阅读说明：本技术 一种利用竹浆生产可降解地膜纸的方法 (Method for producing degradable mulching film paper by using bamboo pulp ) 是由 刘洁 王安睿 张振镇 林广生 于 2020-11-04 设计创作，主要内容包括：本发明提供了一种利用竹浆生产可降解地膜纸的方法,经制浆,浓缩,高浓打浆,流送调料,上网成型,压榨,干燥,卷取,复卷,打包生产而成,使用100％的竹纤维浆,经15％-20％的高浓度打浆后过中浓盘磨打浆,设置上网浓度0.18％-0.45％,上网pH值6.5-7.5,上网成型后经四辊三压区压榨干度45％-48％；所得地膜纸定量40-80g/m~2,纸张干度为8％-9％,透气度15-60μm/Pa·s,纵向抗张强度1.2-3.2kN/m,横向抗张强度0.8-2kN/m,吸水值35-50g/m~2,纸张紧度0.4-0.5g/m~3。本发明以竹纤维为原料,不仅拓展了地膜纸的原料来源、缓解了木浆供应紧张的局面,而且在一定程度上改善了地膜纸的性能。(The invention provides a method for producing degradable mulching film paper by using bamboo pulp, which is produced by pulping, concentrating, pulping with high concentration, delivering seasonings, net surfing and forming, squeezing, drying, reeling, rewinding and packaging, wherein 100 percent of bamboo fiber pulp is used and treated by adding 15 percent of organic solventPulping with 20% high concentration, pulping with medium concentration disc mill, setting the concentration of the upper wire to 0.18% -0.45%, pH value of the upper wire to 6.5-7.5, and pressing with four-roll three-press area to obtain the final product with dryness of 45% -48%; the obtained mulch film paper has a fixed amount of 40-80g/m 2 The dryness of the paper is 8-9%, the air permeability is 15-60 mu m/Pa.s, the longitudinal tensile strength is 1.2-3.2kN/m, the transverse tensile strength is 0.8-2kN/m, and the water absorption value is 35-50g/m 2 Paper tightness of 0.4-0.5g/m 3 . The bamboo fiber is used as the raw material, so that the raw material source of the mulching film paper is expanded, the situation of tension supply of wood pulp is relieved, and the performance of the mulching film paper is improved to a certain extent.)

1. A method for producing degradable mulching film paper by using bamboo pulp comprises pulping, concentrating, pulping at high concentration, delivering seasonings, forming on a net, squeezing, drying, coiling, rewinding and packaging; the method is characterized in that the prepared bamboo fiber pulp is pulped at a high concentration of 15-20% and then is pulped by a medium-consistency disc mill, the concentration of the upper wire is set to be 0.18-0.45%, the pH value of the upper wire is set to be 6.5-7.5, and the dryness of the upper wire is 45-48% after being pressed by a four-roll three-press area.

2. The method for producing degradable mulching paper by using bamboo pulp as claimed in claim 1, which comprises the following steps:

1) pulping: comprises the steps of material selection, chipping, screening, liquid adding, steaming, pulp washing, pulp screening and pulp manufacturing;

2) concentration: concentrating the bamboo pulp by using a vacuum concentrator;

3) pulping: the beating degree of 15-20% high concentration is 25-30 degrees SR, then beating is carried out by double disc milling, and the beating degree after beating is 45-50 degrees SR;

4) delivering seasonings: adding reinforced starch, dry strength agent, retention aid, filter aid, wet strength agent and neutral glue;

5) and (3) net surfing and forming: setting the concentration of the upper net to be 0.18-0.45% and the pH value of the upper net to be 6.5-7.5, and setting the dryness of the upper net to be 24-28% after forming;

6) squeezing: pressing in a four-roll three-press area; setting a squeezing linear pressure value, wherein the squeezing dryness is 45-48%;

7) and (3) drying: placing the paper sheet in an upper cylinder for drying;

8) and (4) winding, rewinding and packaging.

