A preparation system of sizing starch for food carton paper

Abstract

The utility model discloses a kind of preparation systems of sizing starch for food card paper, including stock bin, dispersion tank, sizing buffer tank, sizing storage tank, sizing feeding tank and gluing machine, sizing feeding tank is used for transfer storage sizing material, sizing storage tank pumped over sizing material and sizing machine backflow sizing material are stored and pumped to sizing machine by feeding pump;Dispersion tank and the sizing buffer tank between still be connected with superfine gap arc screen and multistage cyclone washer;Sizing buffer tank and sizing storage tank between still be connected with cooking device;Sizing storage tank and sizing feeding tank between still be connected with sizing material filter;Sizing feeding tank and gluing machine between still be connected with feeding pump, feeding pressure screen and sizing material recovery device;Inorganic ash impurities in starch are removed by the combination mode of superfine gap arc screen and multistage cyclone washer, organic protein is removed by multistage cyclone washer, and the preparation quality of sizing starch glue liquid is effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of papermaking technology, and in particular to a preparation system for surface starch for food cardboard. Background Technology

[0002] In papermaking, surface sizing is an important process, usually located at the end of the drying section of the paper machine. It involves coating the paper with a layer of adhesive while it is not completely dry but still has a certain strength. After subsequent drying, an adhesive film is formed on the surface of the paper or paperboard, thereby changing the surface properties of the paper or paperboard.

[0003] The basis weight range for paperboard used in food packaging is generally 180 g / m³. 2 -400g / m 2 Surface sizing is extremely important in the paperboard production process. Starch adhesive is used to apply surface sizing to the front and back of the paperboard through a film transfer sizing machine, which improves the strength of both sides, reduces the water absorption value of both sides of the paperboard, and reduces fiber shedding and dusting on both sides of the paperboard.

[0004] Currently, the mainstream process for food packaging paperboard involves using cassava starch or corn starch through enzymatic reaction, followed by cooking and gelatinization to prepare a starch slurry for use in the machine. However, in existing technologies, the inorganic ash impurities and organic protein content in the starch can easily clog the scraper grooves, resulting in uneven sizing and affecting the operation of the sizing machine and product quality. As starch is an agricultural product, its quality is affected by raw material selection, origin, production season, production process, and storage time. To improve the stability of surface sizing operation and product quality, major paper manufacturers are constantly exploring and optimizing the preparation process of surface sizing starch slurry to improve adaptability to starch raw materials. This aims to increase operational efficiency and product quality stability while simultaneously reducing costs and improving efficiency. Utility Model Content

[0005] This invention provides a system for preparing surface starch for food-grade cardboard. It removes inorganic ash impurities from starch by combining an ultra-fine slit arc screen and a multi-stage cyclone washer, and removes organic proteins by combining the multi-stage cyclone washer. This effectively improves the quality of the surface starch solution, enhances the operational stability of the surface sizing machine and the quality of the finished paper, and reduces dependence on raw materials.

[0006] The technical solution adopted by this utility model to solve its technical problem is:

[0007] A system for preparing surface starch for food cardboard includes a hopper, a dispersion tank, a surface starch buffer tank, a surface starch storage tank, a surface starch feeding tank, and a sizing machine connected in sequence. The hopper is used for screw unloading of cassava or corn raw starch. The dispersion tank is used for dispersing cassava or corn raw starch with water to a starch solution of 20-25%. The surface starch buffer tank is used for continuous feeding of starch during subsequent cooking and for adding oxidizing bactericides to improve starch denaturation caused by microorganisms during preparation and storage. The surface starch storage tank is used for storing starch slurry after cooking. The surface starch feeding tank is used for transferring and storing slurry and collecting and storing slurry pumped from the surface starch storage tank and slurry returned from the sizing machine, and then pumping it to the sizing machine via the feeding pump.

[0008] The dispersion tank and the surface buffer tank are also connected to an ultra-fine slit arc screen for removing cassava or corn husk impurities, sand, poorly dispersed starch agglomerates and large particles from the starch solution, and a multi-stage cyclone washer with at least seven stages for multi-stage washing to remove proteins and fine inorganic impurities from the starch solution.

[0009] A cooking device for filtering and cooking cassava or corn starch is also connected between the surface sizing buffer tank and the surface sizing storage tank.

[0010] A feed pump and a colloid filter are also connected between the colloid storage tank and the colloid feeding tank to filter out starch that is not fully cooked during the cooking process and to remove precipitated and aggregated lumpy starch.

[0011] The surface adhesive feeding tank and the adhesive applicator are also connected by a feeding pump for conveying adhesive, a feeding pressure screen for cleaning the adhesive liquid, and an adhesive recycling device for filtering the adhesive liquid returned from the adhesive applicator and returning it to the surface adhesive feeding tank for reuse.

