WO2019100749A1

WO2019100749A1 - Manufacturing method for straw particleboard and straw particleboard

Info

Publication number: WO2019100749A1
Application number: PCT/CN2018/098337
Authority: WO
Inventors: 赵治美; 蒋海东; 刘新华; 刘剑英; 胡国良; 程云云; 孙应朋; 蒲黄彪
Original assignee: 万华禾香板业有限责任公司
Priority date: 2017-11-27
Filing date: 2018-08-02
Publication date: 2019-05-31
Also published as: CN107984592A

Abstract

The present invention provides a manufacturing method for a straw particleboard, comprising the following steps: preparing straw chips, screening straw chips, preparing wood chips, screening wood chips, processing coarse wood materials, preparing surface layer materials, preparing core layer materials, and preparing straw particleboards. In the step of screening wood chips, the wood chips are conveyed to a second screening device so as to screen the wood chips and separate the wood chips into coarse wood materials, standard wood materials, and fine wood materials. In the step of preparing surface layer materials, surface layer materials are prepared from a mixture of the standard straw materials and the fine wood materials. The present invention further provides a straw particleboard manufactured by the manufacturing method.

Description

Straw particle board manufacturing method and straw particle board

Technical field

The invention relates to the field of particleboard manufacturing, in particular to a method for manufacturing straw straw particle board mixed with straw and wood shavings and a straw particle board manufactured by the manufacturing method.

Background technique

At present, China's particleboard manufacturing is still dominated by wood raw materials. After the implementation of natural forest protection projects and timber cutting in the country, many particleboard manufacturing enterprises are caught in the shortage of timber resources.

Crop straw is a valuable renewable resource. The annual output of crop straw in China is about 700 million tons. However, due to factors such as consumption concepts and lifestyles, China's straw resources have been in high consumption, high pollution, and low output for a long time. A considerable part of crop straw has been abandoned or incinerated, and has not been properly developed. use. In recent years, research on the comprehensive utilization of crop straw (rice, wheat, soybean, cotton, flax and other crop straws) has received increasing attention. It is one of the important research directions to carry out a series of complicated industrial treatments and compressing straw into sheet.

However, there are some problems with the traditional straw chipboard production line. For example, the manufactured particle board contains only straw shavings and cannot meet the national standard of particleboard. The particle size distribution of the straw shavings of the hammer crusher is wide, which does not meet the requirements of the fiber core of the straw particle board. In some traditional production lines, even if the core layers are pulverized, some coarse materials will appear on the surface of the sheet, which will affect the application of the panel. At the same time, the core layer may contain a considerable amount of coarse material, which will affect the manufacturing. The strength of the straw chipboard; or the core layer contains a considerable amount of fine material, and too much fine material will consume a lot of adhesive. In addition, the quality of the surface layer can be improved by reducing the pore size of the screen, but the fine screen will increase the difficulty of pulverization. In particular, if the moisture content of the straw is not guaranteed, the yield is low. Frequent equipment failures have severely restricted the production capacity of the straw particleboard production line.

Therefore, it is necessary to propose a new method for manufacturing straw straw particle board and straw particle board to solve the above problems.

Summary of the invention

In order to solve at least one of the above technical problems, embodiments of the present invention provide a method of manufacturing a straw particle board and a straw particle board manufactured using the method.

According to an aspect of the invention, a method of manufacturing a straw chipboard is provided, the method comprising the steps of:

Preparation of straw shavings: cutting, drying and pulverizing the straw to obtain straw shavings;

Screening of straw shavings: conveying the straw shavings to a first screening device to sieve the straw shavings into straw raw materials and straw qualified materials;

Preparation of wood shavings: shaving and shaving of wood to produce wood shavings;

Screening of wood shavings: conveying the wood shavings to a second screening device to screen the wood shavings into wood coarse aggregates, wood qualified materials, and wood fines;

Processing of wood coarse aggregate: refining the wood coarse aggregate by using a refining device, and conveying the refined wood coarse aggregate together with the wood shavings to the second screening device to be refined The wood coarse material is further sieved into wood coarse material, wood qualified material and wood fine material;

Preparation of a surface layer: preparing a surface layer material from the mixture of the straw qualified material and the wood fine material;

Core material preparation: preparing a core material from the wood qualified material;

Preparation of Straw Particleboard: Using the surface layer material and the core layer material, the straw particle board is obtained by paving, pre-pressing, hot pressing and post-treatment steps.

