CN114536495A

CN114536495A - Color difference and color regulation and control method for decorative veneering veneer

Info

Publication number: CN114536495A
Application number: CN202210067059.7A
Authority: CN
Inventors: 何盛; 卢晓相; 吴再兴; 丁永欢; 陈玉和
Original assignee: National Forestry And Grassland Bureau Bamboo Research And Development Center
Current assignee: National Forestry And Grassland Bureau Bamboo Research And Development Center
Priority date: 2022-01-20
Filing date: 2022-01-20
Publication date: 2022-05-27
Anticipated expiration: 2042-01-20
Also published as: CN114536495B

Abstract

The invention relates to the technical field of board modification, in particular to a method for regulating and controlling chromatic aberration and color of a decorative veneering veneer. Which comprises the following steps: and (3) color difference regulation: adding sodium carbonate or/and sodium bicarbonate into hydrogen peroxide or/and hypochlorous acid solution, and adjusting the pH to be more than 10 to prepare a treatment solution; placing the veneer in a treatment solution for treatment; color adjustment: and contrasting the target color of the veneer of the decorative veneer, and finishing dyeing treatment to uniformly color the veneer, thereby further reducing the color difference of the veneer. In the application, aiming at the chromatic aberration of the decorative veneering veneer, firstly, a bleaching treatment mode is adopted to remove the color development substance on the surface of the decorative veneering veneer so as to enable the wood skin color to be uniform, and after the bleaching treatment, the chromatic aberration delta E of the decorative veneering veneer is less than or equal to 6. And then, using wood high-pressure dyeing equipment to realize rapid level dyeing of the decorative veneering veneer under a hydraulic condition, wherein delta E is less than or equal to 3 after dyeing treatment.

Description

Color difference and color regulation and control method for decorative veneering veneer

Technical Field

The invention relates to the technical field of board modification, in particular to a color difference and color regulation method for a decorative veneering veneer.

Background

In the process of processing the composite floor, a saw cutting veneer or a sliced veneer of precious wood is usually adopted as a veneering material (or called as a surface plate), and the influence of the surface quality and the dimensional stability of the surface plate on the product quality is very important.

Due to the different needs of different consumers, it is often necessary to design a variety of textured surfaces on the surface sheet for selection, which involves a coloring process of the surface sheet. However, the surface board is usually made of one or more species of trees, and for the surface board with a single species of trees, the color difference of the surface board exists due to the difference of the material taking positions (core material and border material) and the growth time (material color difference of early and late in the annual ring of the wood) of the taken wood; for the surface plate made of various mixed tree species, the difference of the tree species makes the color difference on the surface plate more obvious.

In order to regulate and control the color difference of the surface plate, the common technology is bleaching treatment, for example, a wood color difference bleaching desalination treatment process disclosed in the patent document with the publication number of CN113021544A, which comprises the steps of firstly, wood rough grinding pretreatment, secondly, preparing a bleaching agent by calcium hypochlorite, thirdly, wood dipping ultrasonic bleaching treatment, fourthly, ultrasonic water washing treatment before secondary bleaching, fifthly, secondary spraying bleaching steaming treatment and sixthly, water washing polishing treatment after bleaching; the bleaching agent prepared from calcium hypochlorite is used for bleaching the color difference defects on the surface of the wood, so that the color difference of the produced wood products is greatly reduced. However, in this treatment method, the whole wood is immersed in the bleaching solution, and the bleaching degree of the dark portion and the light portion of the wood is substantially equal to each other, and the degree of color reduction of the two portions is equal to each other.

Patent document CN113334515A discloses a method for adjusting chromatic aberration of a wood veneer, wherein the primary color matching process comprises the following steps: adding sodium carbonate and sodium bicarbonate into water to obtain a buffer solution I, wherein the mass fraction of the sodium carbonate is 2-5%, and the mass fraction of the sodium bicarbonate is 1-5%; taking the buffer solution I, placing the wood veneer into the buffer solution I, adding a toner I, heating to 60-80 ℃, and treating for 20-50 min; the toner I is hydrogen peroxide solution; and in the primary color matching, controlling the pH value of the solution to be 8-10. In the primary color matching, the pH value is 8-10, the alkalinity is low, and the purpose of primary color matching by using alkaline hydrogen peroxide with low concentration is as follows: the content of lignin in the veneer is reduced, the content of cellulose is increased, the thermal stability is improved, and macroscopic corrosion on the surface of the wood veneer is avoided.

Disclosure of Invention

The invention aims to solve the problems and provides a method for regulating and controlling chromatic aberration and color of a decorative veneering veneer.

