CN108677592B - Household paper pulping process with strength and softness - Google Patents

Abstract

The invention relates to the technical field of household paper, in particular to a household paper pulping process with strength and softness, which comprises the steps of adopting bleached softwood kraft pulp and bleached hardwood kraft pulp in a certain proportion as raw materials, pulping by adopting 8-12 ppm biological enzyme, reducing fiber loss in the pulping process, then screening out long fiber pulp and short fiber pulp, and pulping according to a specific proportion to prepare mixed pulp with a beating degree of 30-38 ℃; when pulp is prepared, the proportion of surface layer pulp, bottom layer pulp and long and short fiber pulp in the core layer pulp is respectively controlled so as to improve the strength of paper, meanwhile, a certain amount of softening agent, wet strength agent and dry strength agent are added, the technological conditions of each step are strictly controlled, and through the synergistic effect, the prepared finished paper can have excellent softness and strength, the used chemical reagent is environment-friendly, and the performances of the paper such as strength and the like can not be influenced.

Description

A tissue paper pulping process with both strength and softness

technical field

The invention relates to the technical field of household paper, in particular to a pulping process for household paper with both strength and softness.

Background technique

For tissue paper, softness is one of the important properties of its finished paper. However, if better softness is to be achieved, there is a considerable loss of paper strength, and if better strength is to be achieved, softness is sacrificed. In the current papermaking process, it is difficult to combine the two properties of softness and strength to achieve the desired effect. In addition, in the prior art, the improvement of softness of household paper mainly depends on adding chemical softener in paper production. The main function of chemical softener is to interfere with the bonding between fibers, which is not easy to degrade and can stimulate human skin. Adding chemical softeners will not only affect the strength of the finished paper, but also be detrimental to human health and environmental quality. In addition, wood pulp is mainly used as raw material for household paper. In order to improve the beating strength of wood pulp, a more targeted biological enzyme treatment is selected during beating, thereby improving the performance of the pulp. However, biological enzymes have high requirements on the environment and are affected by various factors such as temperature, pH and dosage, and are difficult to control, which will cause fiber loss, reduce the strength of fibers, and cannot prepare high-strength pulp.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a tissue paper pulping process with both strength and softness in view of the deficiencies of the prior art.

In order to achieve the above object, the present invention adopts the following technical solutions:

Provide a tissue paper pulping process with both strength and softness, including the following steps:

Step a. Preparation of long fiber and short fiber pulp:

The bleached softwood kraft pulp, bleached hardwood kraft pulp and water are mixed in the pulper according to the weight ratio of (40-60): (45-64): (1-3) for beating, and the mass concentration is added at the same time. 8-12ppm of biological enzymes, and control the beating temperature to be 55-60°C, pH to be 6.5-8.5, and beating time to be 40-90min to make a pulp with a beating degree of 25-35°, and then carry out slag removal and After grading and sieving, long fiber pulp and short fiber pulp are obtained respectively, and sent to the short fiber pulping pool and the long fiber pulping pool respectively for standby use;

Step b, mixing and beating:

By weight percentage, add 50-100% of the long-fiber pulp and 0-50% of the short-fiber pulp prepared in step a to the refiner for beating, and control the beating temperature to be 52-58°C and pH to be 8.5-9.5 , to make a mixed slurry with a beating degree of 30-38°, for use;

Step c, mixing pulp:

C1. Configure the surface layer slurry: add a certain amount of softener and wet strength agent to the mixed slurry prepared in step b, mix evenly and make a surface layer slurry with a beating degree of 30-35°, and then pump it to the surface layer Pulp pulping tank for standby;

C2. Configure the core layer pulp: add a certain amount of softener to the long fiber pulp prepared in step a, and beat it to make a core layer pulp with a beating degree of 32-38°, and then pump it to the core layer pulp to become pulp pool reserve;

C3. Configure the bottom pulp: add a certain amount of wet strength agent and dry strength agent to the short fiber pulp prepared in step a, and beat to make a bottom pulp with a beating degree of 30-35°, and then pump it to the bottom pulp The pulping tank is reserved;

Step d, forming on the Internet:

The surface layer slurry, the core layer slurry and the bottom layer slurry prepared in step c are sequentially sprayed onto the forming wire through the headbox and then composited into one body.

In the above technical solution, in step a, the biological enzyme is a mixture of cellulase and hemicellulase, wherein the amount of the cellulase accounts for 75-85% of the total mass of the mixture.

In the above technical solution, in step C1, the dosage of the softener is 1-8 kg/t absolutely dry slurry, and the dosage of the wet strength agent is 2-6 kg/t absolutely dry slurry.

In the above technical solution, in step C2, the amount of the softener is 2-5 kg/t of absolutely dry slurry.