Optionally, the preparing the top layer material by using the mixture of the straw qualified material and the wood fine material comprises:

Transferting the straw qualified material and the wood fine material to a first airflow sorting device for airflow sorting; and

And sizing the mixture of the straw qualified material and the wood fine material subjected to airflow sorting to obtain the surface layer material,

And/or, the preparing the core material with the wood qualified material comprises:

Delivering the wood qualified material to a second airflow sorting device for airflow sorting; and

The wood qualified material subjected to gas flow sorting is sized to produce the core material.

Optionally, the first screening device comprises a first square hole sieve, the first square hole sieve sieving the straw shavings into a straw coarse material and a straw qualified material.

For example, the screen aperture of the first square mesh screen is in the range of 1.3 mm x 1.3 mm to 2.8 mm x 2.8 mm.

Optionally, the second screening device comprises: a second square sieve or a strip sieve; and a third-party sieve, wherein the second square sieve or the strip sieve and the third-party sieve together The wood shavings are classified into wood coarse aggregates, wood qualified materials, and wood fines.

For example, the screen aperture of the second square sieve is in the range of 8 mm × 8 mm to 12 mm × 12 mm, and the screen aperture of the strip sieve is in the range of 3 mm × 30 mm to 4 mm × 40 mm, the third party The mesh aperture of the aperture sieve is in the range of 0.15 mm x 0.15 mm to 0.3 mm x 0.3 mm.

For example, in the sizing step, the applied adhesive comprises an isocyanate gel.

Optionally, in the step of sizing the mixture of the straw qualified material and the wood fine material subjected to gas flow sorting to obtain the surface layer material, the applied amount of the isocyanate rubber is the place to be sized. The weight of the mixture of the straw qualified material and the wood fine material is 3.5 to 5.0%;

And/or, in the step of sizing the wood-qualified material subjected to gas flow sorting to obtain the core material, the isocyanate gum is applied in an amount of 2.5 to 3.0 by weight of the wood-qualified material to be sized. %.

Optionally, the manufacturing method further includes the following steps:

Processing of the straw coarse material: refining the straw coarse material by using another refining device, and conveying the refined straw raw material together with the straw shavings to the first screening device to The straw coarse material is further sieved into straw coarse material and straw qualified material.

Optionally, the preparing steps of the straw particle board include:

Dividing the surface layer into an upper surface layer and a top layer material;

Laminating the underlayer layer, the core layer and the upper surface layer in sequence to obtain a slab;

Pre-pressing the slab;

The slab is hot pressed.

Optionally, the manufacturing method further comprises drying the wood shavings prior to conveying the wood shavings to the second screening device.

For example, the straw includes at least one of rice straw, wheat straw, soybean straw, cotton straw, and hemp straw.

According to another aspect of the present invention, there is further provided a straw particle board which is a straw particle board manufactured according to any of the above manufacturing methods.

According to still another aspect of the present invention, a straw particle board is further provided, the straw particle board comprising:

In the upper surface layer, the upper surface layer comprises straw shavings, wood fines and isocyanate glue;

a core layer comprising wood shavings and isocyanate gum; and

In the lower layer, the lower layer comprises straw shavings, wood fines and isocyanate gum.

Compared with the prior art, the present invention has at least one of the following beneficial effects:

(1) Screening the wood shavings, using the selected wood fine materials for the surface layer material, which can improve the surface hardness and/or toughness of the manufactured straw particle board, and reduce the cracking of the surface paper when the board is covered, and the sheet collapse Risk of the side;

(2) Screening the wood shavings, and using the selected wood fine materials for the surface layer material, that is, avoiding the wood fine material as the core layer material, thereby avoiding excessive consumption of the adhesive by excessive fine materials and reducing the preparation of the core layer. The amount of adhesive applied;

(3) Screening the pulverized straw shavings, only the selected straw qualified materials can be used for the surface layer material, which can prevent the coarse materials from appearing on the surface of the sheet, thereby improving the surface application of the sheet;

(4) Screening of wood shavings, only the selected wood qualified materials can be used for the core layer material, which can prevent excessive coarse materials from being contained in the core layer, thereby ensuring that the strength of the manufactured particle board meets the requirements of national standards. ;

(5) Increasing the re-crushing process, the wood coarse aggregate can be turned into a wood qualified material through the re-grinding process, thereby improving the utilization rate of the wood raw material.

DRAWINGS

Other objects and advantages of the present invention will be apparent from the description of the appended claims.

1 is a process flow diagram of a method of manufacturing a straw particleboard according to an exemplary embodiment of the present invention;

2 is a schematic view showing the structure of a straw particle board manufactured by a manufacturing method according to an embodiment of the present invention.

It should be noted that the drawings are not necessarily to scale, but are only shown in a schematic manner that does not affect the understanding of the reader.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiments of the present invention. It is apparent that the described embodiments are one embodiment of the invention, and not all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the described embodiments of the present invention without departing from the scope of the invention are within the scope of the invention.

Unless otherwise defined, technical terms or scientific terms used in the present invention should be construed in the ordinary meaning of the ordinary skill in the art to which the invention pertains.

In this context, the expression "particle board" refers to a type of artificially processed wood or non-wood plant fiber raw material processed into shavings (or scraps), applied with adhesives (and/or other additives), formed into a preform and hot pressed. board.

The expression "straw" is a generic term for the stems and leaves of a mature crop, and may, for example, include the remainder of wheat, rice, corn, potato, canola, cotton, sugar cane, and other crops (usually coarse grains) after harvesting the seeds. For example, in the present invention, the straw may include at least one of rice straw, wheat straw, soybean straw, cotton straw, and hemp straw. For another example, the hemp straw may include hemp straw, flax straw, hemp straw, and the like.

The expression "shavings" refers to sheets, strips, rods and/or granules of a certain shape and size that have been machined from wood or non-wood materials.

The expressions "coarse material" or "coarse material", "qualified material", "fine material" mainly divide the shavings according to the size of the shavings, and those skilled in the art should understand that they represent the relative size of the shaving size, that is, The size of the "coarse material" or "coarse material" is larger, the size of the "qualified material" is medium, and the size of the "fine material" is smaller. The size of the shavings divided into “coarse material” or “coarse material”, “qualified material” and “fine material” may vary depending on the actual use or application. For example, the size of the "coarse material" or "coarse material", "qualified material", and "fine material" used for the surface layer of the particle board is respectively the "rough material" or "coarse material" for the core layer of the particle board. The size of the shavings of the "qualified materials" and "fine materials" are different.

According to an exemplary embodiment of the present invention, a method of manufacturing a straw particle board is provided, and the manufacturing method may include the following steps:

Treatment of wood coarse aggregate: using a comminution apparatus, pulverizing the wood coarse aggregate, and transporting the pulverized wood coarse aggregate together with the wood shavings to the second screening device to be crushed The wood coarse material is further sieved into wood coarse material, wood qualified material and wood fine material;

Since the plasticity of the wood is better than the plasticity of the straw, and the straw has brittleness, in the above manufacturing method, by adding the sieved wood fine material to the surface layer of the straw particle board, the surface strength of the manufactured straw particle board can be improved. Increase the surface bond strength and modulus of elasticity (MOE) of the surface layer of the straw particle board.

That is, the above manufacturing method has at least one of the following advantageous effects:

A method of manufacturing a straw particle board according to an embodiment of the present invention will be described in further detail with reference to FIG.

In the manufacturing method according to the embodiment of the present invention, the preparing step of the straw shavings may specifically include the following steps:

Straw cutting: The straw is bundled and scattered, and the straw is cut into a certain length by a lawn mower, for example, cut into a length of 5 to 50 mm.

Drying: Use a drum dryer to remove stones, ash and water from the straw, so that the water content of the straw is controlled at 9% to 11%. The drum dryer is an internal heating conduction type rotary drying device. The wet material obtains heat transferred by heat conduction on the outer wall of the drum, removes moisture, and achieves the water content required for drying.

Crushing: The straw is processed into a scrap by a hammer mill.

In the manufacturing method according to the embodiment of the present invention, the step of preparing the wood shavings may specifically include the following steps:

Wood shavings: Wood chips are machined into chips of a certain size and shape using a chipper.

Planer: The flaker machine processes the chips into the required size and shape.

Drying: The moisture content of the shavings is brought to the process by a dryer.

According to an exemplary embodiment, after the straw shavings are produced, the manufacturing method further includes a screening step. In the screening step, the straw shavings are conveyed to a first screening device to sieve the straw shavings into a straw coarse material and a straw qualified material. In one example, the first screening apparatus can include a first square mesh screen that sifts the straw shavings into a straw coarse aggregate and a straw qualified material. For example, the screen aperture of the first square mesh screen is in the range of 1.3 mm x 1.3 mm to 2.8 mm x 2.8 mm. For another example, the screen aperture of the first square mesh may be 2 mm x 2 mm. Thus, by means of the first square sieve, the straw shavings passing through the first square sieve can be used as a straw qualified material, and the straw shavings not passing through the first square sieve can be used as a straw coarse aggregate. In the example in which the sieve aperture of the first square sieve is 2 mm×2 mm, the straw shavings having a size of less than 2 mm×2 mm can be used as the straw qualified material, and the remaining straw shavings can be used as the straw coarse aggregate.

According to an exemplary embodiment, the manufacturing method further includes a processing step of the straw coarse material. In the processing step of the straw coarse material, the straw coarse material is polished by using a grinding device, and the polished straw raw material and the straw shavings are transported together to the first screening device to be polished. The straw straw material is further sieved into straw coarse material and straw qualified material. In one example, the sanding apparatus can be a screen ring sander, such as a BX5612 screen ring sander, to sand the straw material into finer shavings.

According to an exemplary embodiment, the manufacturing method further includes a screening step after the wood shavings are prepared. In the screening step, the wood shavings are conveyed to a second screening stock, and the wood shavings are divided into wood coarse aggregates, wood qualified materials, and wood fines. In one example, the second screening apparatus can include a second square mesh screen or a strip screen; and a third-party aperture screen, wherein the second square aperture screen or strip screen and the third-party aperture screen together The wood shavings are sieved into wood coarse aggregates, wood qualified materials, and wood fines. For example, the screen aperture of the second square sieve may be in the range of 8 mm x 8 mm to 12 mm x 12 mm, and the screen aperture of the strip screen may be in the range of 3 mm x 30 mm to 4 mm x 40 mm. For another example, the screen aperture of the second square mesh may be 10 mm x 10 mm. For example, the screen aperture of the third-party aperture screen may range from 0.15 mm x 0.15 mm to 0.3 mm x 0.3 mm. As another example, the third-party aperture screen may have a mesh aperture of 0.2 mm x 0.2 mm. In the above example, wood shavings with a size of less than 0.2 mm × 0.2 mm can be used as wood fines, wood shavings with a size of 0.2 mm × 0.2 mm to 10 mm × 10 mm can be used as wood qualified materials, and the remaining wood shavings can be used as wood. Coarse material.

According to an exemplary embodiment, the manufacturing method further includes a processing step of the wood coarse aggregate. In the processing step of the wood coarse aggregate, the wood coarse aggregate is further pulverized by a pulverizing apparatus, and the pulverized wood coarse aggregate and the wood shavings are conveyed together to the second screening device to The shredded wood coarse aggregate is further sieved into a wood coarse aggregate and a wood qualified material. In one example, the comminuting apparatus may be a pulverizer to pulverize the wood coarse mass into finer shavings.

According to an exemplary embodiment, in conjunction with FIG. 1, the manufacturing method may further include a gas stream sorting step and a sizing step to prepare a surface layer. In the airflow sorting step, the straw qualified material and the wood fine material may be sent to a first airflow sorting device for airflow sorting. In one example, the first airflow sorting device can include an airflow sorter. In the sizing step, the mixture of the straw grading material and the wood fine material subjected to gas flow sorting is sized to obtain the surface layer material.

According to an exemplary embodiment, the manufacturing method may further include a gas separation step and a sizing step to prepare a core material. In the airflow sorting step, the wood qualified material may be delivered to a second airflow sorting device for airflow sorting. In one example, the second airflow sorting device can include an airflow sorter. In the sizing step, the wood grading material subjected to gas flow sorting is sized to produce the core material.

According to an exemplary embodiment, in the above sizing step, the applied adhesive may comprise an isocyanate gel, such as an MDI isocyanate gel.

For example, the manufacturing method of the straw particle board may specifically include the following steps:

Surface material sizing: The mixture of straw qualified material and wood fine material is quantitatively input into the surface sizing system, and the adhesive is applied according to a preset sizing ratio to obtain a sized surface layer shavings. In an exemplary embodiment of the invention, the applied adhesive is an isocyanate gel, such as an MDI glue. Since the isocyanate gel is an aldehyde-free glue, it is ensured that the manufactured straw chipboard has zero formaldehyde emission. As an example, the mixture of the straw qualified material and the wood fine material can be metered by the belt measuring conveyor, and the automatic and accurate supply of the adhesive is completed through the PLC control center, and the mixture of the straw qualified material and the wood fine material is realized in the closed drum. Uniform mixing of the adhesive from the centrifugal atomizer rotating at high speed. For example, the isocyanate gum is applied in an amount of from 3.5 to 5.0% by weight based on the weight of the mixture of the straw-based material and the wood-fine material to be sized.

Stocking: The mixture of the uniformly sized straw qualified material and the wood fine material is divided into the upper surface layer and the lower layer material by a distributor.

Core material sizing: The wood grading material is sizing into a core sizing system. As an example, the wood qualified material can be metered by a belt measuring conveyor, and the automatic and accurate supply of the adhesive is completed through the PLC control center, so that the wood qualified material is discharged in the closed drum and the high-speed rotating centrifugal atomizer. Uniform mixing of the adhesive. The adhesive may also be an isocyanate gel, such as an MDI gum. For example, the isocyanate gum may be applied in an amount of from 2.5 to 3.0% by weight of the wood grade to be sized. According to an example of the present invention, if the sizing amount of the core material is recorded as A in the weight percentage of the core material, and the sizing amount of the surface layer material is recorded as B in the weight percentage of the surface layer material, then A can be 0.5 to 1 smaller than B, that is, the value of (BA) is in the range of 0.5 to 1.

Paving: The paving machine successively applies the mixture of straw qualified materials and wood fine materials after sizing (as the following layer), the sizing wood qualified materials (as core material), and the stalked straw qualified materials. A mixture of wood fines (as the topsheet) is laid into a slab of three layers of symmetrical structure.

Pre-compression: The slab is pre-pressed by a pre-press to maintain the slab in a certain shape. The slab preload compression ratio is controlled at 45% and the rebound rate is 20%. In order to prevent the sticking board, the surface of the pressure plate and the backing plate should be evenly applied with a release agent.

Hot pressing: The slab is heated and pressurized by the press to cause a complicated chemical reaction between the water in the raw material of the sheet and the isocyanate of the adhesive, and the reaction product binds the raw materials of the sheet together. In order to prevent the pressure plate from sticking to the plate, the upper platen layer should be coated with a uniform release agent.

Post-treatment: The pressed wool board is subjected to a post-treatment process such as cold plate, trimming, cooling homogenization, sanding, etc. to obtain a straw particle board.

Further, the entire flow of manufacturing the straw particle board using the above manufacturing method will be described below with reference to specific examples.

