CN116460948A - Full-loose ultrathin large-flaking oriented strand board and manufacturing method thereof - Google Patents

Abstract

The invention belongs to the technical field of artificial boards, and particularly discloses a full-loose ultrathin large-flaked oriented strand board and a manufacturing method thereof. The full-loose ultrathin large-flaking oriented strand board is prepared from masson pine and Chinese juniper, overcomes the performance defects of the raw wood by degreasing pretreatment to a specific degree, combines the improvement of the existing flaking rotary cutting equipment, optimizes the process treatment operation, and prepares the brand-new full-loose ultrathin large-flaking oriented strand board with the characteristics of low density, light weight, smooth and non-rough surface, no bubbling, low bursting rate, higher mechanical property and the like. The manufacturing method of the full-loose ultrathin large-flaking oriented strand board reduces the production cost, improves the qualification rate of the ultrathin large flaking, overcomes the problem of uneven surface of the existing strand board, also overcomes the defect of poor tackiness and improves the waterproofness. The advantages of the original wood are fully utilized, and meanwhile, the defects of the original wood are avoided through improvement and addition of the process.

Description

Full-loose ultrathin large-flaking oriented strand board and manufacturing method thereof

Technical Field

The invention belongs to the technical field of artificial boards, and particularly relates to a full-loose ultrathin large-flaking oriented strand board and a manufacturing method thereof.

Background

Oriented Strand Board (OSB) is one of new varieties of strand boards, and is a three-layer structure consisting of upper and lower surface layer large strands longitudinally arranged and core layer strands transversely arranged, and the strands of the strand boards are required to have a shape with a larger aspect ratio and a thickness slightly thicker than those of common strand boards. The oriented strand board is an artificial engineering structural board which is manufactured by peeling small-diameter log, cutting the log into slices with a certain geometric shape along the grain direction (the length is 40-140 mm, the width is 5-20 mm and the thickness is 0.40-0.60 mm generally), drying, applying synthetic resin glue and waterproofing agent, simulating the fiber arrangement direction of natural wood, paving the log into a board blank in an oriented manner, and pressing the board at high temperature.

The upper and lower layers of the oriented strand board are symmetrical to the middle surface of the core layer, the surface shavings are longitudinally arranged, and the core layer shavings are transversely arranged; the oriented strand board is paved in an oriented manner, so that the oriented strand board has the characteristic of higher strength in a certain direction, and is often used as a structural material instead of plywood.

The oriented strand board is produced with small diameter standard material, the surface and core layer strands are in the same shape and size, and the oriented pavement is adopted, the core layer strands are transversely arranged, the surface layer strands are longitudinally arranged, and the surface and core layer strands form certain oriented included angles, so that the oriented strand board has the same mechanical properties in all directions. However, such oriented strand board has certain limitations, such as in the aspect of raw material preparation, because the oriented strand board has larger wood shaving size requirements, the required log diameter cannot be too small, and generally needs to be more than 150mm, and wood shavings are prepared after peeling; therefore, the raw material purchasing is limited to a certain extent, the price is higher than that of a common small-diameter material, and the cost of raw material purchasing is increased, so that the cost of the plate is higher.

Therefore, researchers optimize the core shaving materials, and prepare the core shaving through materials such as small-diameter materials, branch materials, waste veneers, sawn edge materials and the like, so that the production cost is reduced, and the utilization rate of wood materials is improved. For example, the report that the surface layer is an ultrathin large-sized shaving oriented strand board and the preparation process thereof adopts the following technical scheme: the method has the advantages that the center layer and the subsurface layer are used for preparing large shavings by adopting rotary-cut veneer offcuts, branches, board skins and the like as raw materials, the surface layer is used for preparing ultrathin large shavings by adopting small-diameter-grade specification materials as raw materials, and the cost is lower than that of the ordinary oriented strand boards. According to the technical scheme, raw material resources can be fully utilized by means of rotary-cut single board offcuts, branches, board skins and the like, but the materials are messy, so that the mechanical property and appearance quality of the boards are greatly reduced, the value of the products is reduced, low-added-value products are easy to appear by using the scheme, the oriented strand board market is disordered, homogenization is serious, and the development of the oriented strand board market is seriously hindered.

