Glued board containing modal fibers and process for producing the same

Abstract

The plywood containing modal fiber and its production process, wood is crushed into particles not more than 30 mesh; coupling agent is sprayed to the modal fiber or steam explosion treatment is adopted; the wood particles and the modal fiber are alternately laid in layers, and phenolic resin glue is sprayed after each layer is laid; the cold pressing pressure is controlled between 1.2-1.8 MPa, the pressing time is set to 12-24 hours, the pressing environment temperature is 20-25 DEG C, the humidity is 45%-55%, and vibration assistance is implemented in the pressing process; after the pressing is completed, the plywood is unloaded and taken out. The production process of the plywood containing the modal fiber provided by the application has remarkable beneficial effects, including improving the strength and stability of the board, improving the processing performance, improving the durability and weather resistance, and realizing the effective utilization of resources. These effects together make the application have broad application prospect and market competitiveness in the field of plywood production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of plywood production, specifically relates to a plywood containing modal fibers and a production process thereof. BACKGROUND

[0002] With the continuous progress of science and technology, plywood, as a widely used building material, plays an important role in many fields such as construction, furniture manufacturing, decoration, etc. However, the traditional plywood still needs to be improved in strength and stability, and the processing performance, durability and weather resistance also need to be further optimized. In order to solve these problems, we are constantly exploring new reinforcing materials in order to improve the overall performance of plywood. Among many potential reinforcing materials, modal fibers have attracted attention due to their softness and good moisture absorption. Modal fibers are a new type of fiber material made of a mixture of wood pulp fibers and cotton fibers. It not only has the softness and comfort of natural fibers, but also has the durability of synthetic fibers. In the clothing industry, modal fibers are favored for their excellent elasticity and recovery. However, the leftover materials generated during the clothing process are often considered waste, which not only wastes resources, but also increases environmental burden. The present application introduces modal fibers into the manufacture of plywood, aiming to investigate whether the reinforcing effect of fibers is suitable for plywood. At the same time, it is investigated whether the addition of modal fibers can also improve the processing performance of plywood, making it more smooth in cutting, drilling and other processing processes, reducing material loss and tool wear. In addition, whether the addition of modal fibers has an impact on the durability and weather resistance of plywood, and verifies the stability of the plywood in harsh environments. At present, the applicant finds that the application of modal fibers faces some challenges, mainly due to the relatively small cohesion between fibers, which is prone to pilling in friction, which will adversely affect the fusion of fibers and wood materials. In order to overcome this difficulty, the present application innovates in the fiber treatment process, and adopts an improved gluing technology to ensure that the modal fibers can be uniformly dispersed in the plywood and form a good combination with the wood material. This combination not only improves the overall performance of the board, but also effectively utilizes the leftover materials generated during the clothing process, realizes the recycling of resources, reduces production costs, and also contributes to environmental protection. SUMMARY

[0003] The technical problem solved by the present application is to provide a plywood containing modal fibers and a production process thereof, which successfully introduces modal fibers as reinforcing materials, significantly improves the physical properties and processing performance of the plywood, and solves the problem of waste of leftover materials in the clothing industry.

[0004] Technical solution: The production process of plywood containing modal fiber, the preparation steps are: wood material preparation: the wood is crushed into particles not more than 30 mesh, and the moisture content of the wood is controlled between 8%-12%; Modal fiber preparation: spraying coupling agent on the modal fiber or using steam explosion treatment, the amount of coupling agent is 0.1%-2.0% of the mass of modal fiber; embryo and glue coating: according to the mass ratio of wood material: modal fiber (90-70):(30-10), the wood particles and modal fiber are alternately laid in layers, and phenolic resin glue is sprayed on each layer, the amount of phenolic resin glue is 70-100Kg / m 3 ; Cold pressing treatment: the cold pressing pressure is controlled between 1.2-1.8MPa, the pressing time is set to 12-24 hours, the pressing environment temperature is 20-25℃, the humidity is 45%-55%, and vibration assistance is implemented during pressing; Pressure relief and removal: after pressing is completed, the plywood is removed after pressure relief.

[0005] Preferably, the above-mentioned coupling agent is an aluminate coupling agent.

[0006] Preferably, the above-mentioned phenolic resin glue is an LPF resin adhesive.

