CN108706912A - A kind of poly- sand sound absorber and preparation method thereof - Google Patents

Abstract

A kind of poly- sand sound absorber of present invention offer and preparation method thereof.The poly- sand sound absorber is molded by poly- sand composition；The poly- sand composition includes base material, binder, curing agent and lubricant；Wherein, it is in terms of 100% by the mass percent of the base material, the addition of the binder is 1-5%, and the addition of preferably 2-4%, curing agent are 0.05-0.5%, and the addition of preferably 0.1-0.4%, lubricant are 0.2-0.5%, preferably 0.3-0.4%.The present invention makes the poly- sand sound absorber being prepared have sound absorbing performance and permeability, and also have antiseep, heat safe characteristic by adjusting the formula rate of poly- sand composition so as to adjust poly- sand composition surface texture.

Description

A kind of gathering sand sound-absorbing device and preparation method thereof

technical field

The invention relates to a sand-accumulating sound-absorbing device and a preparation method thereof, belonging to the field of building chemical materials.

Background technique

The extensive use of surface materials with high sound reflectivity in modern buildings, such as concrete, glass, marble, and metal, results in low sound absorption, disturbing noise or unpleasant sound reflections. The raw material of the sand gathering board is selected from natural sand, which can cause a layer of melting and re-solidification reaction between the outer layers of the sand grains, so that the sand grains gather together as if they were welded. Because the microscopic shape of each sand grain is irregular and unique, when aggregated and accumulated together, a large number of irregular and interconnected tiny pores are naturally formed between the sand grains. The existing sand gathering boards have poor sound absorption and/or air permeability, and do not have anti-permeation properties.

CN105330232A provides a novel double-layer fire-free high-strength permeable floor tile, which is made of the following raw materials in parts by weight: desert sand 50-53, thermoplastic phenolic resin 4-5, urotropine 0.6-0.7, calcium stearate 0.2- 0.22, appropriate amount of water, 42.5 Portland cement 42-45, fly ash 5-6, water-based fluorocarbon emulsion 4-5, redispersible amine powder 7-9, honeycomb cinder 9-11, coconut shell activated carbon 5-6, ceramsite 100-110, silica sand 23-26, silica fume powder 30-33, aluminum sulfonate 2-30. Therefore, the floor tile needs strong water permeability, and therefore, the prepared floor tile is permeable.

Contents of the invention

The problem to be solved by the invention

The object of the present invention is to provide a sand-accumulating sound-absorbing device and a preparation method thereof. By adjusting the formula ratio of the sand-accumulating composition, the surface structure of the sand-accumulating composition can be changed, so that the sand-accumulating sound-absorbing device has sound absorption performance and air permeability, and also has the characteristics of anti-leakage and high temperature resistance.

Furthermore, the present invention also provides a method for preparing a sand-accumulating sound-absorbing device, the raw materials of which are readily available, and the operation is simple and easy.

solutions to problems

The present invention provides a sand-accumulating sound-absorbing device, wherein the sand-accumulating sound-absorbing device is molded from a sand-accumulating composition; the sand-accumulating composition includes a base material, a binder, a curing agent and a lubricant; wherein , based on 100% of the mass percentage of the substrate, the addition of the binder is 1-5%, preferably 2-4%, and the addition of the curing agent is 0.05-0.5%, preferably 0.1-0.4% , The amount of lubricant added is 0.2-0.5%, preferably 0.3-0.4%.

According to the sand-accumulating sound-absorbing device of the present invention, wherein, the base material includes silica sand, desert sand, quartz sand, river sand, lake sand, pearl sand, mountain sand, sea sand, metal sand, forsterite sand, ceramsite At least one of sand, zircon sand, refractory clay and glass beads. Preferably, the average particle size of the substrate is 10-100 mesh, preferably 50-60 mesh.

According to the polysand sound-absorbing device of the present invention, wherein, the curing agent includes ethylenediamine, trimethylhexamethylenediamine, hexamethylenetetramine, diethylenetriamine, methylolethylenediamine , hydroxyethylethylenediamine, dihydroxyethylethylenediamine, hydroxyethyldiethylenetriamine, dihydroxyethylethylenediamine, hydroxyethyldiethylenetriamine, dihydroxyethyldiethylenetriamine, hydroxyl At least one of ethylhexamethylenediamine, monocyanoethylethylenediamine, dicyanoethylethylenediamine, dicyanoethylhexamethylenediamine, dicyandiamide and cyclohexanediamine.