Meanwhile, as the surface wood shavings have larger size and little difference with the core wood shavings, the manufactured panel is uneven, for example, the panel is used for indoor decoration or furniture manufacturing, and finishing decoration, such as sanding, double-sided pasting of veneers with certain thickness and the like, can be performed after secondary processing surface treatment is performed, so that the later processing cost is increased, the processing procedure is increased, and the application range of the panel is limited to a certain extent.

In addition, the existing oriented strand board is not provided with an ultrathin large-sized shaving board, because the following technical problems cannot be solved: (1) The mechanical properties of the existing oriented strand board cannot be improved simultaneously: the elastic modulus and the internal bonding strength are low; (2) the strength must be increased on the premise of increasing the density; (3) uneven surface, easy bubbling and bursting.

Accordingly, there is a need for improved optimization of oriented strand board to provide a new oriented strand board that addresses several of the problems associated with existing oriented strand boards described above.

Disclosure of Invention

Based on the defects of the prior art, the inventor provides a brand new full-loose ultrathin large-flaked oriented strand board and a manufacturing method thereof on the basis of long-term research on the oriented strand board. The full-pine ultrathin large-flaking oriented strand board is prepared from masson pine and Chinese juniper equal-speed raw wood, overcomes the performance defects of the raw wood through performance improvement, and combines specific technological treatment operation to prepare the brand-new full-pine ultrathin large-flaking oriented strand board with the characteristics of low density, light weight, smooth and non-rough surface, no bubbling, low bursting rate, higher mechanical property and the like.

The invention adopts the following technical scheme:

an all-loose ultrathin large-flaked oriented strand board is formed by incomplete degreasing, sizing, functional components, oriented pavement and hot pressing of ultrathin large flakes; wherein, ultra-thin big flaking divide into ultra-thin big flaking in top layer and ultra-thin big flaking in sandwich layer, and the ultra-thin big flaking in top layer's size is: the core layer ultra-thin large flaking size is 80 mm-140 mm long, 20 mm-30 mm wide and 0.3 mm-0.5 mm thick: the raw wood sources of the two raw materials are small-diameter full loose fast-growing wood, wherein the length is 60 mm-80 mm, the width is 20 mm-30 mm, and the thickness is 0.3 mm-0.5 mm; the oil area of the surface layer of the ultrathin large flaking is 10% -20% after incomplete degreasing, namely, the degreasing area accounts for 80% -90% of the whole flaking.

The full-bulk wood may be selected from, for example, masson pine, tamarind pine, etc.

The functional components include conventional functional agents in the art, such as waterproofing agents and/or curing agents.

On one hand, single tree species materials of all pine tree species are used, so that the mixed use of different tree species is avoided, and the problems of deformation, warping, bubbling and the like of an oriented strand board can be solved. On the other hand, the production cycle of the fast-growing wood is short, the yield is high, the material cost is lower, and the problems of raw material purchase limitation and high cost caused by larger log diameter grade corresponding to the oriented strand board are solved; and the shorter production period of the fast-growing wood can lead to lower hardness of the texture, so that ultra-thin large-sized shavings are easier to obtain when the shavings are processed, and excessive shavings fragments are prevented from being doped in the wood.

In addition, the Quan Songsu raw wood generally contains rich grease, and the obtained wood shavings have the characteristics of moisture resistance, oxidation resistance, rosin taste and the like, can be stored for a long time in a dry state, and are suitable for large-scale continuous production.

The ultrathin large flaking with the size has higher toughness and elastic modulus performance, and can ensure that the obtained flakeboard has excellent mechanical properties.

The full-loose ultrathin large-flaked oriented strand board is manufactured by adopting the following process:

s1, preparing ultrathin large flakes:

peeling and rotary cutting the full loose-speed raw wood to obtain ultrathin large flaking with the length of 60 mm-140 mm, the width of 20 mm-30 mm and the thickness of 0.3 mm-0.5 mm.

When rotary cutting equipment is adopted for rotary cutting, the rotary cutting process is improved, the number of the rotary cutting blades is increased to 2, and the angle of the cutting edge of the rotary cutting blade is adjusted to be smaller and longer; specifically, the blade angle (i.e., the cut angle between the rotary cutting blade and the log material) is controlled to be less than 25 ° to obtain an ultra-thin large flake conforming to the above specific thickness; the length of the blade is controlled to be more than 2cm so as to prolong the service life of the rotary cutting blade.

