Silencing film for automobile seat and production process of silencing film

Abstract

The invention belongs to the technical field of silencing films, and discloses a silencing film for an automobile seat and a production process thereof.The silencing film for the automobile seat is arranged between an automobile seat framework and polyurethane foam in an isolated mode and comprises a PE film layer and a non-woven fabric layer which are compounded together, the PE film layer is arranged on the side facing the automobile seat framework, and the non-woven fabric layer is arranged on the side facing the automobile seat framework. And the non-woven fabric layer is in contact with the surface of the polyurethane foam. The automobile seat cushion can be effectively isolated between an automobile seat framework and polyurethane foam for a long time, and the sound attenuation and noise reduction effects are more excellent.

Description

Technical Field

[0001] The invention relates to the technical field of sound-absorbing films, and in particular to a sound-absorbing film for automobile seats and a production process thereof. Background Art

[0002] With the rapid development of the automobile industry, people have put forward higher requirements for the comfort of automobiles. In order to meet people's requirements for high-quality and high-comfort automobile seats, the abnormal noise generated by the seats when riding should be reduced. An important source of noise from automobile seats is the friction sound between the automobile frame and the polyurethane foam (sponge pad), especially the noise is easily generated during the extrusion and deformation of the seat back or seat cushion. At present, there are two ways to traditionally reduce noise and noise. One is to spray a silencer wax coating at the contact position between the polyurethane foam and the automobile frame, and the other is to use a layer of ordinary non-woven fabric to be set between the frame and the polyurethane foam for noise reduction. However, spraying silencer wax has high technical requirements for operators, and there are often cases of over-spraying or missing spraying; using ordinary non-woven fabric isolation can prevent the porous polyurethane foam from directly contacting the smooth surface of the metal automobile seat frame, and reduce noise to a certain extent. However, the non-woven fabric is easy to dislocate during long-term extrusion and twisting, resulting in isolation failure.

[0003] In order to overcome the above problems, a sound-absorbing film for automobile seats and a production process thereof are needed. Summary of the invention

[0004] The purpose of the present invention is to provide a sound-absorbing film for automobile seats and a production process thereof, which can effectively isolate between the automobile seat frame and the polyurethane foam for a long time and has a better sound-absorbing and noise-reducing effect.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] The invention discloses a sound-absorbing membrane for automobile seats, which is isolated and arranged between an automobile seat frame and polyurethane foam, and comprises a composite PE film layer and a non-woven fabric layer, wherein the PE film layer is arranged on a side facing the automobile seat frame, and the non-woven fabric layer contacts the surface of the polyurethane foam.

[0007] Furthermore, the raw material components of the PE film layer include LDPE, LLPE, a matting agent, a softener and flame retardant particles, and the raw material components of the PE film layer also include antistatic particles.

[0008] Furthermore, the raw material components of the non-woven fabric layer include PP, PET, reinforced high-resistance particle material, softener, flame retardant particles and masterbatch, and the non-woven fabric layer is processed by spunbonding or needle punching.

[0009] The present invention also discloses a production process of a sound-absorbing film for automobile seats. To produce the sound-absorbing film for automobile seats described in any of the above items, the PE film layer and the non-woven fabric layer are compounded together by adhesive; the adhesive is a two-component polyurethane adhesive, and a compounding machine is used to apply adhesive to the PE film layer strip and then roll-press the compound non-woven fabric layer strip, which is then rolled up after compounding; the rolled up composite roll needs to be put into an oven for curing for 12 to 20 hours, and then spread into a multi-layer structure, which is sent to a hydraulic cutting machine for die-cutting, and the cut sound-absorbing film products are put into storage.

[0010] Furthermore, the winding tension of the composite roll is not greater than 1 kg-force, the entire composite roll is placed in the oven for heating and curing, the oven is heated by circulating air and the set temperature is 40° C. to 45° C., and a humidifier is provided in the oven.

[0011] Furthermore, the humidifier is in working state within the first 8 hours of drying and curing, and the humidity in the oven is ensured to be within the range of 55% RH to 65% RH.

