CN1042012C - Composite material and method of producing same - Google Patents
Composite material and method of producing same Download PDFInfo
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- CN1042012C CN1042012C CN90103587A CN90103587A CN1042012C CN 1042012 C CN1042012 C CN 1042012C CN 90103587 A CN90103587 A CN 90103587A CN 90103587 A CN90103587 A CN 90103587A CN 1042012 C CN1042012 C CN 1042012C
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- gypsum
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Abstract
The present invention relates to an improved composite material of which the manufacture method includes the steps of mixing gypsum and the matrix granules of firmer materials in dilute slurry; heating the slurry under a pressurization state to make the gypsum converted into calcium sulphate alpha-hemihydrate; basically dewatering the water in the hot slurry before the hemihydrate is converted into the gypsum again. The obtained materials are the uniform block bodies containing gypsum crystal locked and joined with discontinuous matrix granule in a physical mode. The present invention also relates to an improved wall plate having the advantages of fire resistance, stable size and excellent strength character. The invention has the preparation method that composite block bodies are compressed before the composite block bodies are hydrated into final products.
Description
The present invention relates to a kind of new composite.Specifically, the present invention relates to a kind of gypsum/cellulosic fibre composite that is particularly useful for making construction material and plaster product.Or rather, the present invention relates to a kind of fire-resistant composite gypsum/wood-fiber board.
Some characteristic of gypsum (calcium sulfate dihydrate) makes it very generally be used for preparation industry and building putty material and other building products, particularly plaster wall slab.This raw material source is abundant and general cheap, by dehydration and rehydration, by casting, molded or make useful moulded products with other forming method.And this material does not fire, and size keeps relative stability under the wet atmosphere being exposed to.But because it is the fragility crystalline material, tensile strength and bending strength are quite low, so its purposes generally is confined to the application of non-structure, non-bearing and non-impact absorption aspect.
Plaster wall slab also claims plaster board or dry plate, is made of the rehydration gypsum core that is clipped between the multi-ply paper cover plate, is used for the application of inwall and ceiling aspect in a large number.The paper cover plate plays remarkable effect to the intensity of plaster board, and this but nature can damage its fire resistance.In addition, because the fragility of its gypsum core and be difficult for ailing and the turn of the screw, dry plate commonly used itself can not support heavy hanger or absorb significant the impact.
So, seeking to improve gypsum plaster and building products so far always anti-ly stretch, the means of performances such as crooked, ailing and the turn of the screw, and at present this is very paid attention to.
The another kind of easy acquisition that also is widely used in building materials and cheap material be ligno-cellulosic materials, the cellulosic material of lumber fibre and paper fibers form particularly.For instance, except timber, particle board, fiberboard, film pressure plate, glued board and hard plate (high density fiberboard) are some forms of the ligno-cellulosic materials product of the processing used of building industry.This class material has than better stretch-proof of gypsum and bending strength.But their price general chargeds are higher, and fire resistance is poor, and when being exposed to wet atmosphere following time, usually easily swelling or warpage.Therefore, need provide a kind of circumscribed means that can improve because of the building materials made from cellulosic material.
Once did in conjunction with the trial of the advantageous feature of gypsum and cellulose fibre, particularly wood-fibred in the past and succeedd very limitedly.Cellulose fibre (or other fiber of this respect) is added to trial in gypsum plaster and/or the plaster board core intensity is improved or improves very for a short time, produce any remarkable adhesion between fiber and the gypsum because can not make so far.United States Patent (USP) 4,328,178; 4,239,716; 4,392,896 and 4,645,548 disclose recent example, and wherein wood-fibred or other are natural fiber mixed goes into plaster (calcium sulfate hemihydrate) slurry with the reinforcing material as rehydration plasterboard etc.Similarly, the trial that gypsum particle is added to wood fiber product also is out of use, because this method can not make enough gypsum remain in the product, so do not improve the fire resistance or the dimensional stability of stock in fact.
Recently, some manufacturers have obtained limited success in preparation contains the plate product of mixture of gypsum and lumber fibre or paper fiber.In these methods, gypsum (plaster) and the lumber fibre of calcining or paper fiber and water are mixed, be mixed with slurry, then, simultaneously or plaster rehydration is being suppressed before with one-tenth curing gypsum.
In a kind of such method (prior art method A), be that waste paper is mixed in the slurry aqueous solution with plaster, be discharged on the felt conveyer belt then and dehydration.Thin semihydrate/paper cake winding is wrapped on the cylinder, is accumulated as the thickness of plate, then cutting to length.The unprocessed felt bed of material is stacked on the car between hard plate, and water contract 3-4 hour.Then, will harden plate drying, finishing and sand milling seal as required again.
In a kind of what is called " partial desiccation " method (art methods B), be to do plaster and waste paper mixed.Add the required water of a part of rehydration in second mixer, mixed material forms different layers on continuous conveyor.Remaining required water is sprayed on the several layers, before sending into continuous press, these layers is merged into the multilayer bed course then.Behind initial solidification, cut and repair thick plate, and on support belt, " fully solidify ", dry then.
