame (1). A negative pressure tube (24) is provided on the negative pressure box (26), and the negative pressure tube (24) corresponds to one of the plurality of groups of negative pressure holes (23), and a switching member (25) for causing the negative pressure tube (24) to correspond to one of the negative pressure holes (23) is provided in the flattening roller (21).

6. The process for producing a kraft paper-tin foil composite material for packaging bags according to claim 5, characterized in that: The switching member (25) comprises a switching plate (251) disposed in the flattening roller (21), the switching plate (251) being rotatably disposed in the flattening roller (21), a plurality of switching plates (251) being provided, the plurality of switching plates (251) being spaced apart along the inner circumferential wall of the flattening roller (21), the negative pressure hole (23) being located between two adjacent groups of switching plates (251), the switching plate (251) movably blocking the negative pressure hole (23), a clamping rod (252) being provided on the negative pressure box (26), the clamping rod (252) being movably fitted with the switching plate (251), a return member being provided at the rotating shaft of the switching plate (251), the clamping rod (252) being slidably disposed on the negative pressure box (26), and a sliding member (28) for slidingly adjusting the clamping rod (252) being further provided on the negative pressure box (26).

7. The process for producing a kraft paper-tin foil composite material for packaging bags according to claim 6, characterized in that: The sliding member (28) comprises a sliding rack (281) slidably arranged on the negative pressure box (26) and connected to the clamping rod (252); a sliding gear (282) is rotatably connected to the negative pressure box (26); the sliding gear (282) is meshed with the sliding rack (281); and a rotating handle (283) fixed to the rotating shaft of the sliding gear (282) is also provided on the frame (1).

8. The process for producing a kraft paper-tin foil composite material for packaging bags according to claim 7, characterized in that: A coating plate (46) is provided on the side of the coating rod (41) away from the flattening roller (21), and the coating plate (46) is in contact with the surface of the kraft paper (12). A clamping wheel (47) is rotatably provided on the bottom side of the coating rod (41) on the frame (1), and the clamping wheel (47) is provided on the bottom side of the coating plate (46), and the clamping wheel (47) is movably in contact with the bottom side of the tin foil (13). The coating rod (41) is also provided with a coloring member (48) for periodically extruding the zinc silicate fluorescent brightener.

9. The process for producing a kraft paper-tin foil composite material for packaging bags according to claim 8, characterized in that: The coloring member (48) comprises a blocking plate (481) slidably arranged on the paint rod (41), the blocking plate (481) movably blocking the paint hole (411), the end side of the abutting wheel (47) being rotatably connected to a connecting rod (482), the end of the connecting rod (482) away from the abutting wheel (47) being rotatably connected to the blocking plate (481).

Images