(1) The rice straw is cut into grass segments of 20 to 40 mm by a lawn mower.

(2) uniformly drying the grass section by using a drum type airflow dryer with a decontamination device, so that the moisture content of the grass section is reduced to 12 to 13%, and at the same time, stones, dirt, iron blocks, etc. are removed. To prevent debris from entering the next crushing process.

Among them, the drying system can directly use air, the heat exchanger adopts shell-and-tube heat exchanger, the exhaust gas discharge and circulation ratio is 1:1, the air temperature entering the dryer is 180 °C, and the dryer screen adopts 25mm square hole sieve. The wind speed of the air and the pipeline is 20m/s. The exhaust gas is treated by a first-stage cyclone separator, and the exhaust gas is discharged by a bag filter.

(3) The grass segment was pulverized by a 2 x 132 kW double-axis hammer mill.

(4) The pulverized straw shavings are sieved into a straw coarse material and a straw qualified material by using a square hole sieve having a sieve aperture of 2 mm×2 mm.

(5) grinding the straw coarse material by using a BX5612 sieve ring sander, and conveying the polished straw raw material together with the straw shavings to the 2 mm×2 mm square hole sieve to be polished. The straw straw material is further sieved into straw coarse material and straw qualified material.

(6) Using a chipper and a flaker, shaving and shaving the wood to obtain wood shavings.

(7) conveying the wood shavings to a square hole sieve having a mesh opening diameter of 10 mm×10 mm and a square hole sieve having a mesh opening diameter of 0.2 mm×0.2 mm to sieve the wood shavings into wood coarse aggregates, wood Qualified materials and fine wood materials.

(8) using a pulverizer, pulverizing the wood coarse aggregate, and conveying the pulverized wood coarse aggregate together with the wood shavings to the square hole sieve having a sieve aperture of 10 mm×10 mm, The pulverized wood coarse aggregate is further sieved into a wood coarse aggregate and a straw qualified material.

(9) The straw qualified material and the wood fine material are sent to an airflow sorting machine for airflow sorting.

(10) The wood qualified material is sent to a gas flow sorter for gas separation.

(11) Quantitatively input the mixture of straw qualified material and wood fine material into the surface layer sizing system, the applied adhesive is MDI glue, and the application amount of the MDI glue is the mixture of the straw qualified material and the wood fine material to be sized. 4% of the weight.

(12) Dispensing: The mixture of the uniformly stalked straw qualified material and the wood fine material is divided into the upper surface layer and the lower layer material by a distributor.

(13) The wood qualified material is fed into the core layer sizing system for sizing. The applied adhesive was an MDI adhesive which was applied in an amount of 3.0% by weight of the wood grade to be sized.

(14) Paving: The paving machine successively applies the mixture of straw qualified material and wood fine material after sizing (as the following layer), the wood qualified material after sizing (as core material), and after sizing The mixture of straw qualified material and wood fine material (as the upper surface layer) is paved into a slab of three layers of symmetrical structure.

(15) Pre-compression: The slab is pre-pressed by a pre-press to keep the slab in a certain shape. The slab preload compression ratio is controlled at 45% and the rebound rate is 20%.

(16) Hot pressing: The slab is heated and pressurized by a press to cause a complicated chemical reaction between the water in the raw material of the sheet and the isocyanate of the adhesive, and the reaction product binds the raw materials of the sheet together.

(17) Post-treatment: The pressed wool board is subjected to a post-treatment process such as cold plate, trimming, cooling homogenization, sanding, etc. to obtain a straw particle board.