3. The method for producing degradable mulching paper by using bamboo pulp as claimed in claim 2, wherein the press line pressure value is: 70kn/m is pressed for the first time, 90kn/m is pressed for the second time, and 140kn/m is pressed for the third time.

4. The method for producing degradable mulching paper by using bamboo pulp as claimed in claim 2, wherein the method further comprises the following pulp screening steps between the seasoning flowing step and the upper wire forming step: and (4) screening the slurry by using a pressure screen to separate impurities.

5. The method for producing degradable mulching paper by using bamboo pulp as claimed in claim 2, wherein the step 1) comprises the following steps:

A. selecting materials: selecting moso bamboo, green bamboo or sympodial bamboo as raw materials;

B. chipping: chipping the raw materials;

C. screening: selecting bamboo chips with the length of 6-45mm as bamboo chips for pulping;

D. liquid adding: mixing the bamboo chips with the washing liquid after the pulp washing according to the proportion and stirring the bamboo chips;

E. steaming: gradually adding steam into the digester to a set temperature, keeping the temperature for 30min, and then putting into a spraying pot;

F. washing the pulp: pumping the steamed bamboo pulp to a pulp washer for vacuum pulp washing;

G. screening pulp: the method comprises the steps of screening pulp for the first time and screening pulp for the second time, screening out slag contained in the bamboo pulp by a slag washing machine for the second time, crushing the slag by a disc mill, and repeatedly carrying out pulp washing and pulp screening;

H. manufacturing paper: and (5) making paper by using the obtained bamboo pulp.

6. The method for producing degradable mulching paper by using bamboo pulp as claimed in claim 5, wherein the ratio of the alkali solution to the washing solution to the water in the step of adding the solution is 1:3.6 by weight, and the water content of the bamboo chips is 52%.

7. The method for producing degradable mulching paper by using bamboo pulp as claimed in claim 5, wherein the fibrils are maintained during the step 1).

8. The method for producing degradable mulching paper by using bamboo pulp according to claim 5, wherein the steaming process comprises: increasing the temperature from 70 ℃ to 120 ℃ by adding steam for 60 min; raising the temperature from 120 ℃ to 130 ℃ for 30 min; raising the temperature from 130 ℃ to 161 ℃ for 60 min; the holding time is 30 min.

9. The method for producing degradable mulching paper by using bamboo pulp as claimed in any one of claims 1 to 8, wherein the obtained mulching paper has a basis weight of 40-80g/m²The dryness of the paper is 8-9%, the air permeability is 15-60 mu m/Pa.s, the longitudinal tensile strength is 1.2-3.2kN/m, the transverse tensile strength is 0.8-2kN/m, and the water absorption value is 35-50g/m²Paper tightness of 0.4-0.5g/m³。

Technical Field

The invention relates to the technical field of pulping and papermaking, in particular to degradable mulching film paper produced by bamboo pulp and a process method patent cross-bottom book.

Background

The mulching cultivation is an excellent agricultural yield-increasing technology, and can effectively control the temperature and humidity of soil, reduce the loss of water and nutrients, and prevent and control weed production, so that a favorable local growth environment can be created for crops. However, the conventional mulching film generally adopts polymer materials and is difficult to degrade in soil by itself. In response to this problem, researchers in the prior art have developed various degradable mulching films, one of which is a paper mulching film (also referred to as mulching film paper or plant fiber mulching film). The mulching film paper takes plant fiber as a raw material, microorganisms in soil can decompose the plant fiber, and the decomposition product can be used as organic fertilizer to improve the soil fertility and is widely accepted by the market. However, the raw materials of the current mulching paper are mainly wood fibers or grass fibers, which not only have limited raw material sources, but also have high requirements on paper pulp and complex process. In addition, the mulching film paper prepared by the conventional process needs to be improved in the aspects of air permeability, heat sealability, light resistance and the like.

