A composite sheet and its preparation method and application

Abstract

The present invention relates to a composite sheet and a preparation method thereof. The composite sheet is a hot-pressed piece of one or more layers of composite yarn fabric, wherein the composite yarn comprises multi-component fibers and high-strength fibers, wherein the multi-component fibers are selected from core-skin composite fibers with polypropylene as the core layer and ethylene copolymer as the skin layer and three-layer composite fibers with polypropylene as the core layer, ethylene copolymer as the middle layer and polyethylene as the skin layer, and the high-strength fibers are selected from ultra-high molecular weight polyethylene fibers, glass fibers, carbon fibers, aramid fibers and basalt fibers. The composite sheet according to the present invention utilizes multi-component fibers with good thermal processing performance to overcome the problem that some high-strength fibers have low viscosity and / or poor heat resistance and cannot be thermoformed, thereby expanding the application field of these high-strength fibers.

Description

Technical Field

[0001] The present invention belongs to the field of fiber composite materials and specifically relates to a composite sheet material and a preparation method and application thereof. Background Art

[0002] Ultra-high molecular weight polyethylene fiber (UHMWPE) has excellent properties such as low density, high strength and high modulus.

[0003] As a high-performance fiber, ultra-high molecular weight polyethylene fiber has a low elongation at break and good fatigue resistance and friction resistance.

[0004] Since the molecular structure of polyethylene does not contain amino, hydroxyl and other active groups and the molecular crystallinity is high, polyethylene fiber has stable performance in water or other corrosive media, low density, light weight and good energy absorption, making it suitable for use as a lightweight reinforcing material in thermoplastics.

[0005] CN108864664A discloses a long fiber reinforced thermoplastic composite material, wherein the reinforcing fiber used is an ultra-high molecular weight polyethylene fiber.

[0006] CN108529936A discloses an ultra-high molecular weight polyethylene fiber reinforced polymer-based composite material and a preparation method thereof.

[0007] Glass fiber, carbon fiber, aramid fiber and basalt fiber are also high-strength fibers and are often used as reinforcing fibers to reinforce resins.

[0008] CN109206855A discloses a method for preparing a resin-based fiber-reinforced composite material, wherein the reinforcing fibers used are selected from glass fibers, carbon fibers, aramid fibers and basalt fibers.

[0009] However, ultra-high molecular weight polyethylene fibers, glass fibers, carbon fibers, aramid fibers, and basalt fibers have poor adhesion and / or heat resistance and cannot be thermoformed, which limits their application as lightweight, impact-resistant reinforcement materials in many thermoformed plastic products.

[0010] Therefore, it is hoped that the defects of certain high-strength fibers, such as low adhesion and / or poor heat resistance, which make them incapable of thermoforming, can be compensated and they can be used in the preparation of high-strength products. Summary of the invention

[0011] One object of the present invention is to compensate for the defects of certain high-strength fibers that have poor bonding and / or heat resistance and thus cannot be thermoformed, thereby providing a composite material that can be used to prepare high-strength products.

[0012] According to a first aspect of the present invention, there is provided a composite sheet material, which is a hot-pressed part of one or more layers of composite yarn fabric, wherein the composite yarn comprises multi-component fibers and high-strength fibers, wherein the multi-component fibers are selected from core-sheath composite fibers having polypropylene as a core layer and ethylene copolymer or propylene copolymer as a skin layer and three-layer composite fibers having polypropylene as a core layer, ethylene copolymer or propylene copolymer as a middle layer and polyethylene as a skin layer, and the high-strength fibers are selected from ultra-high molecular weight polyethylene fibers, glass fibers, carbon fibers, aramid fibers and basalt fibers.

[0013] According to a second aspect of the present invention, there is provided a method for preparing a composite sheet according to the first aspect of the present invention, comprising the following steps:

[0014] i) providing a composite yarn comprising the multi-component fiber and the high-strength fiber;

[0015] ii) forming the composite yarn into a fabric; and

[0016] iii) hot pressing one or more layers of the fabric, and then cooling to obtain a composite sheet.

[0017] According to a third aspect of the present invention, there is provided a composite sheet material, which is a laminate of at least two layers of multi-component fiber fabrics and at least one layer of high-strength fiber fabric, wherein the bottom layer and the top layer are both the multi-component fiber fabrics, the multi-component fibers are selected from core-skin composite fibers with polypropylene as the core layer and ethylene copolymer or propylene copolymer as the skin layer, and three-layer composite fibers with polypropylene as the core layer, ethylene copolymer or propylene copolymer as the middle layer and polyethylene as the skin layer, and the high-strength fibers are selected from ultra-high molecular weight polyethylene fibers, glass fibers, carbon fibers, aramid fibers and basalt fibers.

[0018] According to a fourth aspect of the present invention, there is provided a method for preparing a composite sheet according to the third aspect of the present invention, comprising:

[0019] i) providing the multi-component fiber fabric and the high-strength fiber fabric;

[0020] ii) stacking at least two layers of multi-component fiber fabrics and at least one layer of high-strength fiber fabric, wherein the bottom layer and the top layer are both the multi-component fiber fabrics; and

[0021] iii) hot-pressing the product obtained in step ii), and then cooling the product to obtain a composite sheet.

