CN113858358A

CN113858358A - Treatment method for reducing content of starch, protein and saccharide in rubber wood

Info

Publication number: CN113858358A
Application number: CN202111118487.XA
Authority: CN
Inventors: 蒋汇川; 李冠君; 陆全济; 李家宁
Original assignee: Rubber Research Institute Chinese Academy Tropical Agricultural Sciences
Current assignee: Rubber Research Institute Chinese Academy Tropical Agricultural Sciences
Priority date: 2021-09-24
Filing date: 2021-09-24
Publication date: 2021-12-31
Anticipated expiration: 2041-09-24
Also published as: CN113858358B

Abstract

The invention relates to a processing method for reducing the content of starch, protein and saccharide in rubber wood, which comprises the following steps: (1) adding a weak acid solution into the rubber wood for ultrasonic acidification treatment; (2) after ultrasonic acidification treatment, adding an alkaline nano sodium silicate solution for ultrasonic neutralization treatment; (3) stacking and air-drying the rubber wood subjected to ultrasonic neutralization treatment until the water content is less than 70-80%, and performing high-temperature drying treatment; (4) the high-temperature drying treatment comprises a heating drying stage and a cooling and humidifying stage. The treatment method can greatly reduce the content of starch, protein and saccharide in the rubber wood, ensure the treated rubber wood to have uniform color, and obtain the long-acting rubber wood which can prevent the rubber wood from mildewing and keep the natural color of the wood.

Description

Treatment method for reducing content of starch, protein and saccharide in rubber wood

Technical Field

The invention relates to the technical field of wood mildew prevention and control, in particular to a treatment method for reducing the content of starch, protein and saccharide in rubber wood.

Background

At present, the conventional drying and high-temperature drying (including thermal modification treatment, namely carbonization) of the rubber wood can reduce the content of starch and sugar in the rubber wood, but the rubber wood cannot be prevented from mildewing is common industry consensus. Humidity, temperature and the kind of nutrients are the most important factors affecting the growth of mold. The growth of the mold is mainly dependent on protein and low molecular carbohydrate in the wood, and the reduction of the content of nutrient substances such as starch, protein and carbohydrate in the rubber wood is an effective means for preventing the rubber wood from mildewing.

The method is characterized in that the method adopts ultrasonic treatment to reduce the nutrient substances of bamboo and prolong the mildew occurrence time by the steps of Guangming, Zhou Ming and Yong (the influence of ultrasonic on the nutrient substances and mildew of bamboo [ J ] bamboo research, 2012 and 31(3)), but the mildew-proof effect is limited, and the growth of mildew is only temporarily inhibited; although the Chinese patent CN106903767A can greatly reduce the nutrient substances such as starch, soluble sugar and the like in the rubber wood and prevent the rubber wood from being damaged by the pink beetle to a certain extent, the treated rubber wood still contains more than 2 percent of starch content and the like, and the problem of whether the rubber wood can be prevented from mildewing or not is not involved. The prior art lacks the problem of effectively preventing the growth of mold in the rubber wood.

Disclosure of Invention

In view of the above, the present invention aims to provide a treatment method for reducing the content of starch, protein and saccharide in rubber wood, and solve the above problems.

The technical scheme of the invention is realized as follows:

a treatment method for reducing the content of starch, protein and saccharide in rubber wood comprises the following steps:

(1) acidifying: adding a weak acid solution with the mass concentration of 0.5-5.0% into the rubber wood to immerse the rubber wood, and carrying out ultrasonic treatment at the temperature of 20-80 ℃, the ultrasonic frequency of 25-80 KHz, the ultrasonic power of 300-5400W and the ultrasonic time of 30-240 min to obtain acidified wood;

(2) and (3) neutralization treatment: adding an alkaline nano sodium silicate solution with the mass concentration of 10-30% into the acidified wood, and performing ultrasonic treatment to obtain neutralized wood;

