Composite material as well as preparation method and application thereof

Abstract

The invention provides a composite material as well as a preparation method and application thereof. The composite material comprises a filling layer, the filling layer is a felt material formed by hot-pressing skin-core yarns, and the skin-core yarns comprise a core layer and a skin layer covering the surface of the core layer; the material of the core layer comprises a first polymer, the material of the skin layer comprises a second polymer, the first polymer and the second polymer are the same in type, and the melting temperature of the material of the skin layer is lower than that of the material of the core layer; the mass of the skin layer accounts for 10%-60% of the mass of the skin core yarn. The composite material has excellent mechanical performance and noise reduction performance, also has light weight performance, durability and water resistance, and can be applied to various scenes.

Description

Technical Field

[0001] This invention relates to a composite material, its preparation method, and its application. Background Technology

[0002] Continuous fiber reinforced thermoplastic composites mostly use continuous fiber structure to reinforce thermoplastic polymer matrix composites. The continuous fibers are selected from one or more of inorganic fibers such as glass fiber and carbon fiber, or organic fibers such as aramid, ultra-high molecular weight polyethylene fiber, and chemical fiber. The thermoplastic polymer matrix used includes thermoplastic resins such as PP, PA, PET, PPS, and PEEK. The resin impregnates the fibers through melt impregnation or solution impregnation, and finally, composite laminates are obtained through layup design and hot molding.

[0003] Continuous fiber reinforced thermoplastic composites have significant advantages such as high specific strength, low density, easy storage and transportation, good chemical corrosion resistance, recyclability, and high molding efficiency, and have broad application prospects in modern industrial fields such as aerospace, rail transportation, automobiles, and sports and leisure.

[0004] Commonly used methods for preparing continuous fiber reinforced thermoplastic composites mainly include melt impregnation and solution impregnation. Solution impregnation involves cumbersome solvent recovery and treatment, incurs high costs, and cannot achieve complete recycling, resulting in significant environmental pollution. Melt impregnation offers higher production efficiency and is cleaner and more environmentally friendly, but the high viscosity of the thermoplastic resin melt makes it difficult to impregnate the fiber gaps, leading to difficulties in fiber-resin composite bonding, poor interfacial adhesion, and unstable molding quality. Therefore, improving the wetting and interfacial effects between the resin matrix and the continuous fiber reinforcement in continuous fiber reinforced thermoplastic composites is crucial for achieving quality control and performance regulation.

[0005] In addition, in the industrial sector, based on textile processing technology and composite material mechanisms, at least two types of thermoplastic fibers such as chopped glass fiber, carbon fiber, hemp fiber, PP, or PET are randomly hybridized and mixed to form a fiber web, which is then needle-punched or hydroentangled to produce nonwoven felt. This type of felt undergoes hot-pressing to melt and bond the thermoplastic fibers to the non-melting reinforcing phase fibers, resulting in composite material sheets with a certain porous structure. The special material combination and porous microstructure of this type of product endow it with excellent vibration damping performance, good lightweighting, and mechanical properties, and it has mature applications in automotive interior and exterior trim, aerospace, and other fields. However, products made from chopped fiber composite felts are limited by their aspect ratio and porous structure, resulting in low fiber strength utilization, poor mechanical properties, tensile strength often below 30 MPa, and insufficient durability. Furthermore, using multiple fibers to form composite felts suffers from poor compatibility and interfacial bonding, leading to easy cracking and poor water resistance in the finished product.

[0006] Therefore, there is a need for a composite material that can fully leverage the synergistic effect of the components of the composite material while maintaining the good noise reduction performance of existing technologies, thereby improving the mechanical strength of the product and expanding its application scenarios. Summary of the Invention

[0007] To address the issue that existing composite materials cannot simultaneously satisfy both noise reduction and mechanical properties, a composite material, its preparation method, and its applications are provided. This composite material possesses excellent mechanical and noise reduction properties, while also exhibiting lightweight, durability, and water resistance, making it suitable for various applications.