[0022] According to a fifth aspect of the present invention, there is provided a product prepared using the above composite sheet.

[0023] The composite sheet of the present invention utilizes multi-component fibers with good thermal processing performance to overcome the problem that some high-strength fibers have poor adhesion and / or heat resistance and cannot be thermoformed, thereby expanding the application field of these high-strength fibers and using them to prepare lightweight, high-strength and efficiently thermoplastic moldable composite products. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In the following, the present invention will be described by way of example with reference to the accompanying drawings, in which:

[0025] Figure 1 A schematic diagram of a process route for preparing a composite sheet according to one aspect of the present invention is shown.

[0026] Figure 2 A schematic diagram of a process route for preparing a composite sheet according to another aspect of the present invention is shown. Specific implementation plan

[0027] Various aspects of the invention as well as further objects, features and advantages will appear more fully hereinafter.

[0028] According to a first aspect of the present invention, there is provided a composite sheet material, which is a hot-pressed part of one or more layers of composite yarn fabric, wherein the composite yarn comprises multi-component fibers and high-strength fibers, wherein the multi-component fibers are selected from core-sheath composite fibers having polypropylene as a core layer and ethylene copolymer as a skin layer and three-layer composite fibers having polypropylene as a core layer, ethylene copolymer as a middle layer and polyethylene as a skin layer, and the high-strength fibers are selected from ultra-high molecular weight polyethylene fibers, glass fibers, carbon fibers, aramid fibers and basalt fibers.

[0029] In a preferred embodiment, in the composite yarn, the multi-component fiber serves as a sheath yarn and the high-strength fiber serves as a core yarn.

[0030] Preferably, the melt flow index (MFI) of the polypropylene is 0.2-60 g / 10 min, more preferably 20-40 g / 10 min, measured at 230° C. using a 2.16 kg weight, for example, Z30S from Sinopec has an MFI of 25 g / 10 min.

[0031] Using polypropylene as the core layer can increase the rigidity modulus and flexural modulus of the composite fiber.

[0032] Preferably, the ethylene copolymer is a copolymer of ethylene as a first monomer and a second monomer selected from propylene, butene, hexene and octene.

[0033] In some embodiments, the ethylene copolymer is a copolymer of ethylene as the first monomer and a second monomer selected from propylene, butene, hexene and octene, wherein the content of the second monomer is 0.1 mol% to 40 mol%, preferably 8 mol% to 35 mol%, such as Engage 8401 and 8450 resins from Dow.

[0034] In some embodiments, the ethylene copolymer is a copolymer of ethylene and propylene, wherein the ethylene content is 0.1 mol% to 30 mol%, preferably 8 mol% to 25 mol%, such as Versify 4000 resin from Dow.

[0035] In some embodiments, the ethylene copolymer is a block copolymer comprising 20 mol% to 80 mol% ethylene blocks and 80 mol% to 20 mol% random ethylene octene or random ethylene butene blocks, preferably a block copolymer comprising 30 mol% to 70 mol% ethylene blocks and 70 mol% to 30 mol% random ethylene octene or random ethylene butene blocks, such as INFUSE 9817 resin from Dow.

[0036] In some embodiments, the ethylene copolymer is a block copolymer comprising 20 mol% to 80 mol% propylene blocks and 80 mol% to 20 mol% random ethylene propylene or ethylene butene or ethylene octene blocks, preferably a block copolymer comprising 30 mol% to 70 mol% propylene blocks and 70 mol% to 30 mol% random ethylene propylene or ethylene butene or ethylene octene blocks, such as INTUNE D5545 resin from DOW.

[0037] Preferably, the polyethylene has a melt flow index (MFI) of 0.2-20 g / 10 min, preferably 1-10 g / min, more preferably 1-6 g / min, measured at 190°C using a 2.16 kg weight, such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and high density polyethylene (HDPE), such as T55-300MHDPE resin from China SABIC (Tianjin) Petrochemical Co., Ltd., whose MFI is 2 g / 10 min.

[0038] Using polyethylene or ethylene copolymers as the skin layer can provide the composite fiber with thermal adhesion.

[0039] Preferably, in the sheath-core composite fiber, the volume ratio of the sheath layer to the core layer is between 1:1 and 1:10, preferably between 1:1 and 1:2.5.

[0040] Preferably, in the three-layer composite fiber, the volume ratio of core layer / middle layer / skin layer is 80%-50% / 10%-25% / 10-25%.

[0041] Preferably, the total fineness of the multi-component fiber is 100-6000 denier (D), preferably 200-3200 denier. Preferably, the tensile strength of the multi-component fiber is not less than 1.5 g / dtex, preferably not less than 2.5 g / dtex.

[0042] In some embodiments, the multicomponent fiber has a total denier of 200-3200 denier and a tensile strength of 2.5-6.0 g / dtex.