(3) air drying treatment: stacking the neutralized wood, air-drying, placing for 1-7 days, and obtaining air-dried wood when the water content of the neutralized wood is less than 70-80%, wherein the air-drying aims to reduce the moisture content, so as to reduce the time of high-temperature quick drying and energy consumption, prolong the aging time, volatilize chemical substances in the treatment solution, and simultaneously facilitate further reduction of the content of nutrient substances such as starch, protein, saccharides and the like;

(4) and (3) high-temperature drying treatment: comprises a heating drying stage and a cooling and humidifying stage; the temperature rising and drying stage is as follows: heating to 92-98 ℃, drying for 6-72 h, exhausting once every 0.5-2.0 h during drying, continuously heating to 130-150 ℃ after drying, heating while continuously spraying steam, stopping spraying steam after heating, drying for 12-96 h, and spraying steam once every 0.5-2.0 h during drying; the cooling and humidifying stage comprises: and after the temperature rise drying stage is finished, cooling and humidity adjustment treatment are carried out to obtain a finished product.

Further, in the step (1), the thickness of the rubber-wood is 1.0-8.5 cm.

Further, in the step (1), the weak acid solution is one of oxalic acid solution, acetic acid solution, citric acid solution or formic acid solution.

Preferably, in the step (1), the ultrasonic treatment conditions are as follows: the temperature is 40-80 ℃, the ultrasonic frequency is 25-60 KHz, the ultrasonic power is 900-1000W, and the ultrasonic time is 60-75 min.

Further, in the step (2), the pH value of the alkaline nano sodium silicate solution is 9-11, the particle size is 10-30 nm, and the modulus is 1.0-2.5.

Further explaining, in the step (2), the mass ratio of the weak acid solution to the alkaline nano sodium silicate solution is 2-5: 3 to 6.

Further, in the step (2), the ultrasonic treatment is: ultrasonic early stage: the ultrasonic power is 500-1500W, and the ultrasonic time is 30-120 min; an ultrasonic oscillation period: after the ultrasonic pretreatment, adjusting the ultrasonic power to 300-1200W, the oscillation frequency to 180-250 r/min and the ultrasonic time to 30-120 min; the ultrasonic period and the ultrasonic oscillation period are a cycle in total, and 1-12 cycles are carried out in total.

Further, in the step (4), the temperature-rising drying stage is as follows: and after the temperature is raised to 92-98 ℃ within 1-24 h, drying for 24-48 h, opening an exhaust window for exhausting once every 0.5-2.0 h during drying, continuously raising the temperature to 130-150 ℃ after drying, continuously spraying steam while raising the temperature, stopping spraying steam after raising the temperature, drying for 48-72 h, and spraying steam once every 0.5-2.0 h during drying.

Preferably, in the step (4), the temperature-rising drying stage is as follows: heating to 95 ℃ within 8h or 12h, drying for 24h or 48h, opening an exhaust window every 1.0h during drying, exhausting for 24h or 48h, continuing to heat to 140 ℃ after drying, continuously spraying steam while heating, stopping spraying steam after heating, drying for 48h or 72h, and spraying steam every 1.0h during drying.

Further, in the step (4), the temperature and humidity reducing stage comprises: and after the temperature rising and drying stage is finished, reducing the temperature to 70-80 ℃, carrying out humidity conditioning treatment when the water content of the air-dried wood is less than 12%, continuously reducing the temperature to less than 35-45 ℃, and obtaining a finished product when the water content of the air-dried wood is 8-12%.

Compared with the prior art, the invention has the beneficial effects that:

(1) the invention adopts acidification treatment, neutralization treatment, air drying treatment and high-temperature drying treatment, can realize the high-efficiency separation of starch, protein and saccharides in the rubber wood, effectively avoid the problem of mildew of the rubber wood, ensure that the treated rubber wood has uniform color and enhanced aesthetic degree, and has the advantages of low cost, simple operation and environment-friendly treatment method, thus being an ideal prevention and treatment means.