[0012] Preferably, the cooking apparatus includes a first screw pump, a pre-cooking filter, a first-stage jet cooker, a reactor, a second screw pump, a second-stage jet cooker, a cooking coil, and a flash chamber connected in sequence. The first screw pump is connected to the outlet of the surface sizing buffer tank via a pipeline, and the flash chamber is connected to the inlet of the surface sizing storage tank. The pipeline between the pre-cooking filter and the first-stage jet cooker is also connected to an amylase addition device for further decomposing residual proteins in cassava or corn starch using biological enzymes.

[0013] Preferably, the adhesive recovery device includes a vibrating screen and a return pressure screen. The vibrating screen is used to remove paper fibers, dried starch lumps and large particulate impurities adhering to the adhesive liquid returned from the sizing machine. The return pressure screen further cleans the adhesive liquid filtered by the vibrating screen and returns the filtered adhesive liquid to the surface adhesive feeding tank.

[0014] Preferably, a slag discharge pipeline is connected between the vibrating screen and the feeding pressure screen to reuse the slag discharged from the feeding pressure screen.

[0015] Preferably, the rear end of the surface starch storage tank is also equipped with a bag filter for screening and removing incompletely cooked starch granules and deposited impurities.

[0016] The beneficial effects of this utility model are:

[0017] The starch preparation and feeding process employs a five-stage screening process to remove slag, addressing the problems of excessive impurities in cassava or corn starch, easy sedimentation in the prepared adhesive solution, and instability in paper quality caused by these issues in existing technologies. The adhesive recycling process utilizes a two-stage screening process to remove slag, using a combination of vibrating screens and return pressure screens to remove paper fibers, sediment, and other impurities from the recycled adhesive.

[0018] The system removes inorganic ash impurities from starch by combining an ultra-fine slit arc screen and a multi-stage cyclone scrubber, removes organic proteins by combining a multi-stage cyclone scrubber, and improves starch denaturation during preparation and storage by adding an oxidizing bactericide. The entire system can significantly improve the preparation quality of surface starch solution, improve the operational stability of the surface sizing machine and the quality of the paper, and reduce dependence on raw materials.

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0020] Figure 1 This is a system schematic diagram of this utility model. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] A system for preparing surface starch for food cardboard, such as Figure 1As shown, the system includes a hopper 1, a dispersion tank 2, a surface sizing buffer tank 5, a surface sizing storage tank 15, a surface sizing feeding tank 18, and a sizing machine 23 connected in sequence. The hopper 1 is used for screw unloading of cassava or corn raw starch. The dispersion tank 2 is used to add water to cassava or corn raw starch and disperse it to a 20-25% starch solution. The surface sizing buffer tank 5 is used for continuous feeding of the starch during subsequent cooking and for adding oxidizing bactericides to improve starch denaturation during preparation and storage. The surface sizing storage tank 15 is used for the starch sizing solution... The surface adhesive loading tank 18 is used for intermediate storage of adhesive materials. It collects and stores the adhesive materials pumped from the surface adhesive storage tank and the adhesive materials returned from the sizing machine, and then pumps them to the sizing machine 23 via the loading pump. Between the dispersion tank 2 and the surface adhesive buffer tank 5, there is also an ultra-fine slit arc screen 3 for removing cassava or corn husk impurities, sand, poorly dispersed starch agglomerates and large particles from the starch adhesive solution, and a multi-stage cyclone washer 4 with seven to nine stages for multi-stage washing to remove proteins and fine inorganic impurities from the starch solution.

[0023] Continue as Figure 1 As shown, a filtration and cooking device for cassava or corn starch is connected between the surface sizing buffer tank 5 and the surface sizing storage tank 15. This cooking device includes a first screw pump 6, a pre-cooking filter 7, a first-stage jet cooker 9, a reactor 10, a second screw pump 11, a second-stage jet cooker 12, a cooking coil 13, and a flash chamber 14, connected in sequence. The first screw pump 6 is connected to the outlet of the surface sizing buffer tank 5 via a pipeline, and the flash chamber 14 is connected to the inlet of the surface sizing storage tank 15. An amylase for adding cassava or corn starch is also connected to the pipeline between the pre-cooking filter 7 and the first-stage jet cooker 9. An amylase addition device 8 further decomposes residual proteins using biological enzymes; a glue filter 17, which is a bag filter, is also installed at the rear end of the surface glue storage tank 15 to screen and remove incompletely cooked starch granules and deposited impurities; a feed pump 16 is connected between the surface glue storage tank 15 and the surface glue feeding tank 18; a feeding pump 19 for pumping glue liquid and a feeding pressure screen 20 for cleaning are connected between the surface glue feeding tank 18 and the glue applicator 23; and a glue recycling device for filtering and removing slag from the glue liquid returned from the glue applicator 23 and returning it to the surface glue feeding tank 18 for reuse.

