CN102658578B - Method for manufacturing fiberboard by using laccase-activated lignosulfonate - Google Patents

Abstract

The invention relates to a method for laccase activating lignin sulfonate to manufacture fiberboard. The purpose of the present invention is to provide a method for activating lignosulfonate with laccase to manufacture fiberboard, which can greatly increase the concentration of active oxygen free radicals and improve the physical and mechanical properties of the board. The technical solution of the present invention is: the method for laccase activating lignosulfonate to manufacture fiberboard, which is characterized in that the steps are as follows: a. separating wood or its processing residues into wood fibers and drying them; b. mixing talcum powder with lacquer Mix the enzymes and mix well, then add lignosulfonate to mix and stir evenly, finally add water and stir evenly to obtain a laccase adhesive; c, use the adhesive obtained in step b, spray and stir the wood fiber in a mixer; d. Paving, pre-pressing, hot-pressing and post-processing the fiber board material obtained in step c. The invention is applicable to the manufacture of fibreboards.

Description

Laccase activated lignin sulfonate manufacturing method for fiberboard

technical field

The invention relates to the processing of wood or non-wood plants, in particular to a method for activating lignin sulfonate with laccase to manufacture fiberboards, which is mainly applicable to the manufacture of fiberboards.

Background technique

Manufacturing wood-based panels without using adhesives and using laccase treatment is a new way to produce formaldehyde-free and environmentally friendly wood-based panels. "A Preliminary Study on the Conditions of Enzyme Activation Treatment and Its Effects on the Gluing Properties of Pine Fibers" ("Forestry Science" Vol. 40, No. 4), reported the theoretical research on the application of laccase to the manufacture of fiberboard. This method takes a long time for laccase treatment. , also need to adjust the pH value of laccase reaction system with buffer solution, the applicant of the present invention finds that the physical and mechanical properties of laccase-treated bamboo particleboard product and The concentration of active oxygen free radicals generated when laccase activated bamboo shavings was closely related (Journal of Beijing Forestry University, Volume 31, Issue 2), and the higher the concentration of active oxygen free radicals, the better the physical and mechanical properties of the board.

Contents of the invention

The technical problem to be solved in the present invention is: to provide a method for laccase-activated lignosulfonate to manufacture fiberboards in view of the above-mentioned problems, which can greatly increase the concentration of active oxygen free radicals, improve the physical and mechanical properties of the board, and at the same time its stickiness The preparation of the mixture does not need to reserve special time for enzyme treatment, and it is not necessary to adjust the pH value of the reaction system, so as to simplify the production process and improve work efficiency.

The technical scheme adopted in the present invention is: the method for laccase activating lignosulfonate to manufacture fiberboard, it is characterized in that the steps are as follows:

a. Separate the wood or its processing residues into wood fibers and dry them to control the moisture content to 3-5%;

b. Mix talcum powder and laccase and mix well, then add lignosulfonate and mix well, finally add water and stir well to obtain laccase adhesive;

C, utilize the binding agent that step b obtains, stir while spraying to wood fiber limit in mixer, the binding agent consumption accounts for the 8-13% ratio calculation of wood fiber dry mass by its solid content;

d. Paving, pre-pressing, hot-pressing and post-processing the fiber sheet material obtained in step c. The pressing time is 10-30s, and the hot pressing time is 30-60s/mm.

The ratio of raw materials for preparing the adhesive in step b is,

20-25 parts by weight of lignosulfonate;

Add 40-55 enzyme activity units of laccase per gram of heavy lignosulfonate absolute dry powder;

Lignosulfonate powder quality 0.5%-1% talcum powder;

145-200 parts by weight of water.

The laccase is dry laccase powder or laccase liquid, wherein the weight of the laccase liquid is included in the amount of water used.

The particle size of the talcum powder is 1000-3000 mesh.

The lignosulfonate is ammonium lignosulfonate or sodium lignosulfonate.

