Preparation method of miscanthus floc sound-absorbing non-woven material for automobile

Abstract

The invention relates to the technical field of sound-absorbing materials, in particular to a preparation method of an automobile miscanthus floc sound-absorbing non-woven material, which comprises the following steps: firstly, removing seeds from collected miscanthus floc to ensure fiber dispersion and sufficient cohesion supporting force; then the miscanthus floridulus is cleaned and then dried, so that the influence of impurities on the subsequent processing performance of the material is avoided; then the miscanthus floridulus is balanced for 24 hours in a standard environment, so that the water content of the miscanthus floridulus fibers is stable, material shrinkage, deformation or non-uniform performance caused by humidity fluctuation in subsequent processing is avoided, and the stability of batch production is improved; finally, the miscanthus floridulus and the needled felt are compounded, the natural porous structure of the miscanthus floridulus can enhance sound wave scattering and energy dissipation, the needled felt provides basic framework support, the miscanthus floridulus and the needled felt are compounded to form a gradient sound absorption structure of porous fibers and a compact framework, and the sound absorption frequency range is widened; or the miscanthus floridulus is mixed with the wool fiber, and the wool fiber has higher porosity among crimped porous fibers.

Description

Technical Field

[0001] This invention relates to the field of sound-absorbing materials technology, and in particular to a method for preparing a five-section fibrous sound-absorbing nonwoven material for automobiles. Background Technology

[0002] Miscanthus floridulus, commonly known as five-jointed miscanthus, is a perennial herbaceous plant belonging to the genus Miscanthus in the family Alternariaceae. It is rich in biological resources and has multiple uses, holding significant value as a wild forage in the hilly and mountainous regions of southern my country. Its culms are relatively tall, with lanceolate-linear leaves that gradually narrow or round from the base, reaching a long acuminate apex. The midrib bulges outwards and is quite robust, hairless on both sides, or with fine, soft hairs on the upper and lower surfaces, and a rougher periphery. Miscanthus floridulus is also frequently called tube grass, cold miscanthus, and miscanthus grass, among other names.

[0003] The five-jointed mango has good applications in ecological and economic fields. Ecologically, it is a renewable biomass material that can be used for soil conservation and slope stabilization, rainwater interception, water conservation, and reducing soil erosion. It can also be converted into heat energy, electrical energy, and some liquid fuels. In addition, it has anti-inflammatory and antibacterial properties, enhances the body's resistance to pathogens, and regular consumption can prevent some infectious diseases. Currently, most research on the five-jointed mango focuses on its stems, primarily on its plant characteristics, chemical composition and biological activity, and absorption efficiency of heavy metals, with very little dedicated research on its inflorescence.

[0004] Miscanthus sinensis is a natural fiber, belonging to agricultural resources. It is widely available, abundant, grows rapidly, is environmentally friendly, and inexpensive, making it suitable for high-value utilization. The cross-section of Miscanthus sinensis is circular with a hollow structure, exhibiting a higher degree of hollowness than typical natural textile fibers, thus representing a potential natural sound-absorbing material. Therefore, a method for preparing sound-absorbing materials using Miscanthus sinensis fibers is needed. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a method for preparing a five-section awn-fiber sound-absorbing nonwoven material for automobiles, thereby solving the problems in the background art.

[0006] To achieve the above objectives, the present invention provides a method for preparing a five-section fibrous sound-absorbing nonwoven material for automobiles, comprising the following steps:

[0007] Step 1: Collect wild Miscanthus sinensis and remove the seeds from the tail end of the Miscanthus sinensis.

[0008] Step 2: Use distilled water to wash the five-jointed awns to remove dust and other impurities from their surface;

[0009] Step 3: Then, dry the five-section awns in an oven at a temperature of 45℃.

[0010] Step 4: Place the dried five-sectioned awns in a standard environment with a temperature of 20℃ and a relative humidity of 65% for 24 hours to equilibrate and complete the pre-humidification.

[0011] Step 5: The treated five-section awns are made into sound-absorbing nonwoven material.

[0012] Preferably, in step five, the needle-punched felt sheet is wrapped around the five sections of the awn to form a sound-absorbing nonwoven material.

[0013] Preferably, the needle-punched felt sheet has a five-segment awn filling density of 1-30 g / cm³. 3 .

[0014] Preferably, the five-sectioned awns and the needle-punched felt are bonded together by ultrasonic welding after being coated with water-based environmentally friendly adhesive.

[0015] Preferably, in step five, the awns are mixed with wool fibers to form a sound-absorbing nonwoven material.

[0016] Preferably, the mixing ratio of the five-segmented awns to wool fibers is 20 / 80, 40 / 60, or 60 / 40.

