A processing method of Eucalyptus macrocarpa veneer bamboo particleboard

Abstract

The invention discloses a processing method of a bamboo particleboard with a veneer of Eucalyptus glomerata, which belongs to the technical field of particleboard processing. The method is as follows: (1) crushing and drying bamboo materials to obtain dried bamboo shavings, then adding a mixed glue consisting of a urea-formaldehyde resin adhesive and a purifier to perform gluing and assembling to obtain a slab; (2) pre-pressing and hot-pressing the slab to obtain a bamboo particleboard; (3) slicing and drying Eucalyptus glomerata veneer to obtain dried Eucalyptus glomerata veneer; (4) applying the mixed glue on the surface of the bamboo particleboard, then assembling the Eucalyptus glomerata veneer and the bamboo particleboard, and hot-pressing after the assembling is completed to obtain a bamboo particleboard with a veneer of Eucalyptus glomerata, thereby solving the problem of high formaldehyde content in the bamboo particleboard with a veneer of Eucalyptus glomerata.

Description

Technical Field

[0001] The invention relates to the technical field of bamboo particleboard processing, in particular to a processing method of a Eucalyptus macrocarpa veneer bamboo particleboard. Background Art

[0002] Eucalyptus cloeziana is a tall tree in the genus Eucalyptus, Myrtaceae. It is naturally distributed in Queensland, Australia, and is highly valued for cultivation, scientific research, and economic development. Due to its rapid growth, pronounced apical dominance, straight, rounded trunk, good natural pruning, and durable wood, it is an important solid timber species, widely used in mine pillars, construction, furniture, and sleepers. Due to its high hardness and yellow-brown to light reddish-brown heartwood, it is commonly known as "Australian Rosewood" in the market.

[0003] Bamboo particleboard is a man-made board material based on bamboo. It can be used for architectural decoration, furniture upholstery, bamboo crafts, train carriage panels, container panels, and automobile formwork. It boasts high utilization of bamboo resources and low manufacturing costs. With the increasing use of bamboo particleboard, the demand for its production is also growing. Using Eucalyptus globulus veneer on the surface of bamboo particleboard can improve the monotonous surface texture and color, better meeting diverse demands for bamboo particleboard.

[0004] Traditional bamboo particleboard with Eucalyptus globulus veneer is made from bamboo shavings, which are then glued, laid, and hot-pressed to create the bamboo particleboard. The Eucalyptus globulus veneer and bamboo particleboard are then assembled and hot-pressed to create the Eucalyptus globulus veneer-faced bamboo particleboard. This type of bamboo particleboard effectively improves the monotonous surface texture and color of bamboo particleboard, meeting the diverse needs of users. However, this traditional manufacturing process produces high formaldehyde emissions and unstable physical and chemical properties. This excessive formaldehyde release poses a serious health risk. This is because the iron in the bamboo particleboard interacts with lignin, generating free radicals. These free radicals combine with lignin to produce formaldehyde, leading to increased formaldehyde emissions.

[0005] Therefore, it is necessary to find a processing method for a bamboo particleboard with a veneer of Eucalyptus macrocarpa to inhibit the generation of free radicals in the bamboo particleboard and reduce the release of formaldehyde. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a method for processing a bamboo particleboard with a veneer of Eucalyptus grandiflora, and to solve the problem of high formaldehyde emission of the bamboo particleboard by improving the traditional processing method of the bamboo particleboard.

[0007] The present invention solves the above technical problems through the following technical means:

[0008] A method for processing a eucalyptus macrocarpa veneer-faced bamboo particleboard, the method comprising the following steps:

[0009] (1) crushing and drying bamboo to obtain dried bamboo shavings, and then adding a mixed glue consisting of a urea-formaldehyde resin adhesive and a scavenger to perform sizing and assembling to obtain a slab;

[0010] (2) pre-pressing and hot-pressing the slab to obtain a bamboo particleboard;

[0011] (3) slicing and drying the Eucalyptus globulus to obtain dried Eucalyptus globulus veneer;

[0012] (4) applying mixed glue on the surface of the bamboo particleboard, and then assembling the Eucalyptus radiata veneer and the bamboo particleboard. After the assembly is completed, hot pressing is performed to obtain the Eucalyptus radiata veneer veneer bamboo particleboard.

[0013] Furthermore, the specific operation of step (1) is as follows: crushing bamboo into bamboo shavings, placing the bamboo shavings into a dryer, controlling the inlet temperature of the dryer to 180-250° C. and the outlet temperature to 108-112° C., drying until the moisture content of the bamboo shavings is 1.5-2.8%, stopping drying to obtain dried bamboo shavings, and then adding mixed glue for sizing, wherein the amount of glue applied is 80-120 g of mixed glue per 1 kg of dried bamboo shavings, paving the bamboo shavings and assembling the blanks to obtain slabs.