The technical scheme for solving the problems is to provide a method for regulating and controlling the chromatic aberration and the color of a decorative veneering veneer, which comprises the following steps:

(1) and (3) color difference regulation: adding sodium carbonate or/and sodium bicarbonate into hydrogen peroxide or/and hypochlorous acid solution, and adjusting the pH to be more than 10 to prepare a treatment solution; placing the veneer in a treatment solution for treatment;

(2) color adjustment: and contrasting the target color of the veneer of the decorative veneer, and finishing dyeing treatment to uniformly color the veneer, thereby further reducing the color difference of the veneer.

Preferably, the veneer comprises at least two tree species.

Preferably, the veneer comprises at least two of black walnut, white cork, teak and buxus.

In this application, adopt the higher processing liquid of basicity, its effect is different from prior art, and it is different based on different tree species timber pH valve, through the pH valve of regulation and control processing liquid, can make effective chemical composition in the processing liquid remove to the tree species timber part of its adaptation, and then puts emphasis bleaching processing to this part to the regulation and control is because the colour difference that the tree species is different and lead to.

Preferably, in the step (1), 0.1-3.0 g/L of sodium carbonate or/and sodium bicarbonate is added into 1-6% of hydrogen peroxide or/and hypochlorous acid solution by mass fraction. In the application, the dosage of the hydrogen peroxide or/and the hypochlorous acid is higher than that of the ammonium carbonate or/and the sodium bicarbonate, so that both lignin and cellulose in the veneer are degraded, the purpose is to allow dyes in the subsequent color adjusting step to enter, and the color difference of the veneer is further reduced.

Based on the thickness of the veneer, the treatment time of the treatment liquid is different, and as the optimization of the invention, in the step (1), the veneer is placed in the treatment liquid for treatment at the temperature of 60-80 ℃; at this temperature, lignin and cellulose are susceptible to alkaline hydrolysis to improve bleaching efficiency. Meanwhile, based on the thickness of the single plate, the treatment time of the treatment liquid is different, and as the optimization of the invention, the treatment time is 4-8 h for the single plate with the thickness of 0.2-1.2 mm; for the veneer with the thickness of 1.2 mm-2.0 mm, the treatment time is 8-16 h.

In order to further reduce the color difference, as a preferable aspect of the present invention, the step (2) includes the steps of:

a. vacuumizing the veneer subjected to color difference regulation and control;

b. placing the veneer subjected to the vacuumizing treatment in a dye solution, and carrying out pressurized dyeing;

c. and vacuumizing the veneer subjected to pressure dyeing.

And (b) after the vacuumizing treatment in the step a, when the single plate is recovered to normal pressure, air is sucked again to form air holes in the single plate so as to allow subsequent dye liquor to enter quickly. Preferably, in the step a, the veneer is processed for 10-30 min under-0.07 to-0.095 MPa.

And (c) the pressurized dyeing in the step (b) can accelerate the dye to uniformly enter the veneer, and preferably, in the step (b), the veneer is placed in a dyeing solution and pressurized dyeing is carried out for 2-12 hours at the pressure of 1.0-2.5 MPa and the temperature of 80-100 ℃.

And c, performing vacuum pumping treatment to drain residual dye liquor in the dyed veneer, so as to avoid the influence of dye residue on the color uniformity of the veneer. Preferably, in the step c, the veneer is treated under-0.07 to-0.095 MPa for 10 to 30 min.

Preferably, the single board with the thickness of 0.2 mm-0.5 mm is subjected to pressure dyeing for 2-4 h; pressurizing and dyeing a veneer with the thickness of 0.5-1.2 mm for 3-8 h; and (3) carrying out pressure dyeing on the veneer with the thickness of 1.2-2.0 mm for 6-12 h.

Preferably, the dye solution comprises 0.02-2.0 g/L of acid dye, 0.005-0.02 g/L of retarding agent, 0.005-0.02 g/L of leveling agent and 0.005-0.02 g/L of penetrating agent in parts by mass. Among them, the commonly used retarding agents include sodium chloride.

The vacuumization treatment in the step c can be used for extracting the dye liquor in the veneer on one hand, so that the veneer color difference caused by residual dye in the storage or use process of the veneer is avoided; on the other hand, in the process of extracting the dye liquor, the dye liquor flows in the veneer, and the veneer is dyed for one time, so that the color difference is further reduced. Preferably, in the step c, the veneer is treated under-0.07 to-0.095 MPa for 10 to 30 min.