[0008] The present invention solves the above-mentioned technical problems through the following technical solutions:

[0009] This invention provides a composite material comprising a filler layer;

[0010] The filling layer is a felt material formed by hot pressing of core-sheath yarn, which includes a core layer and a sheath layer covering the surface of the core layer;

[0011] The core layer is made of a first polymer, and the skin layer is made of a second polymer. The first polymer and the second polymer are of the same type, and the melting temperature of the skin layer material is lower than that of the core layer material.

[0012] The mass of the sheath layer accounts for 10%-60% of the mass of the core yarn.

[0013] In this invention, the first polymer and the second polymer are of the same type. "Same type" means that they are of the same general category but may differ in melting temperature, molecular weight, etc.

[0014] In this invention, preferably, both the first polymer and the second polymer are selected from polypropylene, polyester or nylon.

[0015] Preferably, the nylon is one or more of PA6, PA66, PA6T, MXD6, PA610, and PA56.

[0016] In some embodiments, both the first polymer and the second polymer are selected from polypropylene.

[0017] Preferably, the melting temperature of the first polymer is 160-190°C, for example, 170-180°C.

[0018] Preferably, the melting temperature of the second polymer is 140-170°C, for example, 150-160°C.

[0019] Preferably, the melt index of the first polymer is in the range of 0.5 to 50 g / 10 min, for example, 10 to 20 g / 10 min.

[0020] Preferably, the melt index of the second polymer is in the range of 20 to 100 g / 10 min, for example, 60 to 70 g / 10 min.

[0021] In some other embodiments, both the first polymer and the second polymer are selected from polyesters.

[0022] Preferably, the melting temperature of the first polymer is 240~270℃, for example, 240-260℃.

[0023] Preferably, the melting temperature of the second polymer is 100-130°C, for example, 120-140°C.

[0024] In some other embodiments, both the first polymer and the second polymer are selected from nylon.

[0025] Preferably, the melting temperature of the first polymer is 240-330°C, for example, 245-265°C.

[0026] Preferably, the melting temperature of the second polymer is 180-260°C, for example, 215-235°C.

[0027] Preferably, the melt index of the first polymer is in the range of 1-30 g / 10min, more preferably 1-10 g / 10min, for example 1.5-2 g / 10min.

[0028] Preferably, the melt index of the second polymer is in the range of 2-100 g / 10 min, more preferably 2-20 g / 10 min, for example 5-10 g / 10 min.

[0029] In this invention, preferably, the linear density of the core yarn is 5~80 tex, more preferably 50~80 tex, for example 70 tex.

[0030] In this invention, preferably, the fiber length of the felt material is greater than 5 mm, more preferably 20-30 mm.

[0031] In this invention, preferably, the mass percentage of the sheath layer to the mass percentage of the core yarn is 20%-50%.

[0032] In this invention, preferably, the composite material further includes a reinforcing layer; the reinforcing layer is disposed on at least one side of the filler layer, and the reinforcing layer satisfies the following:

[0033] The reinforcing layer is a fabric composed of the core yarn; preferably, the structure of the fabric includes plain weave, twill weave, satin weave, or multi-axial warp knit.

[0034] Alternatively, the reinforcing layer is a composite sheet; wherein the composite sheet comprises at least one structural layer formed by the first polymer and two structural layers formed by the second polymer; the structural layer formed by the first polymer is disposed between the two structural layers formed by the second polymer; preferably, the draw ratio of the composite sheet is 5 to 20 times; preferably, the thickness of the composite sheet is 0.05 to 3 mm, for example, 0.05 to 2 mm or 0.1 to 3 mm;

[0035] Alternatively, the reinforcing layer is a composite fabric; the composite fabric is woven from a narrow strip obtained by cutting a composite sheet; preferably, the draw ratio of the narrow strip is 5 to 20 times; preferably, the width of the narrow strip is 3 to 20 mm. The composite sheet comprises at least one structural layer formed by the first polymer and two structural layers formed by the second polymer; the structural layer formed by the first polymer is disposed between the two structural layers formed by the second polymer.

[0036] In this invention, preferably, the composite material further includes a functional layer, which is disposed on at least one side of the filler layer or on at least one side of the reinforcing layer, and the material of the functional layer includes the first polymer.

[0037] Preferably, the functional layer has a structure that includes one or more of sheet, membrane, felt and fabric.

