Preparation method of natural color antibacterial fluorine-free and oil-proof packaging paper

Abstract

The invention discloses a method for preparing natural color antibacterial fluorine-free and oil-proof packaging paper, and specifically relates to the field of packaging paper manufacturing. The method comprises: S1: obtaining a paper core layer; S2: obtaining a surface layer; S3: bonding the surface layers to two sides of the paper core layer respectively; the paper core layer uniformly contains nano-scale silicon dioxide molecular antibacterial sol, and the surface layer uniformly contains a hydrophobic agent that does not contain fluorine. In the invention, by bonding the paper core layer containing the nano-scale silicon dioxide molecular antibacterial sol and the surface layer containing the fluorine-free hydrophobic agent to each other, oil-proof and water-proof capabilities superior to conventional packaging paper can be obtained, the density of the nanomaterial can better isolate water molecules and oil molecules to a certain extent, and the hydrophobic ability of the surface layer can not only thicken the packaging paper and improve the use toughness of the packaging paper, but also further improve the overall water resistance of the packaging paper, so that when in use, the design has a better water and oil-proof effect.

Description

Technical Field

[0001] The invention relates to the field of packaging paper manufacturing, and more specifically to a method for preparing natural color antibacterial fluorine-free and oil-proof packaging paper. Background Art

[0002] The wrapping paper used in the food packaging process generally has the requirements of oil-proof and water-proof. The existing additives with oil-proof function contain fluorine element to a greater or lesser extent, and fluorine is harmful to the human body. Therefore, it is urgent to develop a wrapping paper that does not contain fluorine and has water-proof and oil-proof functions. Summary of the invention

[0003] In order to overcome the above-mentioned defects of the prior art, the present invention provides a method for preparing a natural color antibacterial fluorine-free and oil-proof packaging paper. The technical problem to be solved by the present invention is that the packaging paper used in the food packaging process generally has the requirements of being oil-proof and waterproof. The existing additives with oil-proof effects contain fluorine elements to a greater or lesser extent, and fluorine is harmful to the human body. Therefore, it is urgent to develop a packaging paper that does not contain fluorine and has both waterproof and oil-proof functions.

[0004] To achieve the above object, the present invention provides the following technical solution: a method for preparing natural antibacterial fluorine-free and oil-proof packaging paper, the method comprising:

[0005] S1: Get the paper core layer;

[0006] S2: Get the surface layer;

[0007] S3: bonding the surface layer to both sides of the paper core layer respectively;

[0008] The paper core layer uniformly contains nano-scale silicon dioxide molecular antibacterial sol, and the surface layer uniformly contains a hydrophobic agent that does not contain fluorine.

[0009] Preferably, the method for preparing the paper core layer comprises:

[0010] S101: Take a piece of wood and process the wood into shavings;

[0011] S102: putting the obtained wood chips into a cooking pot, cooking, pulping, and grinding at a certain temperature, pressure, and pH to obtain lignin fibers;

[0012] S103: screening lignin fibers to obtain long fiber slurry and short fiber slurry respectively;

[0013] S104: taking a portion of the long fiber slurry, adding the nano-scale silica molecule antibacterial sol to the long fiber slurry to obtain a long mixed solution 1, stirring, and the ratio of the long fiber slurry to the nano-scale silica molecule antibacterial sol is 10:1;

[0014] S105: The mixed solution is squeezed, dried, surface sized, dried, re-moistened, and calendered to obtain a paper core layer.

[0015] Preferably, the method for preparing the surface layer comprises:

[0016] S201: Obtain the short fiber slurry in S103;

[0017] S202: taking one portion of the short fiber slurry, adding a hydrophobic agent not containing fluorine to the short fiber slurry to obtain a second long mixed solution, wherein the ratio of the short fiber slurry to the hydrophobic agent not containing fluorine is 5:1;

[0018] S203: The mixed solution is squeezed, dried, surface sizing is applied, dried, and calendered to obtain a surface layer.

[0019] Preferably, the temperature in S102 is 90-100° C., the pressure is 10-15 bar, and the pH is 9-11.

