A method for preparing a sound-absorbing material based on expanded perlite particles

Abstract

The application discloses a kind of based on the preparation method of expanded perlite particle sound-absorbing material.The present application comprises the following steps: expanded perlite particle sample is screened according to three kinds of particle size, obtain three kinds of particle size of expanded perlite particle, marked as m7, m10, m14;Respectively, volume weighing is carried out, and the volume ratio of each is calculated according to total volume 100%, marked as according to following formula IV or formula V calculation, that is, the prediction value of normal incidence sound absorption characteristics of expanded perlite particle sample or the particle of different particle size range is matched to obtain the required acoustic performance curve, that is, based on the sound-absorbing material of expanded perlite particle;In formula IV, V, α' T,f It is the sound-absorbing performance prediction value of the mixture of different particle size expanded perlite particles in a certain proportion;Alpha T,f It is the sound absorption coefficient reference value of different thickness expanded perlite particles in the frequency range of 100Hz-2000Hz;When f is 100Hz-500Hz, and does not include 500Hz, formula IV is used to calculate α' T,f When f is 500Hz-2000Hz, formula V is used to calculate α' T,f . Formula IV formula V

Description

Technical Field

[0001] This invention relates to a method for preparing sound-absorbing materials based on expanded perlite particles. Background Technology

[0002] Expanded perlite is an inorganic granular material produced from perlite ore through crushing, drying, screening, preheating, calcination, and expansion. The granules have a porous internal structure, providing thermal insulation and sound absorption. Under normal operating conditions, expanded perlite's performance is not easily affected by dryness, extreme cold, high temperature, humidity, electrochemical corrosion, or the growth of insects, fungi, or algae, exhibiting excellent performance stability. It possesses advantages that commonly used porous fiber sound-absorbing materials (such as glass wool and rock wool) lack, and offers a higher cost-performance ratio.

[0003] However, expanded perlite granules are usually a mixture of granules of different sizes, and the proportions of various sizes vary considerably between different manufacturers and batches. This also results in the production of a certain proportion of granular powder (which can clog the pores of the material, thus reducing its sound absorption performance). Due to these factors, the stability of the sound absorption performance of expanded perlite granules is somewhat reduced. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing sound-absorbing materials based on expanded perlite particles. This invention changes the problems of unstable sound absorption performance and poor designability of sound absorption performance parameters of expanded perlite particles.

[0005] This invention provides a method for preparing a sound-absorbing material based on expanded perlite particles, comprising the following steps:

[0006] 1) The expanded perlite particle sample was sieved according to three particle sizes to remove small particles and powder with a particle size of no more than 1.50 mm, and expanded perlite particles with three particle sizes were obtained. The mesh numbers of the three particle sizes are recorded as m7, m10 and m14.

[0007] The sound absorption performance of expanded perlite particles of the three particle sizes at different thicknesses was measured to obtain their respective measured sound absorption coefficients. Then, the arithmetic mean of the measured sound absorption coefficients of expanded perlite particles of the three particle sizes at the same thickness was calculated, and rounded to the nearest 0.05 to obtain the baseline sound absorption coefficients of expanded perlite particles at different thicknesses, denoted as α. T,f ;

[0008] 2) Weigh the expanded perlite particles of the three different sizes by volume respectively;

[0009] 3) Based on the volume obtained from weighing in step 2), calculate the volume percentage of each of the three sizes of expanded perlite particles according to the following formulas I-III, with the total volume of the three sizes of expanded perlite particles being 100%.

[0010]

[0011]

[0012]

[0013] In formulas I-III, The volume percentage of expanded perlite particles with an average particle size of m7 (%).

[0014] The volume percentage of expanded perlite particles with an average particle size of m10 is %.

[0015] The volume percentage of expanded perlite particles with an average particle size of m14 mesh, expressed as %.

[0016] V m7 The weighing volume (L) of expanded perlite particles with an average particle size of m7 is given.

[0017] V m10 The weighing volume of expanded perlite particles with an average particle size of m10 is given in L.

