CN107498652B - High-strength bamboo fiber curtain-OSB container bottom plate and manufacturing method thereof - Google Patents

Abstract

The invention relates to a high-strength bamboo fiber curtain-OSB container floor and a manufacturing method thereof. The structure of the high-strength bamboo fiber curtain-OSB container floor is that a layer of bamboo fiber curtains (2) are laid on the upper and lower layers, and sizing shavings are arranged inwardly. Oriented surface layer (3) and sizing flakes are randomly arranged in the core layer (4), or oriented strand board (5) for the core layer. The manufacturing method includes the following process steps: (1) making bamboo fiber curtains; (2) treating flakes or OSB; (3) sizing; (4) forming blanks and hot pressing. Advantages: Bamboo fiber curtains are combined with flakes or OSB, so that a large amount of bamboo and fast-growing wood can be used on the bottom of the container, which broadens the source of raw materials for the bottom, and has the advantages of wide source of raw materials, beautiful surface and high production efficiency. It is a sustainable circular economy that meets the development requirements of the international container industry.

Description

High-strength bamboo fiber curtain-OSB container bottom plate and its manufacturing method

technical field

The invention relates to a high-strength bamboo fiber curtain-OSB container bottom plate and a manufacturing method thereof, and belongs to the technical field of artificial board manufacturing in the wood industry.

Background technique

With the acceleration of the process of global economic integration, the world's logistics flow has soared, and containers are used more and more for their fast loading and unloading, turnover, convenient and safe transportation. The rapid development of the container transportation industry has prompted the demand for containers to increase with increasing day by day. The bottom plate of the container is required to have sufficient strength, rigidity, vibration absorption, weather resistance and long service life. Apitong and Keruing, the hard hardwoods of tropical rain forests, have always been used as containers. The ideal material for baseplates, until the 1990s, was plywood baseplates made from these two types of wood. Globally, more than 132,000,000 TEU containers have been installed with the same series of tropical rain forest hard broad-leaved wood Apitong and Keruing plywood floors, which seriously affect the ecological environment of tropical rain forests. Taking Indonesia as an example, in the 1950s The forest area of the country was 162 million hectares in the 1990s, but now it is only 95 million hectares, of which 70% of the original forest has been destroyed. Due to the long growth cycle of this kind of tree species, it usually takes more than 50 years. With the over-exploitation of the original tropical rain forest, the supply of raw materials for large-diameter clones and Abidong has been in short supply. To this end, Malaysia and Indonesia have announced policies to restrict the deforestation of tropical rainforests since 1993, and it is imperative to find new materials.

In recent years, bamboo and wood composite container floors have been used more and more, mainly for the container floor of bamboo curtain, bamboo mat and veneer. The walls are roughly cut in half, the thickness is uneven, and the efficiency is low. The hot pressing process of cold in and cold out is required to produce the container bottom plate, which is time-consuming and energy-consuming.

At present, there is a technology that can make fresh bamboo wood in a saturated steam tank with a temperature of 160-190 ° C, using rapid heating and moist heat heat treatment of high-temperature steam. At this time, hemicellulose is rapidly hydrolyzed and pyrolyzed under such high temperature and humidity. , to achieve the purpose of weakening the binding force between the vascular bundles in a short time. After taking it out, separate the bamboo fiber bundles. The diameter of the long bundle of bamboo fibers is 0.25-0.60mm. The bamboo fiber curtain of a certain thickness is impregnated with adhesive, then dehydrated and dried, and then it is made of shavings or OSB blanks to make a board, and a high-strength bamboo fiber curtain with hot in and hot out-OSB container floor can be obtained. It is because the tensile strength of a single bamboo fiber is as high as 1770MPa (chemical separation) and 930MPa (mechanical separation); the tensile strength of vascular bundles reaches 470 MPa (mechanical separation), and the bamboo bundle fibers (through chemical separation or rolling decompression) The tensile strength of bamboo silk fibers with multiple vascular bundles formed by the separation of bamboo parenchyma cells) reaches 610MPa (chemical separation), and when it is applied to the surface layer, it can exert its mechanical properties in the surface and back layers of the slab to the whole board. Significantly improved advantages. After the bamboo fiber is heat treated at high temperature, the bamboo fiber at this time has good dimensional stability, and the thickness of the bamboo bundle curtain is uniform. Anti-corrosion, anti-moth and anti-mildew effect, it is made into a container floor with beautiful surface and high strength. And the OSB material of the core layer comes from a wide range, the long bundle of bamboo fibers on the surface layer comes from a wide range, and the utilization rate of raw materials is high. Moreover, the method can utilize the clump bamboo and the thin-walled bamboo shoots, etc., which are less used now, such as giant dragon bamboo, dragon bamboo, yellow bamboo in Yunnan, Ci bamboo in Sichuan, green bamboo in Guangdong, wood bamboo in Fujian, etc. , and the diameter class of bamboo is not limited.