According to the polysand sound-absorbing device of the present invention, wherein, the binder includes thermosetting phenolic resin and/or thermosetting acrylic resin; preferably, the lubricant includes polytetrafluoroethylene, calcium stearate, zinc stearate and at least one of sodium stearate.

According to the sand-accumulating sound-absorbing device of the present invention, wherein the sand-accumulating composition further includes silane and/or graphite, and the added amount of the silane is 0.1-0.5% based on the mass percentage of the substrate, preferably 0.2-0.4%, the added amount of graphite is 0.05-0.5%, preferably 0.1-0.2%.

According to the sand-accumulating sound-absorbing device of the present invention, wherein the sand-accumulating sound-absorbing device further includes silica sol, the addition amount of the silica sol is 2-5 %, preferably 3-4%.

The present invention provides a method for preparing the sand-accumulating sound-absorbing device according to the present invention, which includes preparing the sand-accumulating sound-absorbing device by molding.

The preparation method according to the present invention, wherein, comprises the following steps:

Preheating step: After preheating the mold, close the mold;

Sand injection step: inject the sand-accumulating composition into the mould;

Hot-pressing step: hot-press the mold injected with the sand-accumulating composition to obtain a sand-accumulating sound-absorbing device.

According to the preparation method of the present invention, between the preheating step and the sand injection step, a step of mixing the sand gathering composition with silica sol is also included.

According to the preparation method of the present invention, wherein, the preparation method of the sand gathering composition includes the step of mixing the components of the sand gathering composition.

The effect of the invention

The present invention can adjust the surface structure of the sand-gathering composition by adjusting the formula ratio of the sand-gathering composition, so that the prepared sand-gathering sound-absorbing device has sound absorption performance and air permeability, and also has anti-leakage and high temperature resistance. characteristic.

Furthermore, the sand-accumulating sound-absorbing device prepared by the present invention can be widely used in sound absorption and noise reduction in wet places, tunnel noise reduction, subway noise reduction, outdoor soundscape construction, outdoor traffic sound barrier engineering, etc. It can also be used as sound-absorbing material for ventilation ducts, inner wall material of muffler, etc.

Detailed ways

Various exemplary embodiments, features, and aspects of the invention are described in detail below. The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior or better than other embodiments.

In addition, in order to better illustrate the present invention, numerous specific details are given in the specific embodiments below. It will be understood by those skilled in the art that the present invention may be practiced without certain of the specific details. In other instances, methods, means, devices and steps well known to those skilled in the art are not described in detail in order to highlight the gist of the present invention.

<First Embodiment>

The first embodiment of the present invention provides a sand-accumulating sound-absorbing device, which is molded from a sand-accumulating composition; the sand-accumulating composition includes a base material, a binder, a curing agent, and a lubricant agent; wherein, based on the mass percentage of the substrate as 100%, the addition of the binder is 1-5%, preferably 2-4%; the addition of the curing agent is 0.05-0.5%, preferably 0.1 -0.4%; the amount of lubricant added is 0.2-0.5%, preferably 0.3-0.4%. The present invention can adjust the surface structure of the sand-gathering composition by adjusting the formula ratio of the sand-gathering composition, so that the prepared sand-gathering sound-absorbing device has sound absorption performance and air permeability, and also has the characteristics of anti-leakage and high temperature resistance .

According to the sand-accumulating sound-absorbing device of the present invention, in the present invention, the base material may not be specifically limited, and generally available sand grains may be used. Preferably, in the present invention, the substrate includes silica sand, desert sand, quartz sand, river sand, lake sand, pearl sand, mountain sand, sea sand, metal sand, forsterite sand, ceramsite sand, zircon At least one of sand, fireclay and glass beads. More preferably, the average particle diameter of the substrate is 10-100 mesh, preferably 50-60 mesh. When the average particle size of the base material is between 10 and 80 meshes, a sand-accumulated sound-absorbing device with excellent sound-absorbing performance and air-permeable performance can be better obtained.