[0043] The high-strength fiber is selected from ultra-high molecular weight polyethylene fiber, glass fiber, carbon fiber, aramid fiber and basalt fiber, and can be obtained from the market or prepared by itself.

[0044] Preferably, the total fineness of the high-strength fiber is 200-1600 denier. Preferably, the tensile strength of the high-strength fiber is not less than 5 g / dtex, more preferably not less than 10 g / dtex.

[0045] In some embodiments, the high-strength fiber has a total fineness of 200-1600 deniers and a tensile strength of 10-40 g / dtex.

[0046] Preferably, in the composite yarn, the weight ratio of the multi-component fiber to the high-strength fiber is in the range of 100:1 to 100:100.

[0047] Preferably, the composite yarn fabric has a gram weight of 100 g / m 2 -500g / m 2 , preferably 150-300g / m 2 .

[0048] In some embodiments, the fabric is a warp and weft fabric.

[0049] Preferably, in the composite sheet, the number of fabric layers is 1-10.

[0050] When the number of layers of the fabric is greater than one, each layer of the multicomponent fiber fabric may be the same or different.

[0051] According to a second aspect of the present invention, there is provided a method for preparing a composite sheet according to the first aspect of the present invention, comprising the following steps:

[0052] i) providing a composite yarn comprising the multi-component fiber and the high-strength fiber;

[0053] ii) forming the composite yarn into a fabric; and

[0054] iii) hot pressing one or more layers of the fabric, and then cooling to obtain a composite sheet.

[0055] Figure 1 A schematic diagram of a process route for preparing a composite sheet according to an embodiment of the second aspect of the present invention is shown. It should be understood that this diagram is only for illustration and is not intended to limit the method of the present invention.

[0056] In some embodiments, step i) includes providing the multicomponent fiber and the high strength fiber.

[0057] The multicomponent fibers can be prepared using conjugate spinning techniques known in the art.

[0058] For example, two screw extruders can be used to place the skin layer material and the core layer material in different screws respectively, and extrude them at a temperature above the melting point of each material. After passing through a layer distributor, they merge into a die, and after stretching and cooling, a skin-core composite fiber is obtained.

[0059] For example, three screw extruders can be used to place the skin layer material, middle layer material and core layer material in different screws respectively, extrude them at a temperature above the melting point of each material, merge into a die after passing through a layer distributor, and obtain a three-layer composite fiber after stretching and cooling.

[0060] The high-strength fiber can be prepared by itself or purchased from the market.

[0061] The composite yarn and the composite yarn fabric can be prepared by methods known in the art. For example, the composite yarn can be obtained by blending.

[0062] The heat pressing may be performed on any suitable equipment.

[0063] Preferably, the hot pressing is performed in a mold or on a flat vulcanizing press.

[0064] Preferably, the hot pressing is carried out at a temperature in the range of 90-160° C., preferably in the range of 110-150° C., and at a pressure in the range of 0.1-100 MPa, preferably in the range of 0.5-20 MPa, for 20 seconds to 0.5 hours, preferably 1 minute to 15 minutes, more preferably 2 minutes to 6 minutes.

[0065] In some embodiments, cooling is performed by allowing the finished product to cool naturally to ambient temperature.

[0066] In some embodiments, cooling is performed by directly cooling the finished product with cold air or water.

[0067] In some embodiments, cooling is performed by cooling the mold.

[0068] Preferably, cooling is performed by cooling the mold with a cooling medium such as cold air or water.

[0069] According to a third aspect of the present invention, there is provided a composite sheet material, which is a laminate of at least two layers of multi-component fiber fabrics and at least one layer of high-strength fiber fabric, wherein the bottom layer and the top layer are both the multi-component fiber fabrics, the multi-component fibers are selected from core-skin composite fibers with polypropylene as the core layer and ethylene copolymer or propylene copolymer as the skin layer, and three-layer composite fibers with polypropylene as the core layer, ethylene copolymer or propylene copolymer as the middle layer and polyethylene as the skin layer, and the high-strength fibers are selected from ultra-high molecular weight polyethylene fibers, glass fibers, carbon fibers, aramid fibers and basalt fibers.

[0070] The laminate may be a heat pressed laminate.

[0071] Preferably, the melt flow index (MFI) of the polypropylene is 0.2-60 g / 10 min, more preferably 20-40 g / 10 min, measured at 230° C. using a 2.16 kg weight, for example, Z30S from Sinopec has an MFI of 25 g / 10 min.

[0072] Preferably, the ethylene copolymer is a copolymer of ethylene as a first monomer and a second monomer selected from propylene, butene, hexene and octene.

[0073] In some embodiments, the ethylene copolymer is a copolymer of ethylene as the first monomer and a second monomer selected from propylene, butene, hexene and octene, wherein the content of the second monomer is 0.1 mol% to 40 mol%, preferably 8 mol% to 35 mol%, such as Engage 8401 and 8450 resins from Dow.

