CN100336759C

CN100336759C - Fiberboard made of straw and its manufacturing method

Info

Publication number: CN100336759C
Application number: CNB03148168XA
Authority: CN
Inventors: 张光辉
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-07-04
Filing date: 2003-07-04
Publication date: 2007-09-12
Anticipated expiration: 2023-07-04
Also published as: CN1475455A

Abstract

The present invention relates to a fiber board made from straws and a manufacturing method of the fiber board. The fiber board uses dry straws as raw material; the fiber board comprises the components, in weight percentages, 20 to 95% of straw fine fiber, 0 to 80% of wood fiber, 0 to 50% of cement, 0 to 30% of resin, 3 to 10% adhesive and a right amount of water. The manufacturing method of the fiber board comprises the procedures of an extracting and cleaning stage, a cutting-off stage, a slurry discharging stage, a squeezing stage, a sheet material molding stage, etc. The fiber board can utilize maximum straws of large amounts of discarded agricultural and sideline products, rice straws and the like for environmental protection. The fiber board has the advantages of favorable bending strength and tensile strength, low price, fire resistance, water resistance, high intensity and easy processing, and can be totally cut, pulled, nailed and connected.

Description

Straw fibreboard made and manufacture method thereof

Technical field

The present invention relates to a kind of straw fibreboard made, especially utilize medium density fibre board (MDF) or the middle density composite fiber plate and the manufacture method thereof of the straw manufacturing of paddy, wheat class.

Background technology

Past, our ancestors are used as straw in raw material, winter oxen and horses feed, farmers''s fuel of straw-made articless such as the compound of covering room material, cob wall with mat, straw bag, straw rope, straw screen or mat, straw hat, straw sandals of thatched cottage etc., and be positioned over the field at present basically, to increase the organism of soil.Straw is made compost in some place, or attempts to produce saccharides with methods such as microorganism, chemistry, but its efficient is low, and productivity still is unrealized.

Full ripe straw contains have an appointment 36% Mierocrystalline cellulose, 20% xylogen, 22% piperylene, 6% crude protein, 13% ashes, and these compositions mutually combine, and forms complicated polymer structure.Other cereal straws also have closely similar structure, contain a large amount of Mierocrystalline celluloses and xylogen.

Cellulosic chemical structure, D-glucose β-1, the 4-glucoside bound forms polymerization (C ₆H ₁₀O ₅) n, the molecular weight of native state reaches several ten thousand to hundreds of thousands of, be the natural polymer fibrous texture, white is tasteless, water-insoluble, alkaline-resisting, and added water decomposition by acid is glucose, Mierocrystalline cellulose finally can be resolved into glucose fully by the cellulase of specified microorganisms, but durable in, the erosion of most of microbe, patience to pharmaceutical chemicals is also stronger, and cellulosic molecule is assembled the formation fiber in a large number, and its least unit is diameter 0.05 μ m, the molecular beam of the above crystalline texture of length 0.6 μ m, cellulosic fibre is immersed or the dilution buck, noncrystalline field between the molecular beam is by swelling, if immerse strong lye, but then swelling to the crystallization field.

On the other hand,, mainly use timber in existing building decorative sheet field, plywood, plasterboards etc., lagging material mainly use urethane or polystyrene foamed material etc.Though plank and plywood are attractive in appearance, price is high relatively, and particularly plywood is easy to moisture absorption and causes flaggy to be separated from each other.A little less than plasterboard was highly brittle, wet fastness was very poor, in case contact water, or presence of fire, will produce toxic gas, very harmful.

Summary of the invention

The objective of the invention is to utilize the agriculture byproduct straw, produce to have and cut that blind rivet connects performance, can regulate humidity, the inexpensive straw fiber plate with extensive practicality, make this a large amount of waste of straw become environment protecting fiber board.

Of the present inventionly advance a purpose and provide and have extremely fireproof, wet fastness, hardness, the straw composite fiber plate and the manufacture method thereof of surface smoothness.

