Particulate sound absorption board and preparation method thereof

Abstract

A particulate sound absorption board and its preparation method. The said particulate sound absorption board consists of binding agent and sound absorption particle; the external surface of sound absorption particle is covered with a layer of binding agent, and the angularity coefficient of particle covered with binding agent is less than 1.3; the said sound absorption particle consists of skeleton particle and filling particle, in which the former is used for sound absorption board skeleton, and the latter flows into the pore between skeleton particles to form sound absorption pore, and the average diameter of cross section of sound absorption pore is 0.07 mm. The two-stage manufacturing technology (i.e. coating, curing and then shaping) is adopted for the said preparation method to prevent the pore between particles from being blocked by excess binding agent, and further improve the angularity coefficient of particle.

Claims

1. A particulate sound absorption board, comprising: an organic binding agent, sound absorption particles, and sound absorption pores formed between the sound absorption particles, wherein the sound absorption particles comprise skeleton particles and filling particles, and an angularity coefficient of the sound adsorption particles is less than 1.5, wherein the organic binding agent is epoxy resin, phenolic resin, urea resin, or furfuryl alcohol resin, wherein the organic binding agent forms a coating over an external surface of the sound absorption particles, and wherein the coating of the organic binding agenthas an average thickness of 0.1-0.2 mm.

2. The particulate sound absorption board according to claim 1, wherein sound absorption pores are formed between the skeleton particles have an average diameter of 0.06-0.09 mm.

3. The particulate sound absorption board according to claim 2, wherein an average diameter the said sound absorption pores is 0.07 mm.

4. The particulate sound absorption board according to claim 1, wherein the size of the skeleton particles is 0.8-1 mm, and the size of the filling particles is 0.15 mm.

5. The particulate sound absorption board according to claim 1, further comprising a curing agent.

6. The particulate sound absorption board according to claim 5, wherein the curing agent causes a cross-linking reaction of the organic binding agent.

7. The particulate sound absorption board according to claim 1, wherein a weight ratio of the skeleton particles and the filling particles is 80-90:10-15.

8. The particulate sound absorption board according to claim 1, wherein the angularity coefficient of sound absorption particle selected is less than 1.3.

9. The particulate sound absorption board according to claim 1, wherein said sound absorption particle is sand, ceramsite, or recycled building waste particle.

10. The particulate sound absorption board according to claim 1, wherein a thickness of the sound absorption board is 10-50 mm.

11. A method of making a particulate sound absorption board of claim 1, comprising: (1) adding sound absorption particles of claim 1 in a sealing device, ventilating the sealing device, stirring suspended particles, spraying an organic binding agent at a rate of 20-40 mg/s so as to form a coating of the organic binding agent on an external surface of sound absorption particles, and forming coated particles after drying; and (2) mixing coated particles obtained from step (1) and a curing agent to form a mixture, and molding the mixture to the particulate sound absorption board of claim 1.

12. The method of preparing a particulate sound absorption board according to claim 11, wherein a top of said sealing device is connected to a dust collector.

13. The method of preparing a particulate sound absorption board according to claim 11, wherein an amount of the organic binding agent is 3%-10% of the weight of sound absorption particles.

Description

DESCRIPTION OF THE FIGURES

(1) FIG. 1 is the three-dimensional structure diagram of particulate sound absorption board of this invention;

(2) FIG. 2 is the cross section diagram of particulate sound absorption board of this invention;

(3) FIG. 3 is the coating diagram of sound absorption particles;

(4) FIG. 4 is the binding diagram of sound absorption particles;

(5) FIG. 5 is the comparison diagram of sound absorption coefficient of mixed particulate sound absorption board and particulate sound absorption board of the same diameter;

(6) FIG. 6 is the schematic diagram of particle pore;

(7) FIG. 7 is the comparison diagram of sound absorption coefficient of embodiments 1-3 and comparative embodiments 1-8 of this invention.

(8) Legend: 1. skeleton; 2. connected pore; 3. semi-connected pore; 4. sound absorption particle; 5. binding agent; 6. binding surface; 7. triangle; 8. arch; 9. sector; 10. pore; 11. skeleton particle; 12. filling particle.

SPECIFIC IMPLEMENTATION WAYS

(9) To clearly understand the purpose, technical scheme and beneficial effect, this invention will be further described below in combination with specific embodiments and drawings, but the protection scope of this invention is not limited to the following embodiments.