[0014] Furthermore, the specific operation of step (2) is as follows: the slab enters the pre-pressing machine, and is pre-pressed at 80-90°C and 0.6MPa, with a pre-pressing time of 6-6.8s / mm; then the slab is sent into the press, and hot-pressed at 180-210°C and 2.7-3.5MPa, with a hot-pressing time of 6-6.8s / mm.

[0015] Furthermore, in step (3), the Eucalyptus grandiflora is sliced ​​to a thickness of 0.6 mm.

[0016] Furthermore, the moisture content of the Eucalyptus veneer after drying in step (3) is 8%-10%.

[0017] Furthermore, the operation of step (4) is: applying the mixed glue on the surface of the bamboo particle board, with the amount of glue applied being 150-200g / m 2 Then, the Eucalyptus veneer is pasted on the glue-coated bamboo particleboard with the front side facing outward, and hot pressed for 300-310s at a temperature of 110-120℃ and a pressure of 1.0-1.2MPa to obtain the Eucalyptus veneer veneer bamboo particleboard.

[0018] Furthermore, the mixed glue is obtained by mixing and stirring a urea-formaldehyde resin adhesive and a purifier in a mass ratio of 3:1 at room temperature.

[0019] Furthermore, the purifier includes the following raw materials: sodium silicate, sodium gluconate, flavonol, disodium hydrogen phosphate, potassium dihydrogen phosphate, and sorbose.

[0020] Furthermore, the ratio of each raw material of the purifier is as follows:

[0021] The mass ratio of sodium silicate, sodium gluconate, flavonol, disodium hydrogen phosphate, potassium dihydrogen phosphate and sorbose is 5: (0.6-0.8): (0.8-1): (0.3-0.4): (0.15-0.2): (1-1.2).

[0022] Furthermore, the preparation method of the purifier is:

[0023] A. Add disodium hydrogen phosphate to deionized water and stir evenly to obtain a disodium hydrogen phosphate solution. Then add potassium dihydrogen phosphate to the disodium hydrogen phosphate solution and continue stirring until completely dissolved to obtain solution A.

[0024] B. Add flavonol to a 10 wt% ethanol solution and stir until completely dissolved to obtain a flavonol solution. Then, add sodium gluconate and sorbitol. After stirring evenly, slowly add 0.1 mol / L sodium hydroxide solution to adjust the solution pH to 8-8.5. Then, add solution A, mix evenly, add sodium silicate, and stir until completely dissolved to obtain a purifier.

[0025] The scavenger prepared by the present invention can well suppress the generation of formaldehyde in particleboard, scavenger and adhesive are mixed and made into mixed glue, then particleboard and Eucalyptus globulus veneer are sizing, bamboo shavings are wrapped, and the generation of formaldehyde in particleboard can be better suppressed. Sodium silicate is added in scavenger, the scavenger made is a kind of viscous liquid, has certain adhesiveness, can offset to a certain extent the consequence that the adhesive bonding effect caused by the addition of scavenger reduces, and has good adsorption, the ferrous ion in particleboard can be adsorbed into scavenger, then coordinated with the sodium gluconate and flavonols in the scavenger by ferrous ion complexing, the ferrous ion complexed cannot be combined with lignin, and then suppresses the generation of formaldehyde. Simultaneously, the pH of scavenger is adjusted to the scope of 8-8.5, solution A is added, the pH of scavenger is protected, and free radical can be effectively suppressed within this pH range, further suppresses the generation of formaldehyde. However, since flavonols are easily oxidized under high temperature conditions of pre-pressing and hot pressing, thus losing their effect, sorbitol is added to the purifier. Sorbitol can wrap the flavonols inside its molecules to protect the flavonols from being oxidized in a high temperature environment, so that the purifier can still maintain its inhibitory effect on formaldehyde under high temperature.

[0026] At the same time, the mass ratio of adhesive to purifier needs to be maintained at 3:1 to ensure that the viscosity and usability of the adhesive are not damaged. If the purifier content is too low, the purifier will not achieve the best effect. If the adhesive content is too low, the bonding effect of the adhesive will be reduced, which will reduce the quality of the bamboo particleboard. Therefore, the mass ratio of adhesive to purifier is 3:1, which is the best choice.

[0027] Beneficial effects:

[0028] Applying Eucalyptus globulus veneer to the surface of a bamboo particleboard conserves valuable dark wood and improves the monochromatic texture of the bamboo particleboard. The veneer provides a decorative effect on the surface of the bamboo particleboard, making it more suitable for the diverse needs of interior decoration, furniture, and construction industries, increasing bamboo material utilization and product added value. Furthermore, by improving upon traditional manufacturing processes, the present invention produces a low-formaldehyde Eucalyptus globulus veneer bamboo particleboard that does not produce formaldehyde over time, thus being more beneficial to people's health. Therefore, compared to traditional bamboo particleboard, the low-formaldehyde Eucalyptus globulus veneer bamboo particleboard obtained by the present invention is more popular among the general public. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 : The Eucalyptus globulus veneer bamboo particleboard made in Example 1 of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be described in detail below with reference to specific embodiments and accompanying drawings:

[0031] Example 1: Preparation of a bamboo particleboard with veneer of Eucalyptus globulus

[0032] In this embodiment, a purifier is prepared before making the Eucalyptus macrocarpa veneer bamboo particleboard, specifically:

[0033] A. Add 0.3 g of disodium hydrogen phosphate to 10 ml of deionized water and stir evenly to obtain a disodium hydrogen phosphate solution. Then add 0.15 g of potassium dihydrogen phosphate to the disodium hydrogen phosphate solution and continue stirring until completely dissolved to obtain solution A.