In the above technical solution, in step C3, the dosage of the dry strength agent is 1-6 kg/t absolutely dry slurry, and the dosage of the wet strength agent is 0.5-3 kg/t absolutely dry slurry.

In the above technical scheme, the softener is a quaternary ammonium salt type, a fatty acid ester type or a silicone resin type softener.

In the above technical solution, the wet strength agent is: glyoxal polyacrylamide resin, polyamine epichlorohydrin resin or urea-formaldehyde resin.

In the above technical solution, the dry strength agent is any one of cationic starch, anionic starch, polyacrylamide and glyoxal polyacrylamide.

The beneficial effects of the present invention are:

The present invention is a tissue pulping process with both strength and softness, using bleached softwood kraft pulp and bleached hardwood kraft pulp in a certain proportion as main raw materials, and using 8-12ppm of biological enzymes for pulping, Reduce the fiber loss during the beating process, and then screen the long fiber pulp and short fiber pulp and refine them according to a specific ratio to make a mixed pulp with a beating degree of 30-38°; Control the ratio of long and short fiber pulp in the surface layer pulp, bottom layer pulp and core layer pulp to improve the strength of the paper, at the same time add a certain amount of softener, wet strength agent and dry strength agent, and strictly control each step of the process. The process conditions, through the above synergistic effect, can finally make the prepared finished paper have both excellent softness and strength. The chemical reagents used are environmentally friendly and will not affect the strength and other properties of the paper. The pulping process is simple and suitable for industrialized large-scale production.

Detailed ways

The present invention will be further described with reference to the following examples.

Example 1.

A tissue paper pulping process with both strength and softness of the present embodiment includes the following steps:

Step a. Preparation of long fiber and short fiber pulp:

The bleached softwood kraft pulp, bleached hardwood kraft pulp and water are mixed into the pulper according to the weight ratio of 40:50:1 for beating, and the biological enzyme with a mass concentration of 8ppm is added at the same time, and the beating temperature is controlled to be 60 ℃, pH is 8.5, beating time is 40min, make pulp with beating degree of 25~35°, and then carry out slag removal and grading screen in order to obtain long fiber pulp and short fiber pulp, and send them into Short fiber pulping pool and long fiber pulping pool are reserved;

Step b, mixing and beating:

By weight percentage, 60% of the long fiber slurry and 40% of the short fiber slurry prepared in step a were added to the refiner for beating, and the beating temperature was controlled to be 52°C, pH was 8.8, and the beating degree was 30~ 38° mixed slurry, spare;

Step c, mixing pulp:

C1, configure the surface layer slurry: to the mixed slurry prepared in step b, add fatty acid ester softener with an amount of 3kg/t absolutely dry slurry and glyoxal polyacrylamide resin of 5kg/t absolutely dry slurry, Mix evenly and make a surface layer slurry with a beating degree of 30-35°, and then pump it to the surface layer slurry forming pool for standby;

C2. Configure core layer pulp: add fatty acid ester softener in an amount of 2kg/t dry pulp to the long fiber pulp prepared in step a, and beat to make a core layer with a beating degree of 32-38° pulp, and then pumped to the core layer pulp pool for standby use;

C3, configure bottom pulp: add glyoxal polyacrylamide resin with an amount of 3kg/t dry pulp and glyoxal polyacrylamide of 1kg/t dry pulp to the short fiber pulp prepared in step a , and beat to make the bottom pulp with a beating degree of 30-35°, and then pump it to the bottom pulp pool for standby use;

Step d, forming on the Internet:

The surface layer slurry, the core layer slurry and the bottom layer slurry prepared in step c are successively sprayed onto the forming wire through the headbox and then composited into one body.

In step a, the biological enzyme is a mixture of cellulase and hemicellulase, wherein the amount of cellulase accounts for 75% of the total mass of the mixture.

Example 2.

A tissue paper pulping process with both strength and softness of the present embodiment includes the following steps:

Step a. Preparation of long fiber and short fiber pulp:

The bleached softwood kraft pulp, bleached hardwood kraft pulp and water were mixed into the pulper according to the weight ratio of 50:56:2 for beating, and the biological enzyme with a mass concentration of 12ppm was added at the same time, and the beating temperature was controlled to be 55 ℃, pH is 6.5, beating time is 40min, make pulp with beating degree of 25-35°, and then carry out slag removal and grading sieve in sequence to obtain long fiber pulp and short fiber pulp, and send them into Short fiber pulping pool and long fiber pulping pool are reserved;

Step b, mixing and beating:

By weight percentage, 80% of the long fiber slurry and 20% of the short fiber slurry prepared in step a are added to the refiner for beating, and the beating temperature is controlled to be 56 ° C, pH is 9.2, and the beating degree is 30~ 38° mixed slurry, spare;