[0074] In some embodiments, the ethylene copolymer is a copolymer of ethylene and propylene, wherein the ethylene content is 0.1 mol% to 30 mol%, preferably 8 mol% to 25 mol%, such as Versify 4000 resin from Dow.

[0075] In some embodiments, the ethylene copolymer is a block copolymer comprising 20 mol% to 80 mol% ethylene blocks and 80 mol% to 20 mol% random ethylene octene or random ethylene butene blocks, preferably a block copolymer comprising 30 mol% to 70 mol% ethylene blocks and 70 mol% to 30 mol% random ethylene octene or random ethylene butene blocks, such as INFUSE 9817 resin from Dow.

[0076] In some embodiments, the ethylene copolymer is a block copolymer comprising 20 mol% to 80 mol% propylene blocks and 80 mol% to 20 mol% random ethylene propylene or ethylene butene or ethylene octene blocks, preferably a block copolymer comprising 30 mol% to 70 mol% propylene blocks and 70 mol% to 30 mol% random ethylene propylene or ethylene butene or ethylene octene blocks, such as INTUNE D5545 resin from DOW.

[0077] Preferably, the polyethylene has a melt flow index (MFI) of 0.2-20 g / 10 min, preferably 1-10 g / 10 min, more preferably 1-6 g / min, measured at 190°C using a 2.16 kg weight, such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and high density polyethylene (HDPE), such as T55-300M HDPE resin from China SABIC (Tianjin) Petrochemical Co., Ltd., which has an MFI of 2 g / 10 min.

[0078] Preferably, in the sheath-core composite fiber, the volume ratio of the sheath layer to the core layer is between 1:1 and 1:10, preferably between 1:1 and 1:2.5.

[0079] Preferably, in the three-layer composite fiber, the volume ratio of core layer / middle layer / skin layer is 80%-50% / 10%-25% / 10-25%.

[0080] Preferably, the total fineness of the multi-component fiber is 100-6000 denier (D), preferably 200-3200 denier. Preferably, the tensile strength of the multi-component fiber is not less than 1.5 g / dtex, preferably not less than 2.5 g / dtex.

[0081] In some embodiments, the multicomponent fiber has a total denier of 200-3200 denier and a tensile strength of 2.5-6.0 g / dtex.

[0082] Preferably, the multi-component fiber fabric has a grammage of 100 g / m 2 -500g / m 2 , preferably 150g / m 2 -300g / m 2 .

[0083] In some embodiments, the multi-component fiber fabric is a warp and weft fabric with a gram weight of 150-300 g / m 2 , preferably a single-layer twill warp and weft cloth, the yarn count ratios in the warp and weft directions are basically the same and evenly distributed.

[0084] The high-strength fiber is selected from ultra-high molecular weight polyethylene fiber, glass fiber, carbon fiber, aramid fiber and basalt fiber, and can be obtained from the market or prepared by itself.

[0085] Preferably, the total fineness of the high-strength fiber is 200-1600 denier. Preferably, the tensile strength of the high-strength fiber is not less than 5 g / dtex, preferably not less than 10 g / dtex.

[0086] In some embodiments, the high-strength fiber has a total fineness of 200-1600 deniers and a tensile strength of 10-40 g / dtex.

[0087] Preferably, the high-strength fiber fabric has a gram weight of 100-200 g / m 2 , which is a single-layer warp and weft cloth or a unidirectional UD cloth.

[0088] Preferably, in the composite sheet, the weight ratio of the multi-component fiber fabric to the high-strength fiber fabric is in the range of 100:1 to 100:100.

[0089] Preferably, the number of layers of the multi-component fiber fabric is 2-10.

[0090] Optionally, the layers of multicomponent fiber fabric may be the same or different.

[0091] Preferably, the number of layers of the high-strength fiber fabric is 1-5.

[0092] When the number of layers of the high-strength fiber fabric is greater than 1, each layer of the high-strength fiber fabric may be the same or different.

[0093] When the number of layers of the high-strength fiber fabric is more than one, it is preferred that there are multiple component fiber fabrics spaced therebetween.

[0094] According to a fourth aspect of the present invention, there is provided a method for preparing a composite sheet according to the third aspect of the present invention, comprising:

[0095] i) providing the multi-component fiber fabric and the high-strength fiber fabric;

[0096] ii) stacking at least two layers of multi-component fiber fabrics and at least one layer of high-strength fiber fabric, wherein the bottom layer and the top layer are both the multi-component fiber fabrics; and

[0097] iii) hot-pressing the product obtained in step ii), and then cooling the product to obtain a composite sheet.

[0098] Figure 2 A schematic diagram of a process route for preparing a composite sheet according to an embodiment of the fourth aspect of the present invention is shown. It should be understood that this diagram is only for illustration and is not intended to limit the method of the present invention.

[0099] In some embodiments, step i) includes providing the multicomponent fiber and the high strength fiber.

[0100] The multicomponent fibers can be prepared using conjugate spinning techniques known in the art.