The beneficial effect of the present invention is: the present invention adds talcum powder in the adhesive raw material as the promotor in the laccase activation reaction, under the same situation of other treatment conditions, greatly improved the concentration of active oxygen free radical (its activity The concentration of oxygen free radicals is 1-5 times higher than that of the reaction system without talc powder), thus improving the physical and mechanical properties of the board, even if no buffer is used to adjust the pH value of the reaction system, and no additional enzyme treatment time is reserved , the strength of the plant fiber board made of the obtained adhesive can also meet the requirements of the national standard; in addition, because the amount of buffer solution and the enzyme treatment time are omitted, not only the cost is saved, but also the production process is greatly simplified and the work efficiency is improved.

Detailed ways

Embodiment 1: The method for activating lignosulfonate with laccase in this embodiment to manufacture fiberboard comprises the following steps,

a. Preparation:

The wood or its processing residues are separated into wood fibers according to the conventional medium density fiberboard production method and dried, and the moisture content of the wood fibers is controlled to 3%;

Laccase, purchased from Novozymes (China) Investment Co., Ltd., an aqueous enzyme preparation - laccase NS51003;

Ammonium lignosulfonate, purchased from Wuhan Huadong Chemical Co., Ltd., is a powder;

Talcum powder, purchased particle size from the chemical store is 1000 mesh talcum powder.

b. The measurement of laccase binder raw materials: the amount of laccase is 40 enzyme activity units (u) per gram (g) of dry ammonium lignosulfonate powder, and the amount of talcum powder is ammonium lignosulfonate powder 0.5% by mass, 20 parts by weight of ammonium lignosulfonate and 145 parts by weight of water. When preparing laccase adhesive, first use the amount of ammonium lignosulfonate as the base, and calculate the total number of enzyme activity units (u) according to its absolute dry mass of 40u/g, and then calculate the laccase activity according to the laccase activity. The consumption of talcum powder is 0.5% of ammonium lignosulfonate powder quality; Finally, the consumption of water is determined by weight ratio, because laccase is laccase liquid in this example, so the consumption of water should include the weight of laccase liquid , and water should finally be added as appropriate in a proportion of 145 parts by weight. Laccase activity can be determined by ABTS—spectrophotometer method, the substrate used is 2,2′-azino-bis-(3-ethylbenzothiazole-6-sulfonic acid) referred to as ABTS, an enzyme activity unit (u) refers to the amount of enzyme required to catalyze the conversion of 1 μmol ABTS to the product per minute (min) under certain reaction conditions.

c. Preparation of laccase adhesive: take each raw material according to the above ratio, first mix talcum powder with laccase liquid, stir to form a paste, then mix the paste with ammonium lignosulfonate and mix Stir well, and finally add water and mix well.

D, the mixing of laccase binder and wood fiber: utilize the binder that step c obtains, stir while spraying to wood fiber limit in mixer, binder consumption accounts for 8% of wood fiber absolute dry mass by its solid content Proportional calculations.

e. Compression of laccase-treated fiberboard: the fiberboard obtained in step d is prepared by conventional procedures, namely paving, pre-pressing, hot-pressing, and post-treatment. The pre-pressing line pressure is 1.5kN/cm, and the hot-pressing temperature is 170°C. The hot pressing pressure is 2.0MPa, the pre-pressing time is 10s, and the hot pressing time is 30s/mm.

Embodiment 2: The method for activating lignosulfonate to manufacture fiberboard with laccase in this embodiment comprises the following steps,

a. Preparation:

The wood or its processing residues are separated into wood fibers according to the conventional medium density fiberboard production method and dried, and the moisture content of the wood fibers is controlled to 5%;

Laccase, purchased from Novozymes (China) Investment Co., Ltd., an aqueous enzyme preparation - laccase NS51003;

Ammonium lignosulfonate, purchased from Wuhan Huadong Chemical Co., Ltd., is a powder;

Talcum powder, purchased particle size from the chemical store is 3000 mesh talcum powder.