Step c, mixing pulp:

C1, configure the surface layer slurry: add the silicone resin softener with an amount of 4kg/t absolute dry slurry and the urea-formaldehyde resin of 2kg/t absolute dry slurry into the mixed slurry prepared in step b, mix evenly and Make the surface layer slurry with a beating degree of 30-35°, and then pump it to the surface layer slurry forming tank for standby;

C2. Configure the core layer pulp: add the silicone resin softener in the amount of 3kg/t dry pulp to the long fiber pulp prepared in step a, and beat the pulp to make a core layer with a beating degree of 32-38° pulp, and then pumped to the core layer pulp pool for standby use;

C3. Configure the bottom layer pulp: add urea-formaldehyde resin in an amount of 0.5kg/t dry pulp and anionic starch of 4kg/t dry pulp to the short fiber pulp prepared in step a, and beat the pulp to make a beating The bottom pulp with a degree of 30-35° is then pumped to the bottom pulp pool for standby use;

Step d, forming on the Internet:

The surface layer slurry, the core layer slurry and the bottom layer slurry prepared in step c are successively sprayed onto the forming wire through the headbox and then composited into one body.

In step a, the biological enzyme is a mixture of cellulase and hemicellulase, wherein the amount of cellulase accounts for 85% of the total mass of the mixture.

Example 3.

A tissue paper pulping process with both strength and softness of the present embodiment includes the following steps:

Step a. Preparation of long fiber and short fiber pulp:

The bleached softwood kraft pulp, bleached hardwood kraft pulp and water were mixed into the pulper according to the weight ratio of 60:45:3 for beating, and the biological enzyme with a mass concentration of 10ppm was added at the same time, and the beating temperature was controlled to 58 ℃, pH is 7, beating time is 60min, make pulp with beating degree of 25-35°, and then carry out slag removal and grading sieve in sequence, respectively obtain long fiber pulp and short fiber pulp, and send them into Short fiber pulping pool and long fiber pulping pool are reserved;

Step b, mixing and beating:

By weight percentage, 70% of the long fiber slurry and 30% of the short fiber slurry prepared in step a were added to the refiner for beating, and the beating temperature was controlled to be 54°C, pH was 8.5, and the beating degree was 30~ 38° mixed slurry, spare;

Step c, mixing pulp:

C1, configure the surface layer slurry: to the mixed slurry prepared in step b, add a fatty acid ester softener with an amount of 2kg/t absolutely dry slurry and a polyamine epichlorohydrin resin of 3kg/t absolutely dry slurry, Mix evenly and make a surface layer slurry with a beating degree of 30-35°, and then pump it to the surface layer slurry forming pool for standby;

C2. Configure core layer pulp: add fatty acid ester softener in an amount of 4kg/t dry pulp to the long fiber pulp prepared in step a, and beat to make a core layer with a beating degree of 32-38° pulp, and then pumped to the core layer pulp pool for standby use;

C3, configure the bottom layer pulp: add the polyamine epichlorohydrin resin in the amount of 1.5kg/t dry pulp and the polyacrylamide of 2kg/t dry pulp to the short fiber pulp prepared in step a, and Beat the pulp to make the bottom pulp with a beating degree of 30-35°, and then pump it to the bottom pulp pool for standby use;

Step d, forming on the Internet:

The surface layer slurry, the core layer slurry and the bottom layer slurry prepared in step c are successively sprayed onto the forming wire through the headbox and then composited into one body.

In step a, the biological enzyme is a mixture of cellulase and hemicellulase, wherein the amount of cellulase accounts for 78% of the total mass of the mixture.

Example 4.

A tissue paper pulping process with both strength and softness of the present embodiment includes the following steps:

Step a. Preparation of long fiber and short fiber pulp:

The bleached softwood kraft pulp, bleached hardwood kraft pulp and water were mixed into the pulper according to the weight ratio of 45:64:2 for beating, and the biological enzyme with a mass concentration of 9ppm was added at the same time, and the beating temperature was controlled to be 56 ℃, pH is 7.5, beating time is 75min, make pulp with beating degree of 25~35°, and then carry out slag removal and grading sieve in sequence, respectively obtain long fiber pulp and short fiber pulp, and send them into Short fiber pulping pool and long fiber pulping pool are reserved;

Step b, mixing and beating:

By weight percentage, the long fiber slurry prepared in step a is added to the refiner for beating, and the beating temperature is controlled to be 52°C and the pH is 9.5 to prepare a mixed slurry with a beating degree of 30-38° for use;

Step c, mixing pulp:

C1, configure the surface layer slurry: add the quaternary ammonium salt softener of 6kg/t absolute dry slurry and glyoxal polyacrylamide resin of 4kg/t absolute dry slurry to the mixed slurry prepared in step b, Mix evenly and make a surface layer slurry with a beating degree of 30-35°, and then pump it to the surface layer slurry forming pool for standby;

