阅读说明：本技术 一种阻燃耐高温定向刨花板及其制备方法 (Flame-retardant high-temperature-resistant oriented strand board and preparation method thereof ) 是由 张芳焕 霍子微 葛立军 李晓升 杨忠华 于 2019-10-09 设计创作，主要内容包括：本发明提供一种阻燃耐高温定向刨花板,包括表层和芯层,表层由大刨花组成；所述芯层由大刨花和细小刨花组成,表层与芯层铺装夹角为45~90°。本发明还提供一种阻燃耐高温定向刨花板的制备方法,包括刨花、刨花初洗、干燥、刨花复洗、沥液、平衡、固化、干燥、混匀、施胶、铺装、热压、裁边、砂光。本发明的有益效果为：本发明的阻燃耐高温定向刨花板热稳定性好,受热不易分层、开裂,能够保证其阻燃性能稳定；受热不易释放有毒物质；加入的阻燃成分能够有效附着于刨花表面,阻燃性能好,能够耐高温侵袭；物理力学性能好,耐用性好。(The invention provides a flame-retardant high-temperature-resistant oriented shaving board, which comprises a surface layer and a core layer, wherein the surface layer is composed of large shavings and small shavings, the core layer is composed of large shavings and small shavings, and the paving included angle between the surface layer and the core layer is 45 ~ 90 degrees.)

1. The flame-retardant high-temperature-resistant oriented strand board comprises a surface layer and a core layer, and is characterized in that the mass ratio of the surface layer to the core layer is 55 ~ 70% to 30 ~ 45%, the surface layer is composed of large wood shavings, the core layer is composed of large wood shavings and small wood shavings, and the mass ratio of the large wood shavings to the small wood shavings is 70 ~ 80% to 20 ~ 30%.

2. The flame-retardant high-temperature-resistant oriented strand board as claimed in claim 1, wherein the included angle between the surface layer and the core layer is 45 ~ 90 degrees, the large wood shavings have the dimensions of 60 ~ 120mm in length, 12 ~ 25mm in width and 0.4 ~ 0.9.9 mm in thickness, and the small wood shavings have the dimensions of 10 ~ 25mm in length, 4 ~ 6mm in width and 0.4 ~ 0.9mm in thickness.

3. A preparation method of a flame-retardant high-temperature-resistant oriented strand board is characterized by comprising the following steps: wood shavings, primarily washing wood shavings, drying, secondarily washing wood shavings, draining, balancing, curing, drying, uniformly mixing, gluing, paving, hot pressing, cutting edges and sanding.

4. The method of preparing a flame retardant high temperature resistant oriented strand board according to claim 3, wherein the strands are initially washed, large strands and fine strands are respectively immersed in 2 times of volume of initial washing liquid, the initial washing pressure is 0.9 ~ 1.5.5 MPa, the stirring speed is 5RPM, and the initial washing time is 30 ~ 40 min;

the initial washing liquid is an aqueous solution containing ammonium polyphosphate, zinc carbonate and sodium metaborate, wherein the weight ratio of the ammonium polyphosphate: zinc carbonate: the ratio of the parts by weight of the sodium metaborate is 2:5: 3.

5. The method for preparing the flame-retardant high-temperature-resistant oriented strand board according to claim 3, wherein the wood shavings are re-washed, large wood shavings and small wood shavings are respectively immersed into 2 times of re-washing liquid, the re-washing pressure is 0.8 ~ 1.2.2 MPa, the stirring speed is 5RPM, and the re-washing time is 20 ~ 30 min;

the compound washing liquid is an aqueous solution containing sodium metaborate and modified nano magnesium hydroxide, wherein the sodium metaborate: the weight ratio of the modified nano magnesium hydroxide is 3: 5;

the modified nano magnesium hydroxide is prepared by placing nano magnesium hydroxide with the particle size of 50 ~ 80nm into 10% polyvinyl alcohol aqueous solution, stirring at the speed of 500 ~ 700RPM and the temperature of 65 ~ 70 ℃ for 30min, heating to 80 ~ 90 ℃ and heating for 20 min.

6. The method for preparing the flame-retardant high-temperature-resistant oriented strand board according to claim 3, wherein the balancing comprises standing the drained big wood shavings and small wood shavings for 12 ~ 18 hours respectively, and keeping the standing temperature at 20 ~ 25 ℃ and the pressure at-0.02 ~ -0.01 MPa.

7. The method for preparing the flame-retardant high-temperature-resistant oriented strand board according to claim 3, wherein the cured large wood shavings and the small wood shavings after the balance are respectively heated for 5 ~ 10min by using infrared light, wherein the heating temperature is 100 ~ 130 ℃, and the wavelength of the infrared light is 3 ~ 7 μm.