[0101] For example, two screw extruders can be used to place the skin layer material and the core layer material in different screws respectively, and extrude them at a temperature above the melting point of each material. After passing through a layer distributor, they merge into a die, and after stretching and cooling, a skin-core composite fiber is obtained.

[0102] For example, three screw extruders can be used to place the skin layer material, middle layer material and core layer material in different screws respectively, extrude them at a temperature above the melting point of each material, merge into a die after passing through a layer distributor, and obtain a three-layer composite fiber after stretching and cooling.

[0103] The high-strength fiber can be prepared by itself or purchased from the market.

[0104] The fabric can be prepared by methods known in the art.

[0105] The hot pressing can be performed on a suitable device, for example, in a hot pressing mold or on a flat vulcanizing machine.

[0106] Preferably, the hot pressing is performed in a mold.

[0107] Preferably, the hot pressing is carried out at a temperature in the range of 90-160° C., preferably in the range of 110-150° C., and at a pressure in the range of 0.1-100 MPa, preferably in the range of 0.5-20 MPa, for 20 seconds to 0.5 hours, preferably 1 minute to 15 minutes, more preferably 2 minutes to 6 minutes.

[0108] In some embodiments, cooling is performed by allowing the finished product to cool naturally to ambient temperature.

[0109] In some embodiments, cooling is performed by directly cooling the finished product with cold air or water.

[0110] In some embodiments, cooling is performed by cooling the mold.

[0111] Preferably, cooling is performed by cooling the mold with a cooling medium such as cold air or water.

[0112] According to a fifth aspect of the present invention, there is provided a product prepared using the above composite sheet.

[0113] The product prepared by using the composite sheet material of the present invention has the characteristics of light weight, high strength and impact resistance.

[0114] As examples of the article, there may be mentioned lightweight luggage, automobile anti-collision parts (such as bumpers, etc.), sports and leisure products, safety protection products such as helmets, and the like.

[0115] The terms “comprising” and “including” described in the present application encompass a case where the component is further comprised or includes other elements not explicitly mentioned as well as a case where the component is composed of the mentioned elements.

[0116] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention belongs. When the definition of a term in this specification conflicts with the meaning commonly understood by those skilled in the art to which the invention belongs, the definition described in this article shall prevail.

[0117] Unless otherwise indicated, all numerical values ​​expressing quantities of ingredients, reaction conditions, and so forth used in the specification and claims are to be understood as modified by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth herein are approximations that can vary depending upon the desired properties desired to be obtained.

[0118] Example

[0119] The following will further illustrate the concept of the present invention and the technical effects produced by the embodiments so that those skilled in the art can fully understand the purpose, features and effects of the present invention. It should be understood that some embodiments are only illustrative and do not constitute a limitation on the scope of the present invention.

[0120] Example 1

[0121] Polypropylene (Z30S from Sinopec, MFI 25 g / 10 min) and ethylene copolymer (Engage 8401 resin from Dow) were used to prepare core-shell composite fibers by composite spinning technology, wherein polypropylene was the core material and ethylene copolymer was the skin material. The spinning process used was as follows:

[0122] Core layer screw extrusion temperature: 200-290℃ (gradually increasing from the feed section to the melt pump section);

[0123] Skin screw extrusion temperature: 180-250℃ (gradually increasing from the feed section to the melt pump section);

[0124] Spinneret temperature: 260°C;

[0125] Number of spinneret holes: 96, hole diameter: 0.2mm;

[0126] Screw L / D ratio: 28;

[0127] Stretching speed: 2000m / min;

[0128] Pump supply: 90g / min;

[0129] Skin-core weight ratio: 4 / 6;

[0130] Quenching air temperature: 25℃;

[0131] The total fineness of the obtained multifilament fiber was 400 deniers and the tensile strength was 2.8 g / dtex.

[0132] The obtained multifilament fiber was blended with ultra-high molecular weight polyethylene fiber (Spectra from Honeywell, with a total fiber fineness of 400 denier and a tensile strength of 30 g / dtex) at a weight ratio of 100:20 to form a composite yarn (using a yarn plying machine, 5 bundles of 400 denier multifilament fibers and 1 bundle of 400 denier Spectra were laid out, plyed and twisted into a composite yarn of 2400 denier), and then the composite yarn was woven into a 250 g / m 2 Warp and weft cloth.

[0133] Four layers of the warp and weft fabrics were stacked in a hot pressing mold and laminated at a temperature of 120° C. and a pressure of 10 MPa for 3 minutes. The mold was then released and the material was cooled at room temperature to obtain a thermoplastic sheet.