The manufacturing method of the invention is realized by adopting new and improved rotary cutting equipment, and compared with common rotary cutting equipment, one rotary cutting blade is added, namely two rotary cutting blades are arranged. The newly added rotary cutting blades are arranged below the log material, and the included angle of the two rotary cutting blades is 30-45 degrees. By controlling the positions of the two rotary cutting blades and the angle and the length of the cutting edges of the two rotary cutting blades, not only the rotary-cut flaking is taken away by the conveyor belt in time, but also the height difference between the cutting edges and the cross beam determines the thickness of the prepared flaking, so that the flaking can be ultrathin; the matched use of the two rotary cutting blades can greatly improve the rotary cutting efficiency, namely, the raw wood can be rotated for one circle to prepare two flaking, and under the condition of the same rotation angle speed, the improved technology can be used for increasing the output by 1 time. Meanwhile, the improvement of the rotary cutting process is also particularly suitable for efficiently preparing large flaking from small-diameter materials such as masson pine, talon pine and the like, and is due to the following steps: the existing rotary cutting equipment is single-blade, only one circle of wood chip can be cut by rotating, a certain gap is needed between the blade and the rotating shaft to extrude and store logs, when the wood core is cut by rotary cutting, the wood core with smaller diameter is insufficient for rotary cutting and is discharged. Therefore, compared with the existing single-blade rotary cutting equipment, the method can maximally improve the flaking production rate of the small-diameter material.

Preferably, the depth of the cutter ring is increased to more than 8mm, so that two shavings can be produced at the same time, shavings with the same length can be stably produced, and the working efficiency is greatly improved. This is due to: in rotary cutting equipment, the fixed knife ring is tangent with the rotary log under normal condition, and the rotary cutting of log is in the flaking through cutting edge and friction rotation mode, but long-time friction and different log materials lead to the cutting edge wearing and tearing on the knife ring, and ordinary knife ring needs to be changed a new knife ring basically for about 6 hours, needs the manual work to waste time and energy to change. The invention preferably increases the depth of the cutter ring, namely the thickness of the cutter blade to more than 8mm, increases the inclination of the cutter blade (namely the length of the cutter blade), increases the tangent part of the cutter blade with log to more than 2cm, and the cutter blade with larger inclination and larger thickness can perform rotary cutting work for a long time, thereby greatly prolonging the continuous working time and improving the working efficiency.

Through the improvement, the ultrathin large flaking with stable size can be obtained, the proportion of the ultrathin large flaking meeting the required size is ensured to reach more than 90%, and the stable large-scale production requirement can be met. The improvement of the rotary cutting process effectively solves the problem that the conventional preparation technology can not stably output the ultrathin large flaking. The existing rotary cutting equipment generally generates more broken shavings and large shavings with uneven thickness (0.5-0.8 mm), the proportion of the ultra-thin large shavings with compliance is generally not more than 40%, and the problems of limited wood shaving output and the like of the rotary cutting equipment restrict the large-scale use of the ultra-thin large shavings.

S2, degreasing the ultrathin large flakes:

and (3) carrying out incomplete degreasing treatment on the ultrathin large flaking until the surface grease area of the ultrathin large flaking is 10% -20%, so as to obtain the incompletely degreased ultrathin large flaking.

Ultrathin large flakes made of small-diameter fully-loose raw wood generally contain rich grease, such as pinus massoniana ester rich in pinus massoniana is mainly composed of two parts of solid resin acid (rosin) and liquid terpenes (turpentine), the grease substances have low affinity with an adhesive, and the subsequent flakes and the adhesive are prevented from forming effective chemical bonds and hydrogen bonds, so that the bonding performance between the flakes and the adhesive is low. The ultra-thin large flaking is subjected to degreasing treatment in advance, so that the effective components of the grease in the ultra-thin large flaking are destroyed or removed, and the subsequent good sizing effect can be ensured when large-scale mass production is performed.

However, the degreasing treatment of the ultrathin large flaking obtained by rotary cutting the wood raw materials should be incomplete degreasing, and firstly, a small amount of grease is kept, so that the waterproof effect can be achieved to a certain extent, and the waterproof performance of the final shaving board is improved; secondly, the natural loose flavor and other odors of the original wood can be reserved; thirdly, avoid the destruction to log self structure that the complete degreasing caused, prevent the performance of the final shaving board of deterioration, and incomplete degreasing can also accelerate degreasing efficiency, promotes panel preparation efficiency.