China has abundant non-wood resources. The bamboos are mainly distributed in Fujian, Sichuan, Guangxi, Guangdong, Guizhou, Yunnan, Zhejiang and other provinces in south, and have obvious regionality and territoriality. Bamboo belongs to a long medium fiber raw material, has large length-width ratio, high cellulose content and low ash content (higher than wood), and is an excellent papermaking fiber raw material.

The fiber cells of the bamboo raw material generally account for 60-70% of the total area of the cells, and are slightly lower than wood and higher than common grass. The bamboo fiber form is different from wood, the wood fiber has grain holes, the bamboo fiber has little and very small grain holes, the bamboo fiber property is similar to broad leaf wood, and is better than general grass, and the bamboo fiber form is not much different among various types and genera. The bamboo fiber has the comprehensive morphological characteristics that: the fiber is slender, the wall thickness cavity is small, the density is high, the fiber is stiffer, and the transparency is high. The bamboo fiber has strong ultraviolet resistance, the ultraviolet transmittance of the bamboo fiber is less than 5% in a 200-400 nm region, and the bamboo fiber has antibacterial property, good usability and environmental protection property, and is a natural environment-friendly green fiber. In this case, if degradable mulching film paper can be produced using bamboo pulp as a raw material, it is expected to expand the source of the raw material and improve the product performance.

Disclosure of Invention

The invention aims to overcome the technical defects in the prior art and provides a method for producing degradable mulching film paper by using bamboo pulp so as to solve the technical problem that the raw material source of the degradable mulching film paper is limited.

Another technical problem to be solved by the invention is that the mulching film paper product prepared by the conventional process needs to be improved in performance.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

a method for producing degradable mulching film paper by using bamboo pulp comprises pulping, concentrating, pulping at high concentration, delivering seasonings, forming on a net, squeezing, drying, coiling, rewinding and packaging; wherein, the prepared bamboo fiber pulp is pulped by high concentration of 15 to 20 percent and then is pulped by a medium concentration disc mill, the concentration of the upper wire is set to be 0.18 to 0.45 percent, the pH value of the upper wire is set to be 6.5 to 7.5, and the dryness of the upper wire is 45 to 48 percent after being shaped by a four-roll three-nip press.

Preferably, the method comprises the steps of:

1) pulping: comprises the steps of material selection, chipping, screening, liquid adding, steaming, pulp washing, pulp screening and pulp manufacturing;

2) concentration: concentrating the bamboo pulp by using a vacuum concentrator;

3) pulping: the beating degree of 15-20% high concentration is 25-30 degrees SR, then beating is carried out by double disc milling, and the beating degree after beating is 45-50 degrees SR;

4) delivering seasonings: adding reinforced starch, dry strength agent, retention aid, filter aid, wet strength agent and neutral glue;

5) and (3) net surfing and forming: setting the concentration of the upper net to be 0.18-0.45% and the pH value of the upper net to be 6.5-7.5, and setting the dryness of the upper net to be 24-28% after forming;

6) squeezing: pressing in a four-roll three-press area; setting a squeezing linear pressure value, wherein the squeezing dryness is 45-48%;

7) and (3) drying: placing the paper sheet in an upper cylinder for drying;

8) and (4) winding, rewinding and packaging.

Preferably, the press line pressure value is: 70kn/m is pressed for the first time, 90kn/m is pressed for the second time, and 140kn/m is pressed for the third time.

Preferably, the method also comprises the following pulp screening steps between the seasoning flowing step and the upper wire forming step: and (4) screening the slurry by using a pressure screen to separate impurities.