[0007] The above-mentioned steam explosion treatment method is: the modal fiber is crushed to 30 mesh or less, soaked with 2wt.% NaOH solution, then the modal fiber is loaded into a sealed steam explosion bin, the steam pressure is controlled at 1.0-7.0MPa, and the modal fiber is treated in high-temperature and high-pressure steam for 15-40 seconds; the pressure is completely released within 0.00875 seconds, and ethanol is used for cleaning.

[0008] Preferably, the steam pressure rises to 7.0MPa and then maintains for 4-5 seconds.

[0009] Preferably, the mass ratio of the above-mentioned wood material: modal fiber is 4:1.

[0010] Preferably, the amount of the above-mentioned LPF resin adhesive is 75Kg / m 3 .

[0011] Preferably, the initial stage of the above-mentioned cold pressing: the pressing starts at a pressure of 0.5-0.8MPa, and the duration is 20%-30% of the total pressing time; the pressure increasing stage: the pressure is increased to 1.4-1.5MPa, and the duration is 40%-50% of the total pressing time; the final pressing stage: the pressure is increased to 1.6MPa in the remaining part of the pressing time.

[0012] Preferably, the parameters of the above-mentioned cold pressing treatment are: the pressure is controlled at 1.5MPa, the pressing time is set to 18 hours, the environment temperature is controlled at 22-24℃, and the humidity is controlled at 48%-52%.

[0013] Preferably, the frequency of the above-mentioned vibration: the micro-vibration is applied in the boosting stage and the final pressure stage, the vibration frequency is controlled between 10-50 Hz; the vibration amplitude: the vibration amplitude of the micro-vibration is controlled between 0.1-0.5 mm; the vibration time: the micro-vibration is applied in the last 10-15 minutes of each pressing stage.

[0014] The plywood containing modal fibers prepared by the above production process.

[0015] Beneficial effects: First, the present application ensures the quality and stability of the base material by strictly controlling the particle size and moisture content of the wood material, laying a solid foundation for the subsequent gluing process. At the same time, the modal fibers are treated with coupling agent or steam explosion, which effectively improves the interfacial compatibility between the fibers and the wood material and the adhesive, and enhances their bonding force.

[0016] Secondly, the present application uses specific group embryos and gluing methods to layer and alternate the wood particles and modal fibers, and sprays phenolic resin adhesive on each layer. This structure not only makes the fibers and wood materials more evenly distributed, but also improves the overall strength and stability of the board. In addition, the selected LPF resin adhesive has good water resistance and weather resistance, further enhancing the durability of the plywood.

[0017] Furthermore, through the optimized cold pressing process, including precise control of pressure, time, environmental temperature and humidity, and vibration assistance during pressing, the fibers and wood particles inside the board are more closely combined, improving the compactness and mechanical properties of the board. This vibration assistance also helps to expel the bubbles and excess glue inside the board, resulting in a more uniform and high-quality plywood.

[0018] Finally, in the preferred embodiment of the present application, by fine-tuning various process parameters, such as the mass ratio of wood material to modal fiber, the amount of LPF resin adhesive, and the parameters of each stage of cold pressing, the performance of the plywood is optimized. These optimization measures not only improve production efficiency, but also reduce production costs, while ensuring the excellent performance of the plywood.

[0019] In summary, the production process of the plywood containing modal fibers provided by the present application has significant beneficial effects, including improving the strength and stability of the board, improving the processing performance, enhancing the durability and weather resistance, and effectively utilizing resources. These effects together make the present application have broad application prospects and market competitiveness in the field of plywood production. DETAILED DESCRIPTION

[0020] The content of the present application is described in more detail through the following examples.

[0021] Example 1

[0022] Wood material preparation: Wood was pulverized into 25 mesh particles, with moisture content controlled at 10 wt.%.

[0023] Modal fiber preparation: Aluminum stearate coupling agent was used for treatment, with a dosage of 0.5 wt.% of fiber mass.

[0024] Assembly and glue application: Wood material and modal fiber mass ratio was 80:20, wood particles and modal fibers were alternately layered, and phenolic resin glue was sprayed for each layer, with a dosage of 80 Kg / m 3 .

[0025] Cold pressing treatment: pressure 1.5 MPa, time 18 hours, ambient temperature 23°C, humidity 50%. Micro-vibration was applied during the pressure increase and final pressure stages, with a frequency of 30 Hz, amplitude of 0.3 mm, and time of 15 minutes at the end of each stage.

[0026] Example 2

[0027] Wood material preparation: Wood was pulverized into 25 mesh particles, with moisture content controlled at 10 wt.%.