In order to carry out incomplete degreasing treatment on the ultrathin large flaking at low cost, the following process means are preferably adopted for treatment:

firstly, soaking or spraying 0.4 to 0.6 weight percent of sodium hydroxide solution onto an ultrathin large flaking, fully mixing, then, steam spraying and steaming for 20 to 30 minutes by using 8 to 15 weight percent of ethanol solution, then, soaking by using 8 to 12 weight percent of hydrogen peroxide solution, and finally, drying to obtain the incompletely defatted ultrathin large flaking.

According to the incomplete degreasing treatment method, degreasing treatment such as soaking, washing and the like is carried out by using low-concentration alkali liquor, low-concentration ethanol solution and low-concentration hydrogen peroxide solution in sequence, so that only the effective components in the ultra-thin large flaked grease are damaged, lignin components are not damaged by immersing the wood, and redundant substances such as sodium hydroxide components, rosin components, ethanol solvents and the like are oxidized, decomposed and dissolved by the hydrogen peroxide solution; and after drying, the surface grease of the obtained degreasing ultrathin large flake is slightly reserved, so that the gluing capability with an adhesive is greatly improved in the subsequent gluing process, the tissue structure inside the flake is not destroyed, and the ultrahigh elastic modulus and static bending property of the large flake are reserved. And a large number of hydrophilic pores are blocked and closed, so that the shaving has extremely high waterproof capability.

S3, screening the degreasing ultrathin large sheets:

and screening the incompletely defatted ultrathin large flakes into surface layer ultrathin large flakes and core layer ultrathin large flakes according to the length. Wherein the length is 80 mm-140 mm and is defined as a surface layer ultrathin large flaking, and the length is 60 mm-80 mm and is defined as a core layer ultrathin large flaking.

S4, sizing and functional component steps:

and respectively applying an adhesive and a functional auxiliary agent to the surface layer ultrathin large flake and the core layer ultrathin large flake to respectively obtain a surface layer paving large flake with the water content of 10-13% and a core layer paving large flake with the water content of 5-8%.

Specifically, the adhesive may be a conventional board adhesive such as urea-based adhesive, MDI-based adhesive, or the like. The functional auxiliary agent generally comprises a water-repellent agent such as a mixture of water-based sodium dodecylbenzene sulfonate and a paraffin emulsion, and a curing agent such as a compound of formula C ₁₁ H ₁₄ O ₃ Medium and high temperature curing agent of (2). Of course, the invention is not limited thereto, and other options conventional in the art may also be selected by those skilled in the art.

S5, directional paving:

preferably, the invention improves the paving equipment, adds the orientation disc therein, adjusts the paving angle, adjusts the inclination angle of the paving disc according to the size proportion of the ultrathin large flaking of the surface layer and the ultrathin large flaking of the core layer, and reduces the gap of the material leakage of the paving disc.

Specifically, 3 layers of directional paving discs are additionally arranged on the paving equipment, the spacing between the multi-layer directional paving discs is controlled to be gradually reduced from top to bottom, and the multi-layer directional paving discs are specifically regularly arranged according to the gap width of the paving discs from top to bottom (the gap is controlled to be 2 cm); and, there is the strip guipure of rotation between the 3-layer directional dish, but the flaking that does not fall on the dish of mating formation, but accords with the dimensional requirement can remove to adjacent directional dish under the effect of rotating the guipure, falls after the gap screening, and the flaking that the angle is deviated also can collide with guipure and directional dish and take place the angle change constantly at directional dish gap and fall, and finally all flaking angles that accord with the size can be unanimously evenly scattered on the belt of mating formation of below. Therefore, after the directional pavement is improved, the directional angle is strictly controlled, disordered and disordered flaking pavement is regularly arranged, the three-layer structure of the oriented strand board is strictly paved according to the criss-cross arrangement mode, the transverse and longitudinal static bending strength and the elastic modulus of the product are improved, and the strength and the toughness of the large flaking are exerted.

Therefore, the upper surface layer, the core layer and the lower surface layer can be crisscrossed and arranged at an approximately vertical angle, and the surface layer large flaking surface layer ultra-thin large flaking is arranged in parallel along the same direction, so that a slab is obtained.

