CN110685187A

CN110685187A - Internal sizing composition for paper pulp and application method and application thereof

Info

Publication number: CN110685187A
Application number: CN201910852729.4A
Authority: CN
Inventors: 关泽殷
Original assignee: Foshan Shunde Wenda Chuangying Packaging Mstar Technology Ltd
Current assignee: Foshan Shunde Wenda Chuangying Packaging Mstar Technology Ltd
Priority date: 2019-09-10
Filing date: 2019-09-10
Publication date: 2020-01-14

Abstract

The present invention provides a pulp internal sizing composition: the acrylate-based composite material comprises a component A and a component B which are independently packaged, wherein the component A is an alkyl ketene dimer, and the component B is an acrylate polymer. The invention is based on neutral sizing agent AKD, and uses the positive ion of it to attract the negative charge of cellulose and the bonding property of hydroxyl groups such as cellulose affinity to carry out prior sizing, and then adds acrylic polymer (NA), and the NA can be firmly bonded with the AKD, thereby tightly wrapping the cellulose combined with the AKD, and in addition, the NA can also be used as a filler for filling fiber. By utilizing the mutual matching of NA and AKD, water molecules are effectively prevented from permeating fiber cells, and the waterproof time of the pulp molding product is remarkably prolonged.

Description

Internal sizing composition for paper pulp and application method and application thereof

Technical Field

The invention belongs to the technical field of papermaking additives, and particularly relates to a paper pulp internal sizing composition, and a use method and application thereof.

Background

The pulp molding is to use waste paper as raw material, and to mold a paper product with a certain shape by a special mold on a molding machine. In recent years, the paper pulp molding product is taken as a new ideal environment-friendly packaging product by virtue of wide raw materials, no pollution, excellent packaging performance and renewable environment-friendly characteristics, gradually replaces wood and plastic products to a certain extent, and is widely applied to the fields of lunch boxes, industrial buffer packaging and the like. However, the paper-plastic product is formed by stacking plant fibers, the fibers are not stably linked, the plant fibers are hydrophilic, and when fiber cells expand and break under the influence of water molecules, the pulp-molding product is permeated by water, so that various physical indexes of the pulp-molding product are changed, and the pulp-molding product is deformed, cracked or perforated. At present, the commonly used pulp molding product has poor waterproofness, so that the application of the pulp molding product in a scene with high humidity is limited.

The sizing operation is a common paper making process which can effectively improve the water resistance, emulsion resistance, corrosion resistance and other performances of the paper pulp molding product, and at present, the sizing is mainly divided into two methods of surface sizing and internal sizing.

As a post-processing method, surface sizing is to spray a layer of waterproof sizing agent which is well proportioned on the surface of a pulp molding finished product (preferably, a smooth surface is selected) to block and slow down the penetration of water. The common sizing agent needs to be diluted and then sized, otherwise, the spraying and the nozzle blocking are difficult. However, the water content of the diluted sizing agent is strictly controlled, and if the water content of the diluted sizing agent is too high, the diluted sizing agent is contacted with paper products, and the water in the diluted sizing agent is easy to permeate the paper products, so that the paper products are damaged. In addition, the conventional surface sizing process involves operations of multiple steps such as surface spraying, glue surface smoothing after gluing, heating, curing and drying, and the like, and the implementation of the operation steps needs corresponding matched equipment and production fields, so that the input labor force and capital greatly increase the production cost and reduce the profit of products.

The internal sizing method is to add sizing agent into paper pulp before forming paper support (during beating or batching), and the current industry is used to adopt the following sizing method:

1) the neutral sizing agent Alkyl Ketene Dimer (AKD) is singly used and is combined with hydroxyl groups of cellulose and the like to be arranged for sizing through the action of positive and negative ions, thereby playing a role in preventing water penetration. The operation is simple, but the hydrophobic groups of AKD can only be aligned on the surface of the fiber and can not wrap the fiber by sizing of single AKD. According to the negative charge characteristic of cellulose, AKD can be modified by adding a cationic starch solution to the AKD, so that the combination of the AKD and hydroxyl groups is enhanced. However, the method needs special equipment with a heating device, and the production cost is greatly increased by purchasing the equipment and heating the equipment by heating and consuming heat energy and electric energy. However, paper products made by internal sizing with AKD modified with cationic starch are also only water repellent for 3-5 days.