SUMMARY OF THE INVENTION

The present invention proposes a high-strength bamboo fiber curtain-OSB container floor and a manufacturing method thereof. The purpose of the invention is to utilize the characteristics that the fibers of bamboo are almost arranged in parallel longitudinally and without transverse fibers to manufacture high-strength long-bundle bamboo fibers, and further manufacture high-strength bamboo fibers. Fiber Curtain - OSB Container Floor.

Technical solution of the present invention:

High-strength bamboo fiber curtain-OSB container bottom plate, the structure of which is that a layer of bamboo fiber curtain (2) is laid on each of the upper and lower layers, and the sizing shavings are oriented inwardly. The surface layer (3) and the sizing shavings are randomly arranged in a core layer (4). , or oriented strand board (5) for the core layer, and a layer of resin-impregnated paper (1) on the outer layers of the upper and lower layers.

Its manufacturing method comprises the following process steps:

(1) Making bamboo fiber curtains;

(2) Processing of flakes or OSB;

(3) Sizing;

(4) grouping and hot pressing.

The invention has the advantages that scattered bamboo and clumped bamboo resources with fast growth, short period, selective cutting every year and long continuous utilization time can be effectively utilized, and the diameter grade of bamboo is not limited. Due to the high-temperature saturated steam treatment, the parenchyma cells between the vascular bundles are easy to separate, and the bamboo fiber has good dimensional stability, as well as anti-corrosion, moth-proof and mildew-proof effects. Fast-growing forest wood is made of shavings or OSB as the core material, and the bamboo fiber curtain and shavings or OSB are assembled into blanks. It has the advantages of wide raw material source, beautiful surface and high production efficiency. It is a sustainable circular economy, which is in line with outdoor The development trend of wood-based panel industry.

Description of drawings

Accompanying drawing 1 is the first kind of high-strength bamboo fiber curtain-OSB container floor structure schematic diagram.

Figure 2 is a schematic diagram of the structure of the second type of high-strength bamboo fiber curtain-OSB container bottom plate.

In the figure: 1 is a layer of phenolic impregnated paper; 2 is a layer of bamboo fiber curtain impregnated with phenolic glue and dried below 70°C, the thickness of the bamboo fiber curtain is 2.0-10.0mm; 3 is a layer of sizing shavings Oriented surface layer; 4 is a layer of sizing chips randomly paved with core layer. 5 is an oriented strand board for a core layer, with a thickness of 23-25 mm and a density of 0.74-0.78 g/cm ³ .

Detailed ways

High-strength bamboo fiber curtain-OSB container floor is characterized in that one layer of bamboo fiber curtain (2) is laid on the upper and lower layers, and the sizing shavings are oriented to the surface layer (3) and the sizing shavings are randomly arranged inwards. The core layer (4) , or oriented strand board (5) for the core layer.

The bamboo fiber curtain (2) is impregnated with phenolic glue, and the glue is dried by using a horizontal dehydrator after pouring the glue, and then dried at a temperature below 70°C to a moisture content of 12-18% and a thickness of 2.0-10.0 mm.

Described sizing shavings oriented surface layer (3) and sizing shavings are randomly arranged in the core layer (4) by applying paraffin wax by 1% by weight of the shavings, and applying phenolic glue at a sizing amount of 8% of the shavings weight; The sheet is formed by surface layer: core layer: core layer: surface layer = 25:25:25:25 group of blanks, wherein the surface layer is oriented and the core layer is randomly paved, the thickness after pressing is 22-25mm, and the density is 0.74-0.78 g/cm ³ .

The oriented strand board (5) for the core layer is coated with phenolic glue, and 5.4 grams of insecticide is added to the phenolic glue according to 1 kg of the phenolic glue, and the amount of glue applied is 200 g/m ² , and the phenolic glue is aged or dried at a temperature lower than 70° C. .