C2. Configure the core layer pulp: add the quaternary ammonium salt softener with an amount of 5kg/t dry pulp to the long fiber pulp prepared in step a, and beat the pulp to make a core layer with a beating degree of 32-38° pulp, and then pumped to the core layer pulp pool for standby use;

C3, configure the bottom layer pulp: add glyoxal polyacrylamide resin in an amount of 3kg/t absolute dry pulp and cationic starch of 5kg/t absolute dry pulp to the short fiber pulp prepared in step a, and beat the pulp to make The bottom pulp with a beating degree of 30 to 35° is then pumped to the bottom pulp pool for standby use;

Step d, forming on the Internet:

The surface layer slurry, the core layer slurry and the bottom layer slurry prepared in step c are successively sprayed onto the forming wire through the headbox and then composited into one body.

In step a, the biological enzyme is a mixture of cellulase and hemicellulase, wherein the amount of cellulase accounts for 82% of the total mass of the mixture.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should The technical solutions of the present invention may be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention.

Claims (8)

1. a tissue paper pulping process with both strength and softness, is characterized in that: comprise the following steps: Step a. Preparation of long fiber and short fiber pulp: The bleached softwood kraft pulp, bleached hardwood kraft pulp and water are mixed in the pulper according to the weight ratio of (40-60): (45-64): (1-3) for beating, and the mass concentration is added at the same time. 8～12ppm of biological enzymes, and control the beating temperature to be 55～60℃, pH to 6.5～8.5, and beating time to be 40～90min to make the pulp with beating degree of 25～35°SR, and then carry out slag removal in sequence After grading and screening, long-fiber pulp and short-fiber pulp are obtained respectively, and sent to the short-fiber pulping pool and the long-fiber pulping pool respectively for standby use; Step b, mixing and beating: By weight percentage, add 50-100% of the long-fiber pulp and 0-50% of the short-fiber pulp prepared in step a to the refiner for beating, and control the beating temperature to be 52-58°C and pH to be 8.5-9.5 , to make a mixed slurry with a beating degree of 30-38°SR, for use; Step c, mixing pulp: C1. Configure the surface layer slurry: add a certain amount of softener and wet strength agent to the mixed slurry prepared in step b, mix evenly and make a surface layer slurry with a beating degree of 30-35°SR, and then pump it to the surface layer. Slurry-forming pool for standby use; C2. Configure the core layer pulp: add a certain amount of softener to the long fiber pulp prepared in step a, and beat it to make a core layer pulp with a beating degree of 32-38°SR, and then pump it to the core layer pulp to form a core layer pulp. Slurry pool spare; C3. Configure the bottom pulp: add a certain amount of wet strength agent and dry strength agent to the short fiber pulp prepared in step a, and beat to make a bottom pulp with a beating degree of 30-35°SR, and then pump it to the bottom layer Pulp pulping tank for standby; Step d, forming on the Internet: The surface layer slurry, the core layer slurry and the bottom layer slurry prepared in step c are sequentially sprayed onto the forming wire through the headbox and then composited into one body. 2. a kind of tissue paper pulping process with both strength and softness according to claim 1, is characterized in that: in step a, described biological enzyme is the mixture of cellulase and hemicellulase, wherein The amount of the cellulase used accounts for 75-85% of the total mass of the mixture. 3. a kind of tissue paper pulping process with both strength and softness according to claim 1, is characterized in that: in step C1, the consumption of described softener is 1～8kg/t absolutely dry pulp, The dosage of the wet strength agent is 2-6 kg/t of absolute dry slurry. 4 . The tissue paper pulping process with both strength and softness according to claim 1 , wherein: in step C2, the amount of the softener is 2-5kg/t dry pulp. 5 . 5. a kind of tissue paper pulping process with both strength and softness according to claim 1, is characterized in that: in step C3, the consumption of described dry strength agent is 1～6kg/t absolutely dry pulp , the dosage of the wet strength agent is 0.5 to 3 kg/t dry slurry. 6. a kind of tissue paper pulping process with both strength and softness according to claim 3 or 4, is characterized in that: described softener is quaternary ammonium salt type, fatty acid ester type or silicone resin type softener. 7. A kind of tissue paper pulping process with both strength and softness according to claim 3 or 5, it is characterized in that: described wet strength agent is: glyoxal polyacrylamide resin, polyamine epoxy resin Chloropropane resin or urea-formaldehyde resin. 8. a kind of tissue paper pulping process with both strength and softness according to claim 1 or 5, is characterized in that: described dry strength agent is cationic starch, anionic starch, polyacrylamide and glyoxal Any of polyacrylamide.