According to the sand-accumulating sound-absorbing device of the present invention, the binder includes thermosetting phenolic resin and/or thermosetting acrylic resin. In the present invention, based on the base material being 100% by mass, the binder is added in an amount of 1-5%, preferably 2-4%. When the amount of binder added is 1-5%, the prepared sand-accumulated sound-absorbing device has excellent sound-absorbing and air-permeable properties; The air permeability of the device is poor; when the amount of binder added is less than 1%, the strength of the prepared sand-acoustic sound-absorbing device is low.

According to the sand-accumulating sound-absorbing device of the present invention, the curing agent includes ethylenediamine, trimethylhexamethylenediamine, hexamethylenetetramine, diethylenetriamine, methylolethylenediamine, hydroxyl Ethylethylenediamine, dihydroxyethylethylenediamine, hydroxyethyldiethylenetriamine, dihydroxyethylethylenediamine, hydroxyethyldiethylenetriamine, dihydroxyethyldiethylenetriamine, hydroxyethyl At least one of hexamethylenediamine, monocyanoethylethylenediamine, dicyanoethylethylenediamine, dicyanoethylhexamethylenediamine, dicyandiamide and cyclohexanediamine.

In the present invention, based on 100% by mass of the substrate, the curing agent is added in an amount of 0.05-0.5%, preferably 0.1-0.4%. Generally speaking, in the present invention, when the content of the curing agent is less than 0.05%, the hardness of the prepared sand-gathering sound-absorbing device is low; when the content of the curing agent is greater than 0.5%, in the process of preparing the sand-gathering composition If it dries too fast, it will affect the performance of the sand gathering sound-absorbing device. Preferably, in the present invention, the amount of curing agent added is 1-10%, preferably 5-10%, of the amount of binder added. Its content can be increased or decreased with the content of the binder.

According to the polysand sound-absorbing device of the present invention, the lubricant includes at least one of polytetrafluoroethylene, calcium stearate, zinc stearate and sodium stearate.

In the present invention, based on 100% by mass of the base material, the added amount of the lubricant is 0.2-0.5%, preferably 0.3-0.4%. In the present invention, when the content of the lubricant is between 0.2-0.5%, the sand-gathering composition can be stirred and dispersed evenly when preparing the sand-gathering composition, thereby ensuring easy release of the sand-gathering sound-absorbing device. When the content of the lubricant is greater than 0.5%, the strength of the prepared sand-accumulating sound-absorbing device will be low; mold.

According to the sand-gathering sound-absorbing device of the present invention, the sand-gathering composition also includes silane and/or graphite, and the addition amount of the silane is 0.1-0.5%, preferably 0.2- 0.4%, the added amount of graphite is 0.05-0.5%, preferably 0.1-0.2%. In the present invention, adding silane and/or graphite can further play the role of assisting demoulding. Generally speaking, in the present invention, the silane may be at least one of monosilane, disilane and trisilane.

In addition, the sand gathering composition of the present invention may also contain high temperature resistant additives, toughening additives and the like.

According to the sand-gathering sound-absorbing device of the present invention, the sand-gathering sound-absorbing device may also include silica sol, and the addition amount of the silica sol is 2- 5%, preferably 3-4%. By using silica sol, the sand gathering sound-absorbing device can have the effect of preventing penetration. After the silica sol is dried, it can form a hydrophobic film to fill the pores between it and the sand particles, so that the sand-accumulating sound-absorbing device can further have the effect of preventing penetration.

<Second Embodiment>

The second embodiment of the present invention provides a method for preparing the sand-accumulating sound-absorbing device according to the present invention, and the sand-accumulating sound-absorbing device is prepared by molding. The molding is to place the sand-accumulating composition of the present invention in a mold and shape it by heating and pressing, so as to prepare a sand-accumulating sound-absorbing device.

The preparation method according to the present invention comprises the following steps:

Preheating step: After preheating the mold, close the mold;

Sand injection step: inject the sand-accumulating composition into the mould;

Hot-pressing step: hot-press the mold injected with the sand-accumulating composition to obtain a sand-accumulating sound-absorbing device.

In the present invention, the mold is preheated to 100-180°C, preferably 120-150°C. The pressure of hot pressing is 5-8 kg, preferably 6-7 kg, and the temperature is 100-180°C, preferably 120-150°C. In addition, the time of hot pressing can be determined according to the thickness of the sand-accumulating sound-absorbing device. In the present invention, the thickness of the sand-accumulating sound-absorbing device may be 5-50mm, and the hot pressing time may be 10-60s, preferably 15-25s.