2) During pulping, dissolved rosin is added in proportion and uniformly distributed, and then aluminum sulfate solution is added to play a role in wrapping, adhering and combining the rosin on fibers. The principle is the same as for AKD sizing agents. The greatest benefit of this approach is its low cost. However, this internal sizing method involves a relatively complicated operation, requires a relatively large labor investment, and takes a relatively long time for each group of sizing agents to react with the pulp separately. In addition, when the sizing agent is used for processing paper products, aluminum sulfate which is an essential effective component of the sizing agent has a corrosive effect on metals, and the aluminum sulfate seriously harms moulds and equipment. However, the paper products made by internal sizing with the sizing agent composed of aluminum sulfate and rosin can only be water-proof for 2-4 days.

At present, most manufacturers apply glue internally by greatly increasing the dosage of AKD, aluminum sulfate and rosin so as to prolong the waterproof time of the pulp molding products to more than 15 days. This is too costly and can also be a severe abrasive wear on the machine and the die.

The market price of the pulp molding product is generally lower, and if the sizing process needs to consume higher production cost, the popularization and the application of the pulp molding product are obviously not facilitated. Therefore, for the paper product industry, the development of a sizing method with low cost and simple operation has great practical significance.

Disclosure of Invention

The invention aims to provide a paper pulp internal sizing composition, a using method and application thereof, so as to effectively improve the water resistance of a paper product.

According to one aspect of the present invention, there is provided a pulp internal sizing composition characterized by: the acrylate-based acrylate copolymer comprises a component A and a component B which are independently packaged, wherein the component A is an acrylate polymer, and the component B is an alkyl ketene dimer.

Preferably, the method comprises the following steps: s1, weighing required raw materials according to the weight, wherein the required raw materials comprise a component A, a component B and papermaking fibers, wherein the component A accounts for 7.5-8.5% of the raw materials by mass, and the component B accounts for 7.25-8.5% of the raw materials by mass; s2, diluting the component A by using 3.5-6 times of purified water according to the mass multiple to obtain an additive A for later use; s3, diluting the component B by using 3.5-6 times of purified water according to the mass multiple to obtain an additive B; s4, adding the additive B into the paper pulp, stirring for 3-8 minutes after the addition is finished, stopping stirring, and standing for 10-15 minutes; s5, adding the additive A into the mixed slurry prepared in the S3, and stirring for 5-8 minutes after the addition is finished.

Preferably, the pulp has a pulp consistency of 8-12%.

Preferably, additive B is ready for use.

Preferably, the temperature of the purified water used in S1 does not exceed 45 ℃.

Preferably, the temperature of the purified water used in S2 does not exceed 45 ℃.

Preferably, in S1, the a component is diluted with 5 times of pure water to obtain additive a.

Preferably, in S2, the B component is diluted with 5 times of pure water to obtain additive B.

According to another aspect of the present invention, there is provided a method of manufacturing a pulp molded article: the secondary fibers are internally sized with the pulp internal sizing composition according to the method of use of the pulp internal sizing composition.

According to another aspect of the invention, there is provided a method of making a cold chain shipping paper package: the pulp is internally sized by using the pulp internal sizing composition according to the using method of the pulp internal sizing composition.

