Method for processing composite fiber by compounding polypropylene with silicon dioxide aerogel

Abstract

The invention relates to the related field of composite fibers, in particular to a method for processing composite fibers by compounding polypropylene with silicon dioxide aerogel, which is characterized in that silicon dioxide aerogel powder is uniformly distributed on the surface layer of a polypropylene film through electrostatic adsorption, and film-split fibers are obtained through laminating, drafting, splitting and other processes; the polypropylene fiber and the silicon dioxide aerogel powder are well combined, the defect that the aerogel material cannot be flexibly processed is overcome, processing of the fibrous aerogel material is achieved, and the fiber product can be widely used for manufacturing protective clothing, thermal insulation materials, industrial cloth, filtering materials and the like.

Description

Technical Field

[0001] The present invention relates to the field of composite fibers, and specifically to a method for processing composite fibers of polypropylene composite silica aerogel. Background Art

[0002] In recent years, with the development and progress of science and technology, various thermal insulation materials have emerged in an endless stream. Silica aerogel has excellent heat insulation performance, adsorption performance and catalytic performance, and is therefore widely used in various fields. For example, it can be used as a heat insulation material in fields such as construction, aerospace, etc. However, it is usually difficult to use as a flexible material. Through the electrostatic action between the polypropylene film and silica aerogel powder, it is dispersed and adsorbed onto the film surface, and then through lamination, rolling, multi-axis stretching, and finally through slitting, composite polypropylene fibers are obtained. Such fibers have both the flexibility and chemical stability of the polypropylene film, as well as the heat insulation performance and adsorption performance of the silica aerogel powder. Therefore, such fibers have broad application prospects in various fields, such as textiles, environmental protection, chemical engineering, etc.

[0003] Polypropylene film split fiber, also known as polypropylene pyrolysis fiber, is a kind of polypropylene fiber prepared by a specific process. Compared with traditional polypropylene fibers, it has some unique properties and uses.

[0004] The process of preparing polypropylene film split fiber usually involves pyrolyzing the polypropylene film to form a fibrous structure. This pyrolysis treatment can be carried out by thermal pyrolysis, chemical pyrolysis or other mechanical pyrolysis methods. In this process, the polypropylene molecular chains are broken and rearranged to form a fiber morphology.

[0005] Polypropylene film split fiber has some special physical and chemical properties. It usually has high strength and tensile properties and can withstand a certain amount of tensile and compressive forces. In addition, it also has good corrosion resistance and chemical resistance and can maintain stