Processing method of preservative and flame-retardant willow wood square

Abstract

The application discloses a kind of processing method of preservative flame-retardant willow wood square, belong to willow wood board processing technical field, after adopting magnesium nitrate and boric acid synchronous willow wood square hydrothermal reaction, magnesium borate salt is generated, can make willow wood square have certain flame-retardant effect.Further alkaliolysis and acidification, borax and magnesium hydroxide are generated in situ in willow wood square, play good flame-retardant effect;Willow wood square utilizes this in-situ borax and magnesium hydroxide generation as main flame-retardant component, has preservative effect, it is applicable to the preservative, flame-retardant, strengthening and size stability enhancement treatment of wood willow wood square material, with wood flame-retardant, preservative, size stability function, additionally have anti-hygroscopic, prevent blue change function, it is applicable to indoor willow wood structural member, flat pole, bed drawer, camp stool, table stool and so on willow wood product preservative flame-retardant treatment.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of willow processing, and particularly relates to a processing method of preservative and flame-retardant willow square. BACKGROUND

[0002] The willow wood is soft with rigidity, and the wood texture is uniform. The willow wood is often used for the floral panel of the folk building in the north. The ancient saying goes, "the willow wood is used in the north, and the camphor wood is used in the south". The willow wood is easy to dry, has good stability, but poor preservative capacity. The willow wood has good elasticity, and the wood texture is similar to that of the camphor wood, and has been widely used. At the same time, the willow wood is suitable for bending, and is used for making circle chairs in the north. The "le" for sowing seeds is seven slanting and eight rows, and the skill is very exquisite. The "nui frame" can only be made of willow wood. The willow wood is first selected for the ancient gold-inlaid cabinet and the bellows. The willow wood is used for large top boxes, large cabinets, and small food boxes. However, the willow wood is easy to catch fire, and the ancient people believe that the willow is "nine fierce". The "nine fierce" is related to the flammable nature of the willow wood, and is related to the fact that the willow wood is used as a material for drilling wood to get fire in ancient times. It is said that the scene that the medium son pushed the willow wood to meet the fire and died also reveals the association of the willow wood with the fire. The water-based transparent wood fireproof paint developed by Wang Xingang et al. can effectively block the spread of fire and heat, protect the base material from being damaged, and can also independently adjust the color, and basically does not affect the physical properties of the wood. The research of Liu Dan et al. shows that under the irradiation intensity of 50 kW / m 2 The water-based intumescent flame-retardant coating can form a dense intumescent carbon layer on the surface of the Douglas fir, isolate the Douglas fir wood from the heat source and oxygen and other combustion-supporting gases, and effectively improve the flame-retardant performance of the wood. CN201810575075.0 discloses a preparation method of flame-retardant willow wood, but the flame-retardant effect is poor. The willow wood strips cannot be frozen in 10-15 min, even if the mineral water is placed in the freezer room of the refrigerator. Moreover, in the cold regions such as the northeast, the wood will be frozen in 10-15 min at-25 DEG C, but the fact is not the case. Actually, the willow wood strips are prepared, and the preservative and flame-retardant effect is poor. The surface coated fireproof paint often cannot meet the decorative performance of the wood material in the use process, and loses the original natural appearance of the willow wood. The transparent coating can improve the defect of the decorative performance, but it is difficult to popularize and apply due to the complex preparation process, high cost and poor environmental performance. Moreover, once the surface flame-retardant coating is damaged due to the reduction of the aging resistance and durability in the use process, the flame-retardant protection function of the wood material will be lost. The wood preservative and flame-retardant is the most important in the modern willow processing industry. It is a trend to develop preservative and flame-retardant willow wood. The technical personnel in the field urgently need to develop a processing method of preservative and flame-retardant willow square to meet the existing application market and performance requirements. SUMMARY

[0003] Therefore, the application provides a processing method of preservative and flame-retardant willow square.

