CN115491930A - Degradable paper pulp molding product and preparation method and application thereof - Google Patents

Abstract

The invention relates to a pulp molded product (IPC classification number: D21J 1/00), in particular to a degradable pulp molded product and a preparation method and application thereof. The raw materials at least comprise the following components in parts by weight: 50-70 parts of plant paper pulp, 1-3 parts of alkyl ketene dimer, 3-5 parts of polyvinyl alcohol, 1-3 parts of waterproof agent, 2-5 parts of reinforcing agent, 3-5 parts of filler and 30-40 parts of water. The invention provides a degradable paper pulp molding product which can be used for products such as tableware and the like. The pulp molding adopts the mixture of the softwood pulp and the bagasse pulp, and under the synergistic action of the polyvinyl alcohol and other additives, the product has the functions of water resistance and oil resistance, and can particularly resist hot oil at 120 ℃. The prepared product has higher mechanical strength and bright surface, and enhances the antifouling capability. In addition, the pulp mould provided by the invention does not contain fluorine, and can be crushed and naturally degraded into planting soil after being discarded.

Description

Degradable paper pulp molding product and preparation method and application thereof

Technical Field

The invention relates to a pulp molded product (IPC classification number: D21J 1/00), in particular to a degradable pulp molded product and a preparation method and application thereof.

Background

Along with the acceleration of life rhythm and the rise of takeaway industry, the consumption of disposable tableware is staggering, which puts great pressure on solid waste treatment and environment, and various national scholars in the world make continuous efforts for seeking degradable and pollution-free green packaging raw materials. The paper tableware mould has beautiful appearance, oil resistance, water resistance, high temperature resistance, no seepage and no leakage, has good air permeability, toughness and strength, is sanitary and nontoxic, can be recycled and can be naturally degraded quickly, and the production process flow is simple, the occupied area of a factory building is small, the investment scale is small, the effect is quick, and the paper tableware mould is the product with the largest production capacity and the largest production enterprises in the substitute of the prior foamed tableware.

Patent application CN201811407719.1 prepares a paper-plastic composite material which can be used for products such as lunch boxes, and in the invention, perfluoroalkyl chemicals are adopted, so that the paper-plastic composite material is toxic and difficult to degrade. Patent application CN109577071A prepared a paper meal molding, which is not environment-friendly because of the use of non-wood fibers and because of their small diameter and short length, a large amount of auxiliaries were used to improve the mechanical strength of the paper meal molding.

Accordingly, the present invention has been made to solve the above problems, and an object of the present invention is to provide a degradable pulp molded product, which can be used for tableware and the like. The pulp molding adopts the mixture of the softwood pulp and the bagasse pulp, and under the synergistic effect of the polyvinyl alcohol and other additives, the fibers of the pulp have stronger bonding force, so that the pulp molding has the functions of water resistance and oil resistance, particularly can resist hot oil at 120 ℃, and the prepared pulp molding has higher mechanical strength and bright surface and enhances the antifouling capability. In addition, the degradable paper pulp provided by the invention is free of fluorine in the molded product, and can be broken and naturally degraded into planting soil after being discarded.

Disclosure of Invention

In order to solve the above problems, a first aspect of the present invention provides a degradable pulp molded product, comprising at least the following raw materials in parts by weight: 50-70 parts of plant paper pulp, 1-3 parts of alkyl ketene dimer, 3-5 parts of polyvinyl alcohol, 1-3 parts of waterproof agent, 2-5 parts of reinforcing agent, 3-5 parts of filler and 30-40 parts of water.

Preferably, the plant pulp is one or more of bagasse pulp, softwood pulp, straw pulp and reed pulp.

Further preferably, the plant pulp is a mixture of softwood pulp and bagasse pulp.

Further preferably, the weight ratio of the softwood pulp to the bagasse pulp is 1:5. the softwood pulp is commercially available, for example, kraft softwood pulp sold by Dalanyang trade company, inc.; the bagasse pulp is commercially available, for example Guangxi Jiayu paper pulp is preferably bleached bagasse pulp produced by Inc.