(2) The invention adopts an ultrasonic-assisted extraction method, can utilize the cavitation, mechanical action and thermal effect of ultrasonic waves, has the effects of cavitation, vibration, crushing, stirring and the like, can effectively destroy the cell walls of the rubber wood, does not change the molecular structure of functional components, and is beneficial to the permeation and the continuous action of treatment liquid; the high-temperature drying treatment can change the property and state of the substances in the cells, further improve the separation rate of the substances, maintain the uniform degree of the color of the rubber wood and enhance the aesthetic degree of the wood.

(3) The invention firstly adopts weak acid solution to treat the rubber wood, can adjust the osmotic pressure inside and outside cells, change the permeability of cell membranes, facilitate the acid and alkali treatment liquid and the subsequent steam to be immersed into the rubber wood with a multilayer organizational structure, and combine with alkaline nano sodium silicate solution, further increase the dissolution rate of substances in cells, improve the separation rate of substances such as protein, starch, saccharides and the like, and can remove components such as latex, rubber element, residual glue juice and the like in the rubber wood, and can also achieve the alkali neutralization treatment after the acid treatment of the rubber wood, realize the uniform degree of the color of the rubber wood, and play the roles of bacteriostasis and mildew resistance.

(4) The invention can realize the effect of long-acting prevention and control of the mildew of the rubber wood by means of ultrasonic treatment, air drying, high-temperature drying and the like, keeps the uniformity of the wood color, has the advantages of simple treatment method, environmental protection, low cost and the like, and is very suitable for the preparation and application of furniture and decoration materials.

Drawings

FIG. 1 is a rubber-wood treated according to example 4 of the present invention and comparative example 1, note that: comparative example 1 is on the left and example 4 is on the right.

Detailed Description

In order to better understand the technical content of the invention, specific examples are provided below to further illustrate the invention.

The experimental methods used in the examples of the present invention are all conventional methods unless otherwise specified.

The materials, reagents and the like used in the examples of the present invention can be obtained commercially without specific description.

Example 1

(1) acidifying: adding 120kg of oxalic acid solution with the mass concentration of 0.5% into rubber wood with the thickness of 1.5cm, immersing the rubber wood, and carrying out ultrasonic treatment for 30min at the temperature of 20 ℃, the ultrasonic frequency of 25KHz and the ultrasonic power of 300W to obtain acidified wood;

(2) and (3) neutralization treatment: according to the mass ratio of 3: adding 160kg of alkaline nano sodium silicate solution with the mass concentration of 10% into the acidified wood, wherein the pH value is 9, the particle size is 10nm, the modulus is 2.5, and carrying out ultrasonic treatment comprising an ultrasonic earlier stage and an ultrasonic oscillation stage, wherein the ultrasonic earlier stage comprises the following steps: the ultrasonic power is 500W, and the ultrasonic time is 30 min; an ultrasonic oscillation period: after the ultrasonic pretreatment, the ultrasonic power is adjusted to be 300W, the oscillation frequency is 180r/min, and the ultrasonic time is 30 min; the ultrasonic period and the ultrasonic oscillation period are a cycle in total, and 1 cycle in total is carried out to obtain the neutralized wood;

(3) air drying treatment: stacking the neutralized wood, air-drying, and placing for 1d to obtain air-dried wood when the water content of the neutralized wood is less than 70%;

(4) and (3) high-temperature drying treatment: comprises a heating drying stage and a cooling and humidifying stage; the temperature rising and drying stage is as follows: heating to 92 ℃ within 1h, drying for 6h, opening an exhaust window every 0.5h during drying, exhausting once, continuing to heat to 130 ℃ after drying, continuously spraying steam while heating, stopping spraying steam after heating, drying for 12h, and spraying steam every 0.5h during drying; the cooling and humidifying stage comprises: and after the temperature rise drying stage is finished, reducing the temperature to 70 ℃, carrying out humidity adjustment treatment when the water content of the air-dried wood is less than 12%, continuously reducing the temperature to less than 35 ℃, and obtaining a finished product when the water content of the air-dried wood is 8%.