The invention utilizes the characteristics of NA which has larger relative molecular weight, has active double bond, is easy to self-polymerize and copolymerize, and based on neutral sizing agent AKD, utilizes the cation of the neutral sizing agent AKD to attract negative charge of cellulose and the bonding property of hydroxyl groups such as cellulose affinity and the like to carry out prior sizing, and then adds acrylic polymer (NA), and the NA can be firmly combined with the AKD, thereby tightly wrapping the cellulose combined with the AKD, and in addition, the NA can also be used as a filler for filling among fibers. By utilizing the mutual matching of NA and AKD, water molecules are effectively prevented from permeating fiber cells, and the waterproof time of the pulp molding product is remarkably prolonged.

On the other hand, the chemical property of the internal sizing composition of the paper pulp is mild, the internal sizing composition of the paper pulp does not corrode equipment and a mould, does not contain highly toxic substances, does not generate byproducts which are difficult to recover or degrade, and meets the requirement of green sustainable development. The internal sizing composition for paper pulp has simple operation and mild reaction conditions, and can achieve the internal sizing effect with high reliability at normal temperature, so that a large amount of heat energy is not required to be consumed for heating, expensive equipment is not required, the production cost is saved, the production benefit is improved, and the yield of finished products is improved.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments.

Example 1

1. Slurry preparation

(1) Respectively weighing 80g of AKD, 80g of NA and 840g of old corrugated paper, and placing the weighed corrugated paper in a shade place for later use;

(2) adding 400g of normal-temperature (room temperature 25 ℃) purified water into the NA, and fully stirring to obtain an additive A;

(3) preparing old corrugated paper pulp (OCC) by using old corrugated paper, wherein the pulp concentration of the OCC is 10%;

(4) adding 400g of normal-temperature (room temperature 25 ℃) purified water into AKD, and fully stirring to obtain an additive B;

(5) enabling the newly-prepared additive B to pass through a stainless steel mesh of 40 meshes, directly adding the obtained filtrate into the OCC, and stirring for 5 minutes after sample adding is finished;

(6) stopping the machine, and standing for 10 minutes;

(7) and (4) adding the prepared additive A into the mixed slurry prepared in the step (6), and stirring for 6 minutes after the sample is added to complete the slurry preparation process.

2. Shaping of

(1) Adsorbing paper pulp on a mold, pumping away water, and squeezing and dewatering paper fibers intercepted by the mold to obtain a wet paper product;

(2) making the wet paper product pass through a drying furnace, and making the semi-finished product output from the drying furnace have a water content of 5-9%;

(3) and (4) heating, pressurizing and shaping the semi-finished product by using a hot-press forming machine, and trimming to obtain the finished product paper holder.

Example 2

1. Slurry preparation

(2) adding 400g of normal-temperature (room temperature 25 ℃) purified water into the NA, and fully stirring to obtain an additive A; adding 400g of normal-temperature (room temperature 25 ℃) purified water into AKD, and fully stirring to obtain an additive B;

(3) preparing OCC by using old corrugated paper, wherein the slurry concentration of the OCC is 10%;

(4) enabling the standby additive B to pass through a stainless steel mesh of 40 meshes, directly adding the obtained filtrate into OCC, and stirring for 5 minutes after sample adding is finished;

(5) stopping the machine, and standing for 10 minutes;

(6) and (5) adding the prepared additive A into the mixed slurry prepared in the step (5), and stirring for 6 minutes after completing sample adding to complete the slurry preparation process.

2. Shaping of

The paper pulp prepared in the embodiment is used for preparing a finished paper holder by the same forming process as the embodiment 1.

Example 3

1. Slurry preparation

(5) mixing the additive A and the newly-prepared additive B, enabling the obtained mixed solution to pass through a 40-mesh stainless steel net, directly adding the filtrate into the OCC, and after the sample addition is finished, starting the machine to stir for 5 minutes;

(6) stopping the machine, standing for 10 minutes, and finishing the slurry preparation process.