[0017] Preferably, the five-segmented awns and wool fibers are bonded together by ultrasonic welding after coating with water-based environmentally friendly adhesive.

[0018] Preferably, in step two, stubborn impurities on the surface of the five-sectioned awn are first removed by ultrasonic waves at a frequency of 28kHz, then washed with distilled water, and finally rinsed once with deionized water.

[0019] The beneficial effects of this invention are as follows: First, the seeds of the collected Miscanthus sinensis fibers are removed to ensure fiber dispersion and sufficient cohesion and support. Then, the Miscanthus sinensis is washed and dried to prevent impurities from affecting the subsequent processing performance. Next, the Miscanthus sinensis is equilibrated under standard conditions for 24 hours to stabilize the fiber moisture content, preventing shrinkage, deformation, or uneven performance due to humidity fluctuations during subsequent processing, thus improving the stability of mass production. Finally, the Miscanthus sinensis is combined with needle-punched felt. The natural porous structure of the Miscanthus sinensis enhances sound wave scattering and energy dissipation, while the needle-punched felt provides basic skeletal support. The combination forms a gradient sound-absorbing structure of "porous fiber + dense skeleton," broadening the sound absorption frequency range. Alternatively, the Miscanthus sinensis can be mixed with wool fiber. Wool fiber itself has crimped and porous characteristics; when mixed with Miscanthus sinensis in a certain proportion, the porosity between fibers is higher, and the elasticity and toughness of the two natural fibers complement each other. The sound absorption performance can be optimized by adjusting the ratio.

[0020] The sound-absorbing materials for the composite of five-jointed awns and needle-punched felt, as well as the blend of five-jointed awns and wool fibers, are prepared by ultrasonic welding using water-based environmentally friendly adhesives. The water-based adhesives have no VOC emissions and meet the environmental standards for automotive interiors. Ultrasonic welding uses high-frequency vibration to quickly cure the adhesive layer, resulting in high bonding strength. It avoids fiber damage caused by traditional hot pressing, and has low energy consumption and high efficiency, making it suitable for continuous industrial production.

[0021] Step two involves cleaning the five-segmented awns using a combination of 28kHz ultrasonic cleaning, distilled water cleaning, and deionized water rinsing. This process more thoroughly removes stubborn impurities, dust, and residual ions from the surface compared to traditional water washing, preventing impurities from affecting the subsequent processing performance of the material.

[0022] When five-section awns are used to cover needle-punched felt sheets or when they are mixed with wool, the sound absorption performance can be guaranteed while avoiding a decrease in the mechanical strength of the material, such as tear strength and abrasion resistance, due to an excessively high proportion of natural fibers, thus achieving a balance between "sound absorption and mechanical properties".

[0023] Five-jointed awns are raw materials collected in the wild, and their cost is lower than that of artificial synthetic fibers; wool fibers or needle-punched felt are mature industrial raw materials with a stable supply chain, and the overall process does not require complex chemical modification, thus reducing the total production cost. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0025] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0026] A method for preparing a five-section fuzzy sound-absorbing nonwoven material for automobiles includes the following steps:

[0027] S1, collect wild five-jointed awns and remove the seeds at the tail of the five-jointed awns;

[0028] S2. First, use 28kHz ultrasonic waves to remove stubborn impurities from the surface of the five-jointed awns, then wash with distilled water, and finally rinse once with deionized water to remove dust and other impurities from the surface of the five-jointed awns.

[0029] S3, and then the five-section awns are dried in an oven at a temperature of 45℃;

[0030] S4. Place the dried five-sectioned awns in a standard environment with a temperature of 20℃ and a relative humidity of 65% for 24 hours to balance and complete the pre-humidification.

[0031] S5, the treated five-section awns are wrapped with needle-punched felt to form a sound-absorbing non-woven material. The five-section awns and needle-punched felt are combined together by ultrasonic welding after being coated with water-based environmentally friendly adhesive.

[0032] Needle-punched felt sheets with diameters of 30 mm were prepared and filled with 0.2 g, 0.5 g, 0.7 g, 1 g, 2 g, and 3 g of five-segmented awns, respectively, which are Comparative Example 1 and Examples 1-5;

[0033] Filling density refers to the degree to which granular materials are filled within a certain volume. The porosity after filling reflects the degree of compactness of the particles in the granular material.

[0034] Formula for calculating filler density:

[0035] Where: m: bulk density; V: filling volume

[0036] The following table shows the filling density of the five-section fibrous fibers in Comparative Example 1 and Examples 1-5, calculated from the above formula:

[0037]

[0038] The sound absorption coefficients of Comparative Example 1 and Examples 1-5 were tested, and the results are shown in the table below:

[0039]

[0040] The table above shows that when the amount of five-section awn filling is between 0.5 and 3g, it exhibits sound absorption properties. When the amount of five-section awn filling felt is between 0 and 1g, the average sound absorption coefficient increases with the increase of the filling amount, and when the filling amount is between 1 and 3g, the sound absorption coefficient begins to decrease.