[0020] Preferably, the specific steps of S103: screening lignin fibers are:

[0021] S1031: placing the lignocellulosic slurry in a shaker;

[0022] S1032: Turn on the vibrator, set the vibrating cycle of the vibrator to 2 seconds, and the vibrator gradually separates the long fibers and short fibers in the wood fiber slurry;

[0023] S1033: adding a suspending agent to the wood fiber slurry, wherein the ratio of the wood fiber slurry to the suspending agent is 20:1;

[0024] S1034: The wood fiber slurry and the suspending agent are fed into a centrifuge together, the power of the centrifuge is adjusted to 4000-7000 rpm, the centrifugation time is 10-20 minutes, and long fibers and short fibers are obtained in batches.

[0025] Preferably, the fluorine-free hydrophobic agent is an alkane long-chain water repellent.

[0026] Preferably, the concentration of the slurry is 4-5%, and the slurry includes long fiber slurry and short fiber slurry.

[0027] Technical effects and advantages of the present invention: In the present invention, by bonding a paper core layer containing nano-scale silica molecular antibacterial sol and a surface layer containing a fluorine-free hydrophobic agent to each other, oil-proof and water-proof capabilities superior to conventional wrapping paper can be obtained. The density of the nanomaterial can, to a certain extent, better isolate water molecules and oil molecules, while the hydrophobic ability of the surface layer can not only thicken the wrapping paper and improve the toughness of the wrapping paper, but also further improve the overall waterproofness of the wrapping paper, so that when in use, the design has a better waterproof and oil-proof effect. DETAILED DESCRIPTION

[0028] Embodiment 1

[0029] A method for preparing natural color antibacterial fluorine-free and oil-proof packaging paper, the method comprising:

[0030] S1: Get the paper core layer;

[0031] S2: Get the surface layer;

[0032] S3: bonding the surface layer to both sides of the paper core layer respectively;

[0033] The paper core layer uniformly contains nano-scale silicon dioxide molecular antibacterial sol, and the surface layer uniformly contains a fluorine-free hydrophobic agent. In the present invention, by bonding the paper core layer containing the nano-scale silicon dioxide molecular antibacterial sol and the surface layer containing the fluorine-free hydrophobic agent to each other, the oil-proof and water-proof capabilities superior to conventional packaging paper can be obtained. The density of the nanomaterial can better isolate water molecules and oil molecules to a certain extent, and the hydrophobic ability of the surface layer can not only thicken the packaging paper and improve the toughness of the packaging paper, but also further improve the overall waterproofness of the packaging paper, so that when used, the design has a better waterproof and oil-proof effect.

[0034] The preparation method of the paper core layer comprises:

[0035] S101: Take a piece of wood and process it into wood shavings; in this embodiment, wood is used for illustration, and it can be known that the raw material is not limited to wood, but can also be waste paper or waste fabric; the wood is put into a debarking drum to peel off the surface of the wood, and then the debarked wood is put into a chipper to obtain pieces of shavings, and then the shavings are put into a wood chip screen, and after screening by the wood chip screen, smaller wood chips and impurities are removed, and the remaining are usable shavings.

[0036] S102: The obtained wood chips are put into a cooking pot, and are cooked, pulped, ground, and lignin fibers are obtained at a certain temperature, pressure, and pH. The cooking process relies on the cooperation of chemical and physical reactions. The wood chips are put into the cooking pot, and then caustic soda and other chemical agents are added to the cooking pot to make the wood chips gradually loose. Then, the wood chips are continuously polished with a grinder, and the wood chips are gradually dissociated by mutual friction between the wood chips, and gradually become bundles or even strands of fibers from a piece of wood chips. Furthermore, according to the thickness of the wrapping paper prepared by the user, the properties of the fibers are improved by physical methods under controllable conditions, that is, mechanical shear force is used to rub and loosen the fiber bundles to change the length of the fibers.

[0037] S103: screening lignin fibers to obtain long fiber slurry and short fiber slurry respectively; utilizing shear force, friction force, twisting force, hydraulic force and other measures to cut, powder, broom and crush the fibers to obtain fibers of different lengths, i.e. long fibers and short fibers, which are mixed with slurry to obtain long fiber slurry and short fiber slurry.