2. Shaping of

Example 4

1. Slurry preparation

(4) adding the additive A into the OCC, and starting up to stir for 6 minutes;

(5) adding 400g of normal-temperature (room temperature 25 ℃) purified water into AKD, and fully stirring to obtain an additive B;

(6) enabling the newly-prepared additive B to pass through a stainless steel mesh with 40 meshes, directly adding the obtained filtrate into the mixed slurry prepared in the step (4), and after sample addition is finished, starting the machine to stir for 5 minutes;

(7) stopping the machine, standing for 10 minutes, and finishing the slurry preparation process.

2. Shaping of

(2) making the wet paper product pass through a drying furnace, and making the semi-finished product output from the drying furnace have a water content of 8-10%;

Example 5

1. Slurry preparation

(1) Respectively weighing 80g of AKD and 920g of old corrugated paper, and placing the weighed materials in a shade place for later use;

(2) preparing OCC by using old corrugated paper, wherein the slurry concentration of the OCC is 10%;

(3) adding 400g of normal-temperature (room temperature 25 ℃) purified water into AKD, and fully stirring to obtain an additive B;

(4) enabling the newly-prepared additive B to pass through a stainless steel mesh of 40 meshes, directly adding the obtained filtrate into the OCC, and stirring for 5 minutes after sample adding is finished;

(5) stopping the machine, and standing for 10 minutes;

(6) and (5) starting the machine to stir the mixed liquid prepared in the step (5) for 6 minutes to finish the slurry preparation process.

2. Shaping of

Example 6

1. Slurry preparation

(1) Respectively weighing 80g of NA and 920g of old corrugated paper, and placing the paper in a shade place for later use;

(3) adding 400g of normal-temperature (room temperature 25 ℃) purified water into the NA, and fully stirring to obtain an additive A;

(4) enabling the newly-prepared additive A to pass through a stainless steel mesh of 40 meshes, directly adding the obtained filtrate into the OCC, and starting up and stirring for 6 minutes after sample adding is finished;

(5) stopping the machine, standing for 10 minutes, and finishing the slurry preparation process.

2. Shaping of

Comparative example 1 without internal sizing

1. Slurry preparation

(1) Preparing OCC with the pulp concentration of 10% by using old corrugated paper;

(2) adding 480g of normal-temperature purified water into OCC, starting the machine, stirring for 5 minutes, stopping the machine, and standing for 10 minutes;

(3) and (3) adding 480g of normal-temperature purified water into the OCC subjected to the operation in the step (2), starting the machine, and stirring for 6 minutes to finish the slurry preparation process.

2. Shaping of

Comparative example 2

1. Preparation of modified AKD neutral sizing agent

(1) 100g of amphoteric soap-free styrene-acrylic polymer emulsion and 460g of AKD are weighed respectively;

(2) melting AKD at 60-80 deg.C, preheating amphoteric soap-free styrene-acrylic polymer emulsion to 60 deg.C, slowly pouring molten AKD into amphoteric soap-free styrene-acrylic polymer emulsion while stirring to form uniform emulsion;

(3) slowly pouring purified water preheated to 60 ℃ into the emulsion prepared in the step (2), fully stirring for 3 minutes, and preparing a uniform semi-finished product AKD emulsion, wherein the mass percent of AKD in the semi-finished product AKD emulsion is 10%;

(4) and pouring the semi-finished product AKD emulsion into a high-shear mixed emulsifier for emulsification, adding the semi-finished product AKD emulsion into frozen purified water under the stirring state, and fully stirring to obtain the finished product AKD emulsion.

2. Slurry preparation

(1) Defibering and pulping old corrugated paper, adding calcium carbonate into the corrugated paper pulp to ensure that the content of the calcium carbonate in the mixed pulp is 10 percent, and diluting to obtain OCC with the pulp concentration of 10 percent;

(2) sequentially adding cationic starch into the OCC, and fully stirring for 1 minute;

(3) and (3) adding the modified AKD neutral sizing agent into the mixed pulp prepared in the step (2), fully stirring for 1 minute to finish pulp blending, wherein the mass percent of the cationic starch and the mass percent of the modified AKD neutral sizing agent in the finished pulp is 8%.