[0018] V m14 The weighing volume (L) of expanded perlite particles with an average particle size of m14 mesh;

[0019] 5) In equations I-III, Substitute into Equation IV or Equation V below to calculate, and obtain the predicted value of the positive incident sound absorption characteristics of the expanded perlite particle sample, or mix particles of different particle size ranges to obtain the required acoustic performance curve, and thus obtain the sound absorption material based on expanded perlite particles.

[0020]

[0021]

[0022] In equations IV and V, f represents the frequency, which is 100Hz to 2000Hz;

[0023] α′ T,f Predicted sound absorption performance of expanded perlite particles of different sizes mixed in a certain proportion;

[0024] α T,f The reference values ​​for the sound absorption coefficient of expanded perlite particles of different thicknesses in the frequency range of 100Hz to 2000Hz;

[0025] When f is between 100Hz and 500Hz, excluding 500Hz, α′ is calculated using Equation IV. T,f ;

[0026] When f is between 500Hz and 2000Hz, α′ is calculated using Equation V. T,f .

[0027] In the above method, the expansion coefficient of the expanded perlite particle sample is 10 to 30 times.

[0028] In the above method, m7, m10, and m14 are 5-8 mesh, 9-10 mesh, and 12-15 mesh, respectively, and can specifically be 7, 10, and 14 mesh.

[0029] In the above method, in step 1), the expanded perlite particles of the three particle sizes can be 50-200 mm thick at different thicknesses, specifically 50 mm, 100 mm, 150 mm, and 200 mm.

[0030] In the above method, the sound absorption performance is measured using the impedance tube method;

[0031] The frequency at which the sound absorption performance is measured can be from 100Hz to 2000Hz.

[0032] In the above method, in formula IV, α′ T,f If its value is greater than 1.00, it takes the value of 1.00.

[0033] In this invention, step 2) can be performed using various weighing devices or containers.

[0034] The present invention also provides a sound-absorbing material based on expanded perlite particles prepared by the above method.

[0035] The present invention has the following beneficial effects:

[0036] This invention uses a screening mechanism to sieve expanded perlite particles of different particle sizes, arranges the particles according to their mesh size, and removes tiny particles and powder. Then, expanded perlite particles of different sizes are combined in the original proportion or in a free combination manner to achieve controllability and predictability of sound absorption performance. This changes the problem of unstable sound absorption performance and poor designability of sound absorption performance parameters of the original expanded perlite particles. Attached Figure Description

[0037] Figure 1 This is the reference value for the sound absorption coefficient of expanded perlite particles of different thicknesses in this invention.

[0038] Figure 2This is a curve showing the calculated and measured values ​​of sample 1 in Example 2 of the present invention, after being mixed with expanded perlite particles of the same size in different proportions.

[0039] Figure 3 This is a curve showing the calculated and measured values ​​of sample 2 in Example 2 of the present invention, after the expanded perlite particles of the same size were mixed in different proportions.

[0040] Figure 4 This is a curve showing the calculated and measured values ​​of sample 3 in Example 2 of the present invention, after the expanded perlite particles of the same size were mixed in different proportions.

[0041] Figure 5 This is a curve showing the calculated and measured values ​​of sample 4 in Example 2 of the present invention, which is a mixture of expanded perlite particles of the same size in different proportions.

[0042] Figure 6 The images show actual photos of the three different particle size ranges (7, 10, and 14 mesh) of expanded perlite particles obtained in Example 1 of this invention. Detailed Implementation

[0043] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0044] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.

[0045] The method for preparing sound-absorbing materials based on expanded perlite particles provided by the present invention includes the following steps:

[0046] 1) Sampling: Randomly take one bag (3-5 kg / bag) of expanded perlite granules (expansion coefficient should be controlled between 10 and 30 times) from a certain manufacturer and a certain batch, mix them thoroughly and pour them out and place them on a sieve;

[0047] 2) Screening: The sample was sequentially passed through 7-mesh (average particle size D > 3.0 mm), 10-mesh (2.0 mm < average particle size D ≤ 3.0 mm), and 14-mesh (1.5 mm < average particle size D ≤ 2.0 mm) sieves to remove tiny particles and powder with a particle size no larger than 1.50 mm, thus obtaining expanded perlite particles in three particle size ranges, such as... Figure 1 As shown;

[0048] 3) Weighing volume: Weigh the volume of the three different particle size ranges of expanded perlite particles obtained from screening. Various weighing equipment or containers can be used for this step.

