CN116041025A - Method for circularly preparing 3D printing sound absorbing material by using waste gypsum board - Google Patents

Method for circularly preparing 3D printing sound absorbing material by using waste gypsum board Download PDF

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CN116041025A
CN116041025A CN202310040023.4A CN202310040023A CN116041025A CN 116041025 A CN116041025 A CN 116041025A CN 202310040023 A CN202310040023 A CN 202310040023A CN 116041025 A CN116041025 A CN 116041025A
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powder
printing
gypsum board
regenerated
absorbing material
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魏永起
马晓嵩
姚武
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Tongji University
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Tongji University
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    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • C04B28/14—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing calcium sulfate cements
    • C04B28/145—Calcium sulfate hemi-hydrate with a specific crystal form
    • C04B28/146—Calcium sulfate hemi-hydrate with a specific crystal form alpha-hemihydrate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B28—WORKING CEMENT, CLAY, OR STONE
    • B28B—SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER
    • B28B1/00—Producing shaped prefabricated articles from the material
    • B28B1/001—Rapid manufacturing of 3D objects by additive depositing, agglomerating or laminating of material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y10/00—Processes of additive manufacturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y70/00—Materials specially adapted for additive manufacturing
    • B33Y70/10—Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B11/00—Calcium sulfate cements
    • C04B11/02—Methods and apparatus for dehydrating gypsum
    • C04B11/024—Ingredients added before, or during, the calcining process, e.g. calcination modifiers
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B11/00—Calcium sulfate cements
    • C04B11/02—Methods and apparatus for dehydrating gypsum
    • C04B11/028—Devices therefor characterised by the type of calcining devices used therefor or by the type of hemihydrate obtained
    • C04B11/032—Devices therefor characterised by the type of calcining devices used therefor or by the type of hemihydrate obtained for the wet process, e.g. dehydrating in solution or under saturated vapour conditions, i.e. to obtain alpha-hemihydrate
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B11/00—Calcium sulfate cements
    • C04B11/26—Calcium sulfate cements strating from chemical gypsum; starting from phosphogypsum or from waste, e.g. purification products of smoke
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
    • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
    • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
    • E04B1/74—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls
    • E04B1/82—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls specifically with respect to sound only
    • E04B1/84—Sound-absorbing elements
    • E04B1/8409—Sound-absorbing elements sheet-shaped
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00034—Physico-chemical characteristics of the mixtures
    • C04B2111/00181—Mixtures specially adapted for three-dimensional printing (3DP), stereo-lithography or prototyping
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
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    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/52—Sound-insulating materials
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04B—GENERAL BUILDING CONSTRUCTIONS; WALLS, e.g. PARTITIONS; ROOFS; FLOORS; CEILINGS; INSULATION OR OTHER PROTECTION OF BUILDINGS
    • E04B1/00—Constructions in general; Structures which are not restricted either to walls, e.g. partitions, or floors or ceilings or roofs
    • E04B1/62—Insulation or other protection; Elements or use of specified material therefor
    • E04B1/74—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls
    • E04B1/82—Heat, sound or noise insulation, absorption, or reflection; Other building methods affording favourable thermal or acoustical conditions, e.g. accumulating of heat within walls specifically with respect to sound only
    • E04B1/84—Sound-absorbing elements
    • E04B2001/8457—Solid slabs or blocks
    • E04B2001/8476—Solid slabs or blocks with acoustical cavities, with or without acoustical filling
    • E04B2001/848—Solid slabs or blocks with acoustical cavities, with or without acoustical filling the cavities opening onto the face of the element
    • E04B2001/8485—Solid slabs or blocks with acoustical cavities, with or without acoustical filling the cavities opening onto the face of the element the opening being restricted, e.g. forming Helmoltz resonators
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies
    • Y02W30/91—Use of waste materials as fillers for mortars or concrete

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Abstract

The invention provides a method for circularly preparing a 3D printing sound absorbing material by using waste gypsum boards, which comprises the following steps: step S1, treating the waste gypsum board to obtain waste gypsum board powder, and preparing regenerated alpha-hemihydrate gypsum powder by using the waste gypsum board powder through a normal-pressure hydrothermal method; s2, doping hydrophobic nano silicon dioxide, soluble starch, sodium oxalate and 2488 PVA micro powder into the regenerated alpha-hemihydrate gypsum powder for synergistic modification to obtain regenerated 3D printing gypsum powder; and S3, 3D printing is carried out by using regenerated 3D printing gypsum powder according to a preset structure, and the 3D printing sound-absorbing material is obtained. The regenerated alpha-hemihydrate gypsum powder prepared by the invention has the advantages of thick particles, regular crystal structure, high dehydration speed and high strength, and the performance is optimized through further cooperative modification.