[0038] In this invention, preferably, the thickness of the composite material is 2 to 20 mm, for example, 8 mm, 10 mm, 12 mm or 17 mm.

[0039] In this invention, preferably, the width of the composite material is 300~3000mm, for example, 2000mm.

[0040] In this invention, preferably, the composite material includes a filler layer and a reinforcing layer.

[0041] Preferably, the thickness of the filler layer is 8 mm and the thickness of the reinforcing layer is 2 mm.

[0042] In this invention, preferably, the composite material includes an N1 filling layer, an N2 reinforcing layer, and an N3 functional layer.

[0043] Preferably, N1 = 1-10, and more preferably 3;

[0044] Preferably, N2 = 1-10, and more preferably 2;

[0045] Preferably, N3 = 1-10, and more preferably 1.

[0046] In one specific embodiment of the present invention, the composite material includes three filler layers and two reinforcing layers.

[0047] Preferably, the thickness of the filler layer is 8 mm and the thickness of the reinforcing layer is 1 mm.

[0048] In one specific embodiment of the present invention, the composite material includes a filler layer, a reinforcing layer, and a functional layer.

[0049] Preferably, the thickness of the filling layer is 8 mm, the thickness of the reinforcing layer is 2 mm, and the thickness of the functional layer is 2 mm.

[0050] The present invention also provides a method for preparing a composite material, which includes the following steps:

[0051] Several core yarns are laid into a mesh, needle-punched, and hot-pressed to form a felt material, which is then used to form a filling layer.

[0052] The core-sheath yarn includes a core layer and a sheath layer covering the surface of the core layer;

[0053] The core layer is made of a first polymer, and the skin layer is made of a second polymer. The first polymer and the second polymer are of the same type, and the melting temperature of the second polymer is lower than that of the first polymer.

[0054] The mass of the sheath layer accounts for 10%-60% of the mass of the core yarn.

[0055] In this invention, preferably, the method for preparing the composite material further includes the following steps:

[0056] The composite material is obtained by laminating and hot-pressing a filler layer, a reinforcing layer, and a functional layer; the reinforcing layer is made of the first polymer and the second polymer; the functional layer is made of the first polymer.

[0057] The temperature of the hot pressing process is preferably 150~380℃, for example 170℃, 190℃ or 240℃.

[0058] The pressure of the hot pressing treatment is preferably 0.1-5 MPa, and more preferably 0.1-3 MPa.

[0059] During the hot pressing process, the moving speed of the filling layer is preferably 1~20 m / min, and more preferably 10 m / min.

[0060] During the hot pressing process, the moving speed of the reinforcing layer is preferably 1~20 m / min, and more preferably 10 m / min.

[0061] During the hot pressing process, the moving speed of the functional layer is preferably 1~20m / min, and more preferably 10m / min.

[0062] Preferably, during the hot pressing process, the filling layer, the reinforcing layer, and the functional layer move at the same speed.

[0063] In this invention, preferably, the method for preparing the core-sheath yarn includes the following steps:

[0064] The melted first polymer and second polymer are spun into a core-sheath yarn to obtain a core-sheath yarn.

[0065] The initial core-sheath yarn is subjected to stretching and cooling treatment in sequence to obtain the core-sheath yarn.

[0066] Preferably, the stretching ratio of the stretching treatment is 5-15 times, for example, 9-15 times, 5-9 times or 6-12 times.

[0067] Cooling and shaping can be performed using methods conventional in this field.

[0068] Preferably, the cooling and shaping process may further include post-treatment, which includes oiling and heat shaping in sequence.

[0069] Preferably, the heat setting temperature is 120-170°C, for example, 140°C, 150°C or 160°C.

[0070] Preferably, the heat setting time is 0.5-2 hours, for example, 1 hour.

[0071] Preferably, the process after spinning also includes a drying step.

[0072] Preferably, the drying temperature is 100-120°C, for example, 110°C.

[0073] Preferably, the drying process takes 2-12 hours, for example, 8 hours.

[0074] In this invention, preferably, the method for preparing the reinforcing layer may include the following steps:

[0075] When the reinforcing layer is a composite sheet, the melted first polymer and the second polymer are processed by co-extrusion coating process, sandwich coating process or hot bonding process to form a structural layer formed by the first polymer and two structural layers formed by the second polymer, and the structural layer formed by the first polymer is disposed between the two structural layers formed by the second polymer.

[0076] Preferably, the thickness of the structural layer formed by the first polymer is 0.5 mm, and the thickness of the structural layer formed by the second polymer is 0.25 mm.

[0077] In this invention, the co-extrusion coating process refers to the process of using two or more extruders to melt and plasticize two or more polymers with different properties, and then using a co-extrusion die to produce a multilayer composite film.

[0078] In this invention, the sandwich coating process refers to the process of casting a polymer by hot melting it in a coating machine, and then pressing and cooling it to form a multi-layer composite film.

[0079] In this invention, the heat-bonding process refers to the process of producing a multilayer composite film by co-extruding and casting two polymers to obtain a film roll, and then pressing it at high temperature.

[0080] When the reinforcing layer is a composite fabric, the composite sheet is cut to obtain a narrow strip, and the narrow strip is woven to form a composite fabric.

[0081] In this invention, preferably, the method for preparing the functional layer may include the following steps: melting the first polymer and then performing melt extrusion (cast film) to obtain the functional layer.

[0082] The temperature of the melt extrusion is preferably 200-300°C, for example, 280°C.

[0083] The present invention also provides a composite material prepared by the method described above.

[0084] The present invention also provides an application of the composite material as described above.

[0085] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain various preferred embodiments of the present invention.

[0086] The reagents and raw materials used in this invention are all commercially available.

[0087] The positive and progressive effects of this invention are as follows:

[0088] This invention utilizes specific first and second polymers to form a core-sheath yarn, which, after hot pressing, creates a filling layer with a unique structure. This filling layer simultaneously possesses excellent mechanical properties and noise reduction performance. Furthermore, the material also exhibits lightweight properties, durability, and water resistance, making it suitable for various applications.

[0089] In some preferred embodiments, the present invention may also include a reinforcement layer and a functional layer, which is beneficial to further improve mechanical properties and noise reduction performance. Detailed Implementation

[0090] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods in the following embodiments that do not specify specific conditions were performed according to conventional methods and conditions, or as selected according to the product instructions.

[0091] Example 1

[0092] The preparation method of composite materials includes the following steps:

[0093] (1) Preparation of core-sheath yarn:

[0094] Select PP with a melting temperature of 170-180℃ and a melt index of 10-20 g / 10min as the first polymer, and select PP with a melting temperature of 150-160℃ and a melt index of 60-70 g / 10min as the second polymer; perform drying treatment on the first and second polymers (drying treatment temperature of 100-110℃, time of 2-8h) to remove moisture; the drying treatment time can be 2-8h, and more than 99% of the moisture needs to be removed.

[0095] The first polymer and the second polymer are melted in two separate melt tanks (the melting temperature is 210-220℃) to achieve an orderly composite flow of the melts of the first polymer and the second polymer. Finally, they are extruded from the same spinneret and then simultaneously ejected through an annular spinneret to obtain the initial product of the core-sheath yarn.

[0096] The above-mentioned core yarn raw products are subjected to stretching treatment (stretching ratio of 9-15 times) and cooling and setting (conventional cooling and setting in this field).

[0097] Post-processing: The above-mentioned cooled core yarn is subjected to oiling treatment (conventional oiling treatment in this field) and heat setting (heat setting temperature is 120-140℃, time is 0.5-2h) to obtain core yarn; among them, the heat setting time within 0.5-2h has little impact on the technical effect and can be ignored.

[0098] The core-sheath yarn consists of a core layer and a sheath layer covering the surface of the core layer; the sheath layer accounts for 50% of the mass of the core-sheath yarn; the linear density of the core-sheath yarn is 70 tex.

[0099] (2) Preparation of the filling layer:

[0100] Several of the above-mentioned core yarns are laid into a web, needle punched, and hot-pressed to form a felt material (the fiber length of the felt material is 20-30mm), which is the filling layer.

[0101] (3) Preparation of the reinforcing layer:

[0102] The reinforcing layer is a composite sheet (with a draw ratio of 10 times). The melted first polymer and second polymer are treated using a conventional co-extrusion and re-coating process to form a structural layer formed by the first polymer and two structural layers formed by the second polymer, with the structural layer formed by the first polymer located between the two structural layers formed by the second polymer. The thickness of the structural layer formed by the first polymer is 0.5 mm, and the thickness of the structural layer formed by the second polymer is 0.25 mm.

[0103] (4) Preparation of composite materials:

[0104] The composite material is obtained by hot-pressing the above three 5mm thick filler layers and two 1mm thick reinforcing layers. The hot-pressing temperature is 170℃, the hot-pressing pressure is 0.1MPa, and the moving speed of the filler layer and the reinforcing layer during the hot-pressing process is 10 m / min.

[0105] The thickness of the above composite material is 10mm (the thickness of each layer will decrease after hot pressing), and the width is 2000mm; the structure of the above composite material is, in sequence, a filler layer, a reinforcing layer, a filler layer, a reinforcing layer, and a filler layer.

[0106] Example 2

[0107] The preparation method of composite materials includes the following steps:

[0108] (1) The preparation of the core yarn is the same as in Example 1.

[0109] (2) The preparation of the filling layer is the same as in Example 1.

[0110] (3) Preparation of the reinforcing layer:

[0111] The reinforcing layer is a composite fabric. The composite sheet of Example 1 is cut to obtain a narrow strip (the stretch ratio of the narrow strip is 10 times and the width of the narrow strip is 10 mm), and the narrow strip is woven to form a composite fabric.

[0112] (4) The preparation of the composite material is the same as in Example 1.

[0113] Example 3

[0114] The preparation method of composite materials includes the following steps:

[0115] (1) Select PET with a melting temperature of 240-260℃ as the first polymer and COPET with a melting temperature of 120-140℃ as the second polymer; the first polymer and the second polymer are melted in two melt boxes respectively (the melting temperature is 230-240℃), and the preparation of the remaining core yarn is the same as in Example 2.

[0116] (2) The preparation of the filling layer is the same as in Example 2.

[0117] (3) The preparation of the reinforcing layer is the same as in Example 2.

[0118] (4) Preparation of functional layers:

[0119] The molten first polymer is melt-extruded (at a temperature of 280°C, cast film) to obtain the functional layer.

[0120] (5) Preparation of composite materials:

[0121] The above-mentioned 8mm thick filler layer, 2mm thick reinforcing layer and 2mm thick functional layer are subjected to hot pressing to obtain a composite material. The filler layer is located between the reinforcing layer and the functional layer. The hot pressing temperature is 170℃ and the hot pressing pressure is 5MPa. During the hot pressing process, the moving speed of the filler layer and the reinforcing layer is 10 m / min.

[0122] The composite material has a thickness of 12 mm and a width of 2000 mm.

[0123] Example 4

[0124] The preparation method of composite materials includes the following steps:

[0125] (1) Preparation of core-sheath yarn:

[0126] PA66 with a melting temperature of 245-265℃ and a melt index of 1.5-2 g / 10min was selected as the first polymer, and PA6 with a melting temperature of 215-235℃ and a melt index of 5-10 g / 10min was selected as the second polymer. The first and second polymers were dried (drying temperature of 120℃ for 8-12 hours) to remove moisture; the drying time could be 8-12 hours, and more than 99% of the moisture should be removed.

[0127] The first polymer and the second polymer are melted in two separate melt tanks (the melting temperature is 260-280℃) to achieve an orderly composite flow of the melts of the first polymer and the second polymer. Finally, they are extruded from the same spinneret and then simultaneously ejected through an annular spinneret to obtain the initial product of the core-sheath yarn.

[0128] The above-mentioned core-sheath yarn raw products are subjected to stretching treatment (stretching ratio of 5-9 times) and cooling and setting in sequence;

[0129] Post-processing: The above-mentioned cooled core yarn is subjected to oiling treatment (conventional oiling treatment in this field) and heat setting (heat setting temperature is 150-170℃, time is 1-2h) to obtain core yarn; among them, the heat setting time within 1-2h has little impact on the technical effect and can be ignored.