Preferably, the alkyl ketene dimers are commercially available, such as cy-960589, sold by Shandong Changyao New materials, inc

More preferably, the weight ratio of the plant pulp to the alkyl ketene dimer is (30-35): 1.

The invention improves the water-proof and oil-proof performance of the pulp molding by limiting the weight ratio of the alkyl ketene dimer to the plant pulp. The applicant speculates that: the alkyl ketene dimer has a low melting point, can easily react with the fiber at a high temperature to form a keto ester derivative, is positioned on the fiber, and has an excellent waterproof property because the hydrophobic end faces the surface of the fiber to form a hydrophobic layer. However, the lactone ring structure of the alkyl ketene dimer makes the lactone ring structure very easy to react with substances with active hydrogen, and the lactone ring structure is unstable in water, so that the performance of the waterproof and oil-proof performance of the product is reduced. In addition, the alkyl ketene dimer requires a long aging time, and also affects the mechanical strength of the product.

Preferably, the polyvinyl alcohol (CAS number: 9002-89-5) is commercially available, for example, as Kpl-23902 available from Kepler Biotech, inc., shandong.

Further preferably, the weight ratio of the polyvinyl alcohol to the alkyl ketene dimer is 2.

The invention not only solves the problems of instability of the alkyl ketene dimer in water and delayed curing by limiting the weight ratio of the polyvinyl alcohol to the alkyl ketene dimer, but also improves the oil-proof and water-proof performance of the pulp molding. The present application speculates that: under the action of an aqueous solution system and high temperature, the hydroxyl of polyvinyl alcohol reacts and is combined with alkyl ketene dimer, and the lactone ring of the alkyl ketene dimer is opened, so that hydrolysis caused by high temperature is avoided, and the delayed curing period of sizing is shortened. The self-excellent film-forming property of the paper pulp improves the oil-proof and water-proof properties of paper pulp molding. However, polyvinyl alcohol, as a thermoplastic resin, has high dissolution difficulty, more foams, and easy skinning, and tends to cause uneven dispersion of plant pulp.

Preferably, the waterproof agent is one or more of rosin size, sodium stearate and organic silicon.

More preferably, the waterproof agent is rosin size. The rosin size is commercially available, for example, MX-1518 sold by Weifang Mingxiang industrialism.

More preferably, the weight ratio of the plant paper pulp to the rosin size is (30-35): 1.

according to the invention, by limiting the type of the rosin size and the weight ratio of the plant paper pulp to the rosin size, the dispersibility of the plant paper pulp is effectively improved, and the mechanical strength and the water and oil resistance of the paper pulp molding are also improved. The applicant speculates that: the rosin size is MX-1518 cation dispersed rosin size, and the dispersion effect on plant pulp is achieved to a certain extent. In addition, the self-carried cation is combined with the negatively charged cellulose to be attached to the surface of the fiber, and the oleophobic group at the other end forms a film with low surface tension on the surface of the fiber, so that the invasion of water molecules or oil molecules is blocked. When the amount is less, the effect of water and oil resistance is not enough. When the amount is too large, fibers are flocculated due to the electropositive property of the pulp, thereby affecting the mechanical strength and water and oil repellency of the product.

Preferably, the strengthening agent is one or two of sodium carboxymethylcellulose and sodium alginate.

Further preferably, the strengthening agent is sodium carboxymethyl cellulose. The sodium carboxymethylcellulose (CAS number: 9004-32-4) is commercially available, for example, from pharmaceutical chemical Co., ltd.

Preferably, the filler is one or more of calcium carbonate, kaolin, talcum powder, titanium dioxide and diatomite.