According to the national standard GB/T4897-2015 of particleboard; according to GB/T 17657-2013 artificial board and veneer board physical and chemical performance test method, according to the above exemplary manufacturing method, the performance indicators are as follows:

Thickness: 18mm

Density: 715kg/m ³

Internal bonding strength: 0.58MPa

Table bonding strength: 1.39MPa

Static bending strength: 20.7MPa

Modulus of elasticity: 2260MPa

Grip screw force: 1310N plate surface, 850N plate edge

2h water absorption thickness expansion rate: 1.96%

Formaldehyde emission: not measured

It can be seen from the physical and chemical performance indexes measured above that the physical and chemical performance indexes of the straw particle board manufactured by the manufacturing method according to the embodiment of the present invention meet the requirements of national standards, and most physical and chemical performance indexes (for example, bonding strength) are greatly improved. Higher than national standards. In particular, since the wood fine material is used for the surface layer, the surface-strength strength of the manufactured straw particle board is relatively high.

Further, in order to study the effect of adding wood fines to the surface layer on the physical and chemical properties of the straw particle board, the comparative test was completed according to the parameters in the following table based on the above similar steps. The results of some tests are as follows:

	实施例Example	对照例Control case
表层原料Surface material	秸秆刨花+木材细料Straw shavings + wood fines	纯秸秆刨花Pure straw shavings
芯层施胶量(％)Core layer sizing amount (%)	2.82.8	3.83.8
厚度(mm)Thickness (mm)	1818	1818
密度(kg/m ³) Density (kg/m ³ )	710710	720720
内结合强度(MPa)Internal bond strength (MPa)	0.520.52	0.470.47
表结合强度(MPa)Table bond strength (MPa)	1.491.49	1.111.11
静曲强度(MPa)Static bending strength (MPa)	17.317.3	14.814.8
弹性模量(MPa)Modulus of elasticity (MPa)	24542454	20672067
板面握钉力(N)Plate holding nail force (N)	11321132	985985
板边握钉力(N)Plate edge holding force (N)	783783	771771
2h吸水厚度膨胀率(％)2h water absorption thickness expansion rate (%)	2.32.3	2.82.8

As can be seen from the above table, by adding the wood fines to the surface layer, the core sizing amount is reduced from 3.8% to 2.8%, and the amount of sizing is compared with the comparative example in which no wood fines are added to the surface layer. The reduction does not reduce the physical and chemical properties of the obtained straw particleboard. That is to say, by adding the wood fine material to the surface layer material, the sizing amount of the core layer can be greatly reduced under the premise of ensuring that the physical and chemical performance indexes of the obtained straw particle board meet the requirements of the national standard, thereby reducing the product cost and improving the product cost. The competitiveness of the product.

According to an exemplary embodiment of the present invention, a straw particle board is provided. As shown in FIG. 2, the straw particle board may include: an upper surface layer 21 comprising straw shavings, wood fines, and isocyanate rubber; and a core layer 22 The core layer comprises wood shavings and isocyanate gum; and a lower layer 23 comprising straw shavings, wood fines and isocyanate gum. The straw particle board may be a straw particle board manufactured according to the manufacturing method of the embodiment shown in Fig. 1.

In one example, the shavings of the straw shavings may be less than 2 mm×2 mm, and the wood fines may be wood shavings having a shaving size of less than 0.2 mm×0.2 mm, and the shaving size of the wood shavings may be 0.2 mm×0.2. In the range of mm ~ 10mm × 10mm.

For the embodiments of the present invention, it should be noted that the embodiments of the present invention and the features of the embodiments may be combined with each other to obtain a new embodiment without conflict.

The above is only the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and the scope of the present invention should be determined by the scope of the claims.

Claims

A method for manufacturing a straw particle board, comprising the steps of:

Preparation of straw shavings: cutting, drying and pulverizing the straw to obtain straw shavings;

Screening of straw shavings: conveying the straw shavings to a first screening device to sieve the straw shavings into straw raw materials and straw qualified materials;

Preparation of wood shavings: shaving and shaving of wood to produce wood shavings;

Screening of wood shavings: conveying the wood shavings to a second screening device to screen the wood shavings into wood coarse aggregates, wood qualified materials, and wood fines;

Processing of wood coarse aggregate: refining the wood coarse aggregate by using a refining device, and conveying the refined wood coarse aggregate together with the wood shavings to the second screening device to be refined The wood coarse material is further sieved into wood coarse material, wood qualified material and wood fine material;