The outer layers of the upper and lower layers of the high-strength bamboo fiber curtain-OSB container floor may also have a layer of resin-impregnated paper, and the resin-impregnated paper is phenolic resin-impregnated paper or melamine resin-impregnated paper.

The manufacturing method of the described high-strength bamboo fiber curtain-OSB container bottom plate is characterized in that comprising the following processing steps:

(1) Making bamboo fiber curtains;

(2) Processing of flakes or OSB;

(3) Sizing;

(4) grouping and hot pressing.

The step (1) of making bamboo fiber curtains includes the following processes:

直径为50～300mm的含水率高于30%的新鲜竹筒或浸泡至含水率高于30%的干燥竹材，按要求截成2000～3000mm长，将其内节去除，保留圆筒或将其劈成3-8片竹片；将竹材用小车堆垛好，竹材之间留有空隙，堆垛时竹材长度方向有斜度，竹青面朝上；

Fresh bamboo tubes with a diameter of 50-300mm with a moisture content higher than 30% or dried bamboo materials soaked to a moisture content of more than 30%, cut into 2000-3000mm long as required, remove the inner section, keep the cylinder or split it Into 3-8 pieces of bamboo; stack the bamboo with a trolley, leaving a gap between the bamboos, when stacking, the length of the bamboo has a slope, and the green side of the bamboo is facing up;

Push the trolley loaded with bamboo into the pressure tank, close the tank door, pass high-temperature saturated steam with a temperature of 160-190°C into the tank, keep the treatment time for 10-60 minutes, and then slowly decompress the steam to discharge, and pull out the trolley;

处理好的竹材再通过多辊碾压纵向碾压，或单辊横向碾压，或用锤击方法，将竹纤维束之间分离开来，得到高强长束竹纤维，长束竹纤维的直径为0.25-0.60mm，竹节处稍大;

The treated bamboo is then rolled vertically by multiple rollers, or horizontally rolled by a single roller, or by hammering, to separate the bamboo fiber bundles to obtain high-strength long bundles of bamboo fibers, the diameter of the long bundles of bamboo fibers. 0.25-0.60mm, the bamboo joint is slightly larger;

用细线将其编织成厚度为2-10mm的竹纤维帘，长度和宽度可以根据需要来调节，并将含水率控制在12%以下。

It is woven into a bamboo fiber curtain with a thickness of 2-10mm with thin threads, the length and width can be adjusted according to needs, and the moisture content is controlled below 12%.

The step (2) treatment of shavings or OSB: the wood is made into shavings (strand), the length of the shavings is required to be 40-150mm, the thickness of the shavings is 0.8-1.1mm, and the moisture content of the shavings is adjusted to 6 before sizing. % or less; or the shavings are first pressed to the surface layer: core layer: core layer: surface layer=25:25:25:25 paving, then apply paraffin by 1% of the shavings weight, 8 of the shavings weight % sizing amount of phenolic glue; wherein the surface layer is oriented and the core layer is randomly paved, pressed into an OSB with a thickness of 22-25mm and a density of 0.74-0.78 g/cm ³ for the core layer, and the two surfaces are sanded.

The step (3) sizing: soak the bamboo fiber curtain with phenolic glue, use a horizontal dehydrator to dry the glue after pouring the glue, and dry it below 70°C to a moisture content of 12-18%; , the phenolic glue is added with 5.4 grams of pesticides per 1 kg of phenolic glue or isocyanate (MDI) with a solid content of 100%, and paraffin is applied according to 1% of the weight of the shavings, and the sizing amount is 8% of the weight of the shavings. ,; The core layer is coated with phenolic glue on the surface layer of OSB, and the coating amount is 200g/m ² , and it is aged or dried below 70°C.

The step (4) of forming the blank and hot pressing: placing the bamboo fiber curtain on the surface and back layer, and pressing the core layer flakes according to the surface layer: core layer: core layer: surface layer=25:25:25:25, wherein the surface layer of the flakes is Orientation, the requirements of random laying of the core layer, press to make the thickness of 22-23mm, the density of 0.74-0.78 g/ ^cm3 to control the chip group blank, or the oriented strand board for the core layer that has been glued in the middle; at the temperature of 140 ～180℃, under the condition of pressure of 3.0～5.5MPa, carry out hot pressing, keep it for 18～45 minutes, and then discharge steam to relieve pressure.