In the application, the technical scheme that the color difference is reduced by bleaching and dyeing is performed to further reduce the color difference is adopted.

Preferably, the treatment solution in step (1) further includes phenylpropane.

Wood has a natural color tone and lignin is the main cause of the different colors of wood. The existence of chromophoric groups (such as carbonyl, carboxyl, alkene and the like conjugated with benzene rings) and chromophoric groups (such as phenolic hydroxyl and alcoholic hydroxyl) in the lignin structure, and the darker the color of a certain part of wood, the higher the lignin content is. The lignin is a complex phenylpropane monomer specific substance, the phenylpropane has good affinity with the lignin in the wood, and hydrogen peroxide or hypochlorous acid can be guided to move to the lignin, so that the bleaching effect of the deep-color part of the wood is improved.

Preferably, the phenylpropane is used for coating the hydrogen peroxide or/and the hypochlorous acid to form a water-in-oil structure, so that the bleaching effect on other parts of the veneer is avoided in the process that the treatment liquid flows to the dark color part of the veneer.

Preferably, the water-in-oil structure is further coated with sodium carbonate or/and sodium bicarbonate to form a water-in-oil-in-water structure, so as to enhance the fluidity of the treatment fluid.

Based on this, as a preferable aspect of the present invention, in the step (1), the treatment liquid is prepared by: primarily mixing hydrogen peroxide or/and hypochlorous acid with an emulsifier and phenylpropane, and shearing at 15000-20000 rpm for 3-8 min to obtain water-in-oil type primary emulsion; and then adding sodium carbonate or/and sodium bicarbonate into the colostrum, and shearing at 10000-12000 rpm for 1-5 min to obtain the treatment fluid.

Preferably, the mixing mass ratio of the hydrogen peroxide or/and the hypochlorous acid to the phenylpropane is (10-60): (0.1 to 3).

Preferably, in the step (2), the dye solution further comprises a solid molecule containing a lone pair of electrons, and the solid molecule containing a lone pair of electrons comprises one or more of Urea, an organic acid, imidazole and amide. The solid molecules containing lone pair electrons can form eutectic ionic liquid with sodium chloride and table salt in the retarding agent, and the eutectic ionic liquid can degrade lignin in the veneer, so that the dye solution is guided to move towards the direction of the lignin, the color of the lignin is filled, and the purposes of accelerating dyeing and improving the dyeing uniformity are achieved.

Preferably, in the step b, after each pressurized dyeing for 30-60 min, the veneer is taken out and subjected to surface plasma treatment, wherein the treatment power is 100-1500W, and the treatment time is 10-30 s. In the lignin part: active particles in the plasma react with polar groups obtained after the treatment of the ionic liquid, so that the polarity of the part is weakened. And in the non-lignin part, activating the veneer, improving the wettability of the wood board and increasing the polarity of the wood board. A positive and a negative to improve the dyeing uniformity.

The invention has the beneficial effects that:

1. in the application, aiming at the chromatic aberration of the decorative veneering veneer, firstly, a bleaching treatment mode is adopted to remove the color development substance on the surface of the decorative veneering veneer so as to enable the wood skin color to be uniform, and after the bleaching treatment, the chromatic aberration delta E of the decorative veneering veneer is less than or equal to 6. And then, using wood high-pressure dyeing equipment to realize rapid level dyeing of the decorative veneering veneer under a hydraulic condition, wherein delta E is less than or equal to 3 after dyeing treatment.

2. In the application, for the decorative veneering veneers with different thicknesses, the rapid processing of the decorative veneering veneers with color difference is realized by combining the bleaching processing with different degrees and a high-pressure dyeing mode.

3. The dyeing method provided by the invention can be applied to the field of color difference regulation of veneers with decorative veneers, and can also be applied to the field of dyeing of wood and bamboo materials. The veneer color difference can be effectively reduced by processing the decorative veneered veneer through the method, the production cost can be saved, the product quality can be improved, and considerable economic benefits can be brought to enterprises.

Detailed Description

The following are specific embodiments of the present invention and further describe the technical solutions of the present invention, but the present invention is not limited to these examples.

Example 1

A color difference and color regulation method of a decorative veneering veneer comprises the following steps:

the veneer is made of black walnut and teak and has a thickness of 0.3 mm.

(1) And (3) color difference regulation:

adding 1g/L sodium carbonate solution into 3% hydrogen peroxide by mass fraction, adjusting pH to 11, and stirring uniformly to obtain a treatment solution for later use.