[0130] The core-sheath yarn consists of a core layer and a sheath layer covering the surface of the core layer; the sheath layer accounts for 50% of the mass of the core-sheath yarn; the linear density of the core-sheath yarn is 70 tex.

[0131] (2) Preparation of the filling layer:

[0132] Several core yarns are laid into a mesh and needle-punched to form a felt material to create a filling layer.

[0133] (3) Preparation of the reinforcing layer:

[0134] The reinforcing layer is a fabric composed of the aforementioned core-sheath yarn, and the fabric has a plain weave structure.

[0135] (4) Preparation of composite materials:

[0136] The above-mentioned 8mm thick filler layer and 2mm thick reinforcing layer are subjected to hot pressing to obtain a composite material. The hot pressing temperature is 240℃, the hot pressing pressure is 5MPa, and the moving speed of the filler layer and the reinforcing layer during the hot pressing process is 10 m / min.

[0137] The composite material has a thickness of 10 mm and a width of 2000 mm.

[0138] Example 5

[0139] The core-sheath yarn includes a core layer and a sheath layer covering the surface of the core layer; the mass of the sheath layer accounts for 10% of the mass of the core-sheath yarn; the remaining conditions are the same as in Example 1.

[0140] Example 6

[0141] The core-sheath yarn includes a core layer and a sheath layer covering the surface of the core layer; the mass of the sheath layer accounts for 60% of the mass of the core-sheath yarn; the remaining conditions are the same as in Example 1.

[0142] Example 7

[0143] The preparation method of composite materials includes the following steps:

[0144] (1) Preparation of core-sheath yarn:

[0145] PET with a melt temperature of 240-260℃ and a melt index of 10-20 g / 10min is selected as the first polymer, and COPET with a melt temperature of 120-140℃ and a melt index of 60-70 g / 10min is selected as the second polymer. The first and second polymers are dried (drying temperature is 120℃, time is 8-12h) to remove moisture. The drying time can be 8-12h, and more than 99% of the moisture needs to be removed.

[0146] The first polymer and the second polymer are melted in two separate melt tanks (the melting temperature is 230-240℃) to achieve an orderly composite flow of the melts of the first polymer and the second polymer. Finally, they are extruded from the same spinneret and then simultaneously ejected through an annular spinneret to obtain the initial product of the core-sheath yarn.

[0147] The above-mentioned core-sheath yarn raw products are subjected to stretching treatment (stretching ratio of 6-12 times) and cooling and setting in sequence;

[0148] Post-processing: The above-mentioned cooled core yarn is subjected to oiling treatment (conventional oiling treatment in this field) and heat setting (heat setting temperature is 160℃, time is 1h) to obtain core yarn;

[0149] The core-sheath yarn consists of a core layer and a sheath layer covering the surface of the core layer; the sheath layer accounts for 50% of the mass of the core-sheath yarn; the linear density of the core-sheath yarn is 70 tex.

[0150] (2) The preparation of the filling layer is the same as in Example 1.

[0151] (3) No enhancement layer and function layer are set.

[0152] (4) Preparation of composite materials:

[0153] The above-mentioned 8mm thick filler layer is used as a composite material with a width of 2000mm.

[0154] Example 8

[0155] The filler layer from Example 1 was used as the composite material.

[0156] Example 9

[0157] The preparation method of composite materials includes the following steps:

[0158] (1) The preparation of the core yarn is the same as in Example 1.

[0159] (2) The preparation of the filling layer is the same as in Example 1.

[0160] (3) Preparation of the reinforcing layer:

[0161] The reinforcing layer is a composite sheet made of hemp fiber (with a draw ratio of 10).

[0162] (4) Preparation of composite materials:

[0163] The above-mentioned 8mm thick filler layer and 2mm thick reinforcing layer are subjected to hot pressing to obtain a composite material. The hot pressing temperature is 190℃, the hot pressing pressure is 5MPa, and the moving speed of the filler layer and the reinforcing layer during the hot pressing process is 10 m / min.

[0164] The composite material has a thickness of 10 mm and a width of 2000 mm.

[0165] Example 1

[0166] The composite material prepared above was subjected to the following tests:

[0167] 1. Tensile strength: Tested in accordance with standard GB1447.