In another kind of so-called " partial desiccation " method (art methods C), do plaster and wood chip mixed in advance.The water of ice or snow crystal shape is metered in the mixture, is sprayed onto then on the ring bed course on the continuous press bottom.After bed course is pressed into desired thickness, will slowly dissolve, aquation takes place then.Behind the plank final curing, with its cutting, finishing and drying.If do not need, can carry out sanded treatment.
Check result to the industrial sheet material that makes with these methods shows that they are to be made of the gypsum that disperses and the closely knit mixture of fibrous material, promptly compare with even complex, and they are physical mixed better mixing things.Although can say the adhesive that becomes to provide or be used as fiber in these sheet materials to gypsum, do not see that it has any help direct physical lock connection or chemical bonding effect between gypsum crystal and fiber.In addition, no matter be because the molding mode of these sheet materials, still because the mechanical mixture mode of gypsum crystal and fiber, and/or because the caking effect of paper fiber or plaster, these sheet materials do not have all even unicity matter (promptly for example density and intensity) on its aspect.
According to the method (art methods D) that the United States Patent (USP) 4,734,163 of recent issue is introduced, gypsum fine grinding thick or not calcining also mixes with the paper pulp of 5-10%.Mixture is by partial dehydration, forms pie, again with pressure roller further dehydration until the ratio of water/solid particle less than 0.4.Pie is cut into hair plates, is layered between the double steel plate layer after the finishing cutting and puts into autoclave.Temperature in the autoclave is raised to about 140 ℃, so that gypsum changes into calcium sulfate-alpha-hemihydrate.In the follow-up cooling procedure gradually of container sheet material, semihydrate rehydration becomes dihydrate (gypsum), obtains sheet material integral body.Then, with the sheet material drying, the words fine finishining again that needs.
The difference of this method and preceding method is that calcined gypsum carries out in the presence of the paper fiber.
Main purpose of the present invention provides a kind of composite, and this material combines gypsum and other high strength material (as wood fibre), is used to prepare firmer casting product, plaster, building materials or other application.
A relevant purpose provides the method for this composite of preparation.
Of the present invention one more specifically purpose provide the no paper wallboard that constitutes by this composite, it is uniform; Has consistent good intensity (comprise and have the intensity that anti-nail and screw are extracted at this level); Dimensional stability is better, even and containing its intensity also can be maintained under the wet atmosphere; Fire-resistant; With under practical cost, can prepare.
Another specific purposes provide a kind of method for preparing above-mentioned wallboard economically.
Say that briefly in the presence of the matrix granule of the higher material of intensity, the gypsum of pressurization calcining and grinding can be realized main purpose of the present invention in rare slurry according to the present invention.
Specifically, composite provided by the invention comprises a kind of matrix granule that has the reinforcing material in space on its surface and/or a part of body, with calcium sulfate alpha-hemihydrate crystal, wherein described at least calcium sulfate alpha-hemihydrate is a needle-like, and some crystal form in the space of matrix granule and on every side on the spot, thereby form the crystal of calcium sulfate matrix that joins with the matrix granule physical locks.
The method of the above-mentioned composite of manufacturing provided by the invention is included in heating and adds to depress in liquid medium gypsum is calcined, and described liquid medium promotes the growth of needle-like calcium sulfate alpha-hemihydrate crystal and contains many matrix granules that are suspended in the described medium and have the permeable space of described liquid medium in its surface and body.
Terminology used here " gypsum " refers to the calcium sulfate of stablizing under the dihydrate state, i.e. CaSO
42H
2O comprises naturally occurring mineral, the synthetic equivalent that obtains and the dihydrate that is formed by calcium sulfate hemihydrate (plaster) or dehydrate aquation.
Term " matrix granule " refers at the molecule that comprises any material except that gypsum (as fiber, small pieces or thin slice etc.).Also should have enterable space in the described particle, no matter pit, crack, crackle, hollow, or other blemish are as long as can form calcium sulphate crystal within it.This class space also preferably is present in the obvious position of particle, and as can be seen, it is The more the better that the space distributes, and then the physical bond power between gypsum and matrix granule is just big more, and geometrical stability is just good more.The matrix granule material should have the characteristic that gypsum lacks, and preferably has advantages of higher tensile strength and bending strength at least.Lignin fiber cellulose fiber, particularly wood-fibred are the matrix granules that is specially adapted to composite of the present invention and method.So, do not plan material and/or the particle of regarding " matrix granule " as are done qualification, below for simplicity, often use wood-fibred to replace the more term of broad sense.
Duan Shao gypsum and matrix granule do not mix with the liquid of capacity, form rare slurry, add then and depress heating with calcined gypsum, make it be converted into the calcium sulfate alpha-hemihydrate.Though do not make microcosmic mechanism of the present invention as yet clear, it is believed that rare slurry has soaked matrix granule, and the calcium sulfate of dissolving is carried in wherein the space.Semihydrate is nucleation at last, and in the space and near form crystal (preponderating) on the spot with acicular crystal.Need, the crystal modification agent can be added in the slurry.The gained complex is the matrix granule that joins with the calcium sulphate crystal physical locks.The effect of this lock connection not only produces good bonding force between the bigger matrix granule of calcium sulfate and intensity, and has prevented that calcium sulfate from moving out from matrix granule at semihydrate when rehydration becomes dihydrate (gypsum) subsequently.