Preferably, step 1) comprises the steps of:

A. selecting materials: selecting moso bamboo, green bamboo or sympodial bamboo as raw materials;

B. chipping: chipping the raw materials;

C. screening: selecting bamboo chips with the length of 6-45mm as bamboo chips for pulping;

D. liquid adding: mixing the bamboo chips with the washing liquid after the pulp washing according to the proportion and stirring the bamboo chips;

E. steaming: gradually adding steam into the digester to a set temperature, keeping the temperature for 30min, and then putting into a spraying pot;

F. washing the pulp: pumping the steamed bamboo pulp to a pulp washer for vacuum pulp washing;

G. screening pulp: the method comprises the steps of screening pulp for the first time and screening pulp for the second time, screening out slag contained in the bamboo pulp by a slag washing machine for the second time, crushing the slag by a disc mill, and repeatedly carrying out pulp washing and pulp screening;

H. manufacturing paper: and (5) making paper by using the obtained bamboo pulp.

Preferably, the proportion in the liquid adding step refers to the weight ratio of the total amount of the added alkali liquor and the washing liquid to the water of 1:3.6, wherein the moisture of the bamboo chips accounts for 52%.

Preferably, the fibrils are retained during step 1).

Preferably, the steaming process comprises: increasing the temperature from 70 ℃ to 120 ℃ by adding steam for 60 min; raising the temperature from 120 ℃ to 130 ℃ for 30 min; raising the temperature from 130 ℃ to 161 ℃ for 60 min; the holding time is 30 min.

Preferably, the obtained mulching film paper has a weight of 40-80g/m²The dryness of the paper is 8-9%, the air permeability is 15-60 mu m/Pa.s, the longitudinal tensile strength is 1.2-3.2kN/m, the transverse tensile strength is 0.8-2kN/m, and the water absorption value is 35-50g/m²Paper tightness of 0.4-0.5g/m³。

In the technical scheme of the invention, 100 percent of bamboo fiber: cl-free^-、SO4^2-、S^2-。

The invention provides a production method of degradable bamboo fiber mulching paper, which takes bamboo fiber as a raw material and produces the degradable mulching paper through the improvement of a production process. Not only expands the raw material source of the mulching film paper, but also relieves the situation of tension supply of wood pulp to a certain extent.

The technical advantages of the invention are focused on the following aspects:

(1) the raw material is changed from wood pulp into bamboo pulp, thus widening the source of the raw material and solving the situation of tense supply of the wood pulp.

(2) Due to the characteristics of the bamboo pulp and the change of the pulping process, the produced mulching film paper has greatly improved air permeability, good heat sealability, light resistance, heat resistance and aroma retention. The paper sheet has smooth and beautiful appearance.

(3) Accords with the national concept of green ecological economic development and is beneficial to the coordinated development of ecological environmental protection and market economy.

Drawings

FIG. 1 is a process flow diagram for producing a mulch paper according to the present invention.

FIG. 2 is a flow chart of the process for preparing bamboo pulp in the present invention.

Detailed Description

Hereinafter, specific embodiments of the present invention will be described in detail. Well-known structures or functions may not be described in detail in the following embodiments in order to avoid unnecessarily obscuring the details. Approximating language, as used herein in the following examples, may be applied to identify quantitative representations that could permissibly vary in number without resulting in a change in the basic function. Unless defined otherwise, technical and scientific terms used in the following examples have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

A process for preparing degradable ground film paper from bamboo pulp includes such steps as pulping, concentrating, beating with high concentration, flowing flavouring, shaping on net, squeezing, drying, winding, rewinding and packing, and features that the raw bamboo pulp (100%) is beaten by dual-disk grinder, its concentration on net is 0.18-0.45%, pH value on net is 6.5-7.5, and after shaping on net, its dryness is 45-48% by squeezing in four-roller three-pressure area, and the ground film paper is quantitatively 40-80g/m²The dryness of the paper is 8-9%, the air permeability is 15-60 mu m/Pa.s, the longitudinal tensile strength is 1.2-3.2kN/m, the transverse tensile strength is 0.8-2kN/m, and the water absorption value is 35-50g/m²Paper tightness of 0.4-0.5g/m³。

The method specifically comprises the following steps:

(1) pulping: comprises the steps of material selection, chipping, screening, liquid adding, steaming, pulp washing and pulp screening;

(2) concentration: concentrating the bamboo pulp by using a vacuum concentrator;

(3) pulping: the beating degree of 15-20% high concentration is 25-30 degrees SR, then beating is carried out by double disc milling, and the beating degree after beating is 45-50 degrees SR;