Further preferably, the filler is a mixture of calcium carbonate and talc. The calcium carbonate has an average particle size of 1250 meshes and an oil absorption value (DOP) of less than or equal to 20mL/100g. The calcium carbonate is commercially available, for example, as CAZ-8022 sold by kunto shoumei new materials, inc. The talc powder has an average particle size of 800 meshes, and an oil absorption value (DOP) of not more than 30mL/100g, and can be sold in markets, such as talc powder sold by Jiangxi sandiskei source new materials Co.

Further preferably, the weight ratio of the calcium carbonate to the talc is 2.

According to the invention, by limiting the particle size and oil absorption value of the calcium carbonate and the talcum powder and the weight ratio of the calcium carbonate to the talcum powder, the mechanical strength of the product is effectively improved, and the anti-seepage effect of the product is ensured, so that the water resistance and the oil resistance are improved, and the performance of hot oil at 120 ℃ can be particularly prevented. The applicant speculates that: the calcium carbonate and the talcum powder selected in the invention improve the mechanical strength of the product by filling micropores among fibers, and the high temperature resistance of the product can prevent the product from being heated at 120 ℃. In addition, the calcium carbonate has small particle size, can adsorb the surfaces of alkyl ketene dimer and polyvinyl alcohol, and is easy to run off in the preparation process, so that the anti-seepage effect of the product is poor, but the talcum powder has certain hydrophobicity and can enhance the anti-seepage property of the product.

The second aspect of the invention provides a method for preparing a degradable pulp molded product.

(1) Introducing the plant paper pulp and water into a pulper barrel for pulping for 20-30 min for later use.

(2) Mixing the pulped paper pulp and a filler, introducing the mixture into a stirrer, stirring the mixture for 30min at the rotating speed of 800-1000 r/min, adding alkyl ketene dimer, heating the mixture to 50-55 ℃, stirring and heating the mixture, and preserving heat to obtain a mixture I;

(3) Mixing polyvinyl alcohol, a reinforcing agent and water, introducing the mixture into a mixing roll, heating the mixture to 85-95 ℃, and cooling the mixture to normal temperature to obtain a second mixture;

(4) Introducing the first mixture and the second mixture into a mixer, heating and stirring until the mixture is pasty, stopping heating, introducing a waterproof agent, and stirring and uniformly mixing to obtain a third mixture;

(5) And (4) guiding the mixture III into a mould, drying and dehydrating at high temperature, and performing compression molding and cutting to obtain a finished product.

Has the advantages that:

1. the invention shortens the fiber of the plant paper pulp by limiting the beating time, has compact arrangement and reduces the wetting performance of grease and water on the product, thereby improving the oil-proof and water-proof performance of the paper pulp molding.

2. The invention effectively improves the mechanical strength of the product and simultaneously ensures the anti-seepage effect of the product by limiting the particle size and the oil absorption value of the calcium carbonate and the talcum powder and the weight ratio of the calcium carbonate to the talcum powder, thereby improving the water resistance and the oil resistance, and particularly being capable of resisting hot oil at 120 ℃.

3. The invention improves the water-proof and oil-proof performance of the pulp molding by limiting the weight ratio of the alkyl ketene dimer to the plant pulp.

4. The invention not only solves the problems of instability of the alkyl ketene dimer in water and delayed curing by limiting the weight ratio of the polyvinyl alcohol to the alkyl ketene dimer, but also improves the oil-proof and water-proof performance of the pulp molding.

5. According to the invention, by limiting the type of the rosin size and the weight ratio of the plant paper pulp to the rosin size, the dispersibility of the plant paper pulp is effectively improved, and the mechanical strength and the water and oil resistance of the paper pulp molding are also improved.

Detailed Description

Examples

Example 1

Embodiment 1 of the present invention provides a degradable pulp molded product, which comprises the following raw materials in parts by weight: 60 parts of plant paper pulp, 2 parts of alkyl ketene dimer, 4 parts of polyvinyl alcohol, 2 parts of waterproof agent, 3 parts of reinforcing agent, 4 parts of filler and 35 parts of water. The plant paper pulp is a mixture of softwood pulp and bagasse pulp

In the softwood pulp of the present example, the weight ratio of the bagasse pulp is 1:5.

softwood pulp in this example was purchased from kraft softwood pulp, from Daliangyun trading, inc.