Example 2

(1) acidifying: adding 120kg of oxalic acid solution with the mass concentration of 5.0% into rubber wood with the thickness of 8.5cm, immersing the rubber wood, and carrying out ultrasonic treatment for 240min by adopting the conditions that the temperature is 80 ℃, the ultrasonic frequency is 80KHz and the ultrasonic power is 5400W to obtain acidified wood;

(2) and (3) neutralization treatment: according to the mass ratio of 4: adding 150kg of alkaline nano sodium silicate solution with the mass concentration of 30% into the acidified wood, wherein the pH value is 11, the particle size is 30nm, the modulus is 1.0, and carrying out ultrasonic treatment comprising an ultrasonic earlier stage and an ultrasonic oscillation stage, wherein the ultrasonic earlier stage comprises the following steps: the ultrasonic power is 1500W, and the ultrasonic time is 120 min; an ultrasonic oscillation period: after the ultrasonic pretreatment, the ultrasonic power is adjusted to 1200W, the oscillation frequency is 250r/min, and the ultrasonic time is 120 min; the ultrasonic period and the ultrasonic oscillation period are a cycle, and 12 cycles are carried out to obtain neutralized wood;

(3) air drying treatment: stacking the neutralized wood, air-drying, and placing for 7d to obtain air-dried wood when the water content of the neutralized wood is less than 80%;

(4) and (3) high-temperature drying treatment: comprises a heating drying stage and a cooling and humidifying stage; the temperature rising and drying stage is as follows: heating to 98 ℃ within 24h, drying for 72h, opening an exhaust window every 2.0h during drying, exhausting once, continuing heating to 150 ℃ after drying, continuously spraying steam while heating, stopping spraying steam after heating, drying for 96h, and spraying steam every 2.0h during drying; the cooling and humidifying stage comprises: and after the temperature rise drying stage is finished, reducing the temperature to 80 ℃, carrying out humidity adjustment treatment when the water content of the air-dried wood is less than 12%, continuously reducing the temperature to less than 45 ℃, and obtaining a finished product when the water content of the air-dried wood is 12%.

Example 3

(1) acidifying: adding 100kg of 3% acetic acid solution into 3.5cm thick rubber wood, immersing the rubber wood, and performing ultrasonic treatment at 40 deg.C, ultrasonic frequency of 45KHz, ultrasonic power of 1000W and ultrasonic time of 60min to obtain acidified wood;

(2) and (3) neutralization treatment: according to the mass ratio of 2: adding 150kg of alkaline nano sodium silicate solution with the mass concentration of 25% into the acidified wood, wherein the pH value is 10, the particle size is 20nm, the modulus is 1.8, and carrying out ultrasonic treatment including an ultrasonic earlier stage and an ultrasonic oscillation stage, wherein the ultrasonic earlier stage is as follows: the ultrasonic power is 1000W, and the ultrasonic time is 60 min; an ultrasonic oscillation period: after the ultrasonic pretreatment, the ultrasonic power is adjusted to be 800W, the oscillation frequency is 220r/min, and the ultrasonic time is 60 min; the ultrasonic period and the ultrasonic oscillation period are a cycle in total, and 8 cycles in total are carried out to obtain neutralized wood;

(3) air drying treatment: stacking the neutralized wood, air-drying, and standing for 5d to obtain air-dried wood when the water content of the neutralized wood is less than 75%;

(4) and (3) high-temperature drying treatment: comprises a heating drying stage and a cooling and humidifying stage; the temperature rising and drying stage is as follows: heating to 95 ℃ within 8h, drying for 24h, opening an exhaust window every 1.0h during drying, exhausting once, continuing heating to 140 ℃ after drying, continuously spraying steam while heating, stopping spraying steam after heating, drying for 48h, and spraying steam every 1.0h during drying; the cooling and humidifying stage comprises: and after the temperature rise drying stage is finished, reducing the temperature to 75 ℃, carrying out humidity adjustment treatment when the water content of the air-dried wood is less than 12%, continuously reducing the temperature to less than 40 ℃, and obtaining a finished product when the water content of the air-dried wood is 10%.