[0034] B. Add 0.8 g of flavonol to 100 ml of a 10 wt% ethanol solution and stir until completely dissolved to obtain a flavonol solution. Then, add 0.6 g of sodium gluconate and 1 g of sorbitol. After stirring evenly, slowly add 0.1 mol / L sodium hydroxide solution to adjust the solution pH to 8. Then, add solution A, mix evenly, add 5 g of sodium silicate, and stir until completely dissolved to obtain a purifier.

[0035] Production method of Eucalyptus globulus veneer bamboo particleboard:

[0036] (1) Select bamboo with a moisture content of about 30% and crush it to obtain bamboo shavings, remove impurities in the raw material and shavings that are not suitable for production, then put the bamboo shavings into a dryer for drying, the inlet temperature of the dryer is controlled at 180°C, and the outlet temperature is controlled at 108°C, and dry to a moisture content of 1.5% to obtain dried bamboo shavings, then sort the dried bamboo shavings into surface shavings and core shavings, and lay them into slabs according to the absolute dry weight ratio of 1:1.2 between the surface and core shavings, mix urea-formaldehyde resin adhesive and purifier at a mass ratio of 3:1 at room temperature to obtain mixed glue and apply glue, apply 80g of mixed glue per 1kg of dried bamboo shavings, and complete assembly to obtain slabs;

[0037] (2) feeding the slab into a pre-pressing machine, pre-pressing the slab at 80° C. and 0.6 MPa for a pre-pressing time of 6 s / mm, and then feeding the slab into a press, hot pressing at 180° C. and 2.7 MPa for a hot pressing time of 6 s / mm to obtain a bamboo particleboard;

[0038] (3) selecting Eucalyptus globulus logs with a moisture content of about 30%, slicing them into 0.6 mm veneers, and then drying them to a moisture content of 8% to obtain dried Eucalyptus globulus veneers;

[0039] (4) Apply mixed glue on the surface of the bamboo particleboard with a coating amount of 150 g / m2, and then stick the Eucalyptus veneris veneer on the glue-coated bamboo particleboard with the front side facing outward, and hot press for 300 s at a temperature of 110 ° C and a pressure of 1.0 MPa to obtain the Eucalyptus veneris veneer veneer bamboo particleboard.

[0040] Example 2: Preparation of Eucalyptus globulus veneer bamboo particleboard

[0041] In this embodiment, a purifier is prepared before making the Eucalyptus macrocarpa veneer bamboo particleboard, specifically:

[0042] A. Add 0.35 g of disodium hydrogen phosphate to 10 ml of deionized water and stir evenly to obtain a disodium hydrogen phosphate solution. Then add 0.18 g of potassium dihydrogen phosphate to the disodium hydrogen phosphate solution and continue stirring until completely dissolved to obtain solution A.

[0043] B. Add 0.9 g of flavonol to 100 ml of a 10 wt% ethanol solution and stir until completely dissolved to obtain a flavonol solution. Then, add 0.7 g of sodium gluconate and 1.1 g of sorbitol. After stirring evenly, slowly add 0.1 mol / L sodium hydroxide solution to adjust the solution pH to 8.3. Then, add solution A, mix evenly, add 5 g of sodium silicate, and stir until completely dissolved to obtain a purifier.

[0044] Production method of Eucalyptus globulus veneer bamboo particleboard:

[0045] (1) Select bamboo with a moisture content of about 35% and crush it to obtain bamboo shavings, remove impurities and shavings not suitable for production in the raw materials, then put the bamboo shavings into a dryer for drying, the inlet temperature of the dryer is controlled at 210°C, and the outlet temperature is controlled at 110°C, and dry to a moisture content of 2% to obtain dried bamboo shavings, then sort the dried bamboo shavings into surface shavings and core shavings, and lay them in a paving assembly according to an absolute dry mass ratio of 1:1.2 between the surface and core shavings, mix urea-formaldehyde resin adhesive and purifier at a mass ratio of 3:1 at room temperature to obtain mixed glue and apply glue, 100g of mixed glue is applied to every 1kg of dried bamboo shavings, and assembling is completed to obtain a slab;

[0046] (2) feeding the slab into a pre-pressing machine, pre-pressing the slab at 85° C. and 0.6 MPa for a pre-pressing time of 6.4 s / mm, and then feeding the slab into a press, hot pressing at 200° C. and 3 MPa for a hot pressing time of 6.4 s / mm to obtain a bamboo particleboard;

[0047] (3) selecting Eucalyptus globulus logs with a moisture content of about 35%, slicing them into 0.6 mm veneers, and then drying them to a moisture content of 9% to obtain dried Eucalyptus globulus veneers;

[0048] (4) Apply mixed glue on the surface of bamboo particleboard with a glue amount of 180g / m 2 Then, the Eucalyptus venezia veneer was pasted on the glued bamboo particleboard with the front side facing outward, and hot pressed for 305s at a temperature of 115°C and a pressure of 1.1MPa to obtain the Eucalyptus venezia veneer veneer bamboo particleboard.