This material can be dry immediately before its cooling, so that a kind of stable but semihydrate of rehydration afterwards to be provided.In addition; if make it directly change into spendable product form at once; then except the required liquid of rehydration; also to from whole liquid, further isolate composite; mix with other similar composite particles; make required form, and then aquation becomes sclerosis and stable gypsum composite block.
These many composite particles are compacted, are pressed into plate, casting, engraving, molding or form the block of required form with other method before final curing.After final sclerosis, composite can cut, chisel and carve, mends with cramps open, holes and other machining.Moreover, this composite has the dimensional stability and because specific enhancing, particularly intensity and the toughness that the matrix granule material is provided of fire resistance and gypsum.
According to the preferred embodiments of the invention, matrix granule is wood-fibred or wooden fragment.According to the present invention, the method for preparing composite gypsum/wood fiber material be make earlier about 0.5%-wood-fibred about 30%, preferably about 10%-20% (weight) with replenish respectively grind but not the gypsum of calcining mix.Then, make and do to mix thing and mix with enough liquid (preferably water), the formation water content is about rare slurry of 70%-95% (weight).This rare slurry is handled in pressure vessel being enough to make gypsum to change under the temperature of calcium sulfate hemihydrate.In this process,, destroy all fibres caking and whole particles are remained under the suspended state preferably by means of gentle agitation or mixing arrangement continuous stirring slurry.From solution, separate out and again after the crystallization, go out the product slurry at semihydrate, when still awfully hot, be dehydrated into filter cake basically from autoclave discharge.On this point of this method, the unconjugated water of about 70-90% should be removed from slurry.
Composite is in half hydration status if desired, then filter cake is kept at high temperature (as, about 180 °F, promptly 82 ℃), until removing all remaining free water.Then, the filter cake of drying can be ground into powder or granular materials, to be easy to disposal, storage and reshaping.
Other method is, can be immediately to the filter cake material compacting of dehydration, molding or with other method moulding, and be cooled to a certain temperature, under this temperature, calcium sulfate hemihydrate becomes gypsum with aquation, the while original place remain in the wood fibre and near.After aquation finishes, preferably that the block that solidifies is dry rapidly to remove any residual free water.
According to another embodiment of the present invention, provide the method for preparing composite gypsum/wood-fiber board.Mix and the method for autoclave processing gypsum and wood-fibred slurry roughly with above-mentioned identical.The additive that some improves technology or improves performance can be added in the product slurry as accelerator, set retarder, loss of weight filler or the like, is preferably in from autoclave discharge to go out the back and adding before dehydration.The product slurry is discharged on the continuous felt conveyer belt (for example papermaking manipulate type), and removes unconjugated water as much as possible.Initial experiment chamber test shows, can remove water up to 90% in this stage.When the gained filter cake is also awfully hot, its wet pressing is become the plate of desired thickness and/or density.If plate will carry out specific surface texture or laminated surface fine finishining then be preferably among this processing step or afterwards carrying out.In wet pressing, (preferably carry out wet pressing to keep the integrality of product) two things take place along with improving pressure gradually.At first removed extra moisture content (the remaining water of 80-90% according to appointment), filter cake further cools off as a result.But, also may need to provide external refrigeration, so that the bed course temperature of compacting drops to below the rehydration temperature in acceptable time.After rehydration is finished, but cutting plate, and the words finishing again that needs is sent in the kiln dry then.It is enough low that baking temperature preferably should keep, to avoid the calcining more from the teeth outwards of any gypsum.
Composite gypsum/the wood-fiber board that makes according to preceding method provides the synergy of desirable characteristics, the characteristic that also provides existing plate not provide.Compare with plaster board commonly used, this composite fiber plate provides improved intensity, comprises that anti-the pulling out of nail and screw draw characteristic.Compare with timber, fiberboard, particle board, pressboard etc., it also provides higher fire resistance and the dimensional stability under wet atmosphere.And, can prepare the very wide complex fiber material of density and thickness range.As shown in the table, the present invention can prepare a kind of rupture modulus (MOR) and the equal composite plate of gypsum fiber panel products that makes with the prior art processes of introducing previously, but its density is low, thereby in light weight, and cost can be littler.
This area professional read in detail following explanation and with reference to the accompanying drawings after can learn these and other advantage of the present invention.The following drawings has constituted the part of this specification, wherein:
Fig. 1 is the schematic diagram that forms the method for composite according to a scheme of the present invention;
Fig. 2 is the schematic diagram that forms composite plate according to another program of the present invention;
Fig. 3 is the micrograph (100 times) of the SEM (SEM) of one group of wood-fibred;
Fig. 4 is the SEM micrograph (100 times) of one group of composite gypsum/wood-fibred particle;
Fig. 5 is the SEM micrograph (1000 times) in cluster wood-fibred cross section;
Fig. 6 is the SEM micrograph (100 times) in composite particle precursor of the present invention cross section;
Fig. 7 is the SEM micrograph (1000 times) on wood-fibred surface;
Fig. 8 be with Fig. 7 in the SEM micrograph (4000 times) of identical wood-fibred, it shows the gypsum crystal in contiguous cavity.