[0038] S104: Take a portion of long fiber slurry, add nano-scale silica molecular antibacterial sol to the long fiber slurry to obtain a long mixed solution, stir, the ratio of long fiber slurry to nano-scale silica molecular antibacterial sol is 10:1; the nano-scale silica molecular antibacterial sol will automatically look for a carrier after entering the long fiber slurry. In the long fiber volume slurry, the long fiber itself has a large volume and is extremely easy to become a carrier of the nano-scale silica molecular antibacterial sol. During the stirring process, as many long fibers as possible can be coated with a layer of nano-scale silica molecular antibacterial sol, and then the paper core layer made of interwoven long fibers can be made. The paper core layer has the effect of waterproof and oil-proof from the outside to the inside; traditional antibacterial agents can inhibit or kill bacteria, but cannot eliminate bacterial debris and the toxins they produce. Most of the organic antibacterial agents have the disadvantages of poor heat resistance, easy volatility, easy decomposition to produce harmful substances, poor safety performance, etc. Nano-scale silica molecular antibacterial sol can overcome the above disadvantages, can kill and eliminate bacteria and their debris together, and can also decompose the toxins secreted by bacteria. Nano-scale silica molecular antibacterial sol mainly contains inorganic antibacterial agents, such as silver, copper, zinc ions and photocatalytic antibacterial agents. Photocatalytic antibacterial agents include nano-scale titanium oxide, zinc oxide, silicon oxide, etc. Nano antibacterial agents have the advantages of thorough sterilization, strong heat resistance, not easy to produce harmful substances, and good safety performance. Nano antibacterial paper can be produced by mixing nano antibacterial agents into slurry or coating.

[0039] S105: The mixed solution is squeezed, dried, sizing, dried, re-moistened, and calendered to obtain a paper core layer. Chemicals are added to the long fiber pulp to enhance the strength of the paper industry and improve the papermaking performance, and then the paper material is evenly and stably distributed along a certain horizontal full width. The long fiber pulp is dehydrated by gravity, vacuum suction, scraper, etc. to form a wet paper sheet. The moisture of the wet paper sheet coming out of the net is squeezed out by mechanical methods to increase the dryness of the paper sheet. The wet paper is dried to the standard moisture content, and the moisture content of the whole body is uniform, and the longitudinal moisture content is continuous and stable. Water-resistant substances are added to the surface of the long fiber pulp or paper sheet to further enhance the delayed fluid penetration performance of the paper sheet; and then the required tightness is achieved through the pressure of the upper and lower rollers, and a certain modification effect is played on the paper surface.

[0040] The preparation method of the surface layer comprises:

[0041] S201: Obtain the short fiber slurry in S103;

[0042] S202: taking one portion of the short fiber slurry, adding a hydrophobic agent not containing fluorine to the short fiber slurry to obtain a second long mixed solution, wherein the ratio of the short fiber slurry to the hydrophobic agent not containing fluorine is 5:1;

[0043] S203: The mixed solution is squeezed, dried, sizing, dried, and calendered to obtain a surface layer. Chemicals are added to the short fiber pulp to enhance the strength of the paper industry and improve the papermaking performance. Then the paper material is evenly and stably distributed along a certain horizontal full width. The short fiber pulp is dehydrated by gravity, vacuum suction, scraper, etc. to form a wet paper sheet. The moisture of the wet paper sheet coming out of the net is squeezed out by mechanical methods to increase the dryness of the paper sheet. The wet paper is dried to the standard moisture content, and the moisture content of the whole paper is uniform, and the longitudinal moisture content is continuous and stable. Water-resistant substances are added to the surface of the short fiber pulp or paper sheet to further enhance the delayed fluid penetration performance of the paper sheet; and then the required tightness is achieved through the pressure of the upper and lower rollers, and a certain modification effect is played on the paper surface.

[0044] Embodiment 2

[0045] Based on the above embodiment, the temperature in S102 is 90-100° C., the pressure is 10-15 bar, and the pH is 9-11.

[0046] The specific steps of S103: screening lignin fibers are:

[0047] S1031: placing the lignocellulosic slurry in a shaker;

[0048] S1032: Turn on the vibrator and set the vibrating cycle of the vibrator to 2S. The vibrator gradually separates the long fibers and short fibers in the wood fiber slurry. The frequent vibrating action of the vibrator can gradually separate the fibers in the slurry.