In the present invention, the meaning of mold closing is to adjust the lower mold of the mold to the joint position with the upper mold.

Combined with the preparation method of the present invention, the shape of the sand-accumulating sound-absorbing device of the present invention can be a floor tile shape, a plate shape, a sheet shape, and a composite shape with other devices.

According to the preparation method of the present invention, between the preheating step and the sand injection step, a step of mixing the sand gathering composition with silica sol is also included. According to the preparation method of the present invention, the preparation method of the sand gathering composition includes the step of mixing the components of the sand gathering composition.

Specifically, according to the preparation method of the present invention, the preparation method of the sand gathering composition comprises the following steps:

Step 1, preheating the base material and mixing it with the binder to obtain coated sand grains. Preferably, the preheating temperature can be 100-180°C, preferably 120-150°C; at high temperature, the adhesive is melted and bonded to the substrate and coated on the surface of the substrate. The coating mixing time is 30-50s.

Preferably, when silane is present, it is mixed with the silane after preheating of the substrate, and then with the binder, optionally graphite, to obtain coated sand grains. More preferably, the time for mixing the substrate with the silane after preheating is 3-10s, preferably 4-6s.

Preferably, when graphite is included, the graphite can be added at 50-70s, preferably 55-60s, after the substrate is preheated and mixed with the binder.

Step 2, mixing the aqueous solution of the curing agent with the coated sand, the resulting water evaporates to rapidly cool the sand (about 45-70 seconds), and cool to normal temperature to obtain cooled coated sand; The mixing of coated sand grains also prevents the chemical reaction of the binder and curing agent in the sand mixer. Preferably, in the aqueous solution of the curing agent, the mass concentration of the curing agent is 20-30 wt%.

Step 3, mixing the cooled coated sand and lubricant to obtain a sand gathering composition. Preferably, the mixing time is 5-15s, more preferably 8-10s. Generally speaking, this step is added before the discharge of the sand mixer, which can improve the flow performance of the sand gathering composition.

Step 4, when the film coating process is completed, transfer the sand gathering composition to a vibrating sieve at a temperature of 60-80°C, and sieve the sand gathering composition to the boiling cooling tank to continue cooling down to 20-30°C , so as to ensure that the sand gathering composition has better storage performance.

In addition, in the present invention, the aqueous solution of the curing agent can also be mixed with the lubricant first, and then mixed with the coated sand particles, and the rest is the same as the preparation method of the above-mentioned sand gathering composition.

Example

Embodiments of the present invention will be described in detail below in conjunction with examples, but those skilled in the art will understand that the following examples are only used to illustrate the present invention, and should not be considered as limiting the scope of the present invention. Those who do not indicate the specific conditions in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used were not indicated by the manufacturer, and they were all commercially available conventional products.

Examples 1-6

According to the formula ratio in Table 1 below, the mass percentage of the base material is used to prepare the sand gathering composition according to the following preparation method, wherein the average particle size of the base material is 50-60 mesh.

The preparation method of poly-sand composition comprises the following steps:

Step 1. Preheat the base material to 130±5°C and then mix and stir with the binder to obtain coated sand grains; the time for coating, mixing and stirring is 40s.

When silane is contained, after the substrate is preheated, it is mixed with silane for 5 seconds, and then mixed with the binder to obtain coated sand grains.

When graphite is included, add graphite at 55-60 seconds after the substrate is preheated and mixed with the binder.

Step 2, mixing the aqueous solution of the curing agent with the coated sand, the resulting water evaporates to rapidly cool the sand (55 ± 5 seconds), and cool to normal temperature to obtain cooled coated sand; wherein, in the aqueous solution of the curing agent, The mass concentration of the curing agent is 25wt%.

Step 3, mixing the cooled coated sand grains with a lubricant to obtain sand gathering compositions 1-6. Preferably, the mixing time is 8-10s.

Step 4, when the film covering process is completed, transfer the sand gathering composition to a vibrating sieve at a temperature of 70°C, sieve the sand gathering composition onto a boiling cooling tank, and continue cooling down to 25°C.