8. The method for preparing the flame-retardant high-temperature-resistant oriented strand board according to claim 3, wherein in the step of drying, the solidified large wood shavings and the solidified fine wood shavings are respectively dried at 90 ~ 110 ℃ until the moisture content of the wood shavings is less than 4.0%;

and uniformly mixing, namely uniformly mixing the dried large wood shavings and the dried small wood shavings according to a preset proportion to obtain the mixed wood shavings.

9. The method for preparing the flame-retardant high-temperature-resistant oriented strand board according to claim 3, wherein the glue is applied, the big wood shavings and the mixed wood shavings are respectively applied with glue, the glue application amount is 9% of the total mass of the glued wood shavings, and the adhesive is a modified urea-formaldehyde resin adhesive;

the modified urea-formaldehyde resin adhesive is prepared by mixing the urea-formaldehyde resin adhesive, the nano silicon carbide ceramic and the aluminum silicate fiber particles, and shearing at a high speed, wherein the shearing speed is 3000-;

the particle size of the nano silicon carbide ceramic is 80 ~ 100nm, the particle size of the aluminum silicate fiber particle is 2 ~ 4 microns, and the weight ratio of the urea-formaldehyde resin adhesive to the nano silicon carbide ceramic to the aluminum silicate fiber particle is 80 ~ 85:5 ~ 10: 8 ~ 15.

10. The method for preparing the flame-retardant high-temperature-resistant oriented strand board according to claim 3, wherein the lower surface layer, the core layer and the upper surface layer are paved in three layers according to a preset specification, wherein the number of the wood shavings of the lower surface layer is equal to that of the upper surface layer, the paving included angle between the surface layer and the core layer is 45 ~ 90 degrees, the surface layer is made of large wood shavings, and the core layer is made of mixed wood shavings.

Technical Field

The invention relates to the field of oriented strand boards, in particular to a flame-retardant high-temperature-resistant oriented strand board and a preparation method thereof.

Background

Oriented strand board is one of the new shaving board varieties, when the shavings are paved and formed, the shavings mixed with glue are longitudinally arranged according to the fiber direction of the shavings on the upper surface layer and the lower surface layer of the oriented strand board, and the shavings on the core layer are transversely arranged to form a three-layer board blank, so that the oriented strand board is manufactured through hot pressing. The shape of such particle boards requires a high aspect ratio and a thickness which is slightly thicker than the strands of conventional particle boards. The directional paving method comprises mechanical orientation and electrostatic orientation. The former is suitable for directional paving of large wood shavings, and the latter is suitable for directional paving of small wood shavings. Oriented paving of the oriented strand board ensures that the oriented strand board has the characteristic of higher strength in a certain direction, and the oriented strand board is often used as a structural material instead of plywood.

Because the directional shaving board has uniform structure and good processing performance, the directional shaving board can be processed into a board with a large width according to requirements, is a raw material for manufacturing furniture with different specifications and styles, and is also a necessary raw material for manufacturing carriages of buildings, trains and automobiles. Furthermore, the finished oriented strand board does not need to be dried again, can be used as it is, and has good sound absorption and sound insulation properties, and thus has been widely used in recent years.

The conventional treatment method of the flame-retardant oriented strand board mainly comprises the following steps: firstly, coating fireproof paint on the surface of a shaving board; secondly, refractory materials are pasted on the surface of the shaving board; thirdly, the wood shavings are subjected to flame retardant treatment. The applicant finds that in the existing flame-retardant oriented strand board and the manufacturing process thereof, the added flame-retardant components or the flame-retardant treatment of the boards improve the flame-retardant performance of the oriented strand board, but have adverse effects on the physical properties and other properties of the oriented strand board, and a person skilled in the art cannot find a proper technical means for achieving the balance of the flame-retardant performance of the oriented strand board and other required properties.

CN107379141A discloses a modified flame-retardant oriented strand board and a preparation method thereof, which uses silicon dioxide to modify a flame retardant, and uses the flame retardant to perform flame-retardant treatment on the oriented strand board. The patent has the following defects: the introduced flame-retardant modified component, namely silicon dioxide, influences the bonding effect of the urea-formaldehyde resin adhesive on the planing pieces in the oriented strand board, and the associativity among the planing pieces is reduced, so that the oriented strand board is poor in thermal stability, and is easy to delaminate and crack when heated, and the inherent flame-retardant property is easy to lose.