Description

Method for circularly preparing 3D printing sound absorbing material by using waste gypsum board
Technical Field
The invention belongs to the field of functional 3D printing materials, and particularly relates to a method for circularly preparing a 3D printing sound absorbing material by using waste gypsum boards.
Background
Gypsum boards are one of the widely used building materials in modern buildings, and a large amount of waste gypsum boards are generated along with reconstruction and demolition of the buildings, and simple landfill disposal releases hydrogen sulfide which is harmful to health, and simultaneously causes resource waste.
The noise problem is one of the main environmental pollution existing at present, and the environmental noise can influence the living comfort of people and even endanger the health of people. In addition, strong noise can affect the accuracy and reliability of industrial equipment. Porous materials have good sound absorption properties and are often used to solve such problems. However, the traditional sound absorption material has poor effect of solving low-frequency noise, and has large weight and volume cost, so that the application scene of the traditional sound absorption material is severely limited. Recently, with the development of 3D printing technology, the control of the propagation of sound waves by designing a sound absorbing structure of a sub-wavelength scale has gradually become an important direction of research on sound absorbing materials. Gypsum has excellent sound absorption performance because of being a porous material, and has great application prospect in preparing high-performance sound absorption metamaterial. It has been observed that the porous nature of the gypsum substrate in the 3D printed sound absorbing metamaterial can enhance the sound absorbing properties of the structure. In addition, the gypsum powder has good adaptability to 3D printing of complex structures and high forming rate. Therefore, recycling waste gypsum board to make high quality 3D printed sound absorbing material is considered to be a high efficiency method to solve the waste gypsum disposal problem.
In order to achieve good sound absorption performance, the sound absorption metamaterial is generally designed into a complex multi-cavity structure, and certain problems still exist in the process of preparing 3D printing gypsum powder from waste gypsum boards for 3D printing sound absorption metamaterial. One of the main reasons is that impurities which are difficult to separate in the waste gypsum can have adverse effects on the crystal morphology of the gypsum, so that the mechanical strength of the regenerated gypsum powder is poor, and the structural quality requirement of the 3D printing sound absorption material is difficult to meet. Gypsum 3D printing, on the other hand, builds 3D objects layer by bonding gypsum powder material using a geometric model. The regenerated gypsum powder has a large caking tendency due to irregular particle shape, so that defects are easily formed in the powder spreading process, and a smooth powder layer is difficult to obtain in a printer. The high flowability of the powder helps to improve powder spreadability, which helps to improve printing accuracy. Furthermore, the practical limitations of 3D printing are the relatively low initial green sample strength and long powder set time, short set and high green strength that can reduce distortion and collapse during printing operations.
Because the existing 3D printing sound absorption material generally takes natural gypsum powder as a raw material, the resource consumption is high. The problems of weak strength, delamination fracture and low printing efficiency exist in the printing process of preparing the regenerated gypsum powder by solid waste, so that the printed finished product has obvious defects, and the application of the regenerated gypsum powder in actual production is limited. Therefore, there is a need to develop a method for circularly preparing a 3D printed sound absorbing material using waste gypsum board, which promotes high quality recycling of the waste gypsum board.
Disclosure of Invention
The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for circularly preparing a 3D printed sound absorbing material using waste gypsum board.
The invention provides a method for circularly preparing a 3D printing sound absorbing material by using waste gypsum boards, which has the characteristics that the method comprises the following steps: step S1, treating the waste gypsum board to obtain waste gypsum board powder, and preparing regenerated alpha-hemihydrate gypsum powder by using the waste gypsum board powder through a normal-pressure hydrothermal method;
s2, doping hydrophobic nano silicon dioxide, soluble starch, sodium oxalate and 2488 PVA micro powder into the regenerated alpha-hemihydrate gypsum powder for synergistic modification to obtain regenerated 3D printing gypsum powder;
and S3, 3D printing is carried out by using regenerated 3D printing gypsum powder according to a preset structure, and the 3D printing sound-absorbing material is obtained.
In the method for circularly preparing the 3D printing sound absorbing material by using the waste gypsum board, the invention can also have the following characteristics: wherein, in step S1, the method comprises the following substeps:
s1-1, crushing and grinding the waste gypsum board, and sieving the crushed and ground waste gypsum board by using a 200-mesh sieve to obtain waste gypsum board powder;
s1-2, adding sodium succinate as a crystal modifier into a calcium chloride solution, and then adding a hydrogen chloride solution or a sodium hydroxide solution to adjust the pH value to prepare a mixed solution for an atmospheric hydrothermal method;
s1-3, preheating a mixed solution in an oil bath, adding waste building gypsum powder into the mixed solution, stirring the mixed solution, and carrying out complete reaction at a preset reaction temperature and a preset reaction time to obtain a reaction solution after the reaction is completed;
s1-4, carrying out solid-liquid separation on the reaction liquid through vacuum filtration to obtain a solid sample, washing the solid sample rapidly by using near-boiling water, washing the solid sample by using absolute ethyl alcohol, drying the solid sample in an oven until the weight is constant, barreling and sieving the dried solid sample, and then putting the dried solid sample into a drying oven for cooling to obtain the regenerated alpha-hemihydrate gypsum powder.