[0028] Modal fiber preparation: Steam explosion treatment was used, and the modal fibers were pulverized to 30 mesh or less, soaked in a 2 wt.% NaOH solution, then loaded into a sealed steam explosion chamber, with a steam pressure of 5.0 MPa and a treatment time of 30 seconds, and the pressure was completely released within 0.00875 seconds, and ethanol was used for cleaning.

[0029] Assembly and glue application: Wood material and modal fiber mass ratio was 80:20, wood particles and modal fibers were alternately layered, and phenolic resin glue was sprayed for each layer, with a dosage of 80 Kg / m 3 .

[0030] Cold pressing treatment: pressure 1.5 MPa, time 18 hours, ambient temperature 23°C, humidity 50%. Micro-vibration was applied during the pressure increase and final pressure stages, with a frequency of 30 Hz, amplitude of 0.3 mm, and time of 15 minutes at the end of each stage.

[0031] Example 3

[0032] Wood material preparation: Wood was pulverized into 30 mesh particles, with moisture content controlled at 8%.

[0033] Modal fiber preparation: Aluminum stearate coupling agent was used for treatment, with a dosage of 0.5 wt.% of fiber mass.

[0034] Assembly and gluing: wood material and modal fiber mass ratio is 75:25, wood particles and modal fiber are laid alternately layer by layer, and phenolic resin glue is sprayed every time a layer is laid, the amount of phenolic resin glue is 75Kg / m 3 .

[0035] Cold pressing treatment: pressure 1.6MPa, time 20 hours, ambient temperature 22℃, humidity 48%. Micro-vibration is applied in the pressure rising and final pressure stages, frequency 30Hz, amplitude 0.3mm, time in the last 15 minutes of each stage.

[0036] Example 4

[0037] Wood material preparation: wood is crushed into 30 mesh particles, and the moisture content is controlled at 8%.

[0038] Modal fiber preparation: steam explosion treatment is adopted, the modal fiber is crushed to 30 mesh or less, soaked with 2wt.% NaOH solution, then the modal fiber is loaded into a sealed steam explosion bin, the steam pressure is 5.0MPa, the treatment time is 30 seconds, the pressure is completely released within 0.00875 seconds, and ethanol is used for cleaning.

[0039] Assembly and gluing: wood material and modal fiber mass ratio is 75:25, wood particles and modal fiber are laid alternately layer by layer, and phenolic resin glue is sprayed every time a layer is laid, the amount of phenolic resin glue is 75Kg / m 3 .

[0040] Cold pressing treatment: pressure 1.6MPa, time 20 hours, ambient temperature 22℃, humidity 48%. Micro-vibration is applied in the pressure rising and final pressure stages, frequency 30Hz, amplitude 0.3mm, time in the last 15 minutes of each stage.

[0041] Example 5

[0042] Wood material preparation: wood is crushed into 20 mesh particles, and the moisture content is controlled at 12%.

[0043] Modal fiber preparation: aluminate coupling agent treatment is adopted, the amount used is 1.0% of the mass of the fiber.

[0044] Assembly and gluing: wood material and modal fiber mass ratio is 75:25, wood particles and modal fiber are laid alternately layer by layer, and phenolic resin glue is sprayed every time a layer is laid, the amount of phenolic resin glue is 75Kg / m 3 .

[0045] Cold pressing treatment: pressure 1.8MPa, time 24 hours, ambient temperature 25℃, humidity 55%. Micro-vibration is applied in the pressure rising and final pressure stages, frequency 30Hz, amplitude 0.3mm, time in the last 15 minutes of each stage.

[0046] Performance testing steps

[0047] Measure the dimensions of each plywood sample, recording its thickness, length, and width.

[0048] Test the bending strength and elastic modulus of the plywood using a universal testing machine.

[0049] Perform water resistance tests by immersing the plywood in water and recording its water absorption and swelling rate at different time points.

[0050] Perform weather resistance tests to simulate the effects of different weather conditions on the plywood, observing changes in its surface and performance degradation.

[0051] 1. Ultraviolet exposure test:

[0052] Exposure time: 1000 hours.

[0053] Ultraviolet intensity: 70°C, 0.55 W / m 2 .

[0054] 2. Salt spray corrosion test:

[0055] Spraying time: Set the total spraying time to 240 hours.

[0056] Spraying amount: Set to 500 mL / m 2 .

[0057] Salt solution concentration: 5% NaCl solution.

[0058] 3. Thermal stability test:

[0059] High temperature condition: Set to 100°C for 48 hours.