[0049] S1033: adding a suspending agent to the wood fiber slurry, wherein the ratio of the wood fiber slurry to the suspending agent is 20:1;

[0050] S1034: The wood fiber slurry and the suspending agent are fed into a centrifuge, the power of the centrifuge is adjusted to 4000-7000rpm, the centrifugation time is 10-20min, and long fibers and short fibers are obtained in batches. The long fibers with heavier weight and the short fibers with lighter weight can be separated from each other through centrifugation.

[0051] The fluorine-free hydrophobic agent is an alkane long-chain water repellent. The fluorine-free hydrophobic agent can be an alkane long-chain water repellent, or can include common metal soaps, paraffins, hydroxymethyl, pyridine, etc. and silicone waterproofing agents.

[0052] The concentration of the slurry is 4-5%, and the slurry comprises long fiber slurry and short fiber slurry.

Claims

1. A method for preparing natural color antibacterial fluorine-free and oil-proof packaging paper, characterized in that: The method comprises: S1: Get the paper core layer; S2: Get the surface layer; S3: bonding the surface layer to both sides of the paper core layer respectively; The paper core layer uniformly contains nano-scale silicon dioxide molecular antibacterial sol, and the surface layer uniformly contains a hydrophobic agent that does not contain fluorine; The preparation method of the paper core layer comprises: S101: Take a piece of wood and process the wood into shavings; S102: putting the obtained wood chips into a cooking pot, cooking, pulping, and grinding at a certain temperature, pressure, and pH to obtain lignin fibers; S103: screening lignin fibers to obtain long fiber slurry and short fiber slurry respectively; S104: taking a portion of the long fiber slurry, adding the nano-scale silica molecule antibacterial sol to the long fiber slurry to obtain a mixed solution 1, stirring, wherein the ratio of the long fiber slurry to the nano-scale silica molecule antibacterial sol is 10:1; S105: The mixed solution is squeezed, dried, surface sized, dried, re-moistened, and calendered to obtain a paper core layer; The nano-scale silicon dioxide molecular antibacterial sol contains an inorganic antibacterial agent, which is selected from silver, copper, zinc ions and photocatalytic antibacterial agents, and the photocatalytic antibacterial agents include nano-scale titanium oxide, zinc oxide and silicon oxide; The preparation method of the surface layer comprises: S201: Obtain the short fiber slurry in S103; S202: taking one portion of the short fiber slurry, adding a hydrophobic agent not containing fluorine to the short fiber slurry to obtain a second mixed solution, wherein the ratio of the short fiber slurry to the hydrophobic agent not containing fluorine is 5:1; S203: The mixed solution is squeezed, dried, surface sizing is applied, dried, and rehumidified and calendered to obtain a surface layer.

2. The method for preparing a natural color antibacterial fluorine-free and oil-proof packaging paper according to claim 1, characterized in that: The temperature in S102 is 90-100° C., the pressure is 10-15 bar, and the pH is 9-11.

3. The method for preparing a natural color antibacterial fluorine-free and oil-proof packaging paper according to claim 2, characterized in that: The specific steps of S103: screening lignin fibers are: S1031: placing the lignin fiber slurry in a vibrating machine; S1032: Turn on the oscillator and set the oscillation period of the oscillator to 2 seconds. The oscillator gradually oscillates the long fibers and short fibers in the lignin fiber slurry; S1033: adding a suspending agent to the lignin fiber slurry, wherein the ratio of the lignin fiber slurry to the suspending agent is 20:1; S1034: The lignin fiber slurry and the suspending agent are input into a centrifuge together, the power of the centrifuge is adjusted to 4000-7000 rpm, the centrifugation time is 10-20 minutes, and long fibers and short fibers are obtained in batches.

4. A method for preparing a natural color antibacterial fluorine-free and oil-proof packaging paper according to any one of claims 1 to 3, characterized in that: The fluorine-free hydrophobic agent is an alkane long-chain water-repellent agent.

5. The method for preparing a natural color antibacterial fluorine-free and oil-proof packaging paper according to claim 4, characterized in that: The concentration of the slurry is 4-5%, and the slurry comprises long fiber slurry and short fiber slurry.