Fig. 9 (a), 9 (b), 9 (c), 9 (d), 9 (e) and 9 (f) are the SEM micrographs (be respectively 20 times, 100 times, 200 times, 500 times, 1000 times and 1000 times) in gypsum/strand board cross section made from art methods; And
Figure 10 (a), 10 (b), 10 (c), 10 (d) and 10 (e) are the SEM micrographs (be respectively 50 times, 100 times, 500 times, 1000 times and 2500 times) in the composite panel cross section that makes by the present invention.
As Fig. 1 illustrative, this basic skills is to mix not calcined gypsum, matrix granule (wood-fibred) and water earlier to form rare aqueous slurry.Gypsum can be selected the byproduct of raw ore or flue gas desulfurization or phosphoric acid process for use.The purity of gypsum should be higher, promptly preferably at least about 92-96%, and fine grinding to the particle of for example 92-96% for being lower than 100 orders or littler.Bigger particle can make transformation time prolong.Can dry powder or introduce gypsum by means of aqueous slurry.
The source of cellulose fibre can be waste paper, wood pulp, wood chip and/or other string.Fiber fiber that is preferably porous, hollow, cracked and/or asperities is so that its physical geometry can provide the gap or the space of the calcium sulfate that infiltrates dissolving.Under any circumstance, cellulose fibre (as wood pulp) requires to be ground into fragment, the excessive or too small material of size of separation in first being processed, and in some cases, the also material relevant with intensity of extracting in advance and/or the impurity that may have a negative impact to calcined gypsum are as hemicellulose, acetate or the like.
Gypsum that ground and wood-fibred are that the weight ratio of 0.5-30% is mixed with the wood-fibred.The water that adds capacity is with the slurry of preparation into about 5-30% (weight) solids content, although 5-10% (weight) solid particle has been enough to processing and processing on available laboratory equipment effectively so far.
Slurry is joined in the pressure vessel of being furnished with continuous stirring or mixing arrangement.Need, can at this moment crystal modifier (as organic acid) be added in the slip to promote or to hinder crystallization or reduce calcining heat.After closed container, steam is injected in the container, so that the internal temperature of container is brought up between about 212 °F (100 ℃) and about 350 °F (177 ℃) spontaneous pressurization; This lower limit temperature is about actual minimum, under this temperature, calcium sulfate dihydrate will be in due course between in be sintered into the hemihydrate attitude; This ceiling temperature is about the maximum temperature of calcining semihydrate, can not emit to make some calcium sulfate hemihydrates be converted into the risk of dead plaster under this temperature.From the work of having done at present, the temperature of autoclave is preferably in about 285 (140 ℃)-305 (152 ℃) scopes.
When slurry is handled the sufficiently long time (15 minutes according to appointment) under these conditions, from the calcium sulfate dihydrate molecule, will deviate from enough water so that it is converted into the semihydrate molecule.Solution (particle being remained in the suspension by means of continuous stirring) will soak and penetrate in the clearance gap of matrix fiber.When solution reaches capacity, semihydrate with nucleation and the space interior, on and begin to form crystal on every side and along the matrix fiber wall.
Be converted into after semihydrate finishes at dihydrate, can add optional additive and slurry is discharged in the dewater unit.In dewater unit, remove slurry water up to 90%, stay the filter cake that contains about 35% (weight) water.In this stage, but filter cake constitute by lignose with the calcium sulfate hemihydrate crystal of rehydration lock connection, and still can be broken into single composite fibre or spherolite, high density is poured into a mould or is compacted in moulding.Be convenient under the state of this rehydration use in the future but if desired composite is remained on, then must it is dry rapidly (being preferably in about 200 °F promptly 93 ℃), before aquation begins, to remove remaining free water.
In addition, also the filter cake of dehydration directly can be formed the required product shape, and then aquation becomes the block of the curing of sulfate composite calcium dihydrate and wood fibre.For this reason, the filter cake temperature that forms is reduced to is lower than below about 120 °F (49 ℃).Although extracting goes out the temperature that a large amount of water will significantly reduce filter cake in dehydration, may also need auxiliary external refrigeration in the suitable time, to reach desired level.
According to the difference of the accelerator that adds in the slip, set retarder, crystal modifier or other additive, hydration reaction only can be a few minutes to one hour or longer.Because needle-like semihydrate crystal and wood fibre lock connection and carrier fluid shift out the migration of having avoided calcium sulfate in a large number from filter cake, stayed uniform complex.The rehydration interaction energy makes semihydrate become dihydrate with rehydration on every side on every side in the space with on wood-fibred, thereby composite is kept evenly.Crystal growth can also make calcium sulphate crystal be connected on the adjacent fiber, forms very big crystal block, and the humidification of wood-fibred improves intensity.
Before aquation was finished, preferably rapid dry composite block was to remove remaining water.Otherwise the moisture absorption wood-fibred tend to keep in addition absorb after will evaporate not in conjunction with water.If abundant cured calcium sulfate surface layer before removing extra water, then fiber may shrink and deviate from from gypsum when unconjugated water evaporates.Therefore, concerning optimum, before the temperature when being preferably in temperature and dropping to aquation and begin, from composite block, remove excessive free water as much as possible.