Therefore, the problem that the irregular large flaking is distributed on the surface of the plate in the prior art, so that the subsequent complex secondary processing can be used as a decorative material is solved, the irregular arrangement lines on the surface of the oriented strand board are solved by the parallel arrangement mode, the surface layer of the oriented strand board is ultrathin, the large flaking is tightly combined, the concave-convex gaps are smaller, the surface of the oriented strand board can be ensured to be even and smooth after the surface of the oriented strand board is polished by fixed thickness, and the facing requirement of the decorative material is met or the oriented strand board is directly used as the decorative material.

S6, hot pressing the plate blank:

and carrying out hot pressing treatment on the plate blank to obtain the full-loose ultrathin large-flaked oriented strand board.

Therefore, the method has the advantages that the special full-loose-rate raw wood is selected as the raw material, the growth period is short, the yield is high, and the production cost is greatly reduced. The second softer original woody place is matched with the improvement of the rotary cutting process, so that the extremely high ultra-thin large flaking qualification rate is ensured to be more easily achieved, excessive broken shavings are prevented from being brought in, and the problem of uneven surface of the existing oriented strand board is avoided. Thirdly, through degreasing treatment on the ultrathin large flaking, the problem of poor tackiness possibly caused by excessive grease of raw materials per se is solved, and the waterproofness is improved. Fourthly, through the improvement to the paving equipment, the ultra-thin big flaking on the surface layer and the ultra-thin big flaking on the core layer are guaranteed to be strictly arranged in a perfect orientation mode to form a plate blank, and the defect of disordered arrangement lines on the surface of the existing oriented strand board is avoided. The manufacturing method provided by the invention not only fully utilizes the advantages of the original wood, but also avoids the disadvantages of the original wood through improvement and addition of the process.

The thus obtained full-loose ultrathin large-flaked oriented strand board had a density of 530kg/m ³ ～550kg/m ³ The light weight and low density are realized; the surface of the composite material is smooth, the composite material is not rough, the bubbling and bursting rate is low, the elastic modulus (parallel elastic modulus can reach about 5000-6000 MPa), static bending strength (parallel static bending strength can reach about 30-50 MPa), internal bonding strength (0.4-0.5 MPa) and other mechanical properties are high, the dimensional stability is higher (the deformation of a finished product is only +/-1.5 mm and measured in a vertical state), the water absorption thickness expansion rate is only about 6-8 percent after 24 hours, the moisture resistance is high, the processing performance is good, the composite material can be used for wood structure buildings, facing wallboards and the like, and paper, PET and PVC facing can be directly impregnated into the surface layer after sanding, and the composite material is used as a furniture board.

Drawings

FIG. 1 is a schematic view of the structure of a cutting portion in a conventional single-blade rotary cutting apparatus;

fig. 2 is a schematic view of the structure of a spinning section in a spinning apparatus according to embodiment 1 of the present invention.

Detailed Description

Hereinafter, the above-mentioned all-loose ultra-thin large-flaked oriented strand board and the manufacturing method thereof according to the present invention will be embodied by specific examples, but the present invention is not limited thereto, and the list of these examples is merely specific examples of the product and the manufacturing method thereof, and those skilled in the art can make equivalent substitutions on the basis of this, in combination with conventional technical means in the art.

Example 1

The embodiment provides a full-loose ultrathin large-flaked oriented strand board and a manufacturing method thereof.

The preparation process comprises the following steps: raw material treatment, preparation of ultrathin large flaking, raw material degreasing treatment, water washing, raw material drying, raw material screening, sizing, paving, hot pressing and post-treatment. The method comprises the following steps:

(1) Raw material treatment

Selecting fresh pine wood of masson pine, removing redundant branches, retaining trunks, and processing by a barking machine to obtain log materials without barks.

(2) Preparation of ultrathin large flaking

The peeled masson pine is processed by a rotary cutter and a long wood flaker to obtain ultrathin large flaking with the length of 60 mm-120 mm, the width of 20 mm-40 mm and the thickness of 0.3 mm-0.5 mm, and the ultrathin large flaking is transported to a treatment groove.