[0049] Example 3: Preparation of three veneer bamboo particleboards with Eucalyptus globulus

[0050] In this embodiment, a purifier is prepared before making the Eucalyptus macrocarpa veneer bamboo particleboard, specifically:

[0051] A. Add 0.4 g of disodium hydrogen phosphate to 10 ml of deionized water and stir evenly to obtain a disodium hydrogen phosphate solution. Then add 0.2 g of potassium dihydrogen phosphate to the disodium hydrogen phosphate solution and continue stirring until completely dissolved to obtain solution A.

[0052] B. Add 1 g of flavonol to 100 ml of a 10 wt% ethanol solution and stir until completely dissolved to obtain a flavonol solution. Then, add 0.8 g of sodium gluconate and 1.2 g of sorbitol. After stirring evenly, slowly add 0.1 mol / L sodium hydroxide solution to adjust the solution pH to 8.5. Then, add solution A, mix evenly, add 5 g of sodium silicate, and stir until completely dissolved to obtain a purifier.

[0053] Production method of Eucalyptus globulus veneer bamboo particleboard:

[0054] (1) Select bamboo with a moisture content of about 45% and crush it to obtain bamboo shavings, remove impurities in the raw material and shavings that are not suitable for production, then put the bamboo shavings into a dryer for drying, the inlet temperature of the dryer is controlled at 250°C, and the outlet temperature is controlled at 112°C, and dry to a moisture content of 2.8% to obtain dried bamboo shavings, then sort the dried bamboo shavings into surface shavings and core shavings, and lay them into slabs according to the absolute dry weight ratio of 1:1.2 between the surface and core shavings, mix urea-formaldehyde resin adhesive and purifier at a mass ratio of 3:1 at room temperature to obtain mixed glue and apply glue, 120g of mixed glue is applied to every 1kg of dried bamboo shavings, and slabs are obtained after assembly;

[0055] (2) feeding the slab into a pre-pressing machine, pre-pressing the slab at 90° C. and 0.6 MPa for a pre-pressing time of 6.8 s / mm, and then feeding the slab into a press, hot pressing at 210° C. and 3.5 MPa for a hot pressing time of 6.8 s / mm to obtain a bamboo particleboard;

[0056] (3) selecting Eucalyptus globulus logs with a moisture content of about 40%, slicing them into 0.6 mm veneers, and then drying them to a moisture content of 10% to obtain dried Eucalyptus globulus veneers;

[0057] (4 Apply mixed glue on the surface of bamboo particle board with a glue amount of 200g / m 2 Then, the Eucalyptus venezia veneer was pasted on the glued bamboo particleboard with the front side facing outward, and hot pressed for 310s at a temperature of 120°C and a pressure of 1.2MPa to obtain the Eucalyptus venezia veneer veneer bamboo particleboard.

[0058] Comparative Example 1: Production of Eucalyptus globulus veneer-faced bamboo particleboard

[0059] This comparative example is compared with Example 1. The only difference is that the preparation method of the purifier in Comparative Example 1 is different. Specifically, sodium silicate is not added during the preparation of the purifier. The specific preparation process is as follows:

[0060] A. Add 0.3 g of disodium hydrogen phosphate to 10 ml of deionized water and stir evenly to obtain a disodium hydrogen phosphate solution. Then add 0.15 g of potassium dihydrogen phosphate to the disodium hydrogen phosphate solution and continue stirring until completely dissolved to obtain solution A.

[0061] B. Add 0.8 g of flavonol to 100 ml of a 10 wt% ethanol solution and stir until completely dissolved to obtain a flavonol solution. Then, add 0.6 g of sodium gluconate and 1 g of sorbitol. After stirring evenly, slowly add 0.1 mol / L sodium hydroxide solution to adjust the solution pH to 8. Then, add solution A and mix evenly to obtain a purifier.

[0062] The method for preparing the bamboo particle board is the same as that in Example 1.

[0063] Comparative Example 2: Production of Eucalyptus globulus veneer bamboo particleboard

[0064] This comparative example is in contrast to Example 1. The only difference is that the preparation method of the purifier in Comparative Example 2 is different. Specifically, sodium gluconate is not added during the preparation of the purifier. The specific preparation process is as follows:

[0065] A. Add 0.3 g of disodium hydrogen phosphate to 10 ml of deionized water and stir evenly to obtain a disodium hydrogen phosphate solution. Then add 0.15 g of potassium dihydrogen phosphate to the disodium hydrogen phosphate solution and continue stirring until completely dissolved to obtain solution A.