[0004] A processing method of preservative and flame-retardant willow wood square, comprising the following steps: first step, in-situ hydrothermal reaction: taking magnesium nitrate hexahydrate, boric acid, sodium hydroxide and water by weight parts, mixing uniformly to obtain a reaction solution, putting into a hydrothermal reaction kettle, putting the willow wood square into the reaction kettle and hydrothermal reaction at 180-200 DEG C for 18-24h, naturally reducing to room temperature, taking out, obtaining the in-situ magnesium borate-containing willow wood square; second step, putting the magnesium borate-containing willow wood square into an alkali solution tank, first heating the alkali solution to 70-80 DEG C, then opening direct steam to increase pressure, when the pressure in the tank reaches 0.03-0.05 MPa, reacting at 150-170 DEG C for 2-3h, then taking out the willow wood square; third step, acidification: stacking the willow wood square obtained in the previous step into a drying tank, sending carbon dioxide gas with a concentration of 15%-20% into the tank, keeping the pressure at 0.02-0.03 MPa, and the temperature at 60-70 DEG C, acidifying for 15-20 min, then cooling to room temperature, obtaining the preservative and flame-retardant willow wood square.

[0005] Hydrothermal process refers to a general term of chemical reactions in water, aqueous solution or steam at certain temperature and pressure.

[0006] The alkali solution reacts with the magnesium borate to generate sodium metaborate and magnesium hydroxide in-situ.

[0007] Mg2B2O5·H2O+2NaOH=2NaBO2+2Mg(OH)2

[0008] Further acidification generates borax.

[0009] 4NaBO2+CO2+10H2O=Na2B4O7·10H2O+Na2CO3;

[0010] The borax is sweet and salty and cool, can detoxify and prevent decay, and is generated in-situ in the willow wood, can fully play the role of preventing decay and insects, and solves the poor penetration of the previous coating method and immersion method. The in-situ generated magnesium hydroxide can reduce temperature, dilute the concentration of combustible material, and effectively isolate air.

[0011] Further, the first step takes 6-7 parts of magnesium nitrate hexahydrate, 3-4 parts of boric acid, 2.8-3.5 parts of sodium hydroxide and 55-60 parts of water.

[0012] Boric acid is a trace element fertilizer, and is often sprayed on leaves when applied. Magnesium nitrate is mainly used as a fertilizer for soilless culture of crops. Magnesium nitrate is extremely soluble in water. Magnesium nitrate can provide water-soluble nitrate nitrogen and water-soluble magnesium to crops, can rapidly supplement magnesium to crops, improve the content of chlorophyll in plants, and promote photosynthesis of crops. Moreover, magnesium nitrate can be completely water-soluble and can be rapidly absorbed by plants. At the same time, magnesium nitrate can be safely used for various crops, and is particularly suitable for use for crop seedlings.

[0013] Further, the second step lye is 3% to 7% sodium hydroxide solution.

[0014] Further, the second step of the immersion willow wood square and lye bath ratio is 2:5 to 7.

[0015] Further, the first step of the hydrothermal reaction willow wood square and reaction liquid bath ratio is 1:4 to 5.

[0016] Further, the willow wood is one of weeping willow or willow or dumpling willow.

[0017] Further, the first step in situ with borate salt willow wood square weight gain rate is 20% to 25%.

[0018] The beneficial effects of the present application are:

[0019] The processing method of the present application is disclosed in the processing method of the anti-corrosion and flame-retardant willow wood square. In the process of testing the moisture content of willow wood in daily production practice, the willow wood square soaked in magnesium nitrate solution can be hydrothermally reacted with boric acid, and then generate borate in situ in the wood. The weight of the willow wood increases, and the willow wood square has certain flame-retardant effect after the reaction of magnesium nitrate and boric acid, but the anti-corrosion effect is poor, and the flame-retardant performance is limited. Through further alkaline hydrolysis and acidification, borax and magnesium hydroxide are generated in situ in the willow wood square, which has good flame-retardant effect. The willow wood square uses borax and magnesium hydroxide generated in situ as the main flame-retardant component, and has anti-corrosion effect. It is suitable for the anti-corrosion, flame-retardant, strengthening and size stability enhancement treatment of willow wood square material, and has wood flame-retardant, anti-corrosion, size stability function. In addition, it has the functions of anti-hygroscopic and anti-blue, and is suitable for the anti-corrosion and flame-retardant treatment of indoor willow wood structural parts, shoulder pole, bed drawer, folding stool, table stool and other willow wood products. DETAILED DESCRIPTION Example 1

[0020] Raw materials: 60mm×80mm willow wood square material purchased from Fuyang Dongsheng Wood; boracic acid from Baili Chemical; magnesium nitrate from Taishan Chemical Plant.