[0134] Example 2

[0135] Polypropylene (Z30S from Sinopec, MFI 25 g / 10 min) and ethylene copolymer (Versify 4000 resin from Dow) were used to prepare core-shell composite fibers by composite spinning technology, wherein polypropylene was the core material and ethylene copolymer was the skin material. The spinning process used was as follows:

[0136] Core layer screw extrusion temperature: 200-290℃ (gradually increasing from the feed section to the melt pump section);

[0137] Skin screw extrusion temperature: 180-250℃ (gradually increasing from the feed section to the melt pump section);

[0138] Spinneret temperature: 260°C;

[0139] Number of spinneret holes: 96, hole diameter: 0.2mm;

[0140] Screw L / D ratio: 28;

[0141] Stretching speed: 2000m / min;

[0142] Pump supply: 90g / min;

[0143] Skin-core weight ratio: 4 / 6;

[0144] Quenching air temperature: 25℃;

[0145] The total fineness of the obtained multifilament fiber was 400 deniers and the tensile strength was 2.9 g / dtex.

[0146] The obtained multifilament fiber was blended with glass fiber (Y3 glass fiber from China Taishan Glass Fiber Co., Ltd., with a yarn density of 45 tex and a tensile strength of 15 g / dtex) at a weight ratio of 100:20 to form a composite yarn (five bundles of 400 denier multifilament fibers and one bundle of Y3 glass fiber were laid out separately using a yarn plying machine, plyed and twisted into a composite yarn of 2400 denier), and then the composite yarn was woven into a 250 g / m 2 Warp and weft cloth.

[0147] Four layers of the warp and weft fabrics were stacked in a hot pressing mold and laminated at a temperature of 150° C. and a pressure of 20 MPa for 5 minutes. The mold was then released and the material was cooled at room temperature to obtain a thermoplastic sheet.

[0148] Example 3

[0149] Polypropylene (Z30S from Sinopec, MFI 25 g / 10 min) and ethylene copolymer (INFUSE 9817 resin from Dow) were used to prepare core-shell composite fibers by composite spinning technology, wherein polypropylene was the core material and ethylene copolymer was the skin material. The spinning process used was as follows:

[0150] Core layer screw extrusion temperature: 200-290℃ (gradually increasing from the feed section to the melt pump section);

[0151] Skin screw extrusion temperature: 180-250℃ (gradually increasing from the feed section to the melt pump section);

[0152] Spinneret temperature: 260°C;

[0153] Number of spinneret holes: 96, hole diameter: 0.2mm;

[0154] Screw L / D ratio: 28;

[0155] Stretching speed: 2000m / min;

[0156] Pump supply: 90g / min;

[0157] Skin-core weight ratio: 4 / 6;

[0158] Quenching air temperature: 25℃;

[0159] The total fineness of the obtained multifilament fiber was 400 deniers and the tensile strength was 3 g / dtex.

[0160] The obtained multifilament fiber was blended with carbon fiber (GQ3522 from Guangwei Composites, with a yarn density of 66 tex and a tensile strength of 20 g / dtex) at a weight ratio of 100:20 to form a composite yarn (six bundles of 400 denier multifilament fiber and one bundle of 66 tex glass fiber were laid out by a yarn plying machine, plyed and twisted into a composite yarn of 3000 denier), and then the composite yarn was woven into a 250 g / m 2 Warp and weft cloth.

[0161] Four layers of the warp and weft fabrics were stacked in a hot pressing mold and laminated at a temperature of 150° C. and a pressure of 20 MPa for 5 minutes. The mold was then released and the material was cooled at room temperature to obtain a thermoplastic sheet.

[0162] Example 4

[0163] Polypropylene (Z30S from Sinopec, MFI 25 g / 10 min) and ethylene copolymer (INTUNE D5545 resin from Dow) were used to prepare core-shell composite fibers by composite spinning technology, wherein polypropylene was the core material and ethylene copolymer was the skin material. The spinning process used was as follows:

[0164] Core layer screw extrusion temperature: 200-290℃ (gradually increasing from the feed section to the melt pump section);

[0165] Skin screw extrusion temperature: 180-250℃ (gradually increasing from the feed section to the melt pump section);

[0166] Spinneret temperature: 260°C;

[0167] Number of spinneret holes: 96, hole diameter: 0.2mm;

[0168] Screw L / D ratio: 28;

[0169] Stretching speed: 2000m / min;

[0170] Pump supply: 90g / min;

[0171] Skin-to-core weight ratio: 4 / 6;

[0172] Quenching air temperature: 25℃;

[0173] The total fineness of the obtained multifilament fiber was 400 deniers and the tensile strength was 3.5 g / dtex.

[0174] The obtained multifilament fiber and aramid fiber (Kevlar from DuPont, with a total fiber fineness of 400 deniers and a tensile strength of 27 g / dtex) were blended into multifilament yarns at a weight ratio of 100:20, and the multifilament yarns were then woven into a 250 g / m 2 Warp and weft cloth.

[0175] Four layers of the warp and weft fabrics were stacked in a hot pressing mold and laminated at a temperature of 150° C. and a pressure of 20 MPa for 5 minutes. The mold was then released and the material was cooled at room temperature to obtain a thermoplastic sheet.