3. Shaping of

Comparative example 3

1. Preparation of cationic rosin size

(1) Putting 180g of epoxy chloropropane into a reaction container with an electric stirrer, a reflux condenser tube and a thermometer, adding 360g of methanol aqueous solution (the volume ratio of methanol to water in the methanol aqueous solution is 1:1), stirring, heating to 40 ℃, keeping the temperature, adding 220g of triethylamine preheated to 40 ℃, controlling the stirring speed at 300rpm/min, stirring for reacting for 4 hours, and performing rotary evaporation to remove methanol and a water solvent to obtain a colorless viscous intermediate;

(2) adding 150g of the viscous intermediate obtained in the step (1), 200g of rosin and 550g of isopropanol into a reaction container with an electric stirrer, a reflux condenser tube and a thermometer, heating, reacting for 7 hours at 80 ℃, and rotationally evaporating to remove the isopropanol solvent to obtain the cationic rosin surface active agent;

(3) dissolving 100g of rosin and 110g of chloroform, adding a cationic rosin surface active agent under the condition of the rotating speed of 100rpm/min, wherein the net weight of the added cationic rosin surface active agent is 2% of the weight of the rosin, after 10 minutes, when the solution turns white, adding 100mL of purified water under the stirring of the rotating speed of 800rpm/min, continuing stirring for 10 minutes until the solution is dispersed into uniform emulsion, and removing the chloroform under the reduced pressure condition to obtain the cationic rosin size.

2. Slurry preparation

(2) adding 8% of aluminum sulfate, 8% of cationic rosin sizing agent, 1% of cationizing agent and 5% of flow aid into OCC to finish size mixing.

3. Shaping of

Example 7

In the present example, finished paper holders prepared in examples 1 to 6 and comparative examples 1 to 3 were used as test products, and tests were conducted to test the water permeability of the test products, wherein all the test products had the same volume and the same shape and structure.

1. Test setup

Transferring the test product into a closed low-temperature room with the temperature of 4 ℃ and the relative humidity of 70 percent (the temperature and the humidity are common cold chain transportation environmental parameters), injecting purified water into the test product, wherein the test is carried out for 25 days, and in the test process, the purified water is supplemented for the test product at 7 points and 19 points every day, so that the volume of the purified water in each test product is always 80 percent of the volume of the paper holder. 100 replicates were set for each test product, one replicate for each test product.

2. Judgment criteria

Whether the test products are permeable or not is judged by wiping the outside of the test products with absolute dry absorbent paper: the water seepage is prevented for more than 21 days, and the product is judged to be qualified; and (5) preventing water seepage for more than 25 days, and judging the product as a good product.

3. Test results

The statistics of the yield of each test product in this example are shown in table 1, and from the statistical data in table 1, example 1 is the most preferable example among examples 1 to 6 and comparative examples 1 to 3.

TABLE 1 test results of the test products of this example

All the test products prepared in example 1 can reach the qualified standard, and at 21 days after the test, the absorbent paper wiped with the test products in example 1 is kept in a dry state, all the test products can still keep the shapes in a completely dry state, and most of the outer surfaces of the test products still keep the completely dry state when the test products are touched by hands. In addition, 76% of the test products were able to maintain the outer surface dry at the end of the test.

In contrast to example 1, example 2 provides an internal sizing process in which additive a is not as-prepared. Compared with example 1, the qualification rate and the good product rate of the reference product of example 2 are both reduced significantly, when the test is carried out for 21 days, part of the outer surface of the reference product seeps water significantly, and at the end of the test, nearly half of the reference product is perforated or collapsed by water penetration.