(4) delivering seasonings: adding reinforced starch, dry strength agent, retention aid, filter aid, neutral glue and wet strength agent;

(5) screening pulp: screening pulp by using a pressure screen to separate impurities;

(6) and (3) net surfing and forming: setting the concentration of the upper net to be 0.18-0.45% and the pH value of the upper net to be 6.5-7.5, and setting the dryness of the upper net to be 24-28% after forming;

(7) squeezing: pressing in a four-roll three-press area; setting a squeezing linear pressure value, wherein the squeezing dryness is 45-48%;

(8) and (3) drying: placing the paper sheet in an upper cylinder for drying;

(9) and (4) winding, rewinding and packaging.

Wherein the press line pressure value is: 70kn/m is pressed for the first time, 90kn/m is pressed for the second time, and 140kn/m is pressed for the third time.

Wherein, the specific process of pulping in the step (1) comprises the following steps:

A. selecting materials: selecting moso bamboo and bamboo as raw materials;

B. chipping: chipping the raw materials;

C. screening: selecting bamboo chips with the length of 6-45mm as bamboo chips for pulping;

D. liquid adding: mixing the bamboo pulp with the washing liquid after the paper pulp is washed according to the proportion, and stirring;

E. steaming: gradually adding steam into the digester to a set temperature, keeping the temperature for 30min, and then putting into a spraying pot;

F. washing the pulp: pumping the steamed bamboo pulp to a pulp washer for vacuum pulp washing;

G. screening pulp: the method comprises the steps of screening pulp for the first time and screening pulp for the second time, screening out slag contained in the bamboo pulp by a slag washing machine for the second time, crushing the slag by a disc mill, and repeatedly carrying out pulp washing and pulp screening;

H. manufacturing paper: and (5) making paper by using the obtained bamboo pulp.

Wherein, the proportion in the liquid adding step refers to the weight ratio of the total amount of the added liquid and the washing liquid to the water of 1:3.6, wherein the water content of the bamboo chips is 52%.

Wherein the steaming process comprises: increasing the temperature from 70 ℃ to 120 ℃ by adding steam for 60 min; raising the temperature from 120 ℃ to 130 ℃ for 30 min; raising the temperature from 130 ℃ to 161 ℃ for 60 min; the holding time is 30 min.

Example 1

As shown in fig. 1, fig. 2, table 1: selecting low-cost and widely-available moso bamboo, green bamboo or sympodial bamboo as a bamboo pulp basic raw material; slicing, screening qualified bamboo chips with the thickness of 6-45mm, and steaming in a digester; before cooking, the weight ratio of the additive to water is 1:3.6, mixing the washing liquid after the pulp washing with the bamboo pulp, and stirring, wherein the water content of the bamboo chips is 52%; gradually adding steam to a set temperature in the cooking pan, wherein the change process and time of the intermediate temperature comprise: increasing the temperature from 70 ℃ to 120 ℃ by adding steam for 60 min; raising the temperature from 120 ℃ to 130 ℃ for 30 min; raising the temperature from 130 ℃ to 161 ℃ for 60 min; the heat preservation time is 30 min; after heat preservation, spraying the mixture into a spraying pot; pumping the steamed bamboo pulp to a pulp washing tank by using a pump for vacuum pulp washing; after pulp washing, pulp screening is carried out, wherein the pulp screening comprises primary pulp screening and secondary pulp screening, the secondary pulp screening is used for screening slag materials contained in the bamboo pulp by a slag washing machine, the slag materials are crushed by a disc mill, and pulp washing and pulp screening operations are repeated; and finally, making paper by using the obtained bamboo pulp.