[0066] B. Add 0.8 g of flavonol to 100 ml of a 10 wt% ethanol solution and stir until completely dissolved to obtain a flavonol solution. Then, add 1 g of sorbitol and stir until evenly mixed. Slowly add 0.1 mol / L sodium hydroxide solution to adjust the solution pH to 8. Then, add solution A and mix evenly. Then, add 5 g of sodium silicate and stir until completely dissolved to obtain a purifying agent.

[0067] The method for preparing the bamboo particle board is the same as that in Example 1.

[0068] Comparative Example 3: Production of Eucalyptus globulus veneer bamboo particleboard

[0069] This comparative example is compared with Example 1. The only difference is that the preparation method of the purifier in Comparative Example 3 is different. Specifically, no flavonol is added during the preparation of the purifier. The specific preparation process is as follows:

[0070] A. Add 0.3 g of disodium hydrogen phosphate to 10 ml of deionized water and stir evenly to obtain a disodium hydrogen phosphate solution. Then add 0.15 g of potassium dihydrogen phosphate to the disodium hydrogen phosphate solution and continue stirring until completely dissolved to obtain solution A.

[0071] B. 0.6 g of sodium gluconate was added to 100 ml of a 10 wt% ethanol solution and stirred until completely dissolved to obtain a sodium gluconate solution. 1 g of sorbitol was then added and stirred until uniformly dissolved. 0.1 mol / L sodium hydroxide solution was slowly added to adjust the solution pH to 8. Solution A was then added and mixed uniformly. 5 g of sodium silicate was added and stirred until completely dissolved to obtain a purifying agent.

[0072] The method for preparing the bamboo particle board is the same as that in Example 1.

[0073] Comparative Example 4: Production of Eucalyptus globulus veneer bamboo particleboard

[0074] This comparative example is compared with Example 1. The only difference is that the preparation method of the purifier in Comparative Example 4 is different. Specifically, solution A, i.e., the solution prepared with potassium dihydrogen phosphate and disodium hydrogen phosphate, is not added during the preparation of the purifier. The specific preparation process is as follows:

[0075] A. Add 0.8 g of flavonol to 100 ml of a 10 wt% ethanol solution and stir until completely dissolved to obtain a flavonol solution. Then, add 0.6 g of sodium gluconate and 1 g of sorbitol. After stirring evenly, slowly add 0.1 mol / L sodium hydroxide solution to adjust the solution pH to 8. Then, add 5 g of sodium silicate and stir until completely dissolved to obtain a purifying agent.

[0076] The method for preparing the bamboo particle board is the same as that in Example 1.

[0077] Comparative Example 5: Production of Eucalyptus globulus veneer bamboo particleboard

[0078] This comparative example is in contrast to Example 1. The only difference is that the preparation method of the purifier in Comparative Example 5 is different. Specifically, sorbitol is not added during the preparation of the purifier. The specific preparation process is as follows:

[0079] A. Add 0.3 g of disodium hydrogen phosphate to 10 ml of deionized water and stir evenly to obtain a disodium hydrogen phosphate solution. Then add 0.15 g of potassium dihydrogen phosphate to the disodium hydrogen phosphate solution and continue stirring until completely dissolved to obtain solution A.

[0080] B. Add 0.8 g of flavonol to 100 ml of a 10 wt% ethanol solution and stir until completely dissolved to obtain a flavonol solution. Then, add 0.6 g of sodium gluconate and stir until evenly mixed. Slowly add 0.1 mol / L sodium hydroxide solution to adjust the solution pH to 8. Then, add solution A and mix evenly. Then, add 5 g of sodium silicate and stir until completely dissolved to obtain a purifying agent.

[0081] The method for preparing the bamboo particle board is the same as that in Example 1.

[0082] Comparative Example 6: Production of Eucalyptus globulus veneer bamboo particleboard

[0083] This comparative example is in contrast to Example 1. The only difference is that the preparation method of the purifier in Comparative Example 6 is different. Specifically, the pH is not adjusted to 8-8.5 during the preparation of the purifier. The specific preparation process is as follows:

[0084] A. Add 0.3 g of disodium hydrogen phosphate to 10 ml of deionized water and stir evenly to obtain a disodium hydrogen phosphate solution. Then add 0.15 g of potassium dihydrogen phosphate to the disodium hydrogen phosphate solution and continue stirring until completely dissolved to obtain solution A.

[0085] B. Add 0.8 g of flavonol to 100 ml of a 10 wt% ethanol solution and stir until completely dissolved to obtain a flavonol solution. Then, add 0.6 g of sodium gluconate and 1 g of sorbitol, followed by solution A. After mixing well, add 5 g of sodium silicate and stir until completely dissolved to obtain a purifying agent.

[0086] The method for preparing the bamboo particle board is the same as that in Example 1.