After final sclerosis, the desirable character that is provided by these two kinds of components is provided this unique composite.Wood-fibred has increased the intensity of plaster matrix, particularly flexural strength, and gypsum has been protected wood-fibred as coating and adhesive, has given fire resistance and has reduced the expansion that causes through moisture.
A particularly suitable application of composite gypsum/wood fiber material discussed above is to produce composite panel.The method of making composite panel is described in flow chart 2.
From the basic skills of Fig. 1, charging is made up of the gypsum particle of not calcining, refining cellulose fibre (preferably wood-fibred) and water.Gypsum and wood-fibred mix with about 5: 1 ratio respectively, join and make the slurry that solids content preferably is about 5-10% in the enough water.In steam autoclave, be preferably under about 285 to 305 temperature and under self-generated pressure, handle this slurry time enough, so that all gypsum change into fibrous calcium sulfate alpha-hemihydrate.When transforming, preferably slurry is mixed continuously or stir with the caking that destroys fiber and make raw material be in suspended state.
In hot press operation, it is believed that the calcium sulfate of dissolving infiltrates in the space of wood-fibred, then with the semihydrate crystal settling of needle-like in the space, on and on every side and on the surface of wood-fibred.After conversion is finished, add required additive and slurry is come on the dewatering conveyer.When the temperature of product slurry is still higher, removes as much as possible and anhydrate.After the dehydration, before the temperature of filter cake was reduced to the temperature that is lower than rehydration, wet pressing filter cake a few minutes were with the content of further reduction water and reach the thickness and/or the density of end product.If desired,, the temperature of filter cake is reduced to is lower than about 120 °F, thereby the rehydration reaction can take place by means of external refrigeration.Rehydration makes the gypsum recrystallization in situ, and with wood-fibred physical locks connection then at about 110 °F (43 ℃) to 125 °F (52 ℃), be preferably dry rapidly repressed plate under the temperature of about 120 (49 ℃), can cut sclerosis and dry sheet material, re-refine into required specification in addition.
Plate is carried out under the refining situation of special surface in hope, preceding method is equally applicable to improved additional step.For example, can foretell, the dihydrate of the dry grinding that adds can be added in the product slurry of discharging from autoclave; Spray is spilt thereon in its surface or before the filter cake that forms dewaters fully when hot slurry is emitted on the dewatering conveyer, thereby more level and smooth, brighter painted and/or production board with enrichment gypsum surface is provided.When wet pressing is operated, can give filter cake special superficial makings, thereby the plate with texture surface layer is provided.After the wet pressing step, also can before final drying, can carry out the processing of lamination or coating on the surface.In a word, those skilled in the art will be easy to this of this method done many other improvement on the one hand.
Because product is the no cardboard of basic dehydration, therefore dry required energy will be lower than significantly makes the required energy of corresponding conventional plaster board, and this is another foreseeable feature of this method.
Below four kinds of samples of the listed composite of table 1 be to adopt batch systems to make by 4 kinds of different experiments of said method.Under each situation, Duan Shao gypsum charging is not the grey earth with 92-96% less than 100 purpose particles, and the matrix granule charging is the pine slurry of hot machine finish.
All four kinds of sample A, B, C and D are pressed into the plate sample subsequently.Pressurization to dehydrating slurry should make the pressure to plate progressively increase to 48,103,173,243,311 and 380 PSI (pound/square inch) every 30 seconds.But sample A pressurizeed only just arrived the maximum of 173 PSI in 1-0.5 minute.As a result, the temperature of sample A is enough to take place under the dry temperature sample A that is tested mainly is made of the semihydrate material remaining on before the rehydration.
On the other hand, wet pressing sample B, C and D3 minute and then aquation, thus be completed into dihydrate.
Get two samples of each sample, measure its density and MOR, the mean value that secondary is measured is listed in the Table I.Density is to record divided by the volume of measuring by the weight that will measure, and MOR then measures according to ASTM D1037 test method(s).
Table 1
| Sample | Solid | The weight % of aqueous slurry total amount | Calcining heat | Pressure time (branch) | Pressurization back hydration time (branch) | Thickness (inch) | Density pound/inch 3 | MOR (psi) | ||
| The weight % of gypsum solid total amount | The weight % of wood-fibred solid amount | °F | (℃) | |||||||
| A B C D | 83.3％ 83.3％ 89.9％ 89.9％ | 16.7％ 16.7％ 10.1％ 10.1％ | 89.3 89.3 94.3 92.2 | 277 284 295 295 | (136) (140) (146) (146) | 1-1/2 3 3 3 | 0 60 60 60 | 0.688 0.826 1.12 0.558 | 38.8 45 47.6 56.8 | 396 967 841 984 |
The data of Table I show, can produce the very wide composite gypsum/wood-fiber board of density range.In fact, the density range of the sample that made of laboratory is about 26 pounds/cubic feet paramount about 60 pounds/cubic feet.The conclusion of more also having supported the experimental work acquisition of the measured value of MOR and corresponding density data in the Table I, promptly the intensity of composite plate is different with density to a certain degree.It is believed that the intensity of sample C is low may to be to be difficult to handle due to rarer slurry with not refining experimental provision.