The bagasse pulp in this example was purchased from bleached bagasse pulp, a preferred company for paper pulp, guangxi Jiayu.

The waterproof agent in the embodiment is rosin size; the reinforcing agent is sodium carboxymethyl cellulose; the filler is a mixture of calcium carbonate and talcum powder.

The alkyl ketene dimer in this example was purchased from cy-960589, a new material, inc., changyao, shandong.

Polyvinyl alcohol (CAS number: 9002-89-5) in this example was purchased from Kpl-23902, hiden Kepler Biotech, inc.

The rosin size purchase in this example was from MX-1518, a Weifang Ming Do liability company.

The sodium carboxymethylcellulose (CAS number: 9004-32-4) in this example was purchased from Wuhan La Na pharmaceuticals, inc.

The calcium carbonate in the example has an average particle size of 1250 mesh and an oil absorption value (DOP) of not more than 20mL/100g. The calcium carbonate in this example was purchased from CAZ-8022 of guangdong shijiemei new materials ltd.

The talc powder in this example has an average particle size of 800 meshes and an oil absorption value (DOP) of not more than 30mL/100g, and is purchased from Jiangxi sanden Haiyuan new materials, inc.

The weight ratio of calcium carbonate to talc in this example was 2.

The preparation method of the pulp molded product in the embodiment comprises the following steps:

(1) Introducing the plant paper pulp and water into a pulper barrel for pulping for 30min for later use.

(2) Mixing the pulped paper pulp and the filler, introducing the mixture into a stirrer, stirring the mixture for 30min at the rotating speed of 900r/min, adding alkyl ketene dimer, heating the mixture to 53 ℃, stirring and heating the mixture, and preserving the heat to obtain a first mixture;

(3) Mixing polyvinyl alcohol, a reinforcing agent and water, introducing the mixture into a mixing roll, heating to 90 ℃, and cooling to normal temperature to obtain a mixture II;

(4) Introducing the first mixture and the second mixture into a mixer, heating and stirring until the mixture is pasty, stopping heating, introducing a waterproof agent, and stirring and mixing uniformly to obtain a third mixture;

(5) And (4) introducing the mixture III into a mold, drying and dehydrating at high temperature, and performing compression molding and cutting to obtain a finished product.

Example 2

Example 2 the embodiment is the same as example 1, except that the amount of the plant pulp added in example 2 is 65 parts.

Example 3

Example 3 is the same as example 1; except that the amount of the water repellent added in example 3 was 1.7 parts.

Comparative example 1

The embodiment of comparative example 1 is the same as example 1; except that the amount of the filler added in comparative example 1 was 2 parts.

Comparative example 2

Comparative example 2 the same embodiment as in example 1; except that in comparative example 2 no alkyl ketene dimer was added.

Comparative example 3

Comparative example 3 is the same as example 1; except that the weight ratio of calcium carbonate and talc in comparative example 3 was 10.

Performance test data

(1) Determination of tensile strength: the tensile strength of the pulp molded dinner plate (specification: diameter: 20.5cm, height: 2.5cm, thickness: 0.15 cm) prepared as described above was measured by using ZB-L300 tensile Strength tester.

(2) Measuring the water absorption capacity, namely taking two prepared paper pulp molded dinner plates (the specification: the diameter is 20.5cm, the height is 2.5cm and the thickness is 0.15 cm) according to the national standard GB18006.1-2009 general technical conditions of plastic disposable degradable tableware, putting the two prepared paper pulp molded dinner plates on an enamel plate lined with filter paper, filling hot water at the temperature of 95 +/-5 ℃, moving the plates into a constant temperature box at the temperature of 60 ℃, standing the plates for 30 minutes, observing whether a sample is deformed, whether the sample has the signs of color change and leakage due to vaginal infiltration, emptying the water in the tableware (until the water in the tableware does not drip down) and weighing the weight of the tableware before and after adding the water by using an electronic balance to calculate the weight difference, wherein the weight difference is the water absorption capacity.