[0041] A method for preparing a five-section fuzzy sound-absorbing nonwoven material for automobiles includes the following steps:

[0042] S1, collect wild five-jointed awns and remove the seeds at the tail of the five-jointed awns;

[0043] S2. First, use 28kHz ultrasonic waves to remove stubborn impurities from the surface of the five-jointed awns, then wash with distilled water, and finally rinse once with deionized water to remove dust and other impurities from the surface of the five-jointed awns.

[0044] S3, and then the five-section awns are dried in an oven at a temperature of 45℃;

[0045] S4. Place the dried five-sectioned awns in a standard environment with a temperature of 20℃ and a relative humidity of 65% for 24 hours to balance and complete the pre-humidification.

[0046] S5 is made by mixing treated awns with wool fibers to form a sound-absorbing nonwoven material. The awns and wool fibers are then bonded together by ultrasonic welding after being coated with water-based environmentally friendly adhesive.

[0047] Examples 6-8 show that the mixing ratio of five-jointed awns to wool fiber is 20 / 80, 40 / 60, and 60 / 40, while Comparative Examples 2-3 show that the mixing ratio of five-jointed awns to wool fiber is 50 / 50 and 80 / 20.

[0048] The sound absorption coefficient test data of Examples 6-8 and Comparative Examples 2-3 are shown in the table below:

[0049]

[0050] As shown in the table above, the sound absorption performance of the five-jointed awn / wool felt first decreases with increasing five-jointed awn content, then increases, and finally decreases again. The average sound absorption coefficient reaches its lowest point when the five-jointed awn / wool mixture ratio is 80 / 20, but is still greater than 0.2, indicating continued sound absorption performance. Furthermore, at ratios of 20 / 80, 40 / 60, and 60 / 40, the average sound absorption coefficient exceeds 0.5, demonstrating the properties of an ideal high-sound-absorbing material and promising further development in the field of sound absorption.

[0051] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and many other variations of different aspects of the invention as described above exist, which are not provided in detail for the sake of brevity. Any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A method for preparing a five-section awn-fiber sound-absorbing nonwoven material for automobiles, characterized in that, It includes the following steps: Step 1: Collect wild Miscanthus sinensis and remove the seeds from the tail end of the Miscanthus sinensis. Step 2: Use distilled water to wash the five-jointed awns to remove dust and other impurities from their surface; Step 3: Then, dry the five-section awns in an oven at a temperature of 45℃. Step 4: Place the dried five-sectioned awns in a standard environment with a temperature of 20℃ and a relative humidity of 65% for 24 hours to equilibrate and complete the pre-humidification. Step 5: The treated five-section awns are made into sound-absorbing nonwoven material.

2. The method for preparing a five-section awn-fiber sound-absorbing nonwoven material for automobiles according to claim 1, characterized in that, In step five, the needle-punched felt sheet is wrapped around the five sections of the awn to form a sound-absorbing nonwoven material.

3. The method for preparing a five-section awn-fiber sound-absorbing nonwoven material for automobiles according to claim 2, characterized in that, The needle-punched felt has a five-segment awn filling density of 1-30 g / cm³. 3 .

4. The method for preparing a five-section awn-fiber sound-absorbing nonwoven material for automobiles according to claim 3, characterized in that, The five-sectioned awns and needle-punched felt are bonded together by ultrasonic welding after being coated with water-based environmentally friendly adhesive.

5. The method for preparing a five-section awn-fiber sound-absorbing nonwoven material for automobiles according to claim 1, characterized in that, In step five, the five-section awns are mixed with wool fibers to form a sound-absorbing nonwoven material.

6. The method for preparing a five-section awn-fiber sound-absorbing nonwoven material for automobiles according to claim 5, characterized in that, The mixing ratio of the five-segmented awns to wool fibers is 20 / 80, 40 / 60, or 60 / 40.

7. The method for preparing a five-section awn-fiber sound-absorbing nonwoven material for automobiles according to claim 6, characterized in that, The five-section awns and wool fibers are bonded together by ultrasonic welding after being coated with water-based environmentally friendly adhesive.

8. The method for preparing a five-section awn-fiber sound-absorbing nonwoven material for automobiles according to claim 1, characterized in that, In step two, stubborn impurities on the surface of the five-sectioned awn are first removed with ultrasonic waves at a frequency of 28kHz, then washed with distilled water, and finally rinsed once with deionized water.

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