The rotary cutter used in this embodiment is provided with two rotary cutting blades, which are respectively located above (i.e., blade 21 in fig. 2) and obliquely below (i.e., blade 22 in fig. 2) the log material. Wherein the angle of the cutting edge of the rotary cutting blade is controlled to be smaller than 25 degrees to ensure that ultra-thin large flaking with the thickness of 0.3 mm-0.5 mm is obtained, the length of the cutting edge is slightly larger than 2cm, and the lengths of the blades are respectively 2.6m and 4.2m according to log materials.

That is, the conventional single-blade rotary cutting apparatus generally adopts a mode of a single-press roller on one side and a double-press roller on the opposite side, and clamps the log material to be rotary cut, while referring to fig. 1, the conventional single-blade 2 is arranged on the side of the single-press roller, the distance between the single-press roller and the single-blade 2 is the thickness of the sliced log, and the log material 1 rotates one round and can only be rotary cut by one round of sliced log amount.

In the rotary cutting apparatus used in the present embodiment, as shown in fig. 2, the first blade 21 is disposed at the same position as in the single-blade rotary cutting apparatus, and is substantially horizontal, while the second blade 22 forms an angle of 30 ° to 45 ° with the first blade 21 and is added directly below the first blade 21. The second blade 22 has a higher blade extension (i.e. blade length) than the first blade 21, i.e. the second blade 22 located below is tangential to and preferably in contact with the lower part of the log material 1; thus, when the first blade 21 in a horizontal shape cannot rotate the wood core, the second blade 22 positioned below can continue to rotate until the rotation is finished.

Thus, when the log material 1 rotates one revolution, the flaking amount can be cut out for two weeks.

(3) Degreasing treatment

The fresh masson pine ultra-thin large flaking on the conveying roller rolls and is fully immersed by a 0.4% sodium hydroxide solution trough, so that the passing flaking is immersed in alkali liquor; then the material is immersed by an 8% ethanol solution water tank; the flaking is conveyed to a next water tank to be soaked in 10% hydrogen peroxide solution; finally, after washing, the incompletely defatted ultrathin large sheet with the surface grease area of 10-20% is obtained and transported to a wet storage bin for storage.

(4) Drying of the raw materials

And drying the incompletely defatted ultrathin large sheet by adopting a single-channel roller dryer until the water content is about 3%.

(5) Raw material screening

Separating the core layer and the surface layer material through mechanical screening, wherein the core layer and the surface layer material are ultrathin large flakes with the length of more than 8cm, the core layer is ultrathin large flakes with the length of less than 8cm, and impurities contained in the raw materials are removed.

(6) Sizing and functional components

Respectively slicing the surface layer ultra-thin large slice and the core layer ultra-thin large sliceThe adhesive is stirred by a roller adhesive stirrer, and the adhesive adopted in the embodiment is MDI adhesive (CAS number is 9017-23-8, the content of effective components is 99.4%, and the density is 1.24 g/cm) ³ ) The sizing amount is as follows: the surface layer is 3.5 percent, the core layer is 3.2 percent, and the dry weight of the corresponding flaking is calculated.

Meanwhile, a functional auxiliary agent waterproof agent and a curing agent are respectively added.

Wherein the waterproof agent is specifically a mixture of water-based sodium dodecyl benzene sulfonate and paraffin emulsion (48% of solid content) with the mass ratio of 1:5; the addition amount of the surface layer is 2%, and the addition amount of the core layer is 1.5% based on the dry weight of the corresponding flaking.

The curing agent is specifically a medium-high temperature curing agent, and the indexes are as follows: the molecular formula: c (C) ₁₁ H ₁₄ O ₃ The content of the effective component is 98.5%, the content of tert-butyl hydroperoxide is 0.1%, the acidity (calculated by benzoic acid) is 0.05%, the moisture is 0.1%, and the density is 1.036g/cm ³ ～1.045g/cm ³ The refractive index is 1.495-1.505, the total hydrolyzable chlorine is less than or equal to 0.005%, and Fe is less than or equal to 0.0005%. The addition amount of the surface layer was 2.5%, and the addition amount of the core layer was 2%.

Natural water is properly added according to the water content of the slab, so that the water content of the surface layer paved large flaking after sizing is ensured to be 10% -13%, and the water content of the core layer paved large flaking is approximately 5% -8%.

(7) Paving

In this embodiment, an improved paving apparatus is used, and a directional plate is additionally provided in the improved paving apparatus.