[0012] Compared with the prior art, the beneficial technical effects of the present invention are:

[0013] The noise-absorbing film for automobile seats of the present invention adopts a composite film, and the smooth PE film layer contacts the automobile seat frame, which can reduce the friction resistance between the two. When the polyurethane foam is compressed and deformed, the composite film can be displaced back and forth relative to the automobile seat frame, that is, when the pressure deformation disappears, it will be reset smoothly immediately without leaving the original isolation position, and the soft and smooth surface of the PE film layer will not cause noise when it contacts the galvanized or painted surface of the automobile seat frame. The non-woven fabric layer contacts the porous surface of the polyurethane foam, and the contact friction between the two is relatively large, which ensures that the composite film is adaptively displaced following the deformation of the polyurethane foam.

[0014] In addition, by adding flame retardant particles and antistatic particles to the raw materials of the PE film layer, the flame retardant effect of the PE film layer is improved, and the accumulation of static charges on the composite film is avoided, and the antistatic effect is good. By adding flame retardant particles to the raw material components of the non-woven fabric layer, its flame retardant performance is improved, which is conducive to reducing the electrical fire loss of the seat; by selecting two non-woven fabric layers made by different processes, the applicability of the silencing film on the surface of the seat frame in different conditions can be improved.

[0015] The production process of the sound-absorbing film for automobile seats of the present invention adopts a compounding machine to glue and compound the rolled materials, with high production efficiency and uniform glue coating. The adhesive is heated and cured in an oven to avoid the peeling of the PE film layer and the non-woven fabric layer in the subsequent processing steps. By arranging a humidifier in the oven, it is possible to ensure that the sound-absorbing film coil is in a humid environment in the early stage of drying and curing. The non-woven fabric layer increases the wettability of the adhesive under the intrusion of moisture, ensuring that the adhesive can better penetrate into the interior of the non-woven fabric layer instead of just surface bonding. Curing in this way can not only ensure good adhesion but also further improve the strength of the non-woven fabric layer itself. By controlling the winding tension of the composite roll, it is ensured that there is a certain gap between the layers of the coil placed in the oven, ensuring that moisture can penetrate into the interior of the coil. Through this concave-convex shape, the bonding area between the adhesive and the non-woven fabric layer can be increased, thereby achieving the purpose of improving the bonding strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below in conjunction with the accompanying drawings.

[0017] Figure 1 It is a schematic diagram of the cross-sectional structure of the sound-absorbing membrane for automobile seats of the present invention;

[0018] Figure 2 This is a sample picture of the noise-absorbing film for automobile seats of the present invention before testing;

[0019] Figure 3 This is a sample picture of the sound-absorbing film for automobile seats after testing of the present invention;

[0020] Figure 4 This is a real picture of the sound-absorbing film for automobile seats of the present invention.

[0021] Description of the accompanying drawings: 1. PE film layer; 2. Non-woven fabric layer. DETAILED DESCRIPTION

[0022] The core of the present invention is to provide a sound-absorbing film for automobile seats and a production process thereof, which can effectively isolate between the automobile seat frame and the polyurethane foam for a long time, and has a more excellent sound-absorbing and noise-reducing effect.

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0025] Example 1

[0026] like Figure 1 and Figure 4 As shown, the sound-absorbing film for automobile seats of the present invention is a sound-absorbing film for automobile seats, which is isolated and arranged between the automobile seat frame and the polyurethane foam, and includes a composite PE film layer 1 and a non-woven fabric layer 2, wherein the PE film layer 1 is arranged on the side facing the automobile seat frame, and the non-woven fabric layer 2 is in contact with the surface of the polyurethane foam. Obviously, the sound-absorbing film for automobile seats can be directly placed in the groove of the polyurethane foam, or can be made into a bag form and sleeved on the automobile seat frame.

[0027] Compared with the traditional method of using ordinary non-woven fabrics to isolate the car seat frame and polyurethane foam, the present invention uses a composite film, and the smooth PE film layer 1 contacts the car seat frame, which can reduce the friction resistance between the two. When the polyurethane foam is compressed and deformed, the composite film can be reciprocated relative to the car seat frame, that is, when the pressure deformation disappears, it will be reset smoothly without leaving the original isolation position, and the soft and smooth surface of the PE film layer 1 will not cause noise when it contacts the galvanized or painted surface of the car seat frame. The non-woven fabric layer 2 contacts the porous surface of the polyurethane foam, and the contact friction between the two is large, which ensures that the composite film can be adaptively displaced following the deformation of the polyurethane foam.