b. The measurement of laccase binder raw materials: the amount of laccase is 55 enzyme activity units (u) per gram (g) of dry ammonium lignosulfonate powder, and the amount of talcum powder is ammonium lignosulfonate powder 1% by mass, 25 parts by weight of ammonium lignosulfonate and 200 parts by weight of water. When preparing laccase adhesive, first use the amount of ammonium lignosulfonate as the base, and calculate the total number of enzyme activity units (u) according to its absolute dry mass of 55u/g, and then calculate the laccase activity according to the laccase activity. The consumption of talcum powder is 1% of the quality of ammonium lignosulfonate powder; Finally, the consumption of water is determined by weight ratio, because laccase is laccase liquid in this example, so the consumption of water should include the weight of laccase liquid , and water should finally be added as appropriate in a proportion of 200 parts by weight. Laccase activity can be determined by ABTS—spectrophotometer method, the substrate used is 2,2′-azino-bis-(3-ethylbenzothiazole-6-sulfonic acid) referred to as ABTS, an enzyme activity unit (u) refers to the amount of enzyme required to catalyze the conversion of 1 μmol ABTS to the product per minute (min) under certain reaction conditions.

c. Preparation of laccase adhesive: take each raw material according to the above ratio, first mix talcum powder with laccase liquid, stir to form a paste, then mix the paste with ammonium lignosulfonate and mix Stir well, and finally add water and mix well.

D, the mixing of laccase binder and wood fiber: utilize the binder that step c obtains, stir while spraying to wood fiber limit in mixer, binder consumption accounts for 13% of wood fiber absolute dry mass by its solid content Proportional calculations.

e. Compression of laccase-treated fiberboard: the fiberboard obtained in step d is prepared by conventional procedures, namely paving, pre-pressing, hot-pressing, and post-treatment. The pre-pressing line pressure is 2.5kN/cm, and the hot-pressing temperature is 200°C. The hot pressing pressure is 3.5MPa, the pre-pressing time is 30s, and the hot pressing time is 60s/mm.

Embodiment 3: In this embodiment, the method for activating lignosulfonate with laccase to manufacture fiberboard includes the following steps,

a. Preparation:

Wood or its processing residues are separated into wood fibers according to conventional medium density fiberboard production methods and dried to control the moisture content of wood fibers to 4%;

Laccase, purchased from Novozymes (China) Investment Co., Ltd., an aqueous enzyme preparation - laccase NS51003;

Ammonium lignosulfonate, purchased from Wuhan Huadong Chemical Co., Ltd., is a powder;

Talcum powder, purchased particle size from the chemical store is 2000 mesh talcum powder.

b. The measurement of laccase binder raw materials: the dosage of laccase is 50 enzyme activity units (u) per gram (g) of dry ammonium lignosulfonate powder, and the dosage of talcum powder is ammonium lignosulfonate powder 0.75% by mass, 22.5 parts by weight of ammonium lignosulfonate and 170 parts by weight of water. When preparing laccase adhesive, first use the amount of ammonium lignosulfonate as the base, and calculate the total number of enzyme activity units (u) according to its absolute dry mass of 50u/g, and then calculate the laccase activity according to the laccase activity. The consumption of talcum powder is 0.75% of ammonium lignosulfonate powder quality; Finally, the consumption of water is determined by weight ratio, because laccase is laccase liquid in this example, so the consumption of water should include the weight of laccase liquid , and water should finally be added as appropriate in a proportion of 170 parts by weight. Laccase activity can be determined by ABTS—spectrophotometer method, the substrate used is 2,2′-azino-bis-(3-ethylbenzothiazole-6-sulfonic acid) referred to as ABTS, an enzyme activity unit (u) refers to the amount of enzyme required to catalyze the conversion of 1 μmol ABTS to the product per minute (min) under certain reaction conditions.

c. Preparation of laccase adhesive: take each raw material according to the above ratio, first mix talcum powder with laccase liquid, stir to form a paste, then mix the paste with ammonium lignosulfonate and mix Stir well, and finally add water and mix well.

D, the mixing of laccase binder and wood fiber: utilize the binder that step c obtains, stir while spraying to wood fiber limit in mixer, binder consumption accounts for 11% of wood fiber absolute dry mass by its solid content Proportional calculations.

e. Compression of laccase-treated fiberboard: the fiberboard obtained in step d is prepared by conventional procedures, namely paving, pre-pressing, hot-pressing, and post-treatment. The pre-pressing line pressure is 2kN/cm, and the hot-pressing temperature is 185°C. The pressing pressure is 3MPa, the pre-pressing time is 20s, and the hot pressing time is 45s/mm.