[0060] 4. Wet heat cycle test:

[0061] High temperature and high humidity conditions: Temperature set to 60°C, humidity to 95%, each cycle duration 24 hours.

[0062] Cycle number: Perform 10 cycles.

[0063] Star rating criteria:

[0064] Appearance change:

[0065] 5 stars: No visible changes.

[0066] 4 stars: Slight color change, no cracks or deformation.

[0067] 3 stars: Moderate color change, may have slight cracks.

[0068] 2 stars: noticeable color change, slight cracking or deformation.

[0069] 1 star: severe color change, significant cracking or deformation.

[0070] Performance indicators:

[0071] Based on the changes in performance indicators before and after the experiment (such as tensile strength, compressive strength, etc.). Performance decline within 5% is 5 stars, 5-10% is 4 stars, 10-20% is 3 stars, 20-30% is 2 stars, and more than 30% is 1 star.

[0072] Overall rating:

[0073] Combining the appearance changes and performance indicators, give a comprehensive star rating. For example, both are 5 stars, the comprehensive evaluation is 5 stars, and so on.

[0074] Table 1. Comprehensive performance comparison

[0075]

[0076] Perform processing performance tests on the plywood, including cutting, drilling, etc., to evaluate the ease of processing and tool wear during processing, and perform the following tests:

[0077] I. Material preparation:

[0078] Prepare the boards made in Examples 1-5 and commercially available ordinary plywood as a control; prepare the same type of cutting blades and drill bits.

[0079] II. Cutting experiment:

[0080] Use the same cutting parameters (speed, depth, etc.) to cut all sample boards. Record the cutting time, cutting surface quality (flatness, burr, etc.) of each sample board. Measure the wear of the cutting blade after cutting.

[0081] III. Drilling experiment:

[0082] Drill all sample boards under the same drilling parameters (rotation speed, feed speed, etc.). Record the drilling time, hole quality (smoothness, hole diameter accuracy). Measure the wear of the drill bit.

[0083] IV. Material loss measurement:

[0084] During the processing, collect and record the material loss of each sample board.

[0085] V. Data recording and analysis:

[0086] Record all experimental data in Table 2. Compare and analyze the differences in processing performance of different sample boards.

[0087] Table 2. Processability comparison data

[0088]

Claims

1. A process for the production of plywood containing modal fibres, characterised in that, The preparation steps are: wood material preparation: the wood is crushed into particles not more than 30 mesh, and the moisture content of the wood is controlled between 8%-12%; modal fiber preparation: the modal fiber is treated by steam explosion, the steam explosion treatment method is: the modal fiber is crushed to 30 mesh or less, soaked with 2wt.% NaOH solution, then the modal fiber is loaded into a sealed steam explosion bin, the steam pressure is controlled at 1.0-7.0 MPa, treated in high temperature and high pressure steam for 15-40 seconds, the steam pressure is maintained for 4-5 seconds after rising to 7.0 MPa; the pressure is completely released within 0.00875 seconds, and ethanol is used for cleaning; assembly and gluing: the wood particles and modal fibers are alternately layered and laid according to the mass ratio of wood material: modal fiber 4:1, and phenolic resin glue is sprayed for each layer, the phenolic resin glue is LPF resin adhesive, and the amount of phenolic resin glue is 75Kg / m 3 ; cold pressing treatment: the cold pressing pressure is controlled at 1.5 MPa, the pressing time is set to 18 hours, the pressing environment temperature is 22-24℃, and the humidity is 48%-52%, vibration assistance is implemented during the pressing process; the initial stage of the cold pressing: the pressing starts at a pressure of 0.5-0.8 MPa, and the duration is 20%-30% of the total pressing time; the pressure increasing stage: the pressure is increased to 1.4-1.5 MPa, and the duration is 40%-50% of the total pressing time; the final pressing stage: the pressure is increased to 1.6 MPa in the remaining part of the pressing time; the vibration frequency: micro-vibration is applied in the pressure increasing stage and the final pressing stage, and the vibration frequency is controlled between 10-50 Hz; the vibration amplitude: the vibration amplitude of the micro-vibration is controlled between 0.1-0.5 mm; the vibration time: the micro-vibration is applied in the last 10-15 minutes of each pressing stage; pressure relief and removal: after the pressing is completed, the pressure is relieved and the plywood is removed.

2. Plywood comprising modal fibres produced by the production process of claim 1.

Images