Preparation of a surface layer: preparing a surface layer material from the mixture of the straw qualified material and the wood fine material;

Core material preparation: preparing a core material from the wood qualified material;

Preparation of Straw Particleboard: Using the surface layer material and the core layer material, the straw particle board is obtained by paving, pre-pressing, hot pressing and post-treatment steps.
The method for manufacturing a straw particle board according to claim 1, wherein the preparing the top layer material by using the mixture of the straw qualified material and the wood fine material comprises:

Transferting the straw qualified material and the wood fine material to a first airflow sorting device for airflow sorting; and

And sizing the mixture of the straw qualified material and the wood fine material subjected to airflow sorting to obtain the surface layer material,

And/or, the preparing the core material with the wood qualified material comprises:

Delivering the wood qualified material to a second airflow sorting device for airflow sorting; and

The wood qualified material subjected to gas flow sorting is sized to produce the core material.
The method for manufacturing a straw particle board according to claim 1 or 2, wherein the first screening device comprises a first square hole sieve, and the first square hole sieve divides the straw shavings into straw raw materials. And straw qualified materials.
The method of manufacturing a straw particleboard according to claim 3, wherein the sieve aperture of the first square sieve is in the range of 1.3 mm x 1.3 mm to 2.8 mm x 2.8 mm.
The method for manufacturing a straw particle board according to any one of claims 1 to 4, wherein the second screening device comprises: a second square sieve or a strip sieve; and a third-party sieve, wherein The second square aperture screen or strip screen and the third party aperture screen together sift the wood shavings into wood coarse aggregates, wood grades and wood fines.
The method for manufacturing a straw particle board according to claim 5, wherein the mesh aperture of the second square sieve is in the range of 8 mm × 8 mm to 12 mm × 12 mm, and the sieve aperture of the strip sieve is In the range of 3 mm x 30 mm to 4 mm x 40 mm, the mesh aperture of the third-party perforated screen is in the range of 0.15 mm x 0.15 mm to 0.3 mm x 0.3 mm.
The method of manufacturing a straw particleboard according to claim 3, wherein in the sizing step, the applied adhesive comprises an isocyanate gel.
The method for producing a straw particle board according to claim 7, wherein the step of sizing the mixture of the straw qualified material and the wood fine material subjected to air flow sorting to obtain the surface layer material The application amount of the isocyanate gum is 3.5 to 5.0% by weight of the mixture of the straw qualified material and the wood fine material to be sized;

And/or, in the step of sizing the wood-qualified material subjected to gas flow sorting to obtain the core material, the isocyanate gum is applied in an amount of 2.5 to 3.0 by weight of the wood-qualified material to be sized. %.
The method of manufacturing a straw particleboard according to claim 1, wherein the manufacturing method further comprises the following steps:

Processing of the straw coarse material: using another equipment to refine the straw coarse aggregate, and conveying the refined straw coarse material together with the straw shavings to the first screening device to be refined The straw coarse material is further sieved into straw coarse material and straw qualified material.
The method of manufacturing a straw particle board according to claim 1, wherein the step of preparing the straw particle board comprises:

Dividing the surface layer into an upper surface layer and a top layer material;

Laminating the underlayer layer, the core layer and the upper surface layer in sequence to obtain a slab;

Pre-pressing the slab;

The slab is hot pressed.
The method of manufacturing a straw particle board according to claim 1, wherein the manufacturing method further comprises: drying the wood shavings before conveying the wood shavings to the second screening device.
The method for producing a straw particle board according to claim 1, wherein the straw comprises at least one of rice straw, wheat straw, soybean straw, cotton straw, and hemp straw.
A straw particle board, characterized in that the straw particle board is a straw particle board manufactured according to the manufacturing method according to any one of claims 1-12.
A straw particle board, characterized in that the straw particle board comprises:

In the upper surface layer, the upper surface layer comprises straw shavings, wood fines and isocyanate glue;

a core layer comprising wood shavings and isocyanate gum; and

In the lower layer, the lower layer comprises straw shavings, wood fines and isocyanate gum.