In order to show some characteristic of the composite plate that the present invention makes, sample B is delivered and conventional plaster board, wood-fibred and merchant sell the sample of gypsum/fiber composite plate and make comparisons, and as described, some comparative sample is that the technology that has earlier that this specification is discussed is at the beginning made.Purpose relatively only is to select new composite plate in the common environment of the panel products that can compete.Because specific nature can change, even in specific template or sample scope, so the reader need not be interested in being difficult to draw concrete conclusion.Unless note that at last with asterisk (*) and indicate, the listed used data of Table II all are actual measurements and getting in the laboratory.Data with the asterisk mark are taken from available document.
Table 2
| Sample | Explanation | Thickness (inch) | Density pound/inch 3 | Weight (lbs/msf) | MOR (psi) | Nail pulls out admittedly and draws (lbs/F) | Anti-flammability burning expansion stage |
| B D E F G H | The present invention, (17% wood-fibred, 83% plasterboard, (gypsum core paper layer) gypsum wallboard *The wood-fiber board glued board of wood-fiber board (cover plate) intermediate density | 0.826 0.507 0.625 *0.553 1/2 (demarcation) 1/2 (demarcation) | 45.0 41.4 48.6 * 17.2 49.6 37.8 | 3103 1724 2535 * 788 2067 1468 | 967 MD 932 CD 307 MD 672 * CD 224 MD 450 5718 4319 | 25.3 3.0 5.5 N.A. | I level (expection) I level I level *III level or IV level III/IV level III level |
Table 2 (continuing)
| Sample | Explanation | Thickness (inch) | Density pound/inch 3 | Weight (lbs/msf) | MOR (psi) | Nail pulls out admittedly and draws (lbs/F) | Anti-flammability burning expansion stage |
| I J K | Prior art method C, (plaster/wood chip) prior art method B, (paper fiber/plaster) prior art method A, (paper/plaster) | 0.506 0.244 0.477 ** 0.499 | 70 70.3 59.2 75.5 | 2953 1433 2209 3146 | 1153 N.A. N.A. 1062 | 32-100 50-60 40-45 42-70 | I level N.A. N.A. |
MD=machine trend
CD=is horizontal
*Contain pearlite
Can obtain some overview from the data of Table II.Pay particular attention to, can learn from the comparison of density and MOR, new composite gypsum/wood-fiber board can provide the MOR value that adapts to building industry with the density lower than the plaster board that can compete.Also can be observed, the fire performance that new composite plate will provide (can up to the I level), and wood-fiber board can not, simultaneously can also on all directions, provide uniform high strength, particularly can provide to pull out admittedly and draw (nail pull-out) intensity than the bigger nail of conventional I level plaster board.
Though the data of Table II do not have to reflect that but the cost of the composite plate that makes new advances is lower than the cost of great majority competing product, this can expect.The cost of new composite plate of the present invention is higher than very cheap plaster board, but is lower than wood-fiber board.Can expect that the cost of the composite plate that the present invention produces will be lower than other gypsum/group of fibers plywood.
The micrograph of the ESEM shown in Fig. 3-10 (SEM) shows the special-effect of unique complex that the present invention produces.
Fig. 3 has shown the exposed wood-fibred of a tuftlet that is used as matrix granule in the sample of new composite.The observer can see the high aspect ratio and the random geometry of these wood-fibreds.
Fig. 4 shown by method of the present invention and gypsum in conjunction with the similar wood-fibred of the similar tuftlet in back.These fibers seem looser and are evenly coated basically by gypsum.
Fig. 5 has shown the amplification cross section of the wood-fibred that the cluster similar with Fig. 3 separates, and this picture has disclosed used wood-fibred or matrix granule in fact often is many single hollow fibers that are strapped in together.In this picture, wood-fibred (bunch) be compressed slightly.However, still demonstrate typical hollow or space in these particles.
Fig. 6 has shown the similar amplification cross section of matrix wood-fibred, and this wood-fibred is handled by method of the present invention.In this picture, can more easily find out in the hollow of single fiber and the end and the established needle-like gypsum crystal of outer surface of matrix granule.
Fig. 7 has shown surface and the lip-deep several concave points of wood-fibred or space and several discontinuous hemihydrate crystal of matrix wood-fibred.Especially notice that please this crystal has clearly illustrated on one of pit of matrix fiber and formed with the acicular crystal that shows of letter ' X ' in the picture of further amplification shown in Figure 8.
Make comparisons with the resulting inhomogeneous material that mixes of prior art of making plaster board for the even composite that the present invention is produced, Fig. 9 (a) has provided a picture group sheet (enlarged drawing) of the cross section of the plate that makes by prior art method C to 9 (f).For ease of comparing, Figure 10 (a) has provided a picture group sheet (enlarged drawing) of the cross section of composite of the present invention to 10 (f).
Please see Figure 9 (a), wood chip is obviously distinguished with plaster block on every side.Please see Figure 9 (b) again, gypsum as if embedding the amorphous block of wood chip, as embedding filler particles.Further watch Fig. 9 (c) to 9 (f) again, notice is concentrated on the concrete wood chip of indicating with " Y " among Fig. 9 (b), be clear that so more the wood chip that the stone body of paste is embedded in separates.At last, please pay special attention to 9 (f), the open cavity of wood chip does not have any gypsum.