In the method for circularly preparing the 3D printing sound absorbing material by using the waste gypsum board, the invention can also have the following characteristics: wherein in the step S1-2, the mass fraction of the calcium chloride solution is 10-45 wt%, the addition amount of the sodium succinate is 0-0.05%, the concentration of the hydrogen chloride solution and the sodium hydroxide solution is 0.2-5 mol/L, and the pH is regulated to 1-8.
In the method for circularly preparing the 3D printing sound absorbing material by using the waste gypsum board, the invention can also have the following characteristics: in the step S1-3, the mixed solution is preheated to 70-95 ℃ in an oil bath, the adding ratio of the waste building gypsum powder to the mixed solution is 1:1.5-1:6, the stirring speed during stirring is 50-300 rpm, the preset reaction temperature is 95+/-8 ℃, and the preset reaction time is 1-4 h.
In the method for circularly preparing the 3D printing sound absorbing material by using the waste gypsum board, the invention can also have the following characteristics: in the step S1-4, washing times of near boiling water and absolute ethyl alcohol are 2-4 times, the drying temperature is 60-90 ℃ and the drying time is 4-6 hours when the near boiling water and absolute ethyl alcohol are dried in an oven, dry barreling is adopted when a dried solid sample is barreled, the barreling rotating speed is 90-150 r/min, the barreling time is 20-40 min, and a 200-mesh sieve is adopted when sieving.
In the method for circularly preparing the 3D printing sound absorbing material by using the waste gypsum board, the invention can also have the following characteristics: wherein step S2 comprises the sub-steps of:
s2-1, mixing and barreling the regenerated alpha-hemihydrate gypsum powder with hydrophobic nano silicon dioxide and soluble starch to obtain first powder;
s2-2, mixing and barreling the first powder and sodium oxalate to obtain second powder;
and S2-3, mixing and barreling the second powder and 2488 type PVA micro powder, and sieving to obtain the regenerated 3D printing gypsum powder.
In the method for circularly preparing the 3D printing sound absorbing material by using the waste gypsum board, the invention can also have the following characteristics: in the step S2-1, the mixing amount percentage of the hydrophobic nano silicon dioxide is 1-2%, the mixing amount percentage of the soluble starch is 1-3%, in the step S2-2, the mixing amount percentage of the sodium oxalate is 0.1-1.5%, in the step S2-3, the mixing amount percentage of the 2488 type PVA micro powder is 0-8%, in the steps S2-1, S2-2 and S2-3, dry barreling is adopted during mixing barreling, the barreling rotating speed is 90-150 r/min, the barreling time is 20-40 min, the grinding balls used during barreling are zirconium oxide balls, the mass ratio of the grinding balls to the regenerated alpha-hemihydrate gypsum powder to the first powder to the second powder is 1-1.5:1, the environmental humidity is lower than 50%, and a 200-mesh sieve is adopted during sieving in the step S2-3.
In the method for circularly preparing the 3D printing sound absorbing material by using the waste gypsum board, the invention can also have the following characteristics: wherein the average grain diameter of the regenerated 3D printing gypsum powder is 50-200 mu m, the repose angle is 30.28-39.84 degrees, the initial setting time is 2.3-9.6 min, the final setting time is 4.3-10.5 min, and the compressive strength of the green embryo obtained by 3D printing of the regenerated gypsum 3D printing powder is 0.91-3.97 MPa.
In the method for circularly preparing the 3D printing sound absorbing material by using the waste gypsum board, the invention can also have the following characteristics: the preset structure is a Hall-slit sound absorption structure, and the specific structure of the Hall-slit sound absorption structure is as follows: the Hall-slit sound absorption structure is provided with vertical multiple layers, each layer comprises n cavities and n slits, the n cavities are annular and sleeved in the same plane, the radius of the n cavities is gradually increased from inside to outside, the first cavity is positioned at the innermost side, the nth cavity is positioned at the outermost side, and each layer of cavity is formed by 3 multiplied by 2 n-1 A plurality of cavity separating sheets transversely extending in the vertical direction for separating and supporting the cavities of each layer into 3×2 cavities n-1 The Hall resonance cavity is characterized in that a first slit is cylindrical and is positioned in the center of the first cavity, the remaining slits are annular and are sequentially positioned between two adjacent cavities, the radius of each slit is gradually increased from inside to outside, the slit is positioned at the innermost side and is positioned at the outermost side and is positioned at the nth slit, and the slits except the first slit are formed by 6 multiplied by 2 n-1 A slit separating sheet for separating and supporting the slits into 6×2 slit sheets n-1 And the Hall resonance pipelines and the Hall resonance cavities in each layer are connected in a staggered manner through cylindrical small pipes.