Example 4

(1) acidifying: adding 100kg of oxalic acid solution with the mass concentration of 3% into rubber wood with the thickness of 3.5cm, immersing the rubber wood, and carrying out ultrasonic treatment for 75min at the temperature of 60 ℃, the ultrasonic frequency of 60KHz and the ultrasonic power of 900W to obtain acidified wood;

(2) and (3) neutralization treatment: according to the mass ratio of 2: adding 150kg of alkaline nano sodium silicate solution with the mass concentration of 20% into the acidified wood, wherein the pH value is 10, the particle size is 20nm, the modulus is 1.5, and carrying out ultrasonic treatment including an ultrasonic earlier stage and an ultrasonic oscillation stage, wherein the ultrasonic earlier stage is as follows: the ultrasonic power is 800W, and the ultrasonic time is 45 min; an ultrasonic oscillation period: after the ultrasonic pretreatment, the ultrasonic power is adjusted to be 600W, the oscillation frequency is 220r/min, and the ultrasonic time is 45 min; the ultrasonic period and the ultrasonic oscillation period are a cycle in total, and 8 cycles in total are carried out to obtain neutralized wood;

(4) and (3) high-temperature drying treatment: comprises a heating drying stage and a cooling and humidifying stage; the temperature rising and drying stage is as follows: heating to 95 ℃ within 12h, drying for 48h, opening an exhaust window every 1.0h during drying, exhausting once, continuing heating to 140 ℃ after drying, continuously spraying steam while heating, stopping spraying steam after heating, drying for 72h, and spraying steam every 1.0h during drying; the cooling and humidifying stage comprises: and after the temperature rise drying stage is finished, reducing the temperature to 75 ℃, carrying out humidity adjustment treatment when the water content of the air-dried wood is less than 12%, continuously reducing the temperature to less than 40 ℃, and obtaining a finished product when the water content of the air-dried wood is 10%.

Example 5

This example differs from example 4 in that: in the step (1), the oxalic acid solution is replaced by the citric acid solution, and the steps are as follows:

(1) acidifying: adding 150kg of citric acid solution with mass concentration of 2% into 3.5cm thick rubber wood, immersing the rubber wood, and performing ultrasonic treatment at 60 deg.C, ultrasonic frequency of 60KHz and ultrasonic power of 900W for 75min to obtain acidified wood;

(2) and (3) neutralization treatment: according to the mass ratio of 3: 5, adding 250kg of alkaline nano sodium silicate solution with the mass concentration of 15% into the acidified wood, wherein the pH value is 10, the particle size is 20nm, and the modulus is 1.5; the rest of the procedure was the same as in example 4.

Example 6

This example differs from example 4 in that: in the step (2), the ultrasonic treatment is different, namely, the ultrasonic treatment is carried out according to the mass ratio of 2: 3, adding 150kg of alkaline nano sodium silicate solution with the mass concentration of 20% into the acidified wood, wherein the pH value is 10, the particle size is 45nm, the modulus is 4.5, and carrying out ultrasonic treatment for 120min at the ultrasonic power of 600W to obtain neutralized wood; the rest of the procedure was the same as in example 4.

Comparative example 1

This comparative example differs from example 4 in that: the acidification treatment and the neutralization treatment are not carried out, and the steps are as follows:

(1) air drying treatment: stacking the rubber wood with the thickness of 3.5cm, air-drying, placing for 5d, and obtaining air-dried wood when the water content of the rubber wood is less than 75%;

(2) and (3) high-temperature drying treatment: comprises a heating drying stage and a cooling and humidifying stage; the temperature rising and drying stage is as follows: after the temperature is raised to 95 ℃ within 12 hours, drying is carried out for 120 hours, and the exhaust window is opened every 1.0 hour during the drying period to exhaust once; the cooling and humidifying stage comprises: and after the temperature rise drying stage is finished, reducing the temperature to 75 ℃, carrying out humidity adjustment treatment when the water content of the air-dried wood is less than 12%, continuously reducing the temperature to less than 40 ℃, and obtaining a finished product when the water content of the air-dried wood is 10%.