Please see Figure 10 (a) and 10 (b) now, can see the more even character of the composite that makes new advances significantly, differentiable gypsum crystal accumulate in various wood-fibreds around be connected different wood-fibreds on.Please continue to observe Figure 10 (c) to 10 (e), notice be concentrated on a pair of wood-fibred and around wood-fibred end and its and on the many gypsum crystals that form in the hollow of wood-fibred.
As the clear demonstration of picture, when gypsum and wood-fibred add man-hour by method of the present invention, promptly add to depress gypsum is calcined in the slurry that contains the matrix wood-fibred, when then before gypsum rehydration, sloughing the water in the slurry, gypsum can be recrystallized around the neutralization of the space of wood-fibred and phase interlocking connection, thereby the complex of the synergism with useful advantage is provided.Proved that the composite that obtains is especially suitable for use as wallboard.
Though got in touch specific embodiments the present invention has been discussed, after in a single day those skilled in the art have the knack of the present invention, will have done various modifications, change and improvement to composite, its manufacture method and its purposes, these still belong to scope of the present invention.
Claims (26)
1. composite, comprise a kind of matrix granule that on its surface and/or a part of body, has the reinforcing material in space, with calcium sulfate alpha-hemihydrate crystal, it is characterized in that described at least calcium sulfate alpha-hemihydrate is that needle-like and some crystal form on the spot in the space of matrix granule and on every side, thereby form the crystal of calcium sulfate matrix that joins with the matrix granule physical locks.
2. composite as claimed in claim 1 is characterized in that matrix granule is sheet, thin slice or fibrous.
3. composite as claimed in claim 2 is characterized in that matrix granule is the lignin-cellulosic material that comprises wood-fibred.
4. composite as claimed in claim 1, contain the calcium sulfate hemihydrate crystal that comprises gypsum, it is characterized in that this crystal exists with the formation of rehydration needle-like alpha-hemihydrate crystal, described crystal forms in the space of matrix granule and on every side on the spot, thus the basic block uniformly that the gypsum crystal that formation is joined by the disperse matrix practical physical lock with reinforcing material is formed.
5. composite as claimed in claim 3 is characterized in that matrix granule is 0.5 to 30% (weight) of composite.
6. composite as claimed in claim 4 is characterized in that described matrix granule is a wood-fibred, and described block has formed wallboard.
7. composite as claimed in claim 6 is characterized in that the density of block of the compacting of wallboard is 642-802 kilogram/cubic meter.
8. composite as claimed in claim 7 is characterized in that containing the wood-fibred of 10-20% (weight).
9. method of making composite, be included in heating and add to depress in liquid medium gypsum is calcined, it is characterized in that described liquid medium promotes the growth of needle-like calcium sulfate alpha-Fa hydrate crystal and contains many matrix granules that are suspended in the described medium and have the permeable space of described liquid medium in its surface and body.
10. method as claimed in claim 9, thus it is characterized in that comprising that the matrix granule of the gypsum that will grind and reinforcing material and enough liquid mix makes rare slurry of being made up of the liquid of at least 70% (weight); In the presence of matrix granule by depressing the rare slurry of heating gypsum calcined adding, thereby form needle-like calcium sulfate alpha-hemihydrate crystal; Before semihydrate rehydration becomes gypsum from the calcining gypsum and matrix granule isolate most of liquid.
11. the method for manufacturing composite as claimed in claim 10 stirs slurry continuously when it is characterized in that further being included in calcined gypsum and forming semihydrate.
12. method as claimed in claim 11 is characterized in that further comprising adding and depresses the heating slurry and stir slurry when finishing basically continuously up to the gypsum calcining.
13. the method for manufacturing composite as claimed in claim 9, it is characterized in that comprising that the gypsum that will grind and many matrix granules and enough water are mixed together to form slurry, described matrix granule is water insoluble usually, but have the permeable space of the slurry solvent that contains gypsum suspension and/or stable in its surface and/or body, described slurry fully is diluted to slurry solvent to soak the space in the described matrix granule and promotes to add when depressing heating growth at calcium sulfate alpha-semihydrate crystal; Add to depress and be heated to temperature and be enough to gypsum is sintered into the calcium sulfate alpha-hemihydrate, remain on to add and depress the heating slurry, make calcium sulfate molecule nucleation and form crystal on the spot around the neutralization of the space of matrix granule simultaneously; Release of pressure and slurry dewatering to heating; With the solid of drying and dehydrating, to remove residual free water basically, calcium sulphate crystal then still joins with the matrix granule physical locks.
14. the method for manufacturing composite as claimed in claim 13, it is characterized in that further comprising that the temperature that makes slurry and dewatered solid remains on is higher than calcium sulfate hemihydrate rehydration and becomes the required temperature of calcium sulfate dihydrate, till having removed all excessive trip water gagings basically by dehydration and drying.
15. the method for manufacturing composite as claimed in claim 14 is characterized in that further comprising that the temperature that makes slurry remains on is higher than 93 ℃, and is dehydrated basically and dry up to slurry.
16. method as claimed in claim 13, it is characterized in that further being included in temperature and be lower than the solid that the full thing crystal of calcium sulfate half water rehydration becomes the temperature required following cooled dehydrated of calcium sulfate dihydrate, and react to carry out this rehydration before removing residual free water at the block that drying has been dewatered.