CN105946087A discloses a flame retardant shaving board and a preparation method thereof, wherein the flame retardant shaving board is prepared by adding a compound flame retardant and an adhesive into dried shavings and extruding the mixture, which has the following disadvantages: the components such as zinc stearate, a waterproof agent and the like in the flame retardant affect the bonding effect of the urea-formaldehyde resin adhesive on the planing pieces in the oriented strand board, and the bonding property among the planing pieces is reduced, so that the oriented strand board has poor thermal stability, is easy to delaminate and crack when heated, and is easy to lose the required flame retardant property.

CN104760111A discloses a flame-retardant shaving board and a production method thereof, wherein a spraying mode is adopted, and flame-retardant liquid is sprayed on the shaving board, and then the finished flame-retardant shaving board is prepared after drying, gluing, paving and hot pressing. The patent has the following defects: the flame-retardant treatment mode of the shaving board has the advantages that flame-retardant components are not easy to attach to the surfaces of the shaving boards, the flame retardant is seriously lost, the waste of the flame retardant is caused, and the flame-retardant effect of the shaving board is not ideal.

In summary, the following technical problems exist in the existing flame-retardant oriented strand board and the preparation method thereof:

(1) in the existing flame-retardant oriented strand board, the added flame-retardant components can influence the bonding of the urea resin adhesive to the flappers, the bonding property among the flappers is reduced, and the bonding strength in a high-temperature environment is low;

(2) in the existing preparation process of the flame-retardant oriented strand board, the added flame-retardant components are not easy to attach to the surfaces of the strands, and the loss of the flame retardant is serious.

Disclosure of Invention

In order to solve the defects in the prior art, the invention provides a flame-retardant high-temperature-resistant oriented strand board and a preparation method thereof, aiming at overcoming the following technical problems:

(1) the problems that the added flame-retardant components of the conventional flame-retardant oriented strand board can influence the bonding of the urea resin adhesive to the flappers, the bonding performance among the flappers is reduced, and the bonding strength in a high-temperature environment is low are solved;

(2) the problems that in the existing preparation process of the flame-retardant oriented strand board, flame-retardant components are not easy to attach to the surfaces of strands, and the loss of flame retardant is serious are solved.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a flame-retardant high-temperature-resistant oriented strand board comprises a surface layer and a core layer;

the mass ratio of the surface layer to the core layer is 55 ~ 70% to 30 ~ 45%;

the paving included angle between the surface layer and the core layer is 45 ~ 90 degrees;

the surface layer consists of large wood shavings, the core layer consists of large wood shavings and small wood shavings, and the mass ratio of the large wood shavings to the small wood shavings is 70 ~ 80% to 20 ~ 30%;

the big wood shavings have the size of 60 ~ 120mm in length, 12 ~ 25mm in width and 0.4 ~ 0.9.9 mm in thickness;

the fine wood shavings were 10 ~ 25mm long, 4 ~ 6mm wide and 0.4 ~ 0.9.9 mm thick.

A method for preparing flame-retardant high-temperature-resistant oriented strand board comprises shaving, primarily washing the shaving, drying, re-washing the shaving, draining, balancing, curing, drying, uniformly mixing, gluing, paving, hot-pressing, cutting edges and sanding.

The wood shaving method is characterized in that large-diameter logs are cut and shaved by a shaving machine to obtain large wood shavings and small wood shavings with preset specifications. The large-diameter log is eucalyptus or poplar.

The wood shaving is primarily washed, large wood shavings and small wood shavings are respectively immersed into primary washing liquid with the volume of 2 times, the primary washing pressure is 0.9 ~ 1.5.5 MPa, the stirring rotating speed is 5RPM, and the primary washing time is 30 ~ 40min, the primary washing liquid is an aqueous solution containing ammonium polyphosphate, zinc carbonate and sodium metaborate, wherein the weight ratio of the ammonium polyphosphate to the zinc carbonate to the sodium metaborate is 2:5: 3.

And (3) drying, namely drying the large wood shavings and the small wood shavings which are primarily washed at 50 ~ 60 ℃ respectively until the water content of the wood shavings is less than 12.0%.

The wood shaving backwashing is characterized in that large wood shavings and small wood shavings are respectively immersed into backwashing liquid with the volume 2 times, the backwashing pressure is 0.8 ~ 1.2.2 MPa, the stirring rotating speed is 5RPM, and the backwashing time is 20 ~ 30min, wherein the backwashing liquid is an aqueous solution containing sodium metaborate and modified nano-magnesium hydroxide, and the weight part ratio of the sodium metaborate to the modified nano-magnesium hydroxide is 3: 5.

The modified nano magnesium hydroxide is prepared by placing nano magnesium hydroxide with the particle size of 50 ~ 80nm into 10% polyvinyl alcohol aqueous solution, stirring at the speed of 500 ~ 700RPM and the temperature of 65 ~ 70, stirring for 30min, heating the nano magnesium hydroxide at the temperature of 80 ~ 90 ℃ for 20min, and obtaining the modified nano magnesium hydroxide.