Comparative example 2

(2) and (3) high-temperature drying treatment: comprises a heating drying stage and a cooling and humidifying stage; the temperature rising and drying stage is as follows: heating to 95 ℃ within 12h, drying for 48h, opening an exhaust window every 1.0h during drying, exhausting once, continuing heating to 130 ℃ after drying, continuously spraying steam while heating, stopping spraying steam after heating, drying for 72h, and spraying steam every 1.0h during drying; the cooling and humidifying stage comprises: and after the temperature rise drying stage is finished, reducing the temperature to 75 ℃, carrying out humidity adjustment treatment when the water content of the air-dried wood is less than 12%, continuously reducing the temperature to less than 40 ℃, and obtaining a finished product when the water content of the air-dried wood is 10%.

Comparative example 3

This comparative example differs from example 4 in that: the method adopts hydrothermal treatment to replace acidification treatment and neutralization treatment, and comprises the following steps:

(1) hydrothermal treatment: adding 100kg of water into 3.5cm thick rubber wood, immersing the rubber wood, and soaking at 60 ℃ for 120min to obtain hydrothermal wood;

(2) air drying treatment: stacking the hydrothermal wood, air-drying, and standing for 5 days to obtain air-dried wood when the water content of the rubber wood is less than 75%;

(3) and (3) high-temperature drying treatment: comprises a heating drying stage and a cooling and humidifying stage; the temperature rising and drying stage is as follows: heating to 95 ℃ within 12h, drying for 48h, opening an exhaust window every 1.0h during drying, exhausting once, continuing heating to 140 ℃ after drying, continuously spraying steam while heating, stopping spraying steam after heating, drying for 72h, and spraying steam every 1.0h during drying; the cooling and humidifying stage comprises: and after the temperature rise drying stage is finished, reducing the temperature to 75 ℃, carrying out humidity adjustment treatment when the water content of the air-dried wood is less than 12%, continuously reducing the temperature to less than 40 ℃, and obtaining a finished product when the water content of the air-dried wood is 10%.

Comparative example 4

This comparative example differs from example 4 in that: the neutralization treatment and the high-temperature treatment are not carried out, and the steps are as follows:

(1) acidifying: adding 100kg of oxalic acid solution with the mass concentration of 2% into rubber wood with the thickness of 3.5cm, immersing the rubber wood, and performing immersion treatment at the temperature of 30 ℃ for 120min to obtain acidified wood;

(2) air drying treatment: stacking the acidified wood, air-drying, and standing for 5d to obtain air-dried wood when the water content of the neutralized wood is less than 75%;

(3) and (3) high-temperature drying treatment: comprises a heating drying stage and a cooling and humidifying stage; the temperature rising and drying stage is as follows: heating to 95 ℃ within 12h, drying for 48h, opening an exhaust window every 1.0h during drying, exhausting once, keeping the temperature at 95 ℃ after drying, drying for 72h, and spraying steam once every 1.0h during drying; the cooling and humidifying stage comprises: and after the temperature rise drying stage is finished, reducing the temperature to 75 ℃, carrying out humidity adjustment treatment when the water content of the air-dried wood is less than 12%, continuously reducing the temperature to less than 40 ℃, and obtaining a finished product when the water content of the air-dried wood is 10%.