17. method as claimed in claim 13, it is characterized in that further comprising that the slurry to heating dewaters to form filter cake, temperature and pressure filter cake then makes the temperature of filter cake be reduced to calcium sulfate hemihydrate rehydration before dry this filter cake and becomes the required temperature of gypsum crystal.
18. method as claimed in claim 13 is characterized in that further comprising that the slurry by heating forms a kind of bed course, makes bed course dewater back wet pressing bed course basically with the density of compression material to thickness that reduces and/or increase.
19. method as claimed in claim 18, the temperature that it is characterized in that further comprising the material that makes compacting is reduced to and is lower than calcium sulfate rehydration and becomes the required temperature of gypsum and this rehydration reaction is proceeded to the gypsum of matrix granule physical locks connection to be connected similar crystal, thereby form complete uniform blocks, dry then this block is to remove residual free water.
20. the method for manufacturing composite as claimed in claim 13 is characterized in that further comprising: be emitted on hot slurry on the porous, shaped surface and remove most of to form filter cake; Filter cake pressurization forming plate, and is reduced in the temperature of plate and removes wherein unnecessary water before being lower than the temperature that calcium sulfate hemihydrate rehydration becomes gypsum; Plate is cooled to the temperature that is lower than rehydration and makes calcium sulfate hemihydrate rehydration become gypsum; With drying plate to remove residual free water.
21. method as claimed in claim 20 is characterized in that matrix granule is a wood-fibred.
22. method as claimed in claim 21 is characterized in that the solid in slurry contains the wood-fibred of 10-20% (weight).
23. method as claimed in claim 20 is characterized in that rare slurry contains the water of 70-95% (weight) at least, slurry is heated to temperature at 140 ℃ to 152 ℃ in pressurizing vessel.
24. each described method among the claim 20-23, the temperature that wherein heats slurry remains on and is higher than 93 ℃, is become plate up to dewatering basically with wet pressing.
25. as each described method among the claim 20-23, wherein will be cooled to temperature by the plate that the pressurization to filter cake forms is 49 ℃, thereby carries out the rehydration of calcium sulfate hemihydrate before final drying.
26. as each described method among the claim 20-23, wherein Tuo Shui filter cake is pressed into plate, this plate is the 642-802 kilograms per cubic meter in aquation and dried density.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN90103587A CN1042012C (en) | 1990-05-17 | 1990-05-17 | Composite material and method of producing same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN90103587A CN1042012C (en) | 1990-05-17 | 1990-05-17 | Composite material and method of producing same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1056457A CN1056457A (en) | 1991-11-27 |
| CN1042012C true CN1042012C (en) | 1999-02-10 |
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| CN90103587A Expired - Lifetime CN1042012C (en) | 1990-05-17 | 1990-05-17 | Composite material and method of producing same |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US7273579B2 (en) * | 2004-01-28 | 2007-09-25 | United States Gypsum Company | Process for production of gypsum/fiber board |
| US7703243B2 (en) * | 2006-02-13 | 2010-04-27 | Usg Interiors, Inc. | Ceiling tile construction |
| CN112341115B (en) * | 2020-10-21 | 2022-04-15 | 中国地质大学（武汉） | A kind of method that utilizes phosphogypsum to prepare paperless surface and fiberless high-strength gypsum board |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3822340A (en) * | 1972-03-27 | 1974-07-02 | Franklin Key | Calcium sulfate whisker fibers and the method for the manufacture thereof |
| US4392896A (en) * | 1982-01-18 | 1983-07-12 | Sakakibara Sangyo Kabushiki Kaisha | Method of producing a gypsum plaster board |
| US4734163A (en) * | 1984-05-25 | 1988-03-29 | Babcock Bsh Aktiengesellschaft | Method of and apparatus for producing gypsum fiber boards (plasterboard) |
-
1990
- 1990-05-17 CN CN90103587A patent/CN1042012C/en not_active Expired - Lifetime
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3822340A (en) * | 1972-03-27 | 1974-07-02 | Franklin Key | Calcium sulfate whisker fibers and the method for the manufacture thereof |
| US4392896A (en) * | 1982-01-18 | 1983-07-12 | Sakakibara Sangyo Kabushiki Kaisha | Method of producing a gypsum plaster board |
| US4734163A (en) * | 1984-05-25 | 1988-03-29 | Babcock Bsh Aktiengesellschaft | Method of and apparatus for producing gypsum fiber boards (plasterboard) |
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| CN1056457A (en) | 1991-11-27 |
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| Date | Code | Title | Description |
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| C06 | Publication | ||
| PB01 | Publication | ||
| C53 | Correction of patent for invention or patent application | ||
| CB02 | Change of applicant information |
Applicant after: Woosgo Enterprise Co., Ltd. Applicant before: Gypsum Co. |
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| COR | Change of bibliographic data |
Free format text: CORRECT: APPLICANT; FROM: GYPSUM CO. TO: VOSGO ENTERPRISE CO., LTD. |
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| C15 | Extension of patent right duration from 15 to 20 years for appl. with date before 31.12.1992 and still valid on 11.12.2001 (patent law change 1993) | ||
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Granted publication date: 19990210 |