Embodiment 4: The method for activating lignosulfonate to manufacture fiberboard with laccase in this embodiment includes the following steps,

a. Preparation:

Wood or its processing residues are separated into wood fibers according to conventional medium density fiberboard production methods and dried to control the moisture content of wood fibers to 4%;

Laccase, purchased from Novozymes (China) Investment Co., Ltd., an aqueous enzyme preparation - laccase NS51003;

Sodium lignosulfonate, purchased from Wuhan Huadong Chemical Co., Ltd., is a powder;

Talcum powder, purchased particle size from the chemical store is 2000 mesh talcum powder.

b. The measurement of laccase binder raw materials: the amount of laccase is 45 enzyme activity units (u) per gram (g) of dry sodium lignosulfonate powder, and the amount of talcum powder is sodium lignosulfonate powder 0.8% by mass, 22 parts by weight of sodium lignosulfonate and 180 parts by weight of water. When preparing laccase adhesive, first use the amount of sodium lignosulfonate as the base, and calculate the total number of enzyme activity units (u) according to its absolute dry mass of 45u/g, and then calculate the laccase activity according to the laccase activity. The consumption of talcum powder is 0.8% of sodium lignosulfonate powder quality; Finally, the consumption of water is determined by weight ratio, because laccase is laccase liquid in this example, so the consumption of water should include the weight of laccase liquid , and water should finally be added as appropriate in a proportion of 180 parts by weight. Laccase activity can be determined by ABTS—spectrophotometer method, the substrate used is 2,2′-azino-bis-(3-ethylbenzothiazole-6-sulfonic acid) referred to as ABTS, an enzyme activity unit (u) refers to the amount of enzyme required to catalyze the conversion of 1 μmol ABTS to the product per minute (min) under certain reaction conditions.

c. Preparation of laccase adhesive: take each raw material according to the above ratio, first mix talcum powder with laccase liquid, stir to form a paste, then mix the paste with sodium lignosulfonate and mix Stir well, and finally add water and mix well.

D, the mixing of laccase binder and wood fiber: utilize the binder that step c obtains, stir while spraying to wood fiber limit in mixer, binder consumption accounts for 10% of wood fiber absolute dry mass by its solid content Proportional calculations.

e. Compression of laccase-treated fiberboard: the fiberboard obtained in step d is prepared by conventional procedures, namely paving, pre-pressing, hot-pressing, and post-treatment. The pre-pressing line pressure is 1.8kN/cm, and the hot-pressing temperature is 180°C. The hot pressing pressure is 2.5MPa, the pre-pressing time is 20s, and the hot pressing time is 40s/mm.

Embodiment 5: The method for activating lignosulfonate to manufacture fiberboard with laccase in this embodiment includes the following steps,

a. Preparation:

The wood or its processing residues are separated into wood fibers according to the conventional medium density fiberboard production method and dried, and the moisture content of the wood fibers is controlled to 3%;

Laccase, purchased from Novozymes (China) Investment Co., Ltd., an aqueous enzyme preparation - laccase NS51003;

Sodium lignosulfonate, purchased from Wuhan Huadong Chemical Co., Ltd., is a powder;

Talcum powder, purchased particle size from the chemical store is 3000 mesh talcum powder.

b. The measurement of laccase binder raw materials: the dosage of laccase is 40 enzyme activity units (u) per gram (g) of dry sodium lignosulfonate powder, and the dosage of talcum powder is sodium lignosulfonate powder 0.8% by mass, 20 parts by weight of sodium lignosulfonate and 145 parts by weight of water. When preparing laccase adhesive, first use the amount of sodium lignosulfonate as the base, and calculate the total number of enzyme activity units (u) according to its absolute dry mass of 40u/g, and then calculate the laccase activity according to the laccase activity. The consumption of talcum powder is 0.8% of sodium lignosulfonate powder quality; Finally, the consumption of water is determined by weight ratio, because laccase is laccase liquid in this example, so the consumption of water should include the weight of laccase liquid , and water should finally be added as appropriate in a proportion of 145 parts by weight. Laccase activity can be determined by ABTS—spectrophotometer method, the substrate used is 2,2′-azino-bis-(3-ethylbenzothiazole-6-sulfonic acid) referred to as ABTS, an enzyme activity unit (u) refers to the amount of enzyme required to catalyze the conversion of 1 μmol ABTS to the product per minute (min) under certain reaction conditions.

c. Preparation of laccase adhesive: take each raw material according to the above ratio, first mix talc powder with laccase liquid, stir to form a paste, then mix the paste with sodium lignosulfonate and mix Stir well, and finally add water and mix well.