[0021] By weight parts, 6.5 parts of magnesium nitrate hexahydrate, 3.5 parts of boric acid, 2.9 parts of sodium hydroxide and 557 parts of water were mixed to obtain a reaction liquid, which was put into a hydrothermal reaction kettle, and then the willow wood square was put into the reaction kettle, and the hydrothermal reaction was carried out at 189℃ for 24h, the bath ratio of hydrothermal reaction willow wood square to reaction liquid was 1:4.5, and then it was naturally cooled to room temperature 25℃, and then the in-situ boric acid magnesium salt-containing willow wood square was obtained, and the weight gain rate of willow wood square was 22%; the second step, the bath ratio of willow wood square to lye was 2:6, the boric acid magnesium salt-containing willow wood square was put into an alkali tank, the lye was 5% sodium hydroxide solution, the lye was heated to 75℃ by steam first, then the pressure was increased by direct steam, when the pressure in the tank reached 0.04MPa, the willow wood square was taken out after reaction at 160℃ for 2.5h; the third step: acidification: longitudinal empty space grid stacking method was adopted, the size of the pad strip was 20mm×20mm, the distance between the pad strips was 0.4m. The size of the stack was 2m in length, 1.7m in width and 1.4m in height, and the pad strips in each layer of the stack should be kept on the same vertical line. The pad strips at the end of the stack should be flush with the stack. The willow wood square obtained in the previous step was stacked in the LGT-Z type drying tank, and carbon dioxide gas with a concentration of 17% was sent into the tank, and the acidification reaction was carried out under the conditions of pressure maintaining 0.025MPa and temperature 65℃ for 18min, then the carbon dioxide flow rate was 5L / h, and the temperature was cooled to room temperature 25℃, and then the product was obtained.

[0022] Product performance: edge wood penetration rate ≥90%; conforms to GB8624-2012 building material combustion performance classification method B2 level, mildew resistance level 1 level; insect resistance according to GB / T29776-2013 standard test sample surface damage evaluation level conforms to 1 level (visible surface no damage), evaluation of insect damage hole conforms to A level no insect damage hole damage; antibacterial rate ≥90%, heartwood penetration depth 5mm. Example 2

[0023] Raw materials: 60mm×80mm willow wood square, purchased from Bozhou Dongyang Wood Sales Department; boric acid from Baili Chemical; agricultural grade magnesium nitrate from Shengxing Chemical.

[0024] Take 6 parts of magnesium nitrate hexahydrate, 3 parts of boric acid, 2.8 parts of sodium hydroxide and 55 parts of water by weight, mix uniformly to get the reaction liquid, put into the hydrothermal reaction kettle, then put the willow wood into the reaction kettle, put it in the hydrothermal reaction kettle at 180℃ for 24h, the bath ratio of hydrothermal reaction willow wood to reaction liquid is 1:4, naturally reduce to room temperature 30℃, get the in-situ borate salt containing willow wood, the weight gain rate of willow wood is 20%; the second step, the bath ratio of willow wood to lye is 2:5, put the borate salt containing willow wood into the alkali tank, the lye is 3% sodium hydroxide solution, first heat the lye to 70℃ with steam; then open the direct steam to increase the pressure, when the pressure in the tank reaches 0.03MPa, react at 150℃ for 2h, then take out the willow wood; the third step: acidification: put the willow wood obtained in the last step into the LGT-Z type drying tank, send 15% carbon dioxide gas into the tank, under the condition of pressure keeping 0.02MPa and temperature 60℃, acidification reaction for 15min, then cool to room temperature 30℃, get the product.

[0025] Product performance: edge material penetration rate ≥90%; in line with GB8624-2012 building material combustion performance classification method B2 level, mildew resistant grade 1; according to GB / T29776-2013 standard test, the surface damage evaluation grade of standard sample is in line with 1 level (visible surface no damage), the evaluation of insect damage hole is in line with A level, no insect damage hole damage; antibacterial rate ≥95%, heartwood penetration depth 6mm. Example 3

[0026] Raw materials: 60mm×80mm steamed bun willow wood from Yuanqing Wood Processing Factory; Fortune Chemicals magnesium nitrate; Boric acid from Baili Chemicals.