[0028] In a specific implementation of this embodiment, the thickness of the PE film layer 1 is between 0.03 mm and 0.1 mm, that is, the PE film layer 1 is a thin plastic film with good softness.

[0029] In a specific implementation of this embodiment, the raw material components of the PE film layer 1 include 45 parts by weight of LDPE resin, 40 parts by weight of LLPE resin, 3 parts by weight of matting agent, 5 parts by weight of softener and 8 parts by weight of flame retardant particles.

[0030] Specifically, the raw materials of the PE film layer 1 also include antistatic particles, and the antistatic particles are 5 to 8 parts by weight.

[0031] With the development of car seats, traditional products can no longer meet the current needs of multi-functional and multi-matching seats. For example, electric seats and massage seats need to be equipped with electronic accessories, motors, heating elements, and massage components inside the seats to realize various functions of the seats. Therefore, the composite film of the partition needs to have flame retardant and antistatic properties.

[0032] By adding flame retardant particles and antistatic particles to the raw materials of the PE film layer 1, the flame retardant effect of the PE film layer 1 is improved, and the accumulation of static charges on the composite film is avoided, and the antistatic effect is good.

[0033] In a specific implementation of this embodiment, the raw material components of the non-woven fabric layer 2 include 30-35 parts by weight of PP, 45-50 parts by weight of PET, 5 parts by weight of reinforced high-resistant particle material, 5 parts by weight of softener, 6 parts by weight of flame retardant particles and 10 parts by weight of masterbatch.

[0034] Specifically, the non-woven fabric layer 2 is processed by a spunbond method or a needle punching method. When the surface of the car seat frame is treated differently: for example, when the seat frame surface is painted, sprayed or coated, it is recommended to use a composite sound-absorbing film made of a non-woven fabric layer 2 processed by a spunbond method. When the surface of the car seat frame is not treated, it is recommended to use a composite sound-absorbing film made of a non-woven fabric layer 2 processed by a needle punching method. The non-woven fabric layer 2 processed by the needle punching method has a high fiber strength and a large thickness, which can prevent the burrs on the surface of the car seat frame from penetrating.

[0035] By adding flame-retardant particles to the raw material components of the non-woven fabric layer 2, its flame retardant properties are improved, which is beneficial to reducing the electrical fire losses of the seat; by selecting the non-woven fabric layer 2 made by two different processes, the applicability of the sound-absorbing film under different conditions on the seat frame surface can be improved.

[0036] like Figure 2 and Figure 3 As shown, the composite sound-absorbing membrane made of the non-woven fabric layer 2 processed by the spunbond method was tested for combustion characteristics in accordance with GB 8410-2006 Combustion Characteristics of Automobile Interior Materials and GS 97038-2020 Combustion Performance of Automobile Interior Materials. It shows that the test result of the sound-absorbing membrane of the present invention is A-0: that is, the sample is exposed to the flame for 15 seconds and still does not burn; or the sample burns and extinguishes before reaching the first measurement mark, which is considered to meet the combustion speed requirements. Figure 3 It can be clearly seen that only a slight burn mark was produced at the ignited position on the top of the sample, and no combustion transfer occurred.

[0037] In summary, the sound-absorbing film for automobile seats of the present invention adopts a composite film, and the smooth PE film layer 1 contacts the frame of the automobile seat, which can reduce the friction resistance between the two. When the polyurethane foam is compressed and deformed, the composite film can be displaced back and forth relative to the frame of the automobile seat, that is, when the pressure deformation disappears, it will be reset smoothly immediately without leaving the original isolation position, and the soft and smooth surface of the PE film layer 1 will not cause noise when it contacts the galvanized or painted surface of the frame of the automobile seat. The non-woven fabric layer 2 contacts the porous surface of the polyurethane foam, and the contact friction between the two is large, which ensures that the composite film is adaptively displaced following the deformation of the polyurethane foam. In addition, by adding flame-retardant particles and antistatic particles to the raw materials of the PE film layer 1, the flame-retardant effect of the PE film layer 1 is improved, and the accumulation of static charge on the composite film is avoided, and the antistatic effect is good. By adding flame-retardant particles to the raw material components of the non-woven fabric layer 2, its flame-retardant performance is improved, which is conducive to reducing the electrical fire loss of the seat; by selecting two non-woven fabric layers 2 made by different processes, the applicability of the sound-absorbing film under different conditions on the surface of the seat frame can be improved.