Concentrating the bamboo pulp by using a vacuum concentrator; because the bamboo pulp fiber is shorter and has more tiny fiber, and the mulching film paper requires higher strength, in order to reduce the cutting of the fiber, the beating concentration is improved as much as possible, and the beating concentration is 45 DEG SR after the double-disc grinding beating of the high-concentration beating degree 25 DEG SR of 15% -20%; adding auxiliary materials such as reinforced starch, retention aid, dry strength agent, filter aid, wet strength agent, neutral glue and the like into the bamboo pulp, and stirring; then, screening the slurry by using a pressure screen to separate impurities; forming on the net by a flap-type pulp flowing box, setting the net concentration to be 0.3 percent and the pH value of the net to be 6.5, and drying the formed net to be 25-26 percent; after the net is molded, squeezing is carried out through a four-roll three-nip press, and a squeezing line pressure value is set: first pressing 70kn/m, second pressing 90kn/m, and third pressing 140 kn/m; placing the paper sheet in an upper cylinder for drying; coiling, rewinding and packaging to obtain the mulching film paper with the fixed weight of 70g/m²The dryness of the paper is 8 to 9 percent, the air permeability is 25 mu m/Pa.s, the longitudinal tensile strength is 2.25kN/m, the transverse tensile strength is 1.4kN/m, and the water absorption value is 36g/m²Paper tightness of 0.4g/m³。

Example 2

As shown in fig. 1, fig. 2, table 1: selecting low-cost and widely-available moso bamboo, green bamboo or sympodial bamboo as a bamboo pulp basic raw material; slicing, screening qualified bamboo chips with the thickness of 6-45mm, and steaming in a digester; before cooking, the weight ratio of the additive to water is 1:3.6, mixing the washing liquid after the pulp washing with the bamboo pulp, and stirring, wherein the water content of the bamboo chips is 52%; gradually adding steam to a set temperature in the cooking pan, wherein the change process and time of the intermediate temperature comprise: increasing the temperature from 70 ℃ to 120 ℃ by adding steam for 60 min; raising the temperature from 120 ℃ to 130 ℃ for 30 min; raising the temperature from 130 ℃ to 161 ℃ for 60 min; the heat preservation time is 30 min; after heat preservation, spraying the mixture into a spraying pot; pumping the steamed bamboo pulp to a pulp washing tank by using a pump for vacuum pulp washing; after pulp washing, pulp screening is carried out, wherein the pulp screening comprises primary pulp screening and secondary pulp screening, the secondary pulp screening is used for screening slag materials contained in the bamboo pulp by a slag washing machine, the slag materials are crushed by a disc mill, and pulp washing and pulp screening operations are repeated; and finally, making paper by using the obtained bamboo pulp.

Concentrating the bamboo pulp by using a vacuum concentrator; because the bamboo pulp fiber is shorter and has more fine fiber, and the mulching film paper requires higher strength, in order to reduce the cutting of the fiber, the beating concentration is improved as much as possible, and the beating concentration is 47 DEG SR after 15% -20% high-concentration beating degree of 27 DEG SR and double-disc grinding beating; adding auxiliary materials such as reinforced starch, retention aid, dry strength agent, filter aid, wet strength agent, neutral glue and the like into the bamboo pulp, and stirring; then, screening the slurry by using a pressure screen to separate impurities; forming on the net by a flap-type pulp flowing box, setting the net concentration to be 0.31 percent and the pH value of the net to be 6.7, and drying the formed net to be 25-26 percent; after the net is molded, squeezing is carried out through a four-roll three-nip press, and a squeezing line pressure value is set: first pressing 70kn/m, second pressing 90kn/m, and third pressing 140 kn/m; placing the paper sheet in an upper cylinder for drying; coiling, rewinding and packaging to obtain the mulching film paper with the fixed weight of 70g/m²The paper dryness is 8-9%, the air permeability is 27 mu m/Pa.s, the longitudinal tensile strength is 2.5kN/m, the transverse tensile strength is 1.5kN/m, the water absorption value is 38g/m2, and the paper tightness is 0.41g/m 3.

Table 1 mulch paper parameter lists for examples 1 and 2

The embodiments of the present invention have been described in detail, but the description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention. Any modification, equivalent replacement, and improvement made within the scope of the application of the present invention should be included in the protection scope of the present invention.