In the method for circularly preparing the 3D printing sound absorbing material by using the waste gypsum board, the invention can also have the following characteristics: wherein, vertical multilayer is 1-5 layers that set up vertically, and every layer thickness is 2mm-10mm, and cavity separates the sheet metal and the slit separates the thickness of sheet metal and is 0.1mm-3mm, and the radius difference of cavity is 2mm-10mm, and the radius difference of annular gap is 1mm-5mm.
Effects and effects of the invention
According to the method for circularly preparing the 3D printing sound absorbing material by using the waste gypsum board, the regenerated alpha-hemihydrate gypsum powder is prepared by using the waste gypsum board powder through a normal-pressure hydrothermal method, the morphology of the regenerated alpha-hemihydrate crystal particles is optimized through a synergistic strategy of doping sodium succinate as a crystal modifier and simultaneously adjusting the pH value of a reaction medium, and the mechanical property of the regenerated alpha-hemihydrate gypsum powder is improved; according to the invention, the hydrophobic nano silicon dioxide, the soluble starch, the sodium oxalate and the 2488 type PVA micro powder are mixed and doped to optimize the performance of the regenerated alpha-semi-hydrated gypsum powder to obtain the regenerated 3D printing gypsum powder, wherein the hydrophobic nano silicon dioxide and the soluble starch can improve the powder fluidity, help to improve the resolution of a final printing product, the sodium oxalate can accelerate the setting time, help to form a certain support in the printing process so as to improve the 3D printing efficiency and precision, the 2488 type PVA micro powder can improve the strength of a printing blank, and can avoid damage in post-treatment processes such as transferring, powder removing and the like, so that the 3D printing product with high precision and quality can be obtained, and therefore, the regenerated alpha-semi-hydrated gypsum powder can obtain high fluidity, short setting time and high green strength through cooperative modification, and the 3D printing product with high precision and quality can be obtained when 3D printing is ensured; meanwhile, the invention also provides a Hall-slit sound absorption structure with good sound absorption effect, the regenerated 3D printing gypsum powder is used as a raw material, and the sound absorption material is prepared according to the design structure, so that the sound absorption material can realize wider effective sound absorption frequency domain and has a sound absorption coefficient peak value larger than 0.9. In summary, according to the method for circularly preparing the 3D printing sound-absorbing material by using the waste gypsum board, the 3D printing sound-absorbing material with good sound-absorbing effect can be prepared by using the waste gypsum board as a raw material, so that the recycling way of the waste gypsum board is widened, and the added value of the waste gypsum board is improved.
Drawings
FIG. 1 is a flow chart of a method of recycling waste gypsum board to make a 3D printed sound absorbing material in an embodiment of the invention;
FIG. 2 is an SEM image of regenerated alpha-hemihydrate gypsum powder in an embodiment of the invention;
FIG. 3 is a 3D printed dusting map of a regenerated alpha-hemihydrate gypsum powder in an embodiment of the present invention;
FIG. 4 is a 3D printed dusting map of a regenerated 3D printed gypsum powder in an embodiment of the present invention;
fig. 5 is a schematic structural view of a 3D printed sound absorbing material in an embodiment of the present invention;
FIG. 6 is a top view of a 3D printed sound absorbing material in an embodiment of the invention;
FIG. 7 is a pictorial view of a finished 3D printed sound absorbing material in an embodiment of the present invention;
fig. 8 is a graph of sound absorption coefficient of a 3D printed sound absorbing material in an embodiment of the present invention.
Detailed Description
In order to make the technical means, creation characteristics, achievement purposes and effects achieved by the present invention easy to understand, the following embodiment describes a method for preparing a 3D printed sound absorbing material by recycling waste gypsum boards in detail with reference to the accompanying drawings.
< example >
Fig. 1 is a flow chart of a method of recycling waste gypsum board to make a 3D printed sound absorbing material in an embodiment of the invention.
As shown in fig. 1, a method for circularly preparing a 3D printed sound absorbing material using waste gypsum boards of this embodiment includes the steps of:
and S1, treating the waste gypsum board to obtain waste gypsum board powder, and preparing the regenerated alpha-hemihydrate gypsum powder by using the waste gypsum board powder through a normal-pressure hydrothermal method.
In step S1, the following sub-steps are included:
and S1-1, crushing and grinding the waste gypsum board, sieving the crushed and ground gypsum board by using a 200-mesh sieve, and removing organic impurities such as paper scraps and the like and particles with larger sizes to obtain waste gypsum board powder.