[0176] Example 5

[0177] The three-layer composite fiber was prepared by composite spinning technology using polypropylene (Z30S from Sinopec, with an MFI of 25 g / 10 min), ethylene copolymer (Versify 4000 resin from Dow), and polyethylene (T55-300 HDPE resin from Sinopec Tianjin Petrochemical Co., Ltd., with an MFI of 2 g / 10 min), wherein polypropylene was the core layer material, ethylene copolymer was the middle layer material, and polyethylene was the skin layer material. The spinning process used was as follows:

[0178] Core layer screw extrusion temperature: 200-290℃ (gradually increasing from the feed section to the melt pump section);

[0179] Middle layer screw extrusion temperature: 180-250℃ (gradually increasing from the feed section to the melt pump section);

[0180] Skin screw extrusion temperature: 190-280℃ (gradually increasing from the feed section to the melt pump section);

[0181] Spinneret temperature: 260°C;

[0182] Number of spinneret holes: 96, hole diameter: 0.2mm;

[0183] Screw L / D ratio: 28;

[0184] Stretching speed: 2000m / min;

[0185] Pump supply: 90g / min;

[0186] Skin / middle / core weight ratio: 2 / 2 / 6;

[0187] Quenching air temperature: 25℃;

[0188] The total fineness of the obtained multifilament fiber was 400 deniers and the tensile strength was 3.2 g / dtex.

[0189] The obtained multifilament fiber was blended with ultra-high molecular weight polyethylene fiber (Spectra from Honeywell, with a total fiber fineness of 400 denier and a tensile strength of 30 g / dtex) at a weight ratio of 100:20 to form a composite yarn (using a yarn plying machine, 5 bundles of 400 denier multifilament fibers and 1 bundle of 400 denier Spectra were laid out, plyed and twisted into a composite yarn of 2400 denier), and then the composite yarn was woven into a 250 g / m 2 Warp and weft cloth.

[0190] Four layers of the warp and weft fabrics were stacked in a hot pressing mold and laminated at a temperature of 150° C. and a pressure of 20 MPa for 5 minutes. The mold was then released and the material was cooled at room temperature to obtain a thermoplastic sheet.

[0191] Example 6

[0192] Polypropylene (Z30S from Sinopec, MFI 25 g / 10 min) and ethylene copolymer (Versify 4000 resin from Dow) were used to prepare core-shell composite fibers by composite spinning technology, wherein polypropylene was the core material and ethylene copolymer was the skin material. The spinning process used was as follows:

[0193] Core layer screw extrusion temperature: 200-290℃ (gradually increasing from the feed section to the melt pump section);

[0194] Skin screw extrusion temperature: 180-250℃ (gradually increasing from the feed section to the melt pump section);

[0195] Spinneret temperature: 260°C;

[0196] Number of spinneret holes: 96, hole diameter: 0.2mm;

[0197] Screw L / D ratio: 28;

[0198] Stretching speed: 2000m / min;

[0199] Pump supply: 90g / min;

[0200] Skin-core weight ratio: 4 / 6;

[0201] Quenching air temperature: 25℃;

[0202] The total fineness of the obtained multifilament fiber was 400 deniers and the tensile strength was 2.8 g / dtex.

[0203] The obtained core-sheath fiber is woven into a 250 g / m 2 In the hot pressing mold, 3 layers of sheath-core fiber warp and weft fabrics and 2 layers of 125g / m 2Ultra-high molecular weight polyethylene fiber warp and weft cloth (warp and weft cloth woven by Honeywell Spectra with a total fineness of 400 denier and a tensile strength of 30g / dtex) is stacked in multiple layers, wherein each layer of ultra-high molecular weight polyethylene fiber warp and weft cloth is sandwiched between two adjacent layers of sheath-core fiber warp and weft cloth, and laminated at a temperature of 120°C and a pressure of 10MPa for 3 minutes, and then the mold is cooled to room temperature by cold water to obtain a thermoplastic sheet.

[0204] Example 7

[0205] The three-layer composite fiber obtained in Example 5 was woven into a 250 g / m 2 In the hot pressing mold, 3 layers of composite fiber warp and weft fabrics and 2 layers of 125g / m 2 Ultra-high molecular weight polyethylene fiber warp and weft cloth (warp and weft cloth woven by Honeywell Spectra with a total fineness of 400 denier and a tensile strength of 30g / dtex) is stacked in multiple layers, wherein each layer of ultra-high molecular weight polyethylene fiber warp and weft cloth is sandwiched between two adjacent layers of composite fiber warp and weft cloth, and laminated at a temperature of 120°C and a pressure of 10MPa for 3 minutes, and then the mold is cooled to room temperature by cold water to obtain a thermoplastic sheet.

[0206] Example 8 (Comparative)

[0207] The 400 denier core-sheath fiber obtained in Example 1 was directly spun into 250 g / m 2 The four layers of warp and weft fabrics were hot pressed on a flat vulcanizer at a temperature of 140°C and a pressure of 10 MPa for 3 minutes, and then the mold was cooled to room temperature by passing cold water to obtain a thermoplastic sheet.

[0208] Example 9

[0209] The mechanical properties of the thermoplastic plates prepared in Examples 1-8 were tested, and the results are summarized in Table 1 below.