In contrast to example 1, in the internal sizing process provided in example 3, additive a and additive B were premixed before the sizing process, and during the premixing process, part of AKD in sizing agent B was wrapped by NA in the sizing agent, thereby greatly reducing the effective content of AKD in the sizing process and significantly reducing the sizing effect. The outer surface of part of the test products was significantly exuded by moisture after the test was performed for about 10 days, and the outer surface of most of the test products was permeated by moisture after the test was performed for 21 days.

In contrast to example 1, example 4 provides an internal sizing process in which the order of addition of the additives is: firstly, adding the additive A, and then adding the additive B. The reference products of this example were also able to achieve a certain degree of water penetration resistance. When the test is carried out for 15 days, the outer surface of the product to be tested is touched by hands, and part of the product to be tested has water seepage feeling; by the time the test was run to day 21, most of the test products were either perforated or collapsed by water penetration.

In distinction from example 1: in the internal sizing process provided in example 5, only additive B was used for internal sizing; in the internal sizing process provided in example 6, only additive a was used for internal sizing. Most of the reference products of examples 5 and 6 were impermeable to water for only 3-6 days, and almost all of the reference products made in examples 5 and 6 were deformed by water permeation 10 days after the test was conducted.

The reference products prepared in comparative example 1 were not subjected to internal sizing, and all of the reference products were permeated with water for a short time after being wetted with water.

Comparative example 2 a majority of the test products were impermeable to water for 5-9 days, and almost all of the test products from example 5 were deformed by water penetration after 15 days of testing.

Comparative example 2 a reference product was prepared by internally sizing a pulp with a sizing agent consisting of aluminum sulfate and rosin, most of the reference products were impermeable to water for 8-12 days, and almost all of the reference products prepared in example 5 were deformed by water penetration after the test was performed for two weeks.

Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the true spirit and scope of the present invention.

Claims

1. An internal sizing composition for pulp characterized by: the acrylate-based acrylate copolymer comprises a component A and a component B which are independently packaged, wherein the component A is an acrylate polymer, and the component B is an alkyl ketene dimer.

2. The method of using the internal sizing composition for pulp according to claim 1, comprising the steps of:

s1, weighing required raw materials according to a certain amount, wherein the required raw materials comprise the component A, the component B and papermaking fibers, the component A accounts for 7.5-8.5% of the raw materials by mass, and the component B accounts for 7.25-8.5% of the raw materials by mass;

s2, diluting the component A by using 3.5-6 times of purified water according to the mass multiple to obtain an additive A for later use;

s3, diluting the component B by using 3.5-6 times of purified water according to the mass multiple to obtain an additive B;

s4, adding the additive B into the paper pulp, stirring for 3-8 minutes after the addition is finished, stopping stirring, and standing for 10-15 minutes;

s5, adding the additive A into the mixed slurry prepared in the S3, and stirring for 5-8 minutes after the addition is finished.

3. The method of using an internal sizing composition for pulp according to claim 2, wherein: the pulp has a pulp concentration of 8-12%.

4. The method of using an internal sizing composition for pulp according to claim 2, wherein: the additive B is prepared for use.

5. The method of using an internal sizing composition for pulp according to claim 2, wherein: the temperature of the purified water used in the S1 does not exceed 45 ℃.

6. The method of using an internal sizing composition for pulp according to claim 2, wherein: the temperature of the purified water used in the S2 does not exceed 45 ℃.

7. The method of using an internal sizing composition for pulp according to claim 2, wherein: and in the S1, diluting the component A by using 5 times of purified water to obtain the additive A.

8. The method of using an internal sizing composition for pulp according to claim 2, wherein: and in the S2, diluting the component B by using 5 times of pure water to obtain the additive B.

9. A method for manufacturing a pulp molded product is characterized in that: internal sizing of the secondary fibers with the pulp internal sizing composition according to claim 1, according to the method of use of the pulp internal sizing composition according to any of claims 2 to 8.

10. A method of making a cold chain shipping paper package characterized by: the pulp is internally sized by using the pulp internal sizing composition of claim 1 and the method of using the pulp internal sizing composition of any of claims 2 to 8.