Example 1:

As shown in Figure 1, the high-strength bamboo fiber curtain-OSB container floor, its structure is that the upper and lower layers are sequentially laid with a layer of resin-impregnated paper 1 and a layer of bamboo fiber curtains impregnated with phenolic glue and dried at lower than 70 ° C from the outside to the inside. 2; Inwards are a layer of sizing shavings oriented surface layer 3, two layers of sizing shavings are randomly arranged core layer 4, a layer of sizing shavings oriented surface layer 3, followed by a layer of impregnated phenolic glue and low The bottom layer of the bamboo fiber curtain 2 dried at 70° C. is a layer of resin-impregnated paper 1 .

Its manufacturing method is as follows:

(1) Making bamboo fiber curtains, including the following processes:

直径为90mm左右的新鲜毛竹筒，按要求截成2.45m长，将其内节去除，保留圆筒，将竹材用小车堆垛好，竹材之间留有空隙，堆垛时竹材长度方向有10°斜度，最好将其竹青面朝上；

Fresh bamboo tube with a diameter of about 90mm, cut into 2.45m long as required, remove the inner section, keep the cylinder, stack the bamboo with a trolley, leave a gap between the bamboo, and the length of the bamboo is 10 when stacking. °Incline, it is best to put its bamboo green side up;

将装有竹材的小车推进压力罐内，关闭罐门，向罐内通入温度为170℃高温饱和蒸汽，保持35min处理时间。然后将蒸汽缓慢减压排出，将小车拉出；

Push the trolley loaded with bamboo into the pressure tank, close the tank door, and inject high-temperature saturated steam with a temperature of 170°C into the tank for 35 minutes. Then the steam is slowly decompressed and discharged, and the trolley is pulled out;

竹材通过多辊碾压纵向碾压后，竹黄层去除，并将竹纤维束之间分离开来，就得到了高强长束竹纤维；

After the bamboo is longitudinally rolled by multi-roller rolling, the bamboo yellow layer is removed, and the bamboo fiber bundles are separated to obtain high-strength long-bundle bamboo fibers;

用细线将其编织成厚度6mm的竹纤维帘，竹纤维帘的幅面为2.45m长*1.25m宽，并将含水率控制在12%以下。

It is woven into a bamboo fiber curtain with a thickness of 6mm with thin threads. The width of the bamboo fiber curtain is 2.45m long * 1.25m wide, and the moisture content is controlled below 12%.

(2) Processing of shavings: The shavings are prepared from wood, and the length of the shavings is 40-150mm, the thickness is 0.8-1.1mm, and the moisture content of the shavings is adjusted to below 6% before sizing.

(3) Sizing: Impregnate the bamboo fiber curtain with phenolic glue, use a horizontal dehydrator to dry the glue after pouring the glue, and dry it below 70°C to a moisture content of 12-18%. Apply paraffin wax according to 1% of the weight of the shavings, add 5.4 grams of insecticide to the glue according to 1 kg of phenolic glue or isocyanate (MDI) (solid content 100%), and then sizing according to 8% of the weight of the shavings. , while applying paraffin at 1% by weight of the flakes.

(4), grouping and hot pressing: put the bamboo fiber curtain on the surface and back layer, and the flakes in the core layer are grouped according to the surface layer: core layer: core layer: surface layer = 25:25:25:25 group of blanks, of which the surface layer flakes Directional paving, random paving of the core layer, and pressing to make a target with a thickness of 23 mm and a density of 0.74-0.78 g/cm ³ to control the group blank. Hot pressing was carried out under the conditions of temperature of 160°C and maximum pressure of 4.5MPa, maintained for 22 minutes, and then exhausted to relieve pressure.

After conventional post-processing, the finished composite container floor can be obtained, and its physical and mechanical properties are as follows:

MOR∥: ≥ 110 MPa

MOR⊥: ≥ 30 MPa

MOE∥: ≥ 11000 MPa

MOE⊥: ≥ 3000 MPa

Density: 0.80～0.90 g/cm ³ .

Example 2:

As shown in Figure 2, the high-strength bamboo fiber curtain-OSB container bottom plate, its structure is that the upper and lower layers are sequentially laid with a layer of bamboo fiber curtain 2 impregnated with phenolic glue and dried below 70 ℃ from the outside to the inside; Oriented strand board 5, and then a layer of bamboo fiber curtain 2 which is impregnated with phenolic glue and dried below 70°C.