[0038] Example 2

[0039] The present invention also discloses a production process of a sound-absorbing film for automobile seats, which is used to produce the sound-absorbing film for automobile seats described in the above embodiment. The PE film layer 1 and the non-woven fabric layer 2 are bonded together by adhesive.

[0040] In a specific implementation of the present embodiment, the adhesive glue adopts a two-component polyurethane adhesive, and the polyurethane adhesive component A and the polyurethane adhesive component B are mixed according to a set ratio and then applied. The glue mixing equipment is arranged next to the compounding machine. The PE film layer 1 and the non-woven fabric layer 2 are both coils before compounding. The PE film layer 1 material strip is coated with glue using a compounding machine, and the mixed two-component polyurethane adhesive is dipped into a coating roller and evenly coated on the bonding surface of the PE film layer 1. The rear end of the compounding machine uses a roller pressing method to compound the non-woven fabric layer 2 material strip to the bonding surface of the PE film layer 1, and the winding roller is used to rewind it after compounding. The rolled composite roll needs to enter the oven for curing for 12 to 20 hours. After the bonding strength is tested to be qualified, the whole roll is removed from the oven. Then the whole roll is transferred to the spreading equipment to reciprocate and flatten it on the workbench, and the spreading is a multi-layer structure. The laid multi-layer sound-absorbing film material is sent to the hydraulic cutting machine for die-cutting, and the cut sound-absorbing film finished product is put into storage.

[0041] The roll materials are glued and laminated using a laminating machine, which has high production efficiency and uniform glue coating. The adhesive is heated and cured in an oven to ensure complete curing and achieve good bonding strength, avoiding the peeling of the PE film layer 1 and the non-woven fabric layer 2 in subsequent processing steps.

[0042] In a specific embodiment, the polyurethane adhesive component A uses the solvent-free polyurethane adhesive 9012-A component, and the polyurethane adhesive component B uses the solvent-free polyurethane adhesive 9012-B component. The spunbonded nonwoven fabric with PP and PET as the main components is a non-polar nonwoven fabric, and the infiltration of the polar adhesive is poor, especially because the relatively dense nonwoven fabric material and the adhesive have poor infiltration, which easily results in only the surface of the nonwoven fabric being bonded.

[0043] In a specific implementation of this embodiment, the winding tension of the composite roll is not greater than 1 kg, that is, a loose winding method is adopted to ensure that the coil can be inserted between adjacent sound-absorbing films after being wound using fingers. The oven is heated by circulating air and the set temperature is 40°C to 45°C, and a humidifier is provided in the oven.

[0044] Specifically, during the first 8 hours of drying and curing, the humidifier is in operation and blows water vapor into the oven to ensure that the humidity in the oven is within the range of 55% RH to 65% RH.

[0045] By setting a humidifier in the oven, the sound-absorbing film coil can be kept in a humid environment in the early stage of drying and curing. The non-woven fabric layer 2 increases its wettability to the adhesive under the intrusion of moisture, ensuring that the adhesive can better penetrate into the interior of the non-woven fabric layer 2 rather than just adhere to the surface. Curing in this way can not only ensure better adhesion but also further improve the strength of the non-woven fabric layer 2. By controlling the winding tension of the composite roll, it is ensured that there is a certain gap between the layers of the coil placed in the oven, ensuring that moisture can penetrate into the interior of the coil.