[0087] Comparative Example 7: Production of Eucalyptus globulus veneer bamboo particleboard

[0088] This comparative example is in contrast to Example 1, and the only difference is the processing method of the bamboo particle board. Specifically, the mixing glue amount of the bamboo shavings is 1:1. The specific bamboo shavings production process is as follows:

[0089] (1) Select bamboo with a moisture content of about 30% and crush it to obtain bamboo shavings, remove impurities in the raw material and shavings that are not suitable for production, then put the bamboo shavings into a dryer for drying, the inlet temperature of the dryer is controlled at 180°C, and the outlet temperature is controlled at 108°C, and dry to a moisture content of 1.5% to obtain dried bamboo shavings, then sort the dried bamboo shavings into surface shavings and core shavings, and lay them into slabs according to the absolute dry weight ratio of 1:1.2 between the surface and core shavings, mix urea-formaldehyde resin adhesive and purifier at a mass ratio of 1:1 at room temperature to obtain mixed glue and apply glue, 80g of mixed glue is applied per 1kg of dried bamboo shavings, and assembling is completed to obtain slabs;

[0090] (2) feeding the slab into a pre-pressing machine, pre-pressing the slab at 80° C. and 0.6 MPa for a pre-pressing time of 6 s / mm, and then feeding the slab into a press, hot pressing at 180° C. and 2.7 MPa for a hot pressing time of 6 s / mm to obtain a bamboo particleboard;

[0091] (3) selecting Eucalyptus globulus logs with a moisture content of about 30%, slicing them into 0.6 mm veneers, and then drying them to a moisture content of 8% to obtain dried Eucalyptus globulus veneers;

[0092] (4) Apply mixed glue on the surface of bamboo particleboard with a glue amount of 150g / m 2 Then, the Eucalyptus venezia veneer was pasted on the glued bamboo particleboard with the front side facing outward, and hot pressed for 300s at a temperature of 110°C and a pressure of 1.0 MPa to obtain the Eucalyptus venezia veneer veneer bamboo particleboard.

[0093] The purifier used in this comparative example is the same as that in Example 1.

[0094] Comparative Example 8: Production of Eucalyptus globulus veneer-faced bamboo particleboard

[0095] This comparative example is in contrast to Example 1, and the only difference is the processing method of the bamboo particle board. Specifically, the ratio of the mixed glue of the bamboo shavings to the mixed glue is 5:1. The specific bamboo shavings production process is as follows:

[0096] (1) Select bamboo with a moisture content of about 30% and crush it to obtain bamboo shavings, remove impurities in the raw material and shavings that are not suitable for production, then put the bamboo shavings into a dryer for drying, the inlet temperature of the dryer is controlled at 180°C, and the outlet temperature is controlled at 108°C, and dry to a moisture content of 1.5% to obtain dried bamboo shavings, then sort the dried bamboo shavings into surface shavings and core shavings, and lay them into slabs according to the absolute dry weight ratio of 1:1.2 between the surface and core shavings, mix urea-formaldehyde resin adhesive and purifier at a mass ratio of 5:1 at room temperature to obtain mixed glue and apply glue, 80g of mixed glue is applied to every 1kg of dried bamboo shavings, and assemble to obtain slabs;

[0097] (2) feeding the slab into a pre-pressing machine, pre-pressing the slab at 80° C. and 0.6 MPa for a pre-pressing time of 6 s / mm, and then feeding the slab into a press, hot pressing at 180° C. and 2.7 MPa for a hot pressing time of 6 s / mm to obtain a bamboo particleboard;

[0098] (3) selecting Eucalyptus globulus logs with a moisture content of about 30%, slicing them into 0.6 mm veneers, and then drying them to a moisture content of 8% to obtain dried Eucalyptus globulus veneers;

[0099] (4) Apply mixed glue on the surface of bamboo particleboard with a glue amount of 150g / m 2 Then, the Eucalyptus venezia veneer was pasted on the glued bamboo particleboard with the front side facing outward, and hot pressed for 300s at a temperature of 110°C and a pressure of 1.0 MPa to obtain the Eucalyptus venezia veneer veneer bamboo particleboard.

[0100] The purifier used in this comparative example is the same as that in Example 1.

[0101] Blank control: production of bamboo particleboard with Eucalyptus globulus veneer

[0102] This comparative example is in contrast to Example 1, the only difference being that no purifier is used in the processing method of the bamboo particle board. The specific processing method of the bamboo particle board is as follows:

[0103] (1) Select bamboo with a moisture content of about 30% and crush it to obtain bamboo shavings, remove impurities and shavings not suitable for production in the raw materials, and then put the bamboo shavings into a dryer for drying. The inlet temperature of the dryer is controlled at 180° C., and the outlet temperature is controlled at 108° C., and dried to a moisture content of 1.5% to obtain dried bamboo shavings. Then, the dried bamboo shavings are sorted into surface shavings and core shavings, and the surface and core shavings are laid and assembled according to an absolute dry mass ratio of 1:1.2. Urea-formaldehyde resin adhesive is added for gluing. 80 g of glue is applied per 1 kg of dried bamboo shavings. After assembly, a slab is obtained;