A kind of straw fibreboard made provided by the present invention is starting material with dry straw, includes straw fine-fibered, lumber fibre, cement, resin, tackiness agent in the component of this fiberboard, and the weight percent of each component is:

Straw fine-fibered 20-95%

Lumber fibre 0-80%

Cement 0-50%

Resin 0-30%

Tackiness agent 3-10%

Water is an amount of

Each component weight sum is 100%.

One side at least at fiberboard among the present invention can be coated with the thick resin of 2 μ m-4mm.

Resin among the present invention can be acrylic acid resin, isobutylene resin, ethenoid resin, silicone resin, polyamide resin or urethane resin.

The manufacture method of straw fibreboard made provided by the present invention comprises following operation:

(A) selected, clean the stage: with the dry immediately keeping of harvested straw, choose high-quality straw then, through spraying water with high pressure, remove in the straw foreign matter such as contained grogs;

(B) the cut-out stage: utilize parting tool such as high speed rotating tool that the straw of cleaning is cut to 1-20mm length;

(C) the blowing stage: will dissolve in the straw immersion alkaline aqueous solution that cut off, the temperature of alkaline aqueous solution is 100-120 ℃, and pressure is 1.5-2.5kg/cm ², heat treated 2-4 hour;

(E) the squeezing stage: utilize suitable squeezing means that straw fiber is applied the merit of physics, promote the fiber pulp;

(F) the plate forming stage: above operation gained fine-fibered slurry is put into forming mould, with 0.3-1.5 ton/m ²Exert pressure through sclerosis in 5 minutes, dry, health, or at the normal pressure compacted under, through 3 days sclerosis, drying, health, is made stock for fibreboard.

Beneficial effect of the present invention is, with the fiberboard that straw is produced as main raw material, the product usability is strong, cuts blind rivet and connects and all can, bending resistance, tensile strength are good, do not produce toxic gas during presence of fire, can regulate humidity, cheap, fire-resistant moisture-proof, the hardness height, processibility is strong, surface smoothing etc.; Can effectively utilize the depleted straw, can also protect environment, reduce the usage quantity of original hardwood plate, the required timber of sawdust-board, for huge contribution is made in environmental protection.

Embodiment

Straw used in the present invention comprises straws such as rice, barley, rye, wheat, oat, wheat straw and corn stalk, the cauline leaf of unifacial leaf yearly plants such as reed rod.

Fibrous plate of the present invention comprises all finishing material sheet materials for building, and lath inserts the heat insulation material of wall body intermediary or sound absorber and sheet material thereof.

In the production process of the required fine-fibered slurry of straw fibreboard made of the present invention, the separation of man-made fiber slurry is as a kind of selection operation, without the production that separates or promptly can be used for through residuum later fiberboard of the present invention.

When straw was gone ahead of the rest the separation chemistry fiber pulp, its rate of recovery was different because of modulating process and purification degree, but the man-made fiber slurry is 33-48% generally speaking, and half man-made fiber slurry is 45-75%, and isolating man-made fiber slurry can be used for stationery production.

No matter fine-fibered of the present invention slurry uses any kind, the physicals of sheet material is not had much influences, and say aspect economic benefit, preferably isolating man-made fiber slurry be can be used for stationery production.

Straw fibreboard made of the present invention is as the criterion with dry weight, is made up of the fine-fibered slurry of 90-97%, the tackiness agent of 3-10%.

Tackiness agent can use any in natural polymer subfamily or the synthetic macromolecule series, as polyurethane binder, improving intensity, be advisable with synthetic macromolecule series in the wet fastness aspect, then be advisable with the natural polymer subfamily aspect environmental protection, the tackiness agent of natural polymer subfamily can be lifted starch, donkey-hide gelatin etc., the tackiness agent of synthetic macromolecule series can be lifted the multiple synthetic resin binder that this industry is generally used, and this is not had particular restriction.

Above adhesive consumption surpasses 10%, then may influence the special-shaped performance of mould and pressing machine, and 3% of less than may influence processability.

The density of above sheet material is 500-800kg/m ³, bending strength (thickness 13mm) is 10-19Mpa.