(3) Oil absorption measurement: according to the national standard GB18006.1-2009 general technical conditions for disposable degradable plastic tableware, two prepared paper pulp molded dinner plates (the specification: the diameter is 20.5cm, the height is 2.5cm and the thickness is 0.15 cm) are taken and placed on an enamel plate lined with filter paper, 15g of vegetable oil with the temperature of 120 +/-5 ℃ is poured, the appearance of deformation and no sign of color change and leakage of a sample is observed after standing for 30 minutes, the vegetable oil in the tableware is emptied, the weights of the tableware before and after water is added are weighed by an electronic balance, and the weight difference is calculated and is the oil absorption. Performance test data:

table 1 shows the evaluation of the appearance of the pulp molded tableware prepared in example 1.

TABLE 1

Index (I)	Status of state
		Color	Has uniform color and luster
Degree of mucosa	Complete formation without defect
		Degree of integrity	No deformation and good toughness

Table 2 shows the performance test of the pulp molded tableware prepared in examples 1 to 3 and comparative examples 1 to 3

TABLE 2

	Tensile Strength/kN/m 2	Water absorption capacity/g	Oil absorption/g
				Example 1	15	1.19	1.05
Example 2	14	1.24	1.09
				Example 3	14	1.27	1.12
Comparative example 1	10	1.46	1.34
				Comparative example 2	9	1.49	1.31
Comparative example 3	11	1.37	1.28

Claims (10)

1. A degradable pulp molding product is characterized in that the degradable pulp molding product at least comprises the following raw materials in parts by weight: 50-70 parts of plant paper pulp, 1-3 parts of alkyl ketene dimer, 3-5 parts of polyvinyl alcohol, 1-3 parts of waterproof agent, 2-5 parts of reinforcing agent, 3-5 parts of filler and 30-40 parts of water.

2. The pulp molded product according to claim 1, wherein the plant pulp is one or more of bagasse pulp, softwood pulp, straw pulp, and reed pulp.

3. The pulp molded product according to claim 2, wherein the plant pulp is a mixture of softwood pulp and bagasse pulp.

4. The pulp molded product according to claim 1, wherein the weight ratio of polyvinyl alcohol to alkyl ketene dimer is 2.

5. The pulp molded product according to claim 1, wherein the water repellent agent is one or more of rosin size, sodium stearate, silicone.

6. The pulp molded product according to claim 5, wherein the water repellent agent is rosin gum.

7. The pulp molded product according to claim 1, wherein the filler is one or more of calcium carbonate, kaolin, talc, titanium dioxide, diatomaceous earth.

8. The pulp molded product according to claim 7, wherein the filler is a mixture of calcium carbonate and talc.

9. A method for preparing a degradable pulp molded product according to any of claims 1 to 8, characterized by comprising at least the steps of:

(1) Introducing plant paper pulp and water into a pulper barrel for pulping for 20-30 min for later use;

(2) Mixing the pulped paper pulp and a filler, introducing the mixture into a stirrer, stirring the mixture for 30min at the rotating speed of 800-1000 r/min, adding alkyl ketene dimer, heating the mixture to 50-55 ℃, stirring and heating the mixture, and preserving heat to obtain a mixture I;

(3) Mixing polyvinyl alcohol, a reinforcing agent and water, introducing the mixture into a mixing roll, heating to 85-95 ℃, and cooling to normal temperature to obtain a mixture II;

(4) Introducing the first mixture and the second mixture into a mixer, heating and stirring until the mixture is pasty, stopping heating, introducing a waterproof agent, and stirring and uniformly mixing to obtain a third mixture;

(5) And (4) guiding the mixture III into a mould, drying and dehydrating at high temperature, and performing compression molding and cutting to obtain a finished product.

10. Use of the degradable pulp molded product according to any one of claims 1 to 8 in tableware.