Table 1

Then, according to the following preparation method, the sand-accumulating sound-absorbing device 1-6 was prepared by using the above-mentioned sand-accumulating composition 1-6 of Examples 1-6.

The preparation method of the polysand sound-absorbing device is as follows:

Preheating step: preheat the mold to 150°C, close the mold, and then start production at a constant temperature.

Sand injection step: inject the sand-accumulating composition into the mold. In an embodiment, the sand injection plate can be pressed down, and the sand gathering composition can be injected into the mold through the sand injection port through the sand injection column. Optionally, add silica sol and mix well. Wherein, based on the mass percentage of the base material, the amount of silica sol added is shown in Table 2 below.

Hot-pressing step: hot-press the mold injected with the sand-accumulating composition to obtain the sand-accumulating sound-absorbing device 1-6. In the embodiment, the thickness of the prepared sand-polyacoustic sound-absorbing device is 8 mm, the hot-pressing time is 20 s, the hot-pressing pressure is 7 kg, and the hot-pressing temperature is 150° C.

Table 2

Performance Test of Polysand Acoustic Absorbing Device 1-6

The prepared sand-accumulating sound-absorbing device was cut to obtain a 300mm×600mm×8mm sand-accumulating sound-absorbing device for performance testing, and the results are shown in Table 3.

1. Penetration performance test

Select the measuring point on the polysand sound-absorbing device, and use a broom and a fine wire brush to remove the dust and debris on the measuring point. Use chalk to draw a circle mark on the cleaned sand-polyacoustic device according to the size of the test instrument base; and apply a circle of sealing material on the polysand-absorbent device along the size of the base, so that the sealing material is embedded in the gap and firmly bonded to the polyacoustic sound-absorbing device. Sand on the sound-absorbing device. Press the base of the assembled water seepage tester firmly on the sealing material ring of the sand-accumulating sound-absorbing device, and press the weight iron ring to press the instrument base to prevent water from flowing out from between the base and the sand-accumulating sound-absorbing device. Turn off the switch below the thin tube, and inject clean water mixed with a small amount of red ink into the upper measuring cylinder of the instrument until the overflow hole at the upper end of the measuring cylinder overflows (the total amount is 600ml). Quickly turn on all the switches, water starts to flow out from the lower part of the thin tube, start the stopwatch immediately, and read the scale of the instrument tube once every 60 seconds, and perform 3 times.

2. Noise reduction coefficient test

Place the prepared sand-accumulating sound-absorbing device in a reverberation chamber for testing, wherein the rear cavity of the sand-accumulating sound-absorbing device is 100 mm ² , and a layer of 50 mm thick 64k glass wool, take several pieces of poly-sand sound-absorbing devices, composite them into a poly-sand sound-absorbing panel of 2.4m×4.2m×8mm (surface area: 10.08m ² ), and then measure its noise reduction coefficient according to GB/T16731-1997.

3. Flexural strength test

Take the polysand sound-absorbing device, cut it into 10mm×120mm×8mm, and test its flexural strength with a universal material testing machine.

4. Fire performance test

Test according to the national standard GB8624-2007.

table 3

It can be seen from Table 1 that the sand-accumulating sound-absorbing devices of Examples 1-5 of the present application have excellent anti-penetration performance, large noise reduction coefficient, high flexural strength, and excellent fireproof performance.

Comparative example 1-5

According to the formula ratio in the following table 4, based on the mass percentage of the base material, and according to the preparation method of Example 1-6, the sand gathering composition A-E is prepared, wherein the average particle size of the base material is 50-60 mesh .

Table 4

Then, according to the preparation methods of Examples 1-6, the corresponding sand-gathering and sound-absorbing devices A-E of Comparative Examples 1-5 were prepared. Wherein, in terms of the mass percentage of the substrate, the amount of silica sol added is shown in Table 5 below.

table 5

Performance test of polysand sound absorbing device A-E

The prepared sand-gathering sound-absorbing device A-E was cut to obtain a 300mm×600mm×8mm sand-gathering sound-absorbing device, and the same performance test as the above-mentioned sand-gathering sound-absorbing device 1-6 in Examples 1-6 was performed, and the results are shown in Table 6 shown.