[0168] 2. Bending strength: Tested in accordance with standard GB1449.

[0169] 3. Tear strength: Tested according to standard GB450.

[0170] 4. Sound absorption coefficient: Tested in accordance with the standard GB / T 18696.2.

[0171] The test results are listed in Table 1 below:

[0172] Table 1

[0173]

[0174] As shown in the table above, the composite material prepared in the above embodiments can achieve a tensile strength of over 23.1 MPa, a flexural strength of over 11.7 MPa, a tear strength of over 103.8 MPa, and a sound absorption coefficient of over 0.869, indicating that the above composite material can simultaneously possess excellent mechanical properties and noise reduction performance. Furthermore, the above material also exhibits lightweight properties, durability, and water resistance, making it applicable to various scenarios.

[0175] According to the results of Examples 1-6, controlling the mass percentage of the sheath layer to the core yarn mass at 20%-50% can further improve tensile strength, flexural strength, tear strength and sound absorption coefficient.

[0176] According to the results of Examples 1 and 8, by providing a reinforcing layer on the filling layer, it is possible to further achieve a tensile strength of 35.2 MPa or more, a flexural strength of 18.3 MPa or more, a tear strength of 162.5 MPa or more, and a sound absorption coefficient of 0.921 or more.

[0177] Based on the results of Examples 1 and 9, it can be seen that the reinforcing layer, using a material comprising a first polymer and a second polymer, can further achieve a tensile strength of 35.2 MPa or more, a flexural strength of 18.3 MPa or more, a tear strength of 162.5 MPa or more, and a sound absorption coefficient of 0.921 or more.

Claims

1. A composite material, characterized by, It comprises a filling layer; The filling layer is a felt material formed by hot pressing of a core-sheath yarn, the core-sheath yarn comprising a core layer and a sheath layer covering the surface of the core layer; The material of the core layer comprises a first polymer, the material of the sheath layer comprises a second polymer, the first polymer and the second polymer are of the same kind, and the melting temperature of the material of the sheath layer is lower than that of the material of the core layer; The mass percentage of the sheath layer in the core-sheath yarn is 10%-60%.

2. The composite material of claim 1, wherein, It meets one or more of the following conditions: (a) The first polymer and the second polymer are both selected from polypropylene, polyester or nylon; Preferably, the nylon is one or more of PA6, PA66, PA6T, MXD6, PA610 and PA56; Alternatively, the first polymer and the second polymer are both selected from polypropylene; Preferably, the melting temperature of the first polymer is 160-190℃, for example 170-180℃; Preferably, the melting temperature of the second polymer is 140-170℃, for example 150-160℃; Preferably, the melt index of the first polymer ranges from 0.5 to 50 g / 10min, for example 10-20 g / 10min; Preferably, the melt index of the second polymer ranges from 20 to 100 g / 10min, for example 60-70 g / 10min; Alternatively, the first polymer and the second polymer are both selected from polyester; Preferably, the melting temperature of the first polymer is 240-270℃, for example 240-260℃; Preferably, the melting temperature of the second polymer is 100-130℃, for example 120-140℃; Alternatively, the first polymer and the second polymer are both selected from nylon; Preferably, the melting temperature of the first polymer is 240-330℃, for example 245-265℃; Preferably, the melting temperature of the second polymer is 180-260℃, for example 215-235℃; Preferably, the melt index of the first polymer ranges from 1 to 30 g / 10min, more preferably from 1 to 10 g / 10min, for example 1.5-2 g / 10min; Preferably, the melt index of the second polymer ranges from 2 to 100 g / 10min, more preferably from 2 to 20 g / 10min, for example 5-10 g / 10min; (b) The linear density of the core-sheath yarn is 5-80 tex, preferably 50-80 tex, for example 70 tex; (c) The fiber length of the felt material is greater than 5mm, preferably 20-30mm.