[0104] (2) feeding the slab into a pre-pressing machine, pre-pressing the slab at 80° C. and 0.6 MPa for a pre-pressing time of 6 s / mm, and then feeding the slab into a press, hot pressing at 180° C. and 2.7 MPa for a hot pressing time of 6 s / mm to obtain a bamboo particleboard;

[0105] (3) selecting Eucalyptus globulus logs with a moisture content of about 30%, slicing them into 0.6 mm veneers, and then drying them to a moisture content of 8% to obtain dried Eucalyptus globulus veneers;

[0106] (4) Apply urea-formaldehyde resin adhesive on the surface of bamboo particleboard with a coating amount of 150g / m 2 Then, the Eucalyptus venezia veneer was pasted on the glued bamboo particleboard with the front side facing outward, and hot pressed for 300s at a temperature of 110°C and a pressure of 1.0 MPa to obtain the Eucalyptus venezia veneer veneer bamboo particleboard.

[0107] Formaldehyde emission and performance tests were performed on the Eucalyptus globulus veneer-faced bamboo particleboards prepared in Example 1 and Comparative Examples 1-8. The test methods are shown in Table 1, and the test results are shown in Table 2.

[0108] Table 1

[0109]

[0110]

[0111] Table 2

[0112]

[0113] From the analysis of Table 2, we can see that:

[0114] 1. Blank control Compared with Example 1, no purifier was used during the production process of the Eucalyptus globulus veneer bamboo particleboard. The prepared Eucalyptus globulus veneer bamboo particleboard had a high formaldehyde emission, and the formaldehyde emission after one month was high, indicating poor quality. This is because the purifier can inhibit the interaction between the iron element and lignin in the bamboo particleboard, reduce the generation of free radicals, and then inhibit the generation of methanol, reducing the emission of formaldehyde.

[0115] 2, Comparative Example 1 compared with Example 1, in the process of preparation scavenging agent, do not add sodium silicate, the large inflorescence eucalyptus veneer bamboo particleboard formaldehyde emission of its preparation is higher, and the formaldehyde emission after one month is higher, and static bending strength is lower, and elastic modulus is lower, and quality is poor.This is because sodium silicate has certain cohesiveness, can offset to a certain extent the consequence that the adhesive bonding effect caused by the adding of scavenging agent reduces, can improve static bending strength and the elastic modulus of bamboo particleboard.Simultaneously, sodium silicate also has good adsorption, can adsorb the ferrous ion in the bamboo particleboard, and then suppresses the generation of formaldehyde in the bamboo particleboard.

[0116] 3. Comparative Example 2, which did not add sodium gluconate compared to Example 1, and Comparative Example 3, which did not add flavonols compared to the example, produced high formaldehyde emissions from the Eucalyptus globulus veneer-faced bamboo particleboard. Even after one month, the formaldehyde emissions were high, indicating poor quality. This is because sodium gluconate and flavonols synergistically complex ferrous ions, preventing the complexed ferrous ions from binding to lignin and thereby inhibiting formaldehyde production.

[0117] 4. Comparative Example 4, compared to Example 1, omitted Solution A (i.e., disodium hydrogen phosphate and potassium dihydrogen phosphate). Comparative Example 6, compared to Example 1, did not adjust the pH to 8-8.5 during the preparation of the purifier. The resulting Eucalyptus globulus veneer-faced bamboo particleboards exhibited high formaldehyde emissions, particularly after one month. This is because stabilizing the purifier's pH to 8-8.5 effectively inhibits the generation of free radicals, and thus the release of formaldehyde.

[0118] 5. Comparative Example 6, in which no sorbitol was added compared to Example 1, produced a high formaldehyde emission from the Eucalyptus grandiflora veneer-faced bamboo particleboard. Even after one month, the high formaldehyde emission level indicated poor quality. This is because flavonols are susceptible to oxidation at high temperatures, and sorbitol can encapsulate and protect the flavonols, maintaining their activity at high temperatures and thus enhancing the purifier's ability to inhibit formaldehyde at high temperatures.

[0119] 6. Comparative Example 7 was mixed at a mass ratio of 1:1 according to urea-formaldehyde resin adhesive and scavenger during gluing. The static bending strength and elastic modulus of the prepared particleboard were significantly reduced. This was because the urea-formaldehyde resin adhesive was too little, and the scavenger destroyed the cohesive force of the adhesive, resulting in insufficient bonding to the bamboo shavings. The compression resistance of the bamboo particleboard deteriorated, and quality significantly decreased. Comparative Example 8 was mixed at a mass ratio of 5:1 according to urea-formaldehyde resin adhesive and scavenger during gluing. Formaldehyde emission and the formaldehyde emission after one month significantly increased. This was because the amount of scavenger was too little, resulting in the incomplete suppression of the scavenger on the production of formaldehyde to the bamboo shavings, resulting in a large amount of formaldehyde release. Therefore, a mass ratio of 3:1 to scavenger was the best choice for suppressing the production of formaldehyde in bamboo particleboard.