D, the mixing of laccase binder and wood fiber: utilize the binder that step c obtains, stir while spraying to wood fiber limit in mixer, binder consumption accounts for 9% of wood fiber absolute dry mass by its solid content Proportional calculations.

e. Compression of laccase-treated fiberboard: the fiberboard obtained in step d is prepared by conventional procedures, namely paving, pre-pressing, hot-pressing, and post-treatment. The pre-pressing line pressure is 1.5kN/cm, and the hot-pressing temperature is 170°C. The hot pressing pressure is 2.0MPa, the pre-pressing time is 15s, and the hot pressing time is 30s/mm.

The laccase described in the above embodiments can also be dry laccase powder produced by Novozymes (China) Investment Co., Ltd., since it does not contain water, its dosage is not included in the water dosage.

In order to further improve the activation effect of laccase, disodium hydrogen phosphate-citric acid buffer can be added to the raw materials for preparing the adhesive in the aforementioned five embodiments, and the amount must ensure that the pH value of the reaction system can be adjusted to 3.5-4.5. And the amount of this buffer should be included in the amount of water used.

In the present invention, talcum powder is used in the reaction system of laccase to activate lignosulfonate. Under the same conditions, the concentration of reactive oxygen species (ROS) free radicals is 1-5 times higher than that of the reaction system without talc powder. times. The following is a list of ROS levels produced by different enzyme dosages and wood treated with and without talc1:

(Table 1)

It can be seen from Table 1 that different enzyme dosages have a significant impact on the concentration of ROS free radicals. When the dosage of enzymes is 40u per gram of absolute dry lignosulfonate, the concentration of ROS free radicals reaches a peak value. When the absolute dry mass of sulfonate is 0.8%, the concentration of ROS free radicals is 1-5 times higher than that without talc. Because of this, even if the pH value of the reaction system is not adjusted with a buffer solution, the temperature is not increased, and the reaction time is not reserved when preparing the adhesive, although the action of the enzyme may not be sufficient, the adhesive produced The strength of wood-based panels can still meet the corresponding national standard requirements, which is hard to predict.

Claims (3)

1. laccase activation lignosulphonates are manufactured a method for fiberboard, it is characterized in that step is as follows:

A, timber or its processing residue material is separated into wood-fibred and is dried, control moisture content is 3-5%;

B, talcum powder mixed with laccase and mix thoroughly, then adding lignosulphonates mixing and stirring, finally adding water and stir and obtain laccase adhesive;

C, the adhesive that utilizes step b to obtain stir injection limit, wood-fibred limit in mixer, and the 8-13% ratio that binder dosage accounts for wood-fibred over dry quality in its solids content is calculated;

D, the fiber plate that step c is obtained are mated formation, precompressed, hot pressing, post processing, precompressed linear pressure 1.5-2.5kN/cm, hot pressing temperature 170-200 ℃, hot pressing pressure 2.0-3.5MPa, squeeze time 10-30 s, hot pressing time 30-60s/mm;

Each raw material proportioning of preparing described adhesive in step b is,

The lignosulphonates of 20-25 weight portion;

In every grammes per square metre lignosulphonates over dry powder, add the laccase of 40-55 enzyme activity unit;

The talcum powder of lignosulphonates opaque amount 0.5%-1%;

The water of 145-200 weight portion;

Described laccase is dry laccase powder or laccase liquid, and wherein the weight of laccase liquid counts in the consumption of water.

2. laccase activation lignosulphonates according to claim 1 are manufactured the method for fiberboard, it is characterized in that: described talcous granularity is 1000-3000 order.

3. laccase activation lignosulphonates according to claim 1 and 2 are manufactured the method for fiberboard, it is characterized in that: described lignosulphonates are ammonium lignin sulfonate or sodium lignosulfonate.