And S1-2, adding 2mol/L hydrogen chloride solution or sodium hydroxide solution into 23wt% calcium chloride solution to adjust the pH to 5, and preparing the mixed solution for the normal pressure hydrothermal method. In this example, sodium succinate was not added as a crystal modifier.
Step S1-3, preheating the mixed solution to 90 ℃ in an oil bath, adding waste building gypsum powder into the mixed solution, stirring the mixed solution at a speed of 120rpm according to a proportion of 1:4, and reacting at 94+/-1 ℃ for 2 hours to obtain a reaction solution.
S1-4, carrying out solid-liquid separation on the reaction liquid through vacuum filtration to obtain a solid sample, quickly washing the solid sample with nearly boiling water for 3 times, washing the solid sample with absolute ethyl alcohol (the filter cake is immersed in the absolute ethyl alcohol) for 2 times, then drying the solid sample in an oven at 80 ℃ for 4 hours until the solid sample is constant in weight, barreling and sieving the dried solid sample, and then putting the solid sample in a drying oven for cooling to obtain the regenerated alpha-hemihydrate gypsum powder.
In the embodiment, when the solid sample is barreled, conventional equipment in the prior art is adopted to barre for 30min in a plastic tank at a rotating speed of 150r/min, the grinding balls are zirconia balls, the mass ratio of the zirconia balls to the powder is 1.2:1, the environmental humidity is lower than 50%, and impurities are removed from the barreled gypsum powder through a 200-mesh sieve.
Fig. 2 is an SEM image of regenerated alpha-hemihydrate gypsum powder in an embodiment of the invention.
As shown in figure 2, the length-diameter ratio of the regenerated alpha-hemihydrate gypsum powder prepared by taking the waste gypsum board as a raw material is 1.07, the crystal length reaches 10 mu m, the 3d compressive strength reaches 25.5Mpa, and the regenerated alpha-hemihydrate gypsum powder has the advantages of thick and strong particles, regular crystal structure and high dehydration speed.
And S2, doping hydrophobic nano silicon dioxide, soluble starch, sodium oxalate and 2488 type PVA micro powder into the regenerated alpha-hemihydrate gypsum powder for synergistic modification to obtain the regenerated 3D printing gypsum powder.
Step S2 comprises the following sub-steps:
s2-1, mixing and barreling the regenerated alpha-hemihydrate gypsum powder, 1% of hydrophobic nano silicon dioxide and 3% of soluble starch to obtain first powder.
And S2-2, mixing and barreling the first powder and 0.8% sodium oxalate to obtain second powder.
And S2-3, mixing and barreling the second powder with 5% of 2488 PVA micro powder, and sieving to obtain the regenerated 3D printing gypsum powder.
In the embodiment, in the steps S2-1, S2-2 and S2-3, dry-method barreling is adopted during mixing barreling, the barreling rotating speed is 150r/min, the barreling time is 30min, barreling is carried out in a plastic tank by adopting conventional equipment in the prior art, the grinding balls are zirconium oxide balls, the mass ratio of the zirconium balls to the powder is 1.2:1, and the environmental humidity is lower than 50%.
In this embodiment, the 3D printing performance is further optimized by mixing and doping hydrophobic nano silica, soluble starch, sodium oxalate and 2488 type PVA micropowder into the regenerated α -hemihydrate gypsum powder for synergistic modification, the hydrophobic nano silica and the soluble starch can improve the powder flowability, the sodium oxalate can accelerate the setting time, and the 2488 type PVA micropowder can improve the strength of the printing green blank.
The regenerated 3D printing gypsum powder prepared by the embodiment has the average grain diameter of 50 μm-200 μm, the fluidity of 38.97, the initial setting time of 3.2min, the final setting time of 4.3min, the compressive strength of the green embryo obtained by 3D printing of the regenerated gypsum 3D printing powder of 0.91MPa-3.97MP, excellent 3D printing performance,
fig. 3 is a 3D printed dusting of regenerated alpha-hemihydrate gypsum powder in an embodiment of the present invention.
As shown in fig. 3, when the regenerated α -hemihydrate gypsum powder of this embodiment is subjected to 3D printing and laying, the gypsum has strong hygroscopicity and large caking tendency, and the powder is not easy to lay flat during printing, so that the layering and breaking phenomena of the material are easily caused.
Fig. 4 is a 3D printed dusting map of regenerated 3D printed gypsum powder in an embodiment of the present invention.
As shown in fig. 4, the regenerated 3D printing gypsum powder of the embodiment is thinner, uniform and smooth to spread when the 3D printing and laying process is performed, and can avoid delamination phenomenon in the 3D printing process.
And S3, 3D printing is carried out by using regenerated 3D printing gypsum powder according to a preset structure, and the 3D printing sound-absorbing material is obtained.
Fig. 5 is a schematic structural view of a 3D printed sound absorbing material in an embodiment of the present invention, and fig. 6 is a structural plan view of a 3D printed sound absorbing material in an embodiment of the present invention.