[0024] Continue as Figure 1 As shown, the adhesive recycling device includes a vibrating screen 22 and a return pressure screen 21. The vibrating screen 22 is used to remove paper fibers, dried starch blocks and large particle impurities adhering to the adhesive liquid returned from the sizing machine 23. The return pressure screen further cleans the adhesive liquid filtered by the vibrating screen 22 and returns the filtered adhesive liquid to the surface adhesive feeding tank 18. A slag discharge pipeline 24 is also connected between the vibrating screen 22 and the feeding pressure screen 20 to reuse the slag discharged from the feeding pressure screen 20.

[0025] The working principle of the entire preparation system in this embodiment is as follows:

[0026] 1. Preparation of starch gelatin solution:

[0027] Cassava or corn starch is discharged from hopper 1 via a screw conveyor to a surface starch dispersion tank 2. Water is added to the dispersion tank 2 and the mixture is stirred to disperse the starch into a 20-25% starch solution. The starch solution then passes through an ultra-fine slit arc screen 3, which uses a 400-mesh stainless steel screen. The ultra-fine slit arc screen 3 removes impurities such as cassava / corn peels, sand, undispersed starch clumps, and large particles from packaging bags entering the system. The cleaned starch solution flows into a multi-stage cyclone scrubber 4, which has seven to nine stages. Through multi-stage washing, proteins, fine sand, and metal particles are removed from the starch solution, preventing sediment buildup. The high protein content in the raw starch makes it prone to flocculation during production, causing sediment buildup and negatively impacting paper quality, reducing surface strength, uniformity, and whiteness. Therefore, it is necessary to remove as much protein as possible from the starch during the cooking process.

[0028] Next, the cleaned starch solution flows into the surface sizing buffer tank 5, which serves as a continuous feed tank. Adding an oxidizing bactericide to the surface sizing buffer tank 5 can improve the denaturation of starch during preparation and storage. The starch solution is then pumped to the reactor 10 by the first screw pump 6. During the pumping process, a pre-cooking filter 7 is present. The pre-cooking filter 7 is a bag filter containing a 100-mesh filter bag, which filters out deposited and aggregated lumpy starch (starch dispersion emulsions are prone to deposition and aggregation). The amylase addition device 8 adds 100-200 ppm of biological amylase (the percentage of oven-dry starch) to the starch solution delivery pipeline. After the starch emulsion and amylase are fully mixed, the mixture is heated to 85-90°C by a jet cooker 9, and then pumped to the stirred reactor 10 for starch gelatinization. The reaction time is 20-30 minutes. The fully gelatinized starch solution is then pumped to the surface sizing storage tank 15 by the second screw pump 11. The starch slurry pumped out of reactor 10 is heated to 125-130°C by a two-stage jet cooker 12. The heated starch slurry enters the cooking coil 13 to inactivate the amylase in the starch slurry, so as to avoid excessive breakage of the starch molecular chain and affect subsequent use. After exiting the cooking coil 13, the starch slurry enters the flash evaporation chamber 14 to remove the steam from the starch slurry. The degassed starch slurry enters the surface slurry storage tank 15 with stirring for storage.

[0029] 2. Use and recycling of starch adhesive:

[0030] The starch slurry in the surface slurry storage tank 15 is pumped to the surface slurry loading tank 18 by the feed pump 16. During this process, the starch slurry passes through the slurry filter 17. The feed pump 16 is also a screw pump, and the slurry filter 17 is a bag filter containing a 200-mesh filter bag to filter out incompletely cooked starch granules and deposited impurities. The slurry in the surface slurry loading tank 18 is pumped to the double-roller film transfer applicator 23 by the feed pump 19. During this process, the slurry passes through the feed pressure screen 20 to remove starch deposits, dried lumps, and other impurities from the slurry. The feed pressure screen 20 is a slotted screen with a stainless steel frame with a precision of 125μm and an automatic slag discharge program. The slag enters the vibrating screen 22. The cleaned slurry after being cleaned by the feed pressure screen 20 is supplied to the applicator 23 for use. The return slurry from the applicator 23 enters the vibrating screen 22. The vibrating screen 22 uses a 200-mesh stainless steel filter screen. The filtered clean adhesive solution flows into the surface adhesive feeding tank 18 via the return pressure screen 21 for reuse, while the slag is discharged into the ditch for treatment. The return pressure screen 21 is a slotted screen with a stainless steel screen frame with a precision of 125μm and an automatic slag discharge program.