(10) As shown in FIGS. 1 and 2, the pore of particulate sound absorption board provided in this invention is formed by closely splicing particles of different diameters. The skeleton 1 of sound absorption board is made from skeleton particles 11, and the sound absorption pore is formed by filling a certain proportion of filling particles 12 (thinner particles) into the pore formed between skeletons so as to form a specific micropore structure required for sound absorption. The average diameter of cross section of sound absorption pore is 0.07 mm. When micropore diameter is 0.07 mm, the structure has excellent sound absorption property, including connected pore 2 that can store air and ventilate and semi-connected pore 3 that can store air, but can't ventilate. Specific manufacturing technology of particulate sound absorption board of this invention is described below with specific embodiments.

Embodiment 1

(11) 1. Selection of raw materials: select the wind-blown sand with angularity coefficient of less than 1.5, and screen out 0.8 mm particles with 20-mesh and 25-mesh screens; screen out 0.15 mm particles with 90-mesh and 100-mesh screens. 2. Mixture of raw materials: uniformly mix 90 kg 0.8 mm particles and 10 kg 0.15 mm particles. 3. Covering of binding agent: put the well-mixed raw materials into a sealing device, start the dust collector connected to the top of sealing device, remove the mud and dust from raw materials, and then close; pump compressed air into the bottom of sealing device, stir suspended raw materials, spray epoxy resin binding agent 3 kg, and control the spraying speed of binding agent at 20 mg/s, take out after spraying, and form coated particles after dying at room temperature. Upon inspection, the angularity coefficient of coated particles is less than 1.3, and average thickness of binding agent on the external surface of particles is 0.12 mm. 4. Preparation of 30 mm thick sound absorption board: fully stir coated particles and appropriate curing agent, and then place into 30 mm mold to ensure small particles can flow into the pore formed between large particles in a better way through vibration, and then pressurize, demould to obtain sound absorption board upon the completion of full cross-linking reaction of curing agent.

(12) The strength and sound absorption effect of the said sound absorption board are inspected, and inspection results are shown in the table below.

Embodiment 2

(13) 1. Selection of raw materials: select the ceramsite with angularity coefficient of less than 1.5, and screen out 0.8 mm particles with 20-mesh and 25-mesh screens; screen out 0.15 mm particles with 90-mesh and 100-mesh screens. 2. Mixture of raw materials: uniformly mix 90 kg 0.8 mm particles and 10 kg 0.15 mm particles. 3. Covering of binding agent: put the well-mixed raw materials into a sealing device, start the dust collector connected to the top of sealing device, remove the mud and dust from raw materials, and then close; pump compressed air into the bottom of sealing device, stir suspended raw materials, spray phenolic resin binding agent 5 kg, and control the spraying speed of binding agent at 40 mg/s, take out after spraying, and form coated particles after dying at room temperature. Upon inspection, the angularity coefficient of coated particles is less than 1.3, and average thickness of binding agent on the external surface of particles is 0.20 mm. 4. Preparation of 30 mm thick sound absorption board: fully stir coated particles and appropriate curing agent, and then place into 30 mm mold to ensure small particles can flow into the pore formed between large particles in a better way through vibration, and then pressurize, demould to obtain sound absorption board upon the completion of full cross-linking reaction of curing agent.

(14) The strength and sound absorption effect of the said sound absorption board are inspected, and inspection results are shown in the table below.

Embodiment 3

(15) 1. Selection of raw materials: select the recycled building waste particle with angularity coefficient of less than 1.5, and screen out 0.8-1 mm particles with 20-mesh and 25-mesh screens; screen out 0.15 mm particles with 90-mesh and 100-mesh screens. 2. Mixture of raw materials: uniformly mix 90 kg 0.8-1 mm particles and 10 kg 0.15 mm particles. 3. Covering of binding agent: put the well-mixed raw materials into a sealing device, start the dust collector connected to the top of sealing device, remove the mud and dust from raw materials, and then close; pump compressed air into the bottom of sealing device, stir suspended raw materials, spray urea resin and furfuryl alcohol resin binding agent 10 kg, and control the spraying speed of binding agent at 30 mg/s, take out after spraying, and form coated particles after dying at room temperature. Upon inspection, the angularity coefficient of coated particles is less than 1.3, and average thickness of binding agent on the external surface of particles is 0.20 mm. 4. Preparation of 30 mm thick sound absorption board: fully stir coated particles and appropriate curing agent, and then place into 30 mm mold to ensure small particles can flow into the pore formed between large particles in a better way through vibration, and then pressurize, demould to obtain sound absorption board upon the completion of full cross-linking reaction of curing agent.

(16) The strength and sound absorption effect of the said sound absorption board are inspected, and inspection results are shown in the table below.

Comparative Embodiment 1

(17) See embodiment 1 for specific operation. It is just that the angularity coefficient of particles selected in step 1 is less than 1.8. Upon inspection, the average thickness of binding agent on the external surface of coated particles is 0.07 mm, and the angularity coefficient of coated particles is less than 1.5.

Comparative Embodiment 2

(18) See embodiment 1 for specific operation. It is just that the angularity coefficient of particles selected in step 1 is less than 1.8. To ensure the angularity coefficient of coated particles is less than 1.3, and dosage of binding agent is increased to 10.5 kg in step 3. Upon inspection, the average thickness of binding agent on the external surface of coated particles is 0.25 mm.

Comparative Embodiment 3

(19) See embodiment 1 for specific operation. It is just that the mixture ratio (the mixture ratio of skeleton particle is unchanged, but the mixture ratio of filling particle is reduced) of raw materials in step 2 is changed as follows: 90 kg 0.8 mm particles and 8 kg 0.15 mm particles. According to the calculation, the dosage of binding agent is 2.94 kg.

Comparative Embodiment 4

(20) See embodiment 1 for specific operation. It is just that the mixture ratio (the mixture ratio of skeleton particle is unchanged, but the mixture ratio of filling particle is increased) of raw materials in step 2 is changed as follows: 90 kg 0.8 mm particles and 20 kg 0.15 mm particles. According to the calculation, the dosage of binding agent is 3.3 kg.

Comparative Embodiment 5

(21) See embodiment 1 for specific operation. It is just that the mixture ratio (the mixture ratio of filling particle is unchanged, but the mixture ratio of skeleton particle is reduced) of raw materials in step 2 is changed as follows: 60 kg 0.8 mm particles and 10 kg 0.15 mm particles. According to the calculation, the dosage of binding agent is 2.1 kg.

Comparative Embodiment 6

(22) See embodiment 1 for specific operation. It is just that the mixture ratio (the mixture ratio of filling particle is unchanged, but the mixture ratio of skeleton particle is increased) of raw materials in step 2 is changed as follows: 100 kg 0.8 mm particles and 10 kg 0.15 mm particles.

(23) According to the calculation, the dosage of binding agent is 3.3 kg.

Comparative Embodiment 7

(24) See embodiment 1 for material selection. It is just that its preparation method is to directly mix, stir and pressurize sound absorption particles, binding agent and curing agent.

Comparative Embodiment 8

(25) See embodiment 1 for specific operation. It is just that only 100 kg 0.8 mm particles are selected.

(26) We compare embodiments and comparative embodiments in this invention as well as the strength and sound absorption effect of commonly used environmentally-friendly sandstone sound absorption brick, expanded perilite sound absorption brick and pottery clay sound absorption brick. See the table below for details:

(27) TABLE-US-00001 Compressive Dosage of Strength at Binding S/N Room Agent (by (30 mm thick Temper- Sound Absorption weight of sample) ature(Mpa) Coefficient(NRC) raw materials) Embodiment 1 29 0.51(Standing 3% wave tube method) Embodiment 2 29 0.50(Standing 3% wave tube method) Embodiment 3 28.5 0.50(Standing 3% wave tube method) Comparative 27 0.42(Standing 3% embodiment 1 wave tube method) Comparative 26.2 0.38(Standing 10% embodiment 2 wave tube method) Comparative 25 0.41(Standing 3% embodiment 3 wave tube method) Comparative 26 0.35(Standing 3% embodiment 4 wave tube method) Comparative 24 0.40(Standing 3% embodiment 5 wave tube method) Comparative 23 0.38(Standing 3% embodiment 6 wave tube method) Comparative 23.5 0.42(Standing 11% embodiment 7 wave tube method) Comparative 23 0.37(Standing 3% embodiment 8 wave tube method) Environmentally- 26.1 0.38(Standing 15% friendly sandstone wave tube sound absorption method) brick expanded perilite 0.3-0.35 0.73(Reverberation 12% sound absorption chamber method) brick Pottery clay sound 10-12 0.47(Standing 15% absorption brick wave tube method)

(28) It can be seen from above results that embodiments 1-3 are the best implementation mode of technical scheme of this invention with high strength, good sound absorption effect and less binding agent dosage, and superior to existing environmentally-friendly sandstone sound absorption brick, expanded perilite sound absorption brick and pottery clay sound absorption brick; it fails to achieve better sound absorption effect even if comparative embodiments 1 and 2 lower the roundness requirements for particles, and comparative embodiments 3-6 correspondingly change the mixture ratio of skeleton particles and filling particles; it still fails to obtain better sound absorption effect when general all-mixed preparation method is used (comparative embodiment 7). In comparative embodiment 8, the sound absorption board is made from particles of the same diameter, but its sound absorption effect and sound absorption bandwidth can't be compared with this invention.

(29) Hence, the technical effect of this invention is achieved based on particle roundness requirements, selection of grading and unique preparation method.