As shown in fig. 5 and 6, the preset structure of the 3D printed sound absorbing material 100 of the present embodiment is a holtz-slit sound absorbing structure, and the specific structure of the holtz-slit sound absorbing structure is as follows: the hall-slot sound absorbing structure has 3 vertical layers, each layer comprising n cavities 10 and n slots 20, n=4 in this embodiment,
the n cavities 10 are annular and sleeved in the same plane, the radius of the n cavities 10 is gradually increased from inside to outside, the first cavity 10 is positioned at the innermost side, the nth cavity 10 is positioned at the outermost side,
each layer of cavity 10 is formed by 3 x 2 n-1 A plurality of cavity separation sheets 11 are supported and separated across the vertical layers, and the cavity separation sheets 11 separate the cavities 10 of each layer into 3×2 cavities n-1 The Hall-Muz resonant cavity body is provided,
the first slit 20 is cylindrical and is positioned at the center of the first cavity 10, the rest slits 20 are annular and are sequentially positioned between the two adjacent cavities 10, the radius of the slit 20 is gradually increased from inside to outside, the innermost slit 20 is positioned, the outermost slit 20 is positioned at the nth,
slits 20 other than the first slit 20 are formed by 6×2 n-1 A plurality of slit separating sheets 21 which are vertically multi-layered across the slit separating sheets 21 to separate the slits 20 into 6X 2 n-1 A Hall's resonance pipeline is arranged on the pipeline,
the hall resonance pipes and the hall resonance cavities in each layer in the vertical direction are connected in a staggered way through a cylindrical small pipe 30.
In this embodiment, in each layer in the vertical direction, the innermost cavity 10 is divided into 3 hall resonant cavities by the cavity separating sheet 11, and is connected with the first slit 20 in the cylindrical shape located in the center through 3 cylindrical small pipes 30, in the remaining adjacent two annular cavities 10 and the annular slit 20 located between the adjacent two cavities 10, the hall resonant pipes divided by the slit 20 are connected with the hall resonant cavities located at two sides in a staggered manner through the cylindrical small pipes 30, that is, one hall resonant pipe is connected with the hall resonant cavity at the inner side, and the next hall resonant pipe is connected with the hall resonant cavity at the outer side.
In this embodiment, the thicknesses of the 3 layers vertically arranged are 5.5mm, 8mm, 5.5mm, respectively, the thicknesses of the cavity separator sheet 11 and the slit separator sheet 21 are 1mm, the radius difference of the annular cavity is 7.4375mm, and the radius difference of the annular slit is 2mm.
Fig. 8 is a graph of sound absorption coefficient of a 3D printed sound absorbing material in an embodiment of the present invention.
As shown in fig. 8, the 3D printed sound absorbing material prepared in this embodiment has a wide effective sound absorption frequency domain and a sound absorption peak coefficient of 0.96, and has a good sound absorption effect.
Effects and effects of the examples
According to the method for circularly preparing the 3D printing sound absorbing material by using the waste gypsum board, the regenerated alpha-hemihydrate gypsum powder is prepared by using the waste gypsum board powder through a normal-pressure hydrothermal method, the morphology of the regenerated alpha-hemihydrate crystal particles is optimized through a synergistic strategy of doping sodium succinate as a crystal modifier and adjusting the pH value of a reaction medium, the mechanical property of the regenerated alpha-hemihydrate gypsum powder is improved, the regenerated alpha-hemihydrate gypsum powder has the advantages of being thick and strong in particles, regular in crystal structure, high in dehydration speed and the like, the length-diameter ratio of crystal particles is reduced to be close to 1 from about 7, the strength is obviously improved, and the 3D compressive strength can reach more than 25.5 MPa; in addition, the hydrophobic nano silicon dioxide, the soluble starch, the sodium oxalate and the 2488 type PVA micro powder are mixed and doped to optimize the performance of the regenerated alpha-semi-hydrated gypsum powder to obtain the regenerated 3D printing gypsum powder, wherein the hydrophobic nano silicon dioxide and the soluble starch can improve the powder fluidity, help to improve the resolution of a final printing product, the sodium oxalate can accelerate the setting time, be beneficial to forming a certain support in the printing process so as to improve the 3D printing efficiency and precision, the 2488 type PVA micro powder can improve the strength of a printing green embryo, avoid damage in post-treatment processes such as transferring, powder removing and the like, and obtain the 3D printing product with high precision and quality, and therefore, the embodiment can ensure that the regenerated alpha-semi-hydrated gypsum powder can obtain the 3D printing product with high fluidity, short setting time and high green embryo strength through cooperative modification, and can obtain the 3D printing product with high precision and quality when 3D printing is carried out; meanwhile, the embodiment also provides a Hall-slit sound absorption structure with good sound absorption effect, the regenerated 3D printing gypsum powder is used as a raw material, and the sound absorption material is prepared according to the design structure, so that the sound absorption material can realize wider effective sound absorption frequency domain and has a sound absorption coefficient peak value larger than 0.9. In summary, according to the method for circularly preparing the 3D printing sound-absorbing material by using the waste gypsum board, the 3D printing sound-absorbing material with good sound-absorbing effect can be prepared by using the waste gypsum board as a raw material, so that the recycling way of the waste gypsum board is widened, and the added value of the waste gypsum board is improved.