Add lumber fibre slurry or bits end in the straw fiber plate of the present invention, promptly can be made into composite fiber plate.Be as the criterion with dry weight, by the fine-fibered slurry of 20-80%, the lumber fibre slurry of 10-77% or bits end, the tackiness agent of 3-10% is formed.

Use softwood tree in the past with, the chemistry of deciduous tree, half chemistry, the sheet material of last mixture is starched or considered to be worth doing to mechanical fiber, and its density is 600-850kg/m ³, bending strength (thickness 13mm) is 16-21Mpa, all increases to some extent.

In the above specific examples, its product equals bits end plate in the past, and the hardboard material is used straw fiber with, can reduce cost, and reduces the timber usage quantity, thereby reaches the effect that promotes environment protection.

Another kind of straw composite fiber plate of the present invention also has a kind of ratio, is 50-95% be as the criterion straw fine-fibered slurry of dry weight promptly, and cement is 5-50%.

In this case, need not use tackiness agent separately, its bending strength and compressive strength are different because of the cement usage quantity, and bending strength scope (thickness 13mm) is 25-38Mpa.

Another type straw composite fiber plate of the present invention is by the straw fine-fibered slurry of 70-95%, 5-30% has acrylic resin, isobutylene resin, ethenoid resin, silicone resin, polyamide resin or urethane resin are formed, and it is inner that these resins fully are impregnated into the fine-fibered slurry, its bending strength (thickness 13mm) is different because of resin kind, pickup, dipping concentration etc., and its scope is 28-47Mpa.

Another type straw fiber plate of the present invention or composite fiber plate apply the acrylic resin that mean thickness is 2 μ m-4mm in one side at least, isobutylene resin, ethenoid resin, silicone resin, polyamide resin, urethane resin, carclazyte or nickel, this operation can improve wet fastness and water-repellancy, increases glossiness.

The resin kind that is used for above coat does not have specific limited, so long as the material of the common use of this industry all can, general available acrylic resin, isobutylene resin, ethenoid resin, silicone resin, polyamide resin, polyurethane resin etc., preferably use high acrylic resin of transparency and ethenoid resin, acrylic resin can select for use solid type powder content to reach the material of 30-60%, and ethenoid resin can select for use solid type powder content to reach the material of 10-25%, these resins are preferably diluted with appropriate solvent, for example press the 20-40% mixed and use toluene or acetone,, improve the production efficiency of operation to promote the equilibrium degree of coat, also can replace resin with inorganics carclazyte or nickel as required according to the method for a preceding part.

Straw fiber plate of the present invention can add sanitas, the incombustible agent of 0.1-0.5% as required, functional additives such as antisatics, and this item is that this industry is in common knowledge, hands-free herein.

Below, further describe the present invention by examples of implementation.

Embodiment 1: the production of fine-fibered slurry

Utilize rotary cutter to fritter selected, the clean straw of process by the 10-15mm size, put into sodium hydroxid 75g and caustic soda 50g in pressure kettle, normal-temperature dissolution immerses straw, at 120 ℃, and pressure 2kg/cm ²Condition under blowing handled about three hours.

Cooling was removed alkali components in 5 minutes with clean water washing then, and drying obtains the fine-fibered of moisture content 80% and starches.

Embodiment 2: the manufacturing of fine-fibered slurry

Embodiment 1 is removed the fiber slurry centrifugation (300g, 3 minutes) of alkali components and isolate the upper strata that the man-made fiber slurry residual is still arranged, obtain residue precipitated fiber slurry residual thing, be the fine-fibered slurry.

Embodiment 3: the manufacturing of fiberboard

Be as the criterion with dry weight, get the fine-fibered slurry 95% of embodiment 1, flour paste 5% stirs, and puts into mould, with 0.5 ton/m ²Exert pressure three minutes was placed normal temperature 24 hours, was fiberboard.

The density of this fiberboard is 527kg/m2, and bending strength (thickness 13mm) is 11.6Mpa.

Embodiment 4: the manufacturing of composite fiber plate

Be as the criterion with dry weight, get the fine-fibered slurry 25% of embodiment 1, Canadian softwood tree man-made fiber slurry 72%, tackiness agent 3% stirs, and puts into mould, with 0.8 ton/m ²Exert pressure three minutes, placed normal temperature 24 hours, be composite fiber plate.