[0210] Table 1 Mechanical properties of the thermoplastic sheets prepared in Examples 1-8

[0211] <![CDATA[ Example ]]> Flexural modulus (MPa) Tensile strength(Mpa) Drop weight impact(J) Test Method ASTM D747 ASTM D638 GB / T 14153-1993 1 1691 124 210 2 2540 110 75 3 2915 130 71 4 950 88 117 5 1805 132 201 6 1140 101 151 7 1335 109 178 8 1510 78 94

[0212] From the results in Table 1, it can be seen that the sheet made of inorganic high-strength fibers such as carbon fiber and glass fiber has a significantly improved bending modulus; the sheet made of aramid fiber has improved impact performance and tensile strength. The sheet made of ultra-high molecular weight polyethylene fiber has significantly improved impact performance, tensile strength and bending rigidity.

[0213] Although some aspects of the present invention have been shown and discussed, it will be appreciated by those skilled in the art that changes may be made to the above aspects without departing from the principles and spirit of the invention, and the scope of the invention shall be defined by the claims and their equivalents.

Claims

1. A composite sheet, characterized in that: It is a hot pressed part of one or more layers of composite yarn fabric, wherein the composite yarn comprises multi-component fibers and high-strength fibers, wherein the multi-component fibers are selected from three-layer composite fibers with polypropylene as a core layer, ethylene copolymer as a middle layer, and polyethylene as a skin layer, and the high-strength fibers are selected from ultra-high molecular weight polyethylene fibers, glass fibers, carbon fibers, aramid fibers, and basalt fibers. Wherein, in the three-layer composite fiber, the volume ratio of the core layer / middle layer / skin layer is 80%-50% / 10%-25% / 10-25%, The weight ratio of the multi-component fiber to the high-strength fiber in the composite yarn is in the range of 100:1 to 100:100, The melt flow index (MFI) of the polypropylene is 0.2-60 g / 10 min, measured at 230° C. using a 2.16 kg weight. The ethylene copolymer is selected from: i) a copolymer of ethylene as a first monomer and a second monomer selected from propylene, butene, hexene and octene, wherein the content of the second monomer is 0.1 mol% to 40 mol%; ii) a copolymer of ethylene and propylene, wherein the ethylene content is from 0.1 mol% to 30 mol%; iii) a block copolymer comprising 20 mol% to 80 mol% of ethylene blocks and 80 mol% to 20 mol% of random ethylene octene or random ethylene butene blocks; and iv) a block copolymer comprising 20 mol% to 80 mol% of propylene blocks and 80 mol% to 20 mol% of random ethylene propylene or ethylene butene or ethylene octene blocks, The melt flow index (MFI) of the polyethylene is 0.2-20 g / 10 min, measured at 190° C. using a 2.16 kg weight. The tensile strength of the multi-component fiber is not less than 1.5 g / dtex.

2. The composite sheet according to claim 1, characterized in that: The melt flow index (MFI) of the polypropylene is 20-40 g / 10 min, measured at 230° C. using a 2.16 Kg weight.

3. The composite sheet according to claim 1 or 2, characterized in that: The melt flow index (MFI) of the polyethylene is 1-10 g / min, measured at 190° C. using a 2.16 Kg weight.

4. The composite sheet according to claim 1 or 2, characterized in that: The melt flow index (MFI) of the polyethylene is 1-6 g / min, measured at 190° C. using a 2.16 Kg weight.

5. The composite sheet according to claim 1 or 2, characterized in that: The total fineness of the multi-component fiber is 100-6000 deniers, and the tensile strength is not less than 2.5 g / dtex.

6. The composite sheet according to claim 5, characterized in that: The total fineness of the multi-component fiber is 200-3200 denier.

7. The composite sheet according to claim 1 or 2, characterized in that: The total fineness of the high-strength fiber is 200-1600 deniers, and the tensile strength is not less than 5g / dtex.

8. The composite sheet according to claim 7, characterized in that: The tensile strength of the high-strength fiber is not less than 10 g / dtex.

9. The composite sheet according to claim 1 or 2, characterized in that: The composite yarn fabric has a gram weight of 100 g / m 2 -500 g / m 2 .

10. The composite sheet according to claim 1 or 2, characterized in that: In the composite sheet, the number of layers of the fabric is 1-10.

11. A method for preparing a composite sheet according to any one of claims 1 to 10, comprising the following steps: i) providing a composite yarn comprising the multi-component fiber and a high-strength fiber; ii) forming the composite yarn into a fabric; and iii) hot pressing one or more layers of the fabric, and then cooling to obtain a composite sheet.

12. The method according to claim 11, characterized in that The hot pressing is performed at a temperature in the range of 100-160° C. and a pressure in the range of 0.1-100 MPa for 20 seconds to 0.5 hours.

13. The method according to claim 11, characterized in that The hot pressing is performed at a temperature in the range of 110-150° C. and a pressure in the range of 0.5-20 MPa for 2 to 6 minutes.

14. An article prepared using the composite sheet according to any one of claims 1 to 10.

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