[0049] 4) Volume ratio calculation: The volume ratio of expanded perlite particles in three different particle size ranges is calculated according to the following formula (Note: Since the particles themselves are light, have irregular and porous surfaces, the volume change after mixing particles of different sizes is negligible, and only linear addition and subtraction relationships are considered).

[0050]

[0051]

[0052]

[0053] in:

[0054] The volume percentage (%) of expanded perlite particles with an average particle size of 7 mesh;

[0055] The volume percentage (%) of expanded perlite particles with an average particle size of 10 mesh;

[0056] The volume percentage (%) of expanded perlite particles with an average particle size of 14 mesh;

[0057]

[0058] V m7 Weigh the volume (L) of expanded perlite particles with an average particle size of 7 mesh;

[0059] V m10 Weigh the volume (L) of expanded perlite particles with an average particle size of 10 mesh;

[0060] V m14 Weigh the volume (L) of expanded perlite particles with an average particle size of 14 mesh;

[0061] 5) Sound absorption performance calculation: Predict and calculate the normal incident sound absorption characteristics of the expanded perlite particles of this manufacturer and this batch according to the following formula; or use the formula to freely mix particles of different particle size ranges to obtain the required sound performance curve, that is, obtain the sound absorption material based on expanded perlite particles.

[0062]

[0063] in:

[0064] α′ T,f The predicted sound absorption performance of expanded perlite particles of different sizes mixed in a certain proportion (if greater than 1.00, take the value as 1.00);

[0065] α T,fThe reference values ​​for the sound absorption coefficients of expanded perlite particles with different thicknesses (50mm, 100mm, 150mm, 200mm) in the frequency range of 100Hz to 2000Hz are shown in Table 1 and... Figure 1 As shown, the sound absorption performance of expanded perlite particles of three different sizes at different thicknesses was measured to obtain their respective measured sound absorption coefficients. Then, the arithmetic mean of the measured sound absorption coefficients of expanded perlite particles of the three sizes at the same thickness was calculated, and rounded to the nearest 0.05 to obtain the baseline value α of the sound absorption coefficient for expanded perlite particles of different thicknesses. T,f .

[0066] From Table 1 and Figure 1 According to the data, ω m7,L ω m10,L ω m14,L The sound absorption coefficient of expanded perlite particles with different mesh sizes accounts for α within the 1 / 3 octave band range of 100Hz to 500Hz (excluding 500Hz). T,f The weighting coefficients are 0.87, 0.98, and 1.13, respectively; ω m7,H ω m10,H ω m14,H To determine the sound absorption coefficient of expanded perlite particles with different mesh sizes within a 1 / 3 octave band range of 500Hz to 2000Hz, accounting for α... T,f The weighting coefficients are 0.98, 0.99, and 1.04, respectively.

[0067] Therefore, the formula for predicting the positive incident sound absorption characteristics of sound-absorbing materials based on expanded perlite particles or obtaining the required acoustic performance curve by mixing expanded perlite particles of different sizes is shown in Equation IV or Equation V below.

[0068]

[0069]

[0070] Table 1

[0071]

[0072] Note: The values ​​in Table 1 have been smoothed by using 0.05 as the minimum multiple.

[0073] Example 1

[0074] According to the preparation method of the sound-absorbing material based on expanded perlite particles described above in this invention, samples 1-4 were screened with expanded perlite particles of three different particle size ranges: 7, 10, and 14 mesh. Samples with expanded perlite particles of different sizes mixed in different proportions were calculated and measured. The data comparison is shown in Table 2 below. The curves of calculated and measured values ​​for samples 1-4, after mixing expanded perlite particles of the same particle size in different proportions, are shown below. Figure 2-5 As shown.

