CN113846505B

CN113846505B - Method for preparing corrugated paper by enzymatic beating

Info

Publication number: CN113846505B
Application number: CN202111039755.9A
Authority: CN
Inventors: 王壮鹏; 蔡建涛
Original assignee: Guangdong Songyang Recycle Resources Co ltd
Current assignee: Guangdong Songyang Recycle Resources Co ltd
Priority date: 2021-11-10
Filing date: 2021-11-10
Publication date: 2022-05-06
Anticipated expiration: 2041-11-10
Also published as: CN113846505A

Abstract

The application provides a method for preparing corrugated paper by enzymatic beating of waste paper pulp, wherein enzymatic beating is used for reducing beating revolution, energy consumption is reduced, and meanwhile, the tensile strength of a product is effectively improved.

Description

Method for preparing corrugated paper by enzymatic beating

Technical Field

The application belongs to the fields of biological enzyme preparations and energy conservation and environmental protection in papermaking, and particularly provides a method for preparing corrugated paper by enzymatic beating of waste paper pulp, wherein cellulase and agarase are used for enzymatic beating.

Background

Corrugated paper is one of the most common packaging materials for various industrial and agricultural products, and consists of a structure in which one or more layers of medium paper with a corrugated structure are glued between face paper boards. Corrugated paper has wide application and large demand, but has low requirements on appearance indexes such as color, luster and the like, and is not generally in direct contact with food, so that the production of the corrugated paper by using wood raw materials causes great waste, and the preparation of the corrugated paper by using partial waste paper or all waste paper becomes a mainstream raw material source in the industry. The pulping process of the paper pulp generally needs higher rotating speed and longer time, consumes a large amount of energy and is one of the main energy consumption points in the paper making process.

At present, a lot of researches on enzymatic pulping by using cellulase and a plurality of hemicellulase hydrolyzed fibers exist, and the results show that the enzymatic pulping can effectively save energy and time, but the advantage of the saving amplitude compared with the cost increased by an enzymatic step is not significant enough, so that the enzymatic pulping is not widely applied. And multiple research results show that the effect of cellulase and hemicellulase in enzymatic pulping has ceiling effect, the effect cannot be further improved by increasing the dosage, and even the performance of paper is reduced when the excessive dosage hydrolyzes fibers. Therefore, it is necessary to explore other enzymes for enzymatic beating.

Agarase is an enzyme which is mainly characterized by degrading agar, and specifically comprises alpha and beta agarase, wherein the beta agarase specifically hydrolyzes beta-1, 4 glycosidic bonds. The current applications of agarase mainly include hydrolysis of seaweed for food/feed preparation, gum recovery in molecular biology and preparation of certain fibers. There have been no reports of their use in papermaking.

Disclosure of Invention

Based on the research of a cooperative unit on the fiber structure of the waste paper, the agarase is matched with the cellulase to be used for enzymatic pulping, so that the tensile strength of the paper is improved while a further energy-saving effect is achieved.

In one aspect, the present application provides a process for the preparation of corrugated board by enzymatic beating, wherein the enzyme used is selected from the group consisting of cellulase and agarase.

Further, the raw material for preparing the corrugated paper is OCC waste paper pulp.

Further, the enzymes used therein are cellulase and β -agarase.

Furthermore, the dosage of the cellulase is 0.05-0.2U/g of oven dry pulp, and the dosage of the beta-agarase is 0.05-0.1U/g of oven dry pulp.

Furthermore, the dosage of the cellulase is 0.1U/g oven dry pulp, and the dosage of the beta-agarase is 0.08U/g oven dry pulp.

In another aspect, the present application provides the use of an enzyme selected from cellulase and agarase in the preparation of corrugated paper by enzymatic pulping using OCC waste pulp as a raw material.

Further, the enzymes used therein are cellulase and β -agarase.

Furthermore, the dosage of the cellulase is 0.05-0.2U/g oven dry pulp, and the dosage of the beta-agarase is 0.05-0.1U/g oven dry pulp.

On the other hand, the application provides a complex enzyme preparation for enzymatic pulping, which is characterized by comprising cellulase and beta-agarase, wherein the enzyme activity ratio of the cellulase to the beta-agarase is 5: 4.

In another aspect, the present application provides the use of the above enzyme preparation for improving the tensile strength of corrugated paper made of OCC waste pulp.

On the other hand, the application provides the application of the enzyme preparation in reducing the pulping energy consumption of corrugated paper prepared from OCC waste paper pulp.

Drawings

FIG. 1: correlation of cellulase dosage to paper tensile strength;

FIG. 2: correlation of cellulase dosage and beating degree at two revolutions;

FIG. 3: the correlation between the agarase dosage in the complex enzyme and the tensile strength of the paper;

FIG. 4: and at two revolutions, the usage amount of the agarase in the compound enzyme is related to the beating degree.

Detailed Description

Main materials, reagents and instruments:

the enzyme dosage is calculated as U/g oven dried pulp throughout the application.

OCC waste paper: the applicant enterprises purchase themselves, the waste paper classification grade standard formulated by China society for recycling and resource belongs to a first-grade waste paper box, and waste paper for test is specially and manually selected to completely remove waste plastics, film-coated magazines and other obviously polluted parts.