Comparative example 5

This comparative example differs from example 4 in that: the ultrasonic and high-temperature treatment is not carried out, and the steps are as follows:

(1) acidifying: adding 150kg of oxalic acid solution with the mass concentration of 1.2% into rubber wood with the thickness of 3.5cm, immersing the rubber wood, and performing immersion treatment for 60min at the temperature of 30 ℃ to obtain acidified wood;

(2) and (3) neutralization treatment: according to the mass ratio of 5: adding 180kg of 25 mass percent alkaline nano sodium silicate solution into the acidified wood, wherein the pH value is 10, the particle size is 20nm, the modulus is 1.5, and performing immersion treatment for 60min to obtain neutralized wood;

(4) and (3) high-temperature drying treatment: comprises a heating drying stage and a cooling and humidifying stage; the temperature rising and drying stage is as follows: heating to 95 ℃ within 12h, drying for 48h, opening an exhaust window every 1.0h during drying, exhausting once, keeping the temperature at 95 ℃ after drying, drying for 72h, and spraying steam once every 1.0h during drying; the cooling and humidifying stage comprises: and after the temperature rise drying stage is finished, reducing the temperature to 75 ℃, carrying out humidity adjustment treatment when the water content of the air-dried wood is less than 12%, continuously reducing the temperature to less than 40 ℃, and obtaining a finished product when the water content of the air-dried wood is 10%.

Comparative example 6

This comparative example differs from example 4 in that: in the step (2), the sodium hydroxide solution is adopted to replace the alkaline nano sodium silicate solution, namely, the sodium hydroxide solution is prepared by mixing the following components in percentage by mass: 3, adding 150kg of sodium hydroxide solution with the mass concentration of 20% into the acidified wood; the rest of the procedure was the same as in example 4.

Test examples

The experimental method comprises the following steps: (1) and (3) content detection: detecting the contents of sucrose, glucose, fructose and xylose in the wood according to the determination of soluble sugar in the forestry biomass raw material analysis method (GB/T36056-2018); detecting the starch content of the wood according to starch determination of a forestry biomass raw material analysis method (GB/T35811-2018), and detecting the protein content according to protein determination of the forestry biomass raw material analysis method (GB/T35809-2018);

(2) and (3) mould experiment: according to a test method for preventing and controlling effects of the mildew preventive on wood mildew and discoloring bacteria (GB/T18261-2013), selecting Aspergillus niger, Trichoderma viride, Penicillium citrinum and Coco globisporus as test strains, and calculating the infection value of the test strains of the test samples according to a classification standard table of the surface infection values of the mildew and discoloring bacteria of the test samples;

(3) according to the Lab mode of CIE, measuring the surface colorimetric parameters of the wood before and after treatment by adopting an Alice Ci60 portable integrating sphere spectrocolorimeter, determining that 6 points are randomly taken for each parameter measurement, measuring brightness values L, chromaticity indexes a and b, averaging, and calculating brightness index difference delta L and color difference delta E, wherein the brightness index difference delta L and the color difference delta E are respectively set to be 0.00 by taking the rubber wood in comparative example 1 as a contrast, and the color difference delta E is calculated as follows:

TABLE 1 results for starch, protein, sucrose, glucose, fructose and xylose content in softwood

TABLE 2 results of the values of the infestation of rubber-wood by moulds and discoloring bacteria and of the differences in the luminous indices DeltaL and the color differences DeltaE

As can be seen from the above table, the scheme of acidification, neutralization, air drying and high-temperature quick drying treatment is scientifically adopted, so that the content of starch, protein, sucrose, glucose, fructose and xylose in the rubber wood can be remarkably reduced, the high-efficiency separation of the starch, the protein and the saccharides in the rubber wood is realized, the infection values of aspergillus niger, trichoderma viride, penicillium citrinum and cocoanut globispora can be remarkably reduced, the problem of mildew of the rubber wood is effectively avoided, and the long-acting prevention and control effect is achieved; compared with the comparative example 1, the brightness index difference delta L and the color difference delta E of the rubber wood in the examples 1 to 5 have higher values, which shows that the invention scientifically combines the treatment means of acidification, neutralization, air drying and high-temperature quick drying, can also improve the color and luster of the rubber wood, enables the treated rubber wood to have uniform color, enhances the aesthetic degree, and further improves the use value and the application of the rubber wood.