[0075]

[0076]

[0077] The consistency between the measured and predicted values ​​was verified by using the intragroup correlation coefficient (ICC). The correlation coefficient (absolute consistency) was above 0.95, indicating that the method of the present invention is accurate. That is, the method of the present invention can obtain accurate predicted values ​​of the sound absorption performance of the mixture of expanded perlite particles with three particle sizes of 7, 10 and 14 mesh, or obtain the required acoustic performance curve by mixing expanded perlite particles of different sizes.

[0078] Table 2

[0079]

[0080]

Claims

1. A method for preparing sound-absorbing materials based on expanded perlite particles, characterized in that, Includes the following steps: 1) The expanded perlite particle sample was sieved according to three particle sizes to remove tiny particles and powder with a particle size no larger than 1.50 mm, resulting in expanded perlite particles of three different sizes. The mesh sizes of the three particle sizes are denoted as follows: , , ; The sound absorption performance of expanded perlite particles of the three particle sizes at different thicknesses was measured to obtain their respective measured sound absorption coefficients. Then, the arithmetic mean of the measured sound absorption coefficients of expanded perlite particles of the three particle sizes at the same thickness was calculated, and rounded to the nearest 0.05 to obtain the baseline sound absorption coefficients for expanded perlite particles of different thicknesses, denoted as [reference value]. ; 2) Weigh the volume of the expanded perlite particles of the three different sizes respectively; 3) Based on the volume obtained from weighing in step 2), calculate the volume percentage of each of the three sizes of expanded perlite particles according to the following formulas I-III, with the total volume of the three sizes of expanded perlite particles being 100%. In formulas I-III, Average particle size m 7. The volume percentage of expanded perlite particles, % Average particle size m The volume percentage of 10-mesh expanded perlite particles, % Average particle size m The volume percentage of 14-mesh expanded perlite particles, % V m7 Average particle size m 7. Weigh the volume of expanded perlite particles, in liters (L). V m10 Average particle size m Weigh the volume of 10-mesh expanded perlite particles, in liters (L). V m14 Average particle size m Weigh the volume of 14-mesh expanded perlite particles, in liters (L). 4) In equations I-III, , , Substitute into Equation IV or Equation V below to calculate, and obtain the predicted value of the positive incident sound absorption characteristics of the mixture of expanded perlite particles of the three particle sizes, or obtain the required acoustic performance curve by proportioning expanded perlite particles of different particle sizes, and thus obtain the sound absorption material based on expanded perlite particles. In formulas IV and V, f Indicates frequency, ranging from 100Hz to 2000Hz; Predicted sound absorption performance of expanded perlite particles of different sizes mixed in a certain proportion; The reference values ​​for the sound absorption coefficient of expanded perlite particles of different thicknesses in the frequency range of 100Hz~2000Hz; when f For frequencies ranging from 100Hz to 500Hz, excluding 500Hz, Equation IV is used for calculation. ; when f For frequencies between 500Hz and 2000Hz, Equation V is used for calculation. .

2. The method according to claim 1, characterized in that, The expansion coefficient of the expanded perlite particle sample is 10 to 30 times.

3. The method according to claim 1 or 2, characterized in that, The m7 , m10 , m14 They are 5-8 mesh, 9-10 mesh, and 12-15 mesh, respectively.

4. The method according to claim 1 or 2, characterized in that, In step 1), the three types of expanded perlite particles have different thicknesses ranging from 50 to 200 mm.

5. The method according to claim 4, characterized in that, In step 1), the three types of expanded perlite particles have different thicknesses of 50mm, 100mm, 150mm, and 200mm.

6. The method according to claim 1 or 2, characterized in that, The sound absorption performance was measured using the impedance tube method; The frequency range for measuring the sound absorption performance is 100Hz~2000Hz.

7. The method according to claim 1 or 2, characterized in that, In formula IV, If its value is greater than 1.00, it takes the value of 1.

00.

8. The sound-absorbing material based on expanded perlite particles prepared by the method of any one of claims 1-7.

Images