3. The composite material of claim 1, wherein, The composite material further comprises a reinforcing layer; the reinforcing layer is arranged on at least one side of the filling layer, and the reinforcing layer meets any one of the following conditions: (a) The reinforcing layer is a fabric composed of the core-sheath yarn; Preferably, the fabric has a structure form comprising plain weave, twill weave, satin weave or multi-axial warp-knitted fabric; (b) the reinforcing layer is a composite sheet; wherein the composite sheet comprises at least one structural layer formed of the first polymer and two structural layers formed of the second polymer; the structural layer formed of the first polymer is disposed between the two structural layers formed of the second polymer; Preferably, the composite sheet has a draw ratio of 5-20; Preferably, the composite sheet has a thickness of 0.05-3 mm, for example 0.05-2 mm or 0.1-3 mm; (c) the reinforcing layer is a composite fabric; the composite fabric is obtained by weaving a narrow strip obtained by cutting the composite sheet; Preferably, the narrow strip has a draw ratio of 5-20; Preferably, the narrow strip has a width of 3-20 mm.

4. The composite material of any one of claims 1-3, wherein, The composite material further comprises a functional layer disposed on at least one side of the filler layer or on at least one side of the reinforcing layer, the material of the functional layer comprising the first polymer; Preferably, the functional layer has a structure selected from one or more of a sheet, a film, a felt and a fabric.

5. The composite material of claim 1, wherein, The composite material satisfies one or more of the following conditions: (a) the composite material has a thickness of 2-20 mm, for example 8 mm, 10 mm, 12 mm or 17 mm; (b) the composite material has a width of 300-3000 mm; (c) the composite material comprises N1 filler layers, N2 reinforcing layers and N3 functional layers; Preferably, N1 = 1-10, preferably 3; Preferably, N2 = 1-10, preferably 2; Preferably, N3 = 1-10, preferably 1.

6. A method of producing a composite material, characterized by, The method comprises the following steps: The core-sheath yarns are laid, needled and hot-pressed to form a felt, thereby forming the filler layer; The core-sheath yarns comprise a core layer and a sheath layer covering the surface of the core layer; The material of the core layer comprises the first polymer, and the material of the sheath layer comprises the second polymer; the second polymer has a lower melting temperature than the first polymer; The mass percentage of the sheath layer in the core-sheath yarns is 10%-60%.

7. The method of claim 6, wherein the step of applying the second layer of material is performed after the step of applying the first layer of material. The method further comprises the following steps: The filler layer, the reinforcing layer and the functional layer are subjected to a lamination and hot-pressing process to obtain the composite material; the material of the reinforcing layer comprises the first polymer and the second polymer; the material of the functional layer comprises the first polymer; Preferably, the hot-pressing process is performed at a temperature of 150-380°C, for example 170°C, 190°C or 240°C; Preferably, the hot-pressing process is performed at a pressure of 0.1-5 MPa, more preferably 0.1-3 MPa; Preferably, during the hot-pressing process, the filler layer moves at a speed of 1-20 m / min, preferably 10 m / min; Preferably, during the hot-pressing process, the reinforcing layer moves at a speed of 1-20 m / min, preferably 10 m / min; Preferably, during the hot-pressing process, the functional layer moves at a speed of 1-20 m / min, preferably 10 m / min; Preferably, the moving speed of the filling layer, the reinforcing layer and the functional layer is the same during the hot-pressing process.

8. The method of producing a composite material according to claim 6 or 7, wherein It comprises one or more of the following conditions: (a) The preparation method of the core-sheath yarn comprises the following steps: spinning the melted first polymer and the second polymer to obtain a core-sheath yarn initial product with a sheath wrapping a core; stretching and cooling the core-sheath yarn initial product in sequence to obtain the core-sheath yarn; (b) The preparation method of the reinforcing layer comprises the following steps: when the reinforcing layer is a composite sheet, a co-extrusion coating process, a sandwich coating process or a hot-sticking process is used to treat the melted first polymer and the second polymer to form a structural layer formed by the first polymer and two structural layers formed by the second polymer, and the structural layer formed by the first polymer is arranged between the two structural layers formed by the second polymer; when the reinforcing layer is a composite fabric, the composite sheet is cut into a narrow strip, and the narrow strip is woven into a composite fabric.

9. A composite material prepared by the method of any one of claims 6-8.

10. Use of the composite material of any one of claims 1-5 and 9.

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