[0046] In general, it is not necessary to fill moisture in the heat curing process of two-component polyurethane adhesive. The curing of two-component polyurethane adhesive depends on the chemical reaction of component A (hydroxy polyol) and component B (isocyanate) to form a polyurethane cross-linked network, which belongs to chemical curing. Filling moisture will also consume isocyanate groups, causing water and isocyanate groups to generate amines and carbon dioxide side reactions, which may cause bubbles or weaken the glue layer. However, specifically in this application, because the wettability of polyurethane adhesive and non-woven fabric is poor, a humidifier is set in the oven and moisture is filled in the initial stage of curing, and moisture penetrates into the non-woven fabric inside the coil through the gap between the layers of loose rolls, reducing the surface tension of the non-woven fabric, promoting the spreading of the adhesive, and moisture can also temporarily suspend the curing of the adhesive, ensuring that there is enough time to immerse in the non-woven fabric before the adhesive is cured. Although water and isocyanate groups react to generate amines and carbon dioxide side reactions, carbon dioxide gas can be removed as soon as possible through the pores of the non-woven fabric, and bubbles will not be formed, which does not affect the bonding strength.

[0047] In the comparative example, the two-component polyurethane adhesive after the PE film layer 1 and the non-woven fabric layer 2 are cured without humidification, and the adhesive is taken out after the same curing time. A small piece of the sound-absorbing film sample is cut, and the tester uses the finger, index finger and thumb to repeatedly rub the sound-absorbing film sample. The sound-absorbing film sample is prone to partial separation of the PE film layer 1 and the non-woven fabric layer 2. However, the sound-absorbing film sample produced by the humidification process of the present application will not peel off a large area of ​​the PE film layer 1 and the non-woven fabric layer 2 even if the PE film layer 1 is rubbed and broken.

[0048] In a specific embodiment of this embodiment, Figure 4 As shown, the non-woven fabric layer 2 can be pressed into a concave and convex shape by a printing roller before being compounded. A common method is to uniformly press pits on the non-woven fabric layer 2.

[0049] By means of such a concave-convex shape, the bonding area between the adhesive and the non-woven fabric layer 2 can be increased, thereby achieving the purpose of improving the bonding strength.

[0050] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0051] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A sound-absorbing film for a car seat, characterized in that: The insulation is arranged between the automobile seat frame and the polyurethane foam, and comprises a composite PE film layer (1) and a non-woven fabric layer (2), wherein the PE film layer (1) is arranged on the side facing the automobile seat frame, and the non-woven fabric layer (2) is in contact with the surface of the polyurethane foam.

2. The sound-absorbing film for automobile seats according to claim 1, characterized in that: The raw material components of the PE film layer (1) include LDPE, LLPE, a matting agent, a softener and flame retardant particles, and the raw material components of the PE film layer (1) also include antistatic particles.

3. The sound-absorbing film for automobile seats according to claim 1, characterized in that: The raw material components of the non-woven fabric layer (2) include PP, PET, reinforced high-resistance granular material, softener, flame retardant granules and masterbatch, and the non-woven fabric layer (2) is processed by a spunbonding method or a needle punching method.

4. A production process for a sound-absorbing film for automobile seats, characterized in that: In producing the sound-absorbing film for automobile seats as described in any one of claims 1 to 3, the PE film layer (1) and the non-woven fabric layer (2) are compounded together by adhesive; the adhesive is a two-component polyurethane adhesive, and a laminating machine is used to apply adhesive to the PE film layer (1) strip and then roll-compound the non-woven fabric layer (2) strip, and the rolled strip is rolled up after compounding; the rolled up composite roll needs to be put into an oven for curing for 12 to 20 hours, and then spread into a multi-layer structure, and sent to a hydraulic cutting machine for die-cutting, and the cut sound-absorbing film products are put into storage.

5. The process for producing a sound-absorbing film for automobile seats according to claim 4, characterized in that: The winding tension of the composite roll is not greater than 1 kg-force. The entire composite roll is placed in the oven for heating and curing. The oven is heated by circulating air and the set temperature is 40° C. to 45° C. A humidifier is provided in the oven.

6. The process for producing a sound-absorbing film for automobile seats according to claim 5, characterized in that: The humidifier is in working state during the first 8 hours of drying and curing, and the humidity in the oven is ensured to be within the range of 55% RH to 65% RH.

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