Its manufacturing method is as follows:

(1) Making bamboo fiber curtains includes the following processes:

直径为200mm左右的新鲜巨龙竹竹筒，按要求截成2.45m长，劈成两半，并将其内节去除，将竹材用小车堆垛好，竹材之间需有空隙，堆垛时竹材长度方向有8°斜度，最好将其竹青面朝上;

The fresh giant dragon bamboo bamboo tube with a diameter of about 200mm is cut into 2.45m long as required, split into two halves, and the inner section is removed, and the bamboo is stacked with a trolley. There is an 8° inclination in the length direction, and it is best to put the bamboo green side up;

将装有竹材的小车推进压力罐内，关闭罐门，向罐内通入温度为180℃高温饱和蒸汽，保持25min处理时间。然后将蒸汽缓慢减压排出，将小车拉出;

Push the trolley loaded with bamboo into the pressure tank, close the tank door, and inject high-temperature saturated steam with a temperature of 180°C into the tank for 25 minutes. Then the steam is slowly decompressed and discharged, and the trolley is pulled out;

竹材通过多辊碾压纵向碾压后，竹黄层去除，并将竹纤维束之间分离开来，就得到了高强长束竹纤维;

After the bamboo is longitudinally rolled by multi-roller rolling, the bamboo yellow layer is removed, and the bamboo fiber bundles are separated to obtain high-strength long-bundle bamboo fibers;

用细线将其编织成厚度6mm的竹纤维帘，竹纤维帘的幅面为2.45m长*1.25m宽，并将含水率控制在12%以下;

Weaving it into a bamboo fiber curtain with a thickness of 6mm with thin threads, the width of the bamboo fiber curtain is 2.45m long * 1.25m wide, and the moisture content is controlled below 12%;

(2) OSB treatment: Press the surface layer: core layer: core layer: surface layer = 25:25:25:25, and then sizing according to the sizing amount of 8%, in which the surface layer is oriented and the core layer is randomly paved Requirements, press into OSB with a thickness of 22-25mm and a density of 0.74-0.78 g/ ^cm3 , and sand its two surfaces.

(3) Sizing: Impregnate the bamboo fiber curtain with phenolic glue, use a horizontal dehydrator to dry the glue after pouring the glue, and dry it below 70°C to a moisture content of 12-18%. The core layer is coated with phenolic glue on the surface layer of the particleboard, and 5.4 grams of pesticides are added to the glue according to ¹ kg of the phenolic glue.

(4) Assembling and hot pressing: Put the bamboo fiber curtain on the surface and back layer, and in the middle is the oriented strand board for the core layer. Hot pressing was carried out under the condition of temperature of 145°C and maximum pressure of 4.5MPa, kept for 16 minutes, and then exhausted to relieve pressure.

After conventional post-processing, the finished composite container floor can be obtained, and its physical and mechanical properties are as follows:

MOR∥: ≥ 110 MPa

MOR⊥: ≥ 30 MPa

MOE∥: ≥ 11000 MPa

MOE⊥: ≥ 3000 MPa

Density: 0.80～0.90 g/cm ³ .

Claims (1)

1. The manufacturing method of the high-strength bamboo fiber curtain-OSB container bottom plate is characterized in that the upper surface layer and the lower surface layer of the high-strength bamboo fiber curtain-OSB container bottom plate are respectively a layer of bamboo fiber curtain (2), the upper surface layer and the lower surface layer are core layers inwards, and the core layers are glue applying plane sheet oriented surface layers (3) and glue applying plane sheets randomly distributed core layers (4) or oriented strand boards (5) for the core layers;

the bamboo fiber curtain (2) is soaked with phenolic glue, the glue is dried by a horizontal dehydrator after being soaked, and the glue is dried at the temperature lower than 70 ℃ until the water content is 12-18% and the thickness is 2.0-10.0 mm;

the glue-applying sliced sheet oriented surface layer (3) and the glue-applying sliced sheet randomly-arranged core layer (4) are assembled into a blank according to the proportion of 1 percent of the weight of the sliced sheet, phenol formaldehyde glue is applied according to the proportion of 8 percent of the weight of the sliced sheet, the sliced sheet is assembled according to the proportion of the surface layer, the core layer, the ratio of 25:25:25:25, wherein the surface layer is oriented, the core layer is randomly paved, the thickness is 22-25mm after pressing, and the density is 0.74-³；