The density of this composite fiber plate is 713kg/m ³, bending strength (thickness 13mm) is 18.3Mpa.

Embodiment 5: the manufacturing of conjugated fibre slurry

Be as the criterion with dry weight, get the fine-fibered slurry 70% of embodiment 2, cement 30% stirs, and puts into and supports in the tool health three days, is composite fiber plate.

The bending strength of this composite fiber plate (thickness 13mm) is 31.2Mpa.

Embodiment 6: the manufacturing of composite fiber plate

With the weight of embodiment 1 is that 80% fine-fibered slurry is that 20% acrylic resin stirs with weight, puts into the mould that is kept 90 ℃ of temperature by water jacket, with 0.8 ton/m ²Exert pressure made it in 15 minutes the sclerosis, be composite fiber plate.

The bending strength of this fiberboard (thickness 13mm) is 34.9Mpa.

Embodiment 7: the manufacturing of composite fiber plate

At the coated on both sides urethane liquid of the fiberboard of embodiment 3, dry and hardened 5 minutes under 120 ℃ of conditions, to form the polyurethane-coated layer of thickness 2mm.

The bending strength of this composite fiber plate (thickness 13mm) is 13.8Mpa.

As mentioned above, fiberboard of the present invention can maximally utilise straws such as a large amount of discarded agricultural byproducts straw, can protect environment; cut blind rivet connect all can, bending strength and tensile strength are good, and toxic gas does not take place during presence of fire; can regulate humidity; cheap, fire-resistant water-fast, the intensity height; be easy to processing as surface smoothing etc.; reduce hardboard in the past, consider the timber usage quantity of last plate to be worth doing, for environmental protection contributes.

Claims

1, a kind of stalk fibreboard made is a raw material with dry stalk, it is characterized in that, includes stalk fine-fibered, lumber fibre, cement, resin, tackiness agent in the component of this fiberboard, and the weight percent of each component is:

Stalk fine-fibered 20-95%

Lumber fibre 0-80%

Cement 0-50%

Resin 0-30%

Tackiness agent 3-10%

Water is an amount of

Each component sum is 100%, and is coated with the thick resin of 2 μ m-4mm in the one side at least of fiberboard.

2, stalk fibreboard made according to claim 1 is characterized in that: described resin is acrylic resin, isobutylene resin, ethenoid resin, silicone resin, polyamide resin or urethane resin.

3, the manufacture method of the described stalk fibreboard made of claim 1 is characterized in that, this method comprises following operation:

(A) selected, the clean stage: with the dry immediately keeping of harvested stalk, choose high-quality stalk then,, remove contained grogs foreign matter in the stalk through spraying water with high pressure;

(B) the cut-out stage: utilize the high speed rotating tool parting tool that the stalk of cleaning is cut to the 1-20 mm length;

(C) the blowing stage: will dissolve in the stalk immersion alkaline aqueous solution that cut off, the temperature of alkaline aqueous solution is 100-120 ℃, and pressure is 1.5-2.5 kilogram/square centimeter, heat treated 2-4 hour;

(E) the squeezing stage: by the squeezing means stalk fibre is pressurizeed, promote the fiber pulp;

(F) the plate forming stage: above operation gained fine-fibered slurry and tackiness agent stirred put into forming mould, with 0.3-1.5 ton/square metre exert pressure, through sclerosis in 5 minutes, dry, health, or at the normal pressure compacted under, through 3 days sclerosis, drying, health, make fiberboard;

(G) the coating stage: the one side at least at above-mentioned fiberboard applies the thick resin of 2 μ m-4mm.

4, the manufacture method of stalk fibreboard made according to claim 3 is characterized in that: the squeezing means in the above-mentioned operation (E) are for adopting a pair of rolling cylinder to the stalk fibre pressure treatment.

5, the manufacture method of stalk fibreboard made according to claim 3 is characterized in that: the alkaline aqueous solution in the above-mentioned operation (C) is the alkaline aqueous solution of at least a compound in lime, caustic soda, sodium hydroxide or the sodium sulphite.