The above embodiments are preferred examples of the present invention, and are not intended to limit the scope of the present invention.

Claims (10)

1. A method for circularly preparing a 3D printed sound absorbing material by using waste gypsum boards, which is characterized by comprising the following steps:
step S1, treating a waste gypsum board to obtain waste gypsum board powder, and preparing regenerated alpha-hemihydrate gypsum powder by using the waste gypsum board powder through a normal-pressure hydrothermal method;
s2, adding hydrophobic nano silicon dioxide, soluble starch, sodium oxalate and 2488 PVA micro powder into the regenerated alpha-hemihydrate gypsum powder for synergistic modification to obtain regenerated 3D printing gypsum powder;
and S3, 3D printing is carried out according to a preset structure by using the regenerated 3D printing gypsum powder, and the 3D printing sound absorbing material is obtained.
2. The method for circularly preparing a 3D printed sound absorbing material using waste gypsum board according to claim 1, wherein:
wherein, in step S1, the method comprises the following substeps:
s1-1, crushing and grinding the waste gypsum board, and sieving the waste gypsum board by using a 200-mesh sieve to obtain waste gypsum board powder;
s1-2, adding sodium succinate as a crystal modifier into a calcium chloride solution, and then adding a hydrogen chloride solution or a sodium hydroxide solution to adjust the pH value to prepare a mixed solution for an atmospheric hydrothermal method;
s1-3, preheating the mixed solution in an oil bath, adding the waste building gypsum powder into the mixed solution, stirring the mixed solution, and carrying out complete reaction at a preset reaction temperature and a preset reaction time to obtain a reaction solution after the reaction is completed;
s1-4, carrying out solid-liquid separation on the reaction liquid through vacuum filtration to obtain a solid sample, washing the solid sample rapidly by using near-boiling water, washing the solid sample by using absolute ethyl alcohol, drying the solid sample in an oven until the weight is constant, barreling and sieving the dried solid sample, and then putting the solid sample into a drying oven for cooling to obtain the regenerated alpha-hemihydrate gypsum powder.
3. The method for circularly preparing a 3D printed sound absorbing material using waste gypsum board according to claim 2, wherein:
in the step S1-2, the mass fraction of the calcium chloride solution is 10-45 wt%, the addition amount of the sodium succinate is 0-0.05%, the concentration of the hydrogen chloride solution and the sodium hydroxide solution is 0.2-5 mol/L, and the pH is regulated to 1-8.
4. The method for circularly preparing a 3D printed sound absorbing material using waste gypsum board according to claim 2, wherein:
in the step S1-3, the mixed solution is preheated to 70-95 ℃ in an oil bath, the adding ratio of the waste building gypsum powder to the mixed solution is 1:1.5-1:6, the stirring speed during stirring is 50-300 rpm, the preset reaction temperature is 95 ℃ +/-8 ℃, and the preset reaction time is 1-4 h.
5. The method for circularly preparing a 3D printed sound absorbing material using waste gypsum board according to claim 2, wherein:
wherein in the step S1-4, the washing times of the near boiling water and the absolute ethyl alcohol are 2-4 times, the drying temperature is 60-90 ℃ when the near boiling water and the absolute ethyl alcohol are dried in an oven, the drying time is 4-6 hours,
and (3) dry barreling is adopted when the dried solid sample is barreled, the barreling rotating speed is 90 r/min-150 r/min, the barreling time is 20 min-40 min, and a 200-mesh sieve is adopted when sieving.
6. The method for circularly preparing a 3D printed sound absorbing material using waste gypsum board according to claim 1, wherein:
wherein step S2 comprises the sub-steps of:
s2-1, mixing and barreling the regenerated alpha-hemihydrate gypsum powder, the hydrophobic nano silicon dioxide and the soluble starch to obtain first powder;
s2-2, mixing and barreling the first powder and the sodium oxalate to obtain second powder;
and S2-3, mixing and barreling the second powder and the 2488 PVA micro powder, and sieving to obtain the regenerated 3D printing gypsum powder.