Specifically, the paving equipment is provided with 3 layers of directional paving discs, and the 3 layers of directional paving discs are regularly distributed from top to bottom according to the gap width of the paving discs of 8 cm-6 cm-4 cm, so that the minimum paving disc interval is not less than 30mm, and the minimum interval is ensured to be larger than the maximum width of the flaking.

According to three-layer directional pavement, the middle core layer pavement large flaking is transverse pavement, the surface layer pavement large flaking of the upper surface layer and the lower surface layer are longitudinally and directionally paved, the shavings of the same layer are in a nearly parallel state, the wood grains are orderly arranged, and the shavings between different layers are arranged in a vertical angle to form ultrathin shavings, so that a slab is obtained.

(8) Hot pressing

Continuous flattening: the slab is subjected to flat pressing, a continuous flat press is adopted, the width is 2550mm (eight-bar line), the length of the press is 42.9m, five hot pressing temperature areas are adopted, the hot pressing temperatures are respectively 230-245 ℃, 210-220 ℃, 200-220 ℃, 190-210 ℃ and 170-190 ℃, the hot pressing speed is 220-260 mm/s, and the hot pressing pressures are respectively five-stage pressures of 2.5-2.8 MPa, 1.8-2.5 MPa, 1.0-1.7 MPa, 0.5-0.9 MPa and 0.1-4 MPa.

The above hot pressing treatment yielded two kinds of plates having a thickness of 15mm and 18mm, respectively.

(9) Post-treatment

The hot-pressed plate is subjected to side sawing, cross cutting, turning plate frame cooling, middle plate cutting, stacking and curing, sanding, grading, packaging and warehousing.

That is, the full-loose ultrathin large-flaked oriented strand board provided in this embodiment uses the full-loose fast-growing wood of masson pine as a raw wood source to prepare ultrathin large flakes.

The performance of the all-loose, ultra-thin, large-flaked oriented strand board obtained in this example was tested according to the test method specified in LY/T1580-2010 and the test results are shown in Table 1 below.

TABLE 1 Performance test results of full-loose ultra-thin large flaked oriented strand boards

As can be seen from the performance data in Table 1, the two full-loose ultrathin large-flaked oriented strand boards with different thicknesses are obtained in the embodiment, and the performance of the full-loose ultrathin large-flaked oriented strand boards exceeds the national standard OSB/3 and 4 type performance and has the performance of high waterproofness for bearing heavy loads.

In the manufacture of the full-loose ultrathin large-flake oriented strand board, the incomplete degreasing treatment of the ultrathin large flakes is particularly important for obtaining the oriented strand board with excellent performance later, and the following comparative experiments of different degreasing degrees are carried out.

Comparative example 1

In this comparative example, the same points as those of embodiment 1 are not described here again, and only the differences from embodiment 1 are described. The difference between the comparative example and the example 1 is that in the degreasing treatment of the step (3), the surface grease of the ultra-thin large flaking is degreased to 7% -8% of the grease area, namely, the degreasing is excessive; two comparative oriented strand boards of 15mm and 18mm thickness were obtained, respectively, as described with reference to example 1.

The performance of these two comparative oriented strand boards was tested in the same manner as in example 1, as shown in Table 2.

Table 2 results of performance test of comparative oriented strand board

As can be seen from the performance data in Table 2, the comparative example obtained two comparative oriented strand boards of different thicknesses, which had properties lower than the national standard OSB/2, had significantly reduced water resistance and mechanical strength.

Comparative example 2

In this comparative example, the same points as those of embodiment 1 are not described here again, and only the differences from embodiment 1 are described. The present comparative example is different from example 1 in that in the degreasing treatment of step (3), the surface grease of the ultra-thin large flake is degreased to 23% -25% of the grease area, that is, the degreasing degree is insufficient; two comparative oriented strand boards of 15mm and 18mm thickness were obtained, respectively, as described with reference to example 1.

The performance of these two comparative oriented strand boards was tested in the same manner as in example 1, as shown in Table 3.

Table 3 results of Performance test of comparative oriented strand boards

As can be seen from the performance data in Table 3, the comparative example obtained two comparative oriented strand boards of different thicknesses, which were also lower than the national standard OSB/2, had no significant decrease in water resistance but significantly decreased mechanical properties.