[0031] In this embodiment, the preparation of the adhesive involves a five-stage screening and slag removal process to maintain the cleanliness of the starch solution. The first stage of slag removal uses a 400-mesh ultra-fine slit arc screen to remove cassava or corn husks, sand, undispersed starch agglomerates, and other large particulate impurities from the starch solution. The second stage of slag removal uses a seven- to nine-stage cyclone scrubber to remove proteins and fine inorganic impurities from the starch solution. The third stage of slag removal uses a 100-mesh bag filter before cooking to remove precipitated lumpy starch, preventing incomplete cooking of the starch during cooking. Residual proteins are further decomposed using biological enzymes, and oxidizing bactericides are added to improve starch denaturation during preparation and storage. The fourth stage of slag removal uses a 200-mesh bag filter after the surface storage tank to remove incompletely cooked starch particles and impurities deposited in the storage tank. The fifth stage of slag removal uses a 125μm precision feeding pressure screen to clean the adhesive solution before it can be used by the sizing machine. The adhesive recycling process involves two stages of screening and slag removal. The first stage uses a 200-mesh vibrating screen to remove large particles such as paper fibers and dried starch lumps adhering to the adhesive solution returned from the sizing machine. The second stage uses a 125μm precision return pressure screen to further clean the adhesive solution after the vibrating screen. The slag discharged from the feeding pressure screen is then reused after being screened again, reducing losses during the production process.

[0032] The above-described embodiments are merely preferred embodiments of this utility model and are not intended to limit the scope of implementation of this utility model. All equivalent changes made in accordance with the shape, structure and principle of this utility model should be covered within the protection scope of this utility model.

Claims

1. A system for preparing a surface sizing starch for food carton paper, characterized by, The system includes a hopper, a dispersion tank, a surface sizing buffer tank, a surface sizing storage tank, a surface sizing feed tank, and a sizing machine connected in sequence. The hopper is used for screw unloading of cassava or corn raw starch. The dispersion tank is used for dispersing cassava or corn raw starch with water to a starch solution of 20-25%. The surface sizing buffer tank is used for continuous feeding of starch during subsequent cooking and for adding oxidizing bactericides to improve starch denaturation caused by microorganisms during preparation and storage. The surface sizing storage tank is used for storing starch sizing solution after cooking. The surface sizing feed tank is used for transferring and storing sizing material and collecting and storing sizing material pumped from the surface sizing storage tank and sizing material returned from the sizing machine, which is then pumped to the sizing machine via the feed pump. The dispersion tank and the surface buffer tank are also connected to an ultra-fine slit arc screen for removing cassava or corn husk impurities, sand, poorly dispersed starch agglomerates and large particles from the starch solution, and a multi-stage cyclone washer with at least seven stages for multi-stage washing to remove proteins and fine inorganic impurities from the starch solution. A cooking device for filtering and cooking cassava or corn starch is also connected between the surface sizing buffer tank and the surface sizing storage tank. A feed pump and a colloid filter are also connected between the colloid storage tank and the colloid feeding tank to filter out starch that is not fully cooked during the cooking process and to remove precipitated and aggregated lumpy starch. The surface adhesive feeding tank and the adhesive applicator are also connected by a feeding pump for conveying adhesive, a feeding pressure screen for cleaning the adhesive liquid, and an adhesive recycling device for filtering the adhesive liquid returned from the adhesive applicator and returning it to the surface adhesive feeding tank for reuse.

2. The preparation system for surface starch of food cardboard according to claim 1, characterized in that: The cooking apparatus includes a first screw pump, a pre-cooking filter, a first-stage jet cooker, a reactor, a second screw pump, a second-stage jet cooker, a cooking coil, and a flash chamber connected in sequence. The first screw pump is connected to the outlet of the surface sizing buffer tank via a pipeline, and the flash chamber is connected to the inlet of the surface sizing storage tank. The pipeline between the pre-cooking filter and the first-stage jet cooker is also connected to an amylase addition device for further decomposing residual proteins in cassava or corn starch using biological enzymes.

3. The preparation system for surface starch for food cardboard according to claim 1, characterized in that: The adhesive recovery device includes a vibrating screen and a return pressure screen. The vibrating screen is used to remove paper fibers, dried starch lumps and large particle impurities adhering to the adhesive liquid returned from the sizing machine. The return pressure screen further cleans the adhesive liquid filtered by the vibrating screen and returns the filtered adhesive liquid to the surface adhesive feeding tank.

4. The preparation system for surface starch for food cardboard according to claim 3, characterized in that: The vibrating screen and the feeding pressure screen are also connected by a slag discharge pipeline for reusing the slag discharged from the feeding pressure screen.

5. The preparation system for surface starch for food cardboard according to claim 1, characterized in that: The rear end of the surface starch storage tank is also equipped with a bag filter for screening and removing incompletely cooked starch granules and deposited impurities.

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