[0027] Take 6 parts of magnesium nitrate hexahydrate, 3 parts of boric acid, 2.8 parts of sodium hydroxide and 55 parts of water by weight, mix uniformly to get the reaction liquid, put into the hydrothermal reaction kettle, then put the willow wood into the reaction kettle, put it in the hydrothermal reaction kettle at 180℃ for 24h, the bath ratio of hydrothermal reaction willow wood to reaction liquid is 1:4, naturally reduce to room temperature 30℃, get the in-situ borate salt containing willow wood, the weight gain rate of willow wood is 20%; the second step, the bath ratio of willow wood to lye is 2:5, put the borate salt containing willow wood into the alkali tank, the lye is 3% sodium hydroxide solution, first heat the lye to 70℃ with steam; then open the direct steam to increase the pressure, when the pressure in the tank reaches 0.03MPa, react at 150℃ for 2h, then take out the willow wood; the third step: acidification: put the willow wood obtained in the last step into the LGT-Z type drying tank, send 15% carbon dioxide gas into the tank, under the condition of pressure keeping 0.02MPa and temperature 60℃, acidification reaction for 15min, then cool to room temperature 30℃, get the product.

[0028] Product performance: edge material penetration rate ≥ 90%; in line with GB8624-2012 building material combustion performance classification method B2 level, mildew resistant grade 1; according to GB / T29776-2013 standard test after the standard sample surface damage evaluation level in line with 1 level (visible surface no damage), the evaluation of the damage of the moth hole is in line with A level, no moth hole damage; antibacterial rate ≥ 90%, heartwood penetration depth 5mm.

[0029] Note: flame retardant performance refers to 8624-2012 building materials and products combustion performance classification; reference insect resistance GB / T29776-2013 textiles insect resistance performance test; antibacterial and mildew resistant JC / T2039-2010 antibacterial and mildew resistant wood decorative board; GB / T22102-2008 preservative wood C4B class requirements.

Claims

1. A method for processing preservative fire-retardant willow wood square, characterized by, The method comprises the following steps: The first step, in-situ hydrothermal reaction: 6-7 parts of magnesium nitrate hexahydrate, 3-4 parts of boric acid, 2.8-3.5 parts of sodium hydroxide and 55-60 parts of water are mixed to obtain a reaction solution, which is put into a hydrothermal reaction kettle, the willow wood is put into the reaction kettle and hydrothermal reaction is carried out at 180-200 ℃ for 18-24 h, and then the willow wood is naturally cooled to room temperature, taken out and obtained; the second step, the willow wood containing magnesium borate salt is put into an alkali tank, the alkali solution is heated to 70-80 ℃, then direct steam is used to increase the pressure, when the pressure in the tank reaches 0.03-0.05 MPa, the willow wood is taken out after reaction at 150-170 ℃ for 2-3 h; the third step, acidification: the willow wood obtained in the above step is stacked in a drying tank, carbon dioxide gas with a concentration of 15%-20% is sent into the tank, the pressure is kept at 0.02-0.03 MPa, and the temperature is 60-70 ℃, and then the willow wood is taken out after acidification reaction for 15-20 min, and the temperature is cooled to room temperature, thereby obtaining the preservative and flame-retardant willow wood.

2. The method of claim 1, wherein the method is characterized by: The alkali solution in the second step is a 3%-7% sodium hydroxide solution.

3. The method of claim 1, wherein the method is characterized by: The ratio of the willow wood to the alkali solution in the second step is 2:5-7.

4. The method of claim 1, wherein the method is characterized by: The ratio of the willow wood to the reaction solution in the first step is 1:4-5.

5. The method of claim 1, wherein the method is characterized by: The willow wood is one of weeping willow, willow or dumpling willow.

6. The method of claim 1, wherein the method is characterized by: The weight gain rate of the willow wood containing magnesium borate salt in the first step is 20%-25%. The willow wood is one of weeping willow, willow or dumpling willow. The weight gain rate of the willow wood containing magnesium borate salt in the first step is 20%-25%.