The oriented strand board (5) for the core layer is coated with phenolic glue on the surface layer, 5.4 g of insecticide is added into 1 kg of phenolic glue, and the glue coating amount is 200g/m²Aging or drying at a temperature of less than 70 ℃;

the outer layers of the upper surface layer and the lower surface layer of the high-strength bamboo fiber curtain-OSB container bottom plate are also provided with a layer of resin impregnated paper, and the resin impregnated paper is phenolic resin impregnated paper or melamine resin impregnated paper;

the manufacturing method of the high-strength bamboo fiber curtain-OSB container bottom plate comprises the following process steps:

(1) manufacturing a bamboo fiber curtain;

(2) processing of flakes or OSB;

(3) sizing;

(4) assembling and hot pressing;

the bamboo fiber curtain manufactured in the step (1) comprises the following processes:

firstly, cutting a fresh bamboo tube with the diameter of 50-300 mm and the water content of more than 30% or a dry bamboo material soaked until the water content of more than 30% into the length of 2000-3000 mm according to requirements, removing inner sections of the fresh bamboo tube, and reserving a cylinder or splitting the fresh bamboo tube into 3-8 bamboo chips; stacking the bamboo materials by using a trolley, wherein gaps are reserved among the bamboo materials, the bamboo materials are inclined at 5-15 degrees in the length direction during stacking, and the green surfaces of the bamboo materials face upwards;

secondly, pushing the trolley filled with the bamboo wood into a pressure tank, closing a tank door, introducing high-temperature saturated steam with the temperature of 160-190 ℃ into the tank, keeping the treatment time for 10-60 min, slowly decompressing and discharging the steam, and pulling out the trolley;

thirdly, separating the bamboo fiber bundles by multi-roller rolling and longitudinal rolling, or single-roller transverse rolling, or hammering method to obtain high-strength long-bundle bamboo fibers, wherein the diameter of the long-bundle bamboo fibers is 0.25-0.60mm, and the bamboo joint is slightly larger;

weaving the bamboo fiber curtain into a bamboo fiber curtain with the thickness of 2-10mm by using thin wires, wherein the length and the width can be adjusted according to requirements, and the water content is controlled to be below 12%;

the step (2) of processing the sliced sheets or OSB: preparing wood into chips, wherein the length of the chips is required to be 40-150mm, the thickness of the chips is required to be 0.8-1.1mm, and the water content of the chips is adjusted to be below 6% before gluing; or paving the shaving pieces according to the weight ratio of the surface layer to the core layer to the surface layer =25:25:25:25, applying paraffin wax according to 1% of the weight of the shaving pieces, and applying phenolic glue according to 8% of the weight of the shaving pieces; wherein the surface layer is oriented, the core layer is randomly paved, and the mixture is pressed into the product with the thickness of 22-25mm and the density of 0.74-0.78g/cm³The core layer is made of oriented strand board, and two surfaces of the oriented strand board are sanded;

the step (3) is sizing: soaking the bamboo fiber curtain with phenolic glue, drying the glue by a horizontal dehydrator after the glue is sprayed, and drying the glue until the water content is 12-18% below 70 ℃; when the glue is applied to the sliced pieces, 5.4 g of insecticide is added into 1 kg of phenolic glue with 100 percent of solid content or isocyanate (MDI) and paraffin is added according to 1 percent of the weight of the sliced pieces; applying glue according to 8% of the weight of the sliced sheets; phenolic glue is coated on the surface layer of the oriented strand board for the core layer, and the glue coating amount is 200g/m²Aging or drying at a temperature of less than 70 ℃;

assembling and hot-pressing in the step (4): placing bamboo fiber curtain on the surface layer and the back layer, pressing into pieces with thickness of 22-23mm and density of 0.74-0.78g/cm according to the requirements of surface layer, core layer and surface layer =25:25:25:25, wherein the surface layer of the pieces is oriented and the core layer is randomly paved³To control the flaking assembly, or the middle is the already glued oriented strand board for core layer; hot pressing is carried out at the temperature of 140-180 ℃ and the pressure of 3.0-5.5 MPa, the temperature is kept for 18-45 minutes, and then steam is discharged for pressure relief.

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