[0120] The above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art will appreciate that the technical solutions of the present invention may be modified or replaced with equivalents without departing from the spirit and scope of the technical solutions of the present invention, and such modifications or equivalents shall be encompassed by the claims of the present invention. Any techniques, shapes, and structures not described in detail herein are well known.

Claims

1. A method for processing a eucalyptus globulus veneer bamboo particleboard, characterized in that: The method comprises the following steps: (1) crushing and drying the bamboo material to obtain dried bamboo shavings, and then adding a mixed glue consisting of a urea-formaldehyde resin adhesive and a purifier to perform sizing and assembling to obtain a slab; (2) pre-pressing and hot-pressing the slab to obtain bamboo particleboard; (3) slicing and drying the Eucalyptus globulus to obtain dried Eucalyptus globulus veneer; (4) applying a mixed glue on the surface of the bamboo particleboard, and then assembling the Eucalyptus veneer and the bamboo particleboard, and hot pressing after the assembly is completed to obtain the Eucalyptus veneer veneer bamboo particleboard; The purifier comprises the following raw materials: sodium silicate, sodium gluconate, flavonol, disodium hydrogen phosphate, potassium dihydrogen phosphate and sorbose.

2. The method for processing a Eucalyptus macrocarpa veneer bamboo particleboard according to claim 1, characterized in that: The specific operation of step (1) is as follows: crushing bamboo into bamboo shavings, placing the bamboo shavings into a dryer, controlling the inlet temperature of the dryer to be 180-250°C and the outlet temperature to be 108-112°C, drying until the moisture content of the bamboo shavings is 1.5-2.8%, stopping drying to obtain dried bamboo shavings, and then adding mixed glue for sizing, the amount of sizing being 80-120g of mixed glue per 1kg of dried bamboo shavings, paving the bamboo shavings and assembling them into blanks to obtain slabs.

3. The method for processing a Eucalyptus macrocarpa veneer bamboo particleboard according to claim 2, characterized in that: The specific operation of step (2) is as follows: the slab enters the pre-pressing machine, and is pre-pressed at 80-90°C and 0.6 MPa for a pre-pressing time of 6-6.8 s / mm; then the slab is sent to the press and hot-pressed at 180-210°C and 2.7-3.5 MPa for a hot-pressing time of 6-6.8 s / mm.

4. The method for processing a Eucalyptus macrocarpa veneer bamboo particleboard according to claim 3, characterized in that: In the step (3), the Eucalyptus globulus is sliced ​​to a thickness of 0.6 mm.

5. The method for processing a Eucalyptus macrocarpa veneer bamboo particleboard according to claim 4, characterized in that: The moisture content of the Eucalyptus veneer dried in step (3) is 30-40%.

6. The method for processing the Eucalyptus macrocarpa veneer bamboo particleboard according to claim 5, characterized in that: The operation of step (4) is: apply mixed glue on the surface of the bamboo particle board, with the amount of glue applied being 150-200g / m 2 Then, the Eucalyptus veneer is pasted on the glue-coated bamboo particleboard with the front side facing outward, and hot pressed for 300-310s at a temperature of 110-120℃ and a pressure of 1.0-1.2MPa to obtain the Eucalyptus veneer veneer bamboo particleboard.

7. The method for processing a Eucalyptus macrocarpa veneer-faced bamboo particleboard according to claim 6, characterized in that: The mixed glue is obtained by mixing and stirring a urea-formaldehyde resin adhesive and a purifier at a mass ratio of 3:1 at room temperature.

8. The method for processing the Eucalyptus macrocarpa veneer-faced bamboo particleboard according to claim 7, characterized in that: The ratio of each raw material of the purifying agent is as follows: The mass ratio of sodium silicate, sodium gluconate, flavonols, disodium hydrogen phosphate, potassium dihydrogen phosphate, and sorbitol is 5: (0.6-0.8): (0.8-1): (0.3-0.4): (0.15-0.2): (1-1.2).

9. The method for processing the Eucalyptus macrocarpa veneer bamboo particleboard according to claim 8, characterized in that: The preparation method of the purifier is: A. Add disodium hydrogen phosphate to deionized water and stir to obtain a disodium hydrogen phosphate solution. Then, add potassium dihydrogen phosphate to the disodium hydrogen phosphate solution and continue stirring until completely dissolved to obtain Solution A. B. Add flavonol to a 10wt% ethanol solution and stir until completely dissolved to obtain a flavonol solution. Then, add sodium gluconate and sorbitol. Stir thoroughly, then slowly add 0.1mol / L sodium hydroxide solution to adjust the pH of the solution to 8-8.

5. Then, add solution A and mix thoroughly. Then, add sodium silicate and stir until completely dissolved to obtain a purifying agent.

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