Waste paper pulp: freeness 20 ° SR, self-prepared using the above OCC waste paper and stored for later use (breaking OCC waste paper into pieces of about 2cm x 2 cm; soaking the pieces for 60 minutes; fluffing for 5 minutes with 4% concentration fiber; desander desanding for later use);

cellulase: purchased from hong rui biotechnology limited, quan city, with an optimum pH of about 7.0;

beta-agarase: the crude enzyme liquid freeze-dried powder (refrigerated storage, used within 14 days) produced by Agarivorans HZ105 has the most suitable pH value of about 8.0-8.5; the agarase enzyme activity adopts the definition common in the field at present: the amount of enzyme required to produce 1umol of reducing sugar per minute was determined by the DNS method ((beta-agar from Pseudomonas sp. W7: purification of the recombinant enzyme from Escherichia coli and the effeacs of salt activity, Biotechnology and applied biochemical.1997, 26(Ptl): l-6)).

Pulping equipment: type D hydropulper, Andrews (China) Ltd

Sheet making machine: IMT-CP-03B, Integron;

beating degree tester: YT-DJ-100, Hangzhou Mingke;

other reagents and instruments are made in the conventional countries.

The detection method comprises the following steps:

beating degree:

self-determination is carried out according to GB/T3332-2004;

and (3) strength of a finished product:

commissioned to the national center for paper product quality supervision and inspection (quality supervision and inspection center of Dongguan city, Guangdong province) (equipment labeled as "Sichuan Yangtze river" brand)

Tensile strength: reference GB/T453-

Ring crush strength: see GB/T2679.8-1995.

Example 1 basic procedure for enzymatic beating Process

Adding water into the waste paper pulp raw material to adjust the beating concentration to 8%, and adjusting the pH to about 7.0 by using HCl or NaOH; adding a desired amount of enzyme; constant temperature treatment at 60 ℃ for 30 minutes; boiling to inactivate enzyme; pulping; the paper making is 120g/m^-2The sheets of paper were dried for testing.

EXAMPLE 2 Effect of cellulase on pulping Process

The influence of different cellulase dosage-0, 0.05, 0.1 and 0.2U/g oven dry pulp on the tensile strength of paper is verified, and the result is shown in figure 1, and the tensile strength of the paper is basically only related to the beating degree within a certain enzyme dosage limit and is not obviously related to the usage/dosage of the cellulase. A similar correlation is shown in terms of ring crush strength (data not shown). According to the research results of other documents in the field and previous verification of the applicant, the excessive use of enzyme easily causes the reduction of certain properties of paper and the increase of cost, so that the use amount should be selected as low as possible under the condition of balancing good properties.

The relationship between the dosage of the enzyme and the beating degree at the beating revolutions of 1200r and 2000r is studied, and the results are shown in figure 2, and the results show that the beating degree can be effectively improved by a certain amount of the enzyme at the same beating revolution, but the dosage of the enzyme has no obvious influence on the beating degree after the dosage of the enzyme exceeds 0.1U/g of oven dry pulp. Namely, the application of a certain amount of cellulase can promote the pulping process and reduce the pulping revolution, which is an important energy consumption index.

Subsequent practice proves that the dosage of cellulase of 0.1U/g oven dry pulp can be reduced by about 200r at the beating revolution when the SR is 40 degrees; the results of the experiments with various other hemicellulases or enzyme blends (data not shown) show that these enzymes or enzyme blends are similar/not significantly better than cellulases (i.e., essentially no effect on paper strength in certain amounts, similar to cellulases in terms of reduced rpm at 40 ° SR), with 0.1U/g of never dried pulp being the best choice for cost and product performance reasons.

Example 3 Effect of the addition of agarase on the beating procedure

On the basis of the previous research and production practice, the dosage of the cellulase is determined to be 0.1U/g oven dry pulp, different dosages of agarase-0, 0.01, 0.02, 0.05, 0.08, 0.1 and 0.2U/g oven dry pulp are matched, the influence of the agarase on the tensile strength of paper is researched, and the result is shown in figure 3. There was no significant improvement in ring crush strength for the same freeness (data not shown).

The relationship between the dosage of the enzyme and the beating degree at the beating revolutions of 1200r and 2000r is studied, and as a result, as shown in figure 4, a certain amount of the enzyme at the same beating revolution can effectively improve the beating degree, but the dosage of the enzyme has no obvious influence on the beating degree after the dosage of the enzyme exceeds 0.05U/g of oven dry pulp. Namely, the application of a certain amount of agarase can promote the pulping process and reduce the important energy consumption index of the pulping revolution. In connection with the above study of tensile strength, the amount of agarase was selected to be 0.08U/g oven dried pulp.

Through subsequent practice verification, on the basis of the cellulase, the dosage of the cellulase of 0.08U/g oven dry pulp can reduce the beating revolution at 40 DEG SR beating degree by about 400 r.

The results show that in the process of preparing corrugated paper by waste paper pulp, the addition of cellulase can effectively promote the pulping process and reduce energy consumption; the addition of agarase can further reduce energy consumption, improve the tensile strength of paper, and simultaneously keep other main performances of the paper, such as color, bursting resistance, wet strength and the like unchanged.

The main problems of the current agarase are as follows: the research on the strain/method for preparing the agarase is insufficient, so that the manufacturing cost/selling price of the agarase is higher, and after the cost of the agarase is reduced by searching a suitable fermentation strain/method or a suitable source, the method can realize industrial production, obviously reduce energy consumption and simultaneously improve the quality of paper.

Claims

1. The method for preparing corrugated paper by enzymatic pulping is characterized in that OCC waste paper pulp is used as a raw material for preparing the corrugated paper; wherein the enzymes used are cellulase and beta-agarase; the dosage of the cellulase is 0.05-0.2U/g of oven dry pulp, and the dosage of the beta-agarase is 0.05-0.1U/g of oven dry pulp.

2. The method of claim 1, wherein the cellulase enzyme is present in an amount of 0.1U/g of oven dried pulp and the β -agarase is present in an amount of 0.08U/g of oven dried pulp.