7. The method for circularly preparing a 3D printed sound absorbing material using waste gypsum board according to claim 6, wherein:
wherein in the step S2-1, the doping amount percentage of the hydrophobic nano silicon dioxide is 1-2%, the doping amount percentage of the soluble starch is 1-3%, in the step S2-2, the doping amount percentage of the sodium oxalate is 0.1-1.5%, in the step S2-3, the doping amount percentage of the 2488 type PVA micro powder is 0-8%,
in the steps S2-1, S2-2 and S2-3, dry-method barreling is adopted during mixing barreling, the barreling rotating speed is 90 r/min-150 r/min, the barreling time is 20 min-40 min, the grinding balls used during barreling are zirconia balls, the mass ratio of the grinding balls to the regenerated alpha-semi-hydrated gypsum powder to the first powder to the second powder is 1-1.5:1, the environmental humidity is lower than 50%,
in step S2-3, a 200 mesh sieve is used for sieving.
8. The method for circularly preparing a 3D printed sound absorbing material using waste gypsum board according to claim 1, wherein:
wherein the average grain diameter of the regenerated 3D printing gypsum powder is 50-200 mu m, the repose angle is 30.28-39.84 degrees, the initial setting time is 2.3-9.6 min, the final setting time is 4.3-10.5 min, and the compressive strength of the green embryo obtained by 3D printing of the regenerated gypsum 3D printing powder is 0.91-3.97 MPa.
9. The method for circularly preparing a 3D printed sound absorbing material using waste gypsum board according to claim 1, wherein:
the preset structure is a Hall-slit sound absorption structure, and the specific structure of the Hall-slit sound absorption structure is as follows: the holtz-slit sound absorbing structure has a vertical multilayer, each layer comprising n cavities and n slits,
the n cavities are annular and sleeved in the same plane, the radius of the n cavities is gradually increased from inside to outside, the first cavity is positioned at the innermost side, the nth cavity is positioned at the outermost side,
each layer of the cavity consists of 3 multiplied by 2 n-1 A plurality of cavity separator sheets spaced apart and supported across said vertical plurality of layers, said cavity separator sheets separating said cavities of each layer into 3 x 2 cavities n-1 The Hall-Muz resonant cavity body is provided,
the first slit is cylindrical and is positioned at the center of the first cavity, the rest slits are annular and are sequentially positioned between two adjacent cavities, the radius of the slits is gradually increased from inside to outside, the slit positioned at the innermost side is the first slit, the slit positioned at the outermost side is the nth slit,
the slits except for the first one are formed by 6×2 n-1 A slit separator sheet disposed transversely across the vertical layers and separating the slits into 6 x 2 slit sheets n-1 A Hall's resonance pipeline is arranged on the pipeline,
and the Hall resonance pipelines and the Hall resonance cavities in each vertical layer are connected in a staggered manner through cylindrical small pipes.
10. The method for circularly preparing a 3D printed sound absorbing material using waste gypsum board according to claim 9, wherein:
wherein the vertical multilayer is 1-5 layers which are vertically arranged, the thickness of each layer is 2-10 mm,
the thickness of the cavity separator sheet and the slit separator sheet are each 0.1mm to 3mm,
the radius difference of the cavity is 2mm-10mm, and the radius difference of the annular gap is 1mm-5mm.
CN202310040023.4A 2023-01-11 2023-01-11 Method for circularly preparing 3D printing sound absorbing material by using waste gypsum board Pending CN116041025A (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107032722A (en) * 2016-10-20 2017-08-11 武汉理工大学 A kind of gypsum base 3D printing high pressure homogenization injection rapid prototyping material and preparation method thereof
CN111377699A (en) * 2020-03-24 2020-07-07 共享智能铸造产业创新中心有限公司 Gypsum powder for 3D printing
CN111732398A (en) * 2020-06-16 2020-10-02 中建科技武汉有限公司 Light high-strength assembly type plate based on waste gypsum board and preparation method thereof

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107032722A (en) * 2016-10-20 2017-08-11 武汉理工大学 A kind of gypsum base 3D printing high pressure homogenization injection rapid prototyping material and preparation method thereof
CN111377699A (en) * 2020-03-24 2020-07-07 共享智能铸造产业创新中心有限公司 Gypsum powder for 3D printing
CN111732398A (en) * 2020-06-16 2020-10-02 中建科技武汉有限公司 Light high-strength assembly type plate based on waste gypsum board and preparation method thereof

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
何志敏: "琥珀酸钠对常压水热法制备α-半水石膏的影响", 贵州师范大学学报（自然科学版）, vol. 40, no. 3, 20 May 2022 (2022-05-20), pages 96 - 101 *
李豪: "基于石膏3D打印的声能吸收超材料研究", 万方学位论文, 28 October 2022 (2022-10-28), pages 30 - 31 *
鲁元竞等: "3D打印石膏粉末流动性的响应曲面优化试验研究", 硅酸盐通报, vol. 41, no. 3, 31 March 2022 (2022-03-31), pages 787 - 794 *

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