In summary, it can be seen that for low cost, small gauge, full-loose raw wood employed in the present invention manufacturing process, a suitable degree of pre-degreasing treatment is critical to the performance control of the final board product.

Claims (8)

1. The full-loose ultrathin large-flaked oriented strand board is characterized by being formed by incomplete degreasing, sizing, functional components, oriented pavement and hot pressing of ultrathin large flakes; the ultrathin large flaking comprises a surface layer ultrathin large flaking and a core layer ultrathin large flaking, wherein the surface layer ultrathin large flaking has the following size: the length is 80 mm-140 mm, the width is 20 mm-30 mm, the thickness is 0.3 mm-0.5 mm, and the size of the ultrathin large flaking of the core layer is as follows: the length is 60 mm-80 mm, the width is 20 mm-30 mm, and the thickness is 0.3 mm-0.5 mm, and the raw wood source of the ultrathin large flaking is small-diameter full loose fast-growing wood; the oil area of the surface layer of the ultrathin large flaking is 10-20 percent after incomplete degreasing.

2. The all-pine ultra-thin large-flaked oriented strand board of claim 1 wherein said all-pine fast-growing wood is selected from the group consisting of masson pine and tamarind pine.

3. The method for manufacturing the full-loose ultrathin large-flaked oriented strand board as claimed in any one of claims 1 or 2, comprising:

s1, preparing ultrathin large flakes: peeling and rotary cutting the full loose-speed raw wood to obtain ultrathin large flaking with the length of 60-140 mm, the width of 20-30 mm and the thickness of 0.3-0.5 mm;

s2, degreasing the ultrathin large flakes: the ultra-thin large flake is subjected to incomplete degreasing until the surface grease area is 10% -20%, so that an incompletely degreased ultra-thin large flake is obtained;

s3, screening: screening the incompletely defatted ultrathin large flakes into surface layer ultrathin large flakes with the length of 80-140 mm and core layer ultrathin large flakes with the length of 60-80 mm;

s4, sizing and functional component steps: respectively applying an adhesive and a functional auxiliary agent to the surface layer ultrathin large flaking and the core layer ultrathin large flaking, and uniformly mixing to obtain surface layer paving large flaking with the water content of 10-13% and core layer paving large flaking with the water content of 5-8% respectively;

s5, directional paving: paving the surface layer ultrathin large flaking and the core layer ultrathin large flaking in a paving device according to the sequence of the upper surface layer, the core layer and the lower surface layer, and ensuring that the angles of two adjacent layers are vertical and the surface layer ultrathin large flaking is arranged in a flat form along the same direction so as to obtain a plate blank;

s6, hot pressing the plate blank: and carrying out hot pressing treatment on the plate blank to obtain the full-loose ultrathin large-flaked oriented strand board.

4. The method according to claim 3, wherein in the step S1, the rotary cutting apparatus used for rotary cutting includes two rotary cutting blades respectively inserted at the upper and lower press rolls, and an angle between the two rotary cutting blades is 30 ° to 45 °.

5. The method according to claim 3, wherein in the step S2, the ultra-thin and large flakes are obtained by first immersing or spraying the ultra-thin and large flakes with 0.4wt% to 0.6wt% alkali solution, sufficiently mixing, then steaming with 8wt% to 15wt% alcohol solution for 20min to 30min, then immersing with 8wt% to 12wt% oxidizer solution, and finally drying.

6. The method according to claim 5, wherein in the step S2, the alkali solution is a sodium hydroxide solution, the alcohol solution is an ethanol solution, and the oxidizing agent is a hydrogen peroxide solution.

7. The method according to claim 3, wherein in the step S4, the adhesive is urea adhesive or MDI adhesive; the functional auxiliary agent comprises a waterproof agent and/or a curing agent.

8. The method according to claim 3, wherein in the step S5, the paving apparatus has 3 directional paving trays, and the paving trays are arranged according to decreasing widths of gaps of the paving trays from top to bottom of 7cm to 9cm, 5cm to 7cm, and 3cm to 5cm, so that the surface ultra-thin and large flaking and the core ultra-thin and large flaking are directionally paved in a manner that two adjacent layers are perpendicular, and the surface ultra-thin and large flaking of the surface large flaking is arranged in parallel along the same direction.