Table 6

Test items unit Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative example 5 Permeability mL/min 13 0 10 0 5 noise reduction factor NRC 0.9 0.3 0.85 0.2 0.7 Flexural strength MPa 5 11 7 12 8 fire performance class A1 A1 A1 A1 B1

It can be seen from Table 6 that in Comparative Example 1, only 0.1% of binder and 0.01% of curing agent are added, and the prepared sand-acoustic device A has poor anti-permeability and low flexural strength. In comparative example 2, 6% of binder and 0.6% of curing agent were added, and the prepared sand-accumulating sound-absorbing device B had a low noise reduction coefficient and poor sound-absorbing performance. In Comparative Example 3, only 0.5% of binder was added, and the anti-permeability of the sand-accumulating sound-absorbing device C prepared by it was poor. In Comparative Example 4, 8% of binder and 0.04% of curing agent were added, and the sand-accumulating sound-absorbing device D prepared by it had a low noise reduction coefficient and poor sound-absorbing performance. In Comparative Example 5, 4% epoxy resin was added as a binder and 0.1% lubricant was added. The prepared sand-accumulating sound-absorbing device E had poor anti-penetration performance, and its fireproof performance could only reach B1 level.

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (10)

1. a kind of poly- sand sound absorber, which is characterized in that the poly- sand sound absorber is molded by poly- sand composition；It is described poly- Sand composition includes base material, binder, curing agent and lubricant；Wherein, with the mass percent of the base material for 100% The addition of meter, the binder is 1-5%, and the addition of preferably 2-4%, curing agent are 0.05-0.5%, preferably 0.1- 0.4%, the addition of lubricant is 0.2-0.5%, preferably 0.3-0.4%.

2. poly- sand sound absorber according to claim 1, which is characterized in that the base material includes silica sand, Desert Sand, quartz Sand, river sand, lake sand, nice foundry sand, mountain sand, sea sand, metal sand, forsterite sand, ceramsite sand, zircon sand, refractory clay and glass At least one of pearl, it is preferable that the average grain diameter of the base material is 10-100 mesh, preferably 50-60 mesh.

3. poly- sand sound absorber according to claim 1 or 2, which is characterized in that the curing agent includes ethylenediamine, front three Base hexamethylene diamine, hexamethylenetetramine, diethyl triamine, methylol ethylenediamine, hydroxyethyl ethylenediamine, dihydroxy ethyl second two Amine, ethoxy diethylenetriamine, dihydroxy ethyl ethylenediamine, ethoxy diethylenetriamine, dihydroxy ethyl diethylenetriamine, ethoxy In hexamethylene diamine, a cyanoethyl ethylenediamine, dicyanoethyl ethylenediamine, dicyanoethyl hexamethylene diamine, dicyandiamide and cyclohexanediamine at least It is a kind of.

4. according to the poly- sand sound absorber of claim 1-3 any one of them, which is characterized in that the binder includes thermosetting property Phenolic resin and/or thermosetting acrylic resin；Preferably, the lubricant includes polytetrafluoroethylene (PTFE), calcium stearate, stearic acid At least one of zinc and odium stearate.

5. according to the poly- sand sound absorber of claim 1-4 any one of them, which is characterized in that the poly- sand composition further includes Silane and/or graphite, in terms of the mass percent of the base material, the addition of the silane is 0.1-0.5%, preferably 0.2- 0.4%, the addition of the graphite is 0.05-0.5%, preferably 0.1-0.2%.

6. according to the poly- sand sound absorber of claim 1-5 any one of them, which is characterized in that the poly- sand sound absorber also wraps Ludox is included, in terms of the mass percent of base material in the poly- sand composition, the addition of the Ludox is 2-5%, preferably For 3-4%.

7. a kind of preparation method according to the poly- sand sound absorber of claim 1-6 any one of them, which is characterized in that including adopting The poly- sand sound absorber is prepared with the method for molding.

8. preparation method according to claim 7, which is characterized in that include the following steps：

Preheating step：After mold is preheated, molded；

Note sand step：Poly- sand composition is injected into mold；

Heat-press step：The mold after poly- sand composition will be injected and carry out hot pressing, obtain poly- sand sound absorber.

9. preparation method according to claim 8, which is characterized in that between the preheating step and the note sand step, Further include the steps that mixing the poly- sand composition with Ludox.

10. preparation method according to claim 8 or claim 9, which is characterized in that the preparation method of the poly- sand composition includes The step of each component of the poly- sand composition is mixed.