The contents of starch, protein, glucose, fructose and the like in the comparative examples 1 to 3 are high, which shows that the dissolution rate of substances in cells can be increased by adopting acid solution treatment and combining with the alkaline nano sodium silicate solution, and the separation rate of the substances such as protein, starch, sugar and the like is improved; the contents of starch, protein and the like in comparative examples 4 and 5 are higher, which shows that the properties and the states of substances in cells can be changed by ultrasonic treatment and high temperature, the separation rate of the substances is further improved, and the attractiveness of the treated rubber wood is enhanced; comparative example 6 adopts sodium hydroxide solution to carry out neutralization treatment, and four moulds have different degrees of growth and poor mildew-proof effect.

The above 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, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A treatment method for reducing the content of starch, protein and saccharide in rubber wood is characterized in that: the method comprises the following steps:

(3) air drying treatment: stacking the neutralized wood, air-drying, placing for 1-7 days, and obtaining air-dried wood when the water content of the neutralized wood is less than 70-80%;

2. The processing method according to claim 1, characterized in that: in the step (1), the thickness of the rubber wood is 1.0-8.5 cm.

3. The processing method according to claim 1, characterized in that: in the step (1), the weak acid solution is one of oxalic acid solution, acetic acid solution, citric acid solution or formic acid solution.

4. The processing method according to claim 1, characterized in that: in the step (1), the ultrasonic treatment conditions are as follows: the temperature is 40-80 ℃, the ultrasonic frequency is 25-60 KHz, the ultrasonic power is 900-1000W, and the ultrasonic time is 60-75 min.

5. The processing method according to claim 1, characterized in that: in the step (2), the pH value of the alkaline nano sodium silicate solution is 9-11, the particle size is 10-30 nm, and the modulus is 1.0-2.5.

6. The processing method according to claim 1, characterized in that: in the step (2), the mass ratio of the weak acid solution to the alkaline nano sodium silicate solution is 2-5: 3 to 6.

7. The processing method according to claim 1, characterized in that: in the step (2), the ultrasonic treatment is as follows: ultrasonic early stage: the ultrasonic power is 500-1500W, and the ultrasonic time is 30-120 min; an ultrasonic oscillation period: after the ultrasonic pretreatment, adjusting the ultrasonic power to 300-1200W, the oscillation frequency to 180-250 r/min and the ultrasonic time to 30-120 min; the ultrasonic period and the ultrasonic oscillation period are a cycle in total, and 1-12 cycles are carried out in total.

8. The processing method according to claim 1, characterized in that: in the step (4), the temperature-rising drying stage is as follows: and after the temperature is raised to 92-98 ℃ within 1-24 h, drying for 24-48 h, exhausting once every 0.5-2.0 h during drying, continuously raising the temperature to 130-150 ℃ after drying, continuously spraying steam while raising the temperature, stopping spraying steam after raising the temperature, drying for 48-72 h, and spraying steam once every 0.5-2.0 h during drying.

9. The processing method according to claim 8, characterized in that: in the step (4), the temperature-rising drying stage is as follows: heating to 95 ℃ within 8h or 12h, drying for 24h or 48h, exhausting once every 1.0h during drying, continuously heating to 140 ℃ after drying, continuously spraying steam while heating, stopping spraying steam after heating, drying for 48h or 72h, and spraying steam once every 1.0h during drying.

10. The processing method according to claim 1, characterized in that: in the step (4), the cooling and humidifying stage is as follows: and after the temperature rising and drying stage is finished, reducing the temperature to 70-80 ℃, carrying out humidity conditioning treatment when the water content of the air-dried wood is less than 12%, continuously reducing the temperature to less than 35-45 ℃, and obtaining a finished product when the water content of the air-dried wood is 8-12%.