And the leaching solution is used for respectively leaching the re-washed large wood shavings and the small wood shavings until no continuous water drops drop from the wood shavings.

And (3) balancing, standing the drained big wood shavings and small wood shavings for 12 ~ 18 hours respectively, and keeping the standing temperature at 20 ~ 25 ℃ and the pressure at-0.02 ~ -0.01 MPa.

And (3) curing, namely heating the balanced large wood shavings and the balanced small wood shavings for 5 ~ 10min by using infrared light respectively, wherein the heating temperature is 100 ~ 130 ℃, and the wavelength of the infrared light is 3 ~ 7 mu m.

And drying, namely respectively drying the cured large wood shavings and the cured small wood shavings at the temperature of 90 ~ 110 ℃ until the water content of the wood shavings is less than 4.0%.

And uniformly mixing, namely uniformly mixing the dried large wood shavings and the dried small wood shavings according to a preset proportion to obtain the mixed wood shavings.

The glue is applied to the large wood shavings and the mixed wood shavings respectively, the glue application amount is 9% of the total mass of the wood shavings to be applied, the adhesive is a modified urea-formaldehyde resin adhesive, the modified urea-formaldehyde resin adhesive is prepared by mixing a urea-formaldehyde resin adhesive, nano silicon carbide ceramics and aluminum silicate fiber particles, and performing high-speed shearing dispersion, wherein the shearing rotation speed is 3000-5500RPM and the shearing time is 15-20min, the modified urea-formaldehyde resin adhesive is prepared, the particle size of the nano silicon carbide ceramics is 80 ~ 100nm, the particle size of the aluminum silicate fiber particles is 2 ~ 4 microns, and the weight part ratio of the urea-formaldehyde resin adhesive to the nano silicon carbide ceramics to the aluminum silicate fiber particles is 80 ~ 85:5 ~ 10: 8 ~ 15.

The method comprises the steps of paving, namely paving in three layers, and paving a lower surface layer, a core layer and an upper surface layer in sequence according to a preset specification, wherein the number of the wood shavings of the lower surface layer is equal to that of the upper surface layer, the paving included angle between the surface layer and the core layer is 45 ~ 90 degrees, the surface layer is made of large wood shavings, and the core layer is made of mixed wood shavings.

And hot pressing, namely hot pressing the paved wood shavings, wherein the hot pressing temperature is 190 ~ 210 ℃ at 210 ℃.

Finally, the flame-retardant high-temperature-resistant oriented strand board is prepared by edge cutting and sanding.

Compared with the prior art, the invention has the beneficial effects that:

(1) the flame-retardant high-temperature-resistant oriented strand board disclosed by the invention is good in thermal stability, the bonding strength among strands reaches 0.31MPa at 250 ℃, the strands are not easy to delaminate and crack when heated, and the flame-retardant performance of the oriented strand board can be ensured to be stable;

(2) the flame-retardant high-temperature-resistant oriented strand board is not easy to release toxic substances when being heated, wherein the formaldehyde release amount in a normal-temperature environment is 0.08 ~ 0.12.12 mg/m³The formaldehyde emission in the environment of 200 ℃ reaches 0.09 ~ 0.12.12 mg/m³The smoke-generating toxicity risk grade of the board is not less than 25mg/L when the board is burnt, and the fire safety is high;

(3) the flame-retardant high-temperature-resistant oriented strand board disclosed by the invention has the advantages that the added flame-retardant components can be attached to the surfaces of strands, the flame-retardant property is good, and the high-temperature-resistant oriented strand board can resist high-temperature attack, and specifically comprises the following components: index of combustion growth rate FIGRA_0.2MJ64W/s, 72s ignition time and 600s total heat release THR_600S3.7MJ, flame tip height of 12mm in 60s, no burning drop/particle in 600s, smoke generation rate index (SMOGRA) of 5.7m²/s²；

(4) The flame-retardant high-temperature-resistant oriented strand board disclosed by the invention has the advantages of good physical and mechanical properties, good durability, difficulty in layering, bulging and cracking, and specifically comprises the following components:

(5) the flame-retardant high-temperature-resistant oriented strand board disclosed by the invention is low in moisture absorption, and the 24-hour water absorption expansion rate reaches 5.3%;

(6) the flame-retardant high-temperature-resistant oriented shaving board has good surface finishing property, and does not influence surface processing, spraying and finishing in the later period.

Detailed Description

In order to more clearly understand the technical features, objects, and effects of the present invention, specific embodiments of the present invention will now be described.