And heating the treatment liquid to 70 ℃, putting the veneer into the treatment liquid, completely immersing the veneer in the treatment liquid, performing immersion treatment for 6 hours, and taking out.

(2) Color adjustment:

a. and (3) treating the single plate for 20min under-0.085 MPa.

b. 1.0g/L of acid dye, 0.01g/L of retarding agent, 0.01g/L of leveling agent and 0.01g/L of penetrating agent are mixed and stirred uniformly to prepare the dye for later use.

And (3) placing the veneer subjected to the vacuumizing treatment in a dye solution, and carrying out pressurized dyeing for 3 hours at the temperature of 90 ℃ under the pressure of 1.5 MPa.

c. And (3) treating the veneer subjected to pressure dyeing for 20min under-0.085 MPa.

Example 2

This embodiment is substantially the same as embodiment 1, except that:

selecting a veneer with the thickness of 1 mm.

In the step b, the dyeing is carried out for 6 hours under pressure.

Example 3

This embodiment is substantially the same as embodiment 1, except that:

a veneer with a thickness of 1.5mm is selected.

In the step (1), the immersion treatment is carried out for 12 hours.

In the step b, the dyeing is carried out for 10 hours under pressure.

Example 4

selecting a veneer which is prepared from black walnut and white suppository and has the thickness of 0.2 mm.

(1) And (3) color difference regulation:

adding 0.1g/L sodium carbonate solution into 1% hydrogen peroxide by mass fraction, adjusting the pH to 10.2, and uniformly stirring to obtain a treatment solution for later use.

And heating the treatment liquid to 60 ℃, putting the veneer into the treatment liquid, completely immersing the veneer in the treatment liquid, performing immersion treatment for 4 hours, and taking out.

(2) Color adjustment:

a. and (3) treating the single board under-0.07 MPa for 10 min.

b. Mixing acid dye 0.02g/L, slow-dyeing agent 0.005g/L, leveling agent 0.005g/L, and penetrating agent 0.005g/L, stirring well to obtain dye for use.

And (3) placing the veneer subjected to the vacuumizing treatment in a dye solution, and dyeing the veneer under the pressure of 1.0MPa and at the temperature of 80 ℃ for 2 hours.

c. And (3) treating the veneer subjected to pressure dyeing for 10min under-0.07 MPa.

Example 5

selecting a veneer which is prepared from black walnut and buxus sinica and has the thickness of 2.0 mm.

(1) And (3) color difference regulation:

adding 3.0g/L sodium carbonate solution into 6% hydrogen peroxide by mass fraction, adjusting pH to 13, and stirring uniformly to obtain a treatment solution for later use.

And heating the treatment liquid to 80 ℃, putting the veneer into the treatment liquid, completely immersing the veneer in the treatment liquid, performing immersion treatment for 16 hours, and taking out.

(2) Color adjustment:

a. and (3) treating the single board for 30min under-0.095 MPa.

b. Mixing acid dye 2.0g/L, slow-dyeing agent 0.02g/L, leveling agent 0.02g/L and penetrating agent 0.02g/L, and stirring uniformly to obtain the dye for later use.

And (3) placing the veneer subjected to the vacuumizing treatment in a dye solution, and carrying out pressurized dyeing for 12 hours at the temperature of 100 ℃ under the pressure of 2.5 MPa.

c. And (3) treating the veneer subjected to pressure dyeing for 30min under-0.095 MPa.

Example 6

the veneer is made of black walnut and teak and has a thickness of 0.3 mm.

(1) And (3) color difference regulation:

adding 30 parts by mass of hydrogen peroxide, 0.1 part by mass of glycerol isostearate and 1.5 parts by mass of phenylpropane into deionized water, and shearing at 18000rpm for 5min to obtain water-in-oil type primary emulsion; then adding a proper amount of sodium carbonate into the colostrum until the pH value of the system reaches 11, and shearing for 3min at 11000rpm to obtain the treatment fluid.

And (3) placing the treatment fluid in a water bath kettle at 70 ℃, preheating for 10min, placing the veneer in the treatment fluid, completely immersing the veneer in the treatment fluid, performing immersion treatment for 6h, and taking out.

(2) Color adjustment:

a. firstly, the veneer is placed under-0.085 MPa for treatment for 20 min.

b. According to the mass parts, 1.0 part of acid dye, 0.01 part of sodium chloride serving as a slow-dyeing agent, 0.01 part of leveling agent 50805M, 0.01 part of sodium dodecyl benzene sulfonate serving as a penetrating agent and 0.5 part of urea are mixed, added into 1000 parts of water and uniformly mixed to prepare a dye solution.

And (3) placing the veneer into a dye solution, and carrying out pressure dyeing at 1.5MPa and 90 ℃, wherein after each 45min of pressure dyeing, taking out the veneer for carrying out surface plasma treatment, wherein the treatment power is 120W, the treatment time is 20s, and the total pressure dyeing is carried out for 3 h.

Comparative example 1

This embodiment is substantially the same as embodiment 1, except that:

step (1) referring to the one-time toning method in patent document with publication number CN 113334515A:

adding sodium carbonate and sodium bicarbonate into water to obtain a buffer solution, wherein the mass fraction of the sodium carbonate is 3%, and the mass fraction of the sodium bicarbonate is 3%.

Placing the veneer into a buffer solution, adding a hydrogen peroxide solution with the mass fraction of 3.0 percent and the mass of 0.1 percent of the mass of the buffer solution, heating to 70 ℃, controlling the pH value of the solution to be 10, treating for 15min, and taking out.

[ COLOR-DIFFERENCE DETECTION ]

The single plate obtained in the example was tested by a color difference tester, and the test results are shown in table 1 below.

Table 1.

As can be seen from Table 1, compared with the comparative example, the color difference can be effectively reduced by regulating the adding sequence of each component, simultaneously increasing the pH value and the processing time and matching with the color regulating step. Meanwhile, in the application, the benzene propane is added, and the phenylpropane is used for guiding the bleaching agent to move towards the lignin, so that the bleaching effect of the part with the deep color of the wood can be improved, and the integral color difference of the wood is effectively reduced.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Claims

1. A color difference and color regulation method of a decorative veneering veneer is characterized in that: the method comprises the following steps:

(1) and (3) color difference regulation: adding sodium carbonate or/and sodium bicarbonate into hydrogen peroxide or/and hypochlorous acid solution, and adjusting the pH to be more than 10 to prepare treatment liquid; placing the veneer in a treatment solution for treatment;

2. The method for regulating and controlling chromatic aberration and color of a decorative veneering veneer according to claim 1, characterized in that: the veneer comprises at least two of black walnut, white cork, teak and buxus sinica.

3. The method for regulating and controlling chromatic aberration and color of a decorative veneering veneer according to claim 1, characterized in that: in the step (1), the veneer is placed in a treatment fluid for treatment at the temperature of 60-80 ℃; for a veneer with the thickness of 0.2-1.2 mm, the treatment time is 4-8 h; for the veneer with the thickness of 1.2 mm-2.0 mm, the treatment time is 8-16 h.

4. The method for regulating and controlling chromatic aberration and color of a decorative veneering veneer according to claim 1, characterized in that: in the step (1), 0.1-3.0 g/L of sodium carbonate or/and sodium bicarbonate is added into 1-6% of hydrogen peroxide or/and hypochlorous acid solution by mass.

5. The method for regulating and controlling chromatic aberration and color of a decorative veneering veneer according to claim 1, characterized in that: the step (2) comprises the following steps:

a. vacuumizing the veneer subjected to color difference regulation and control;

c. and vacuumizing the veneer subjected to pressure dyeing.

6. The method for regulating and controlling the color difference and the color of the decorative veneering veneer according to claim 5, is characterized in that: in the step a, the single board is placed under-0.07 to-0.095 MPa to be processed for 10 to 30 min.

7. The method for regulating and controlling the color difference and the color of the decorative veneering veneer according to claim 5, is characterized in that: in the step b, the single plate is placed in a dye solution and is pressurized and dyed for 2-12 hours at the pressure of 1.0-2.5 MPa and the temperature of 80-100 ℃.

8. The color difference regulation and control method of the decorative veneers according to claim 7, characterized in that: pressurizing and dyeing the veneer with the thickness of 0.2-0.5 mm for 2-4 h; pressurizing and dyeing a veneer with the thickness of 0.5-1.2 mm for 3-8 h; and (3) pressurizing and dyeing the veneer with the thickness of 1.2-2.0 mm for 6-12 h.

9. The method for regulating and controlling the color difference and the color of the decorative veneering veneer according to claim 5, is characterized in that: in the step c, the veneer is processed for 10-30 min under-0.07 to-0.095 MPa.

10. The method for regulating and controlling the color difference and the color of the decorative veneering veneer according to claim 5, is characterized in that: the dye solution comprises 0.02-2.0 g/L of acid dye, 0.005-0.02 g/L of retarding agent, 0.005-0.02 g/L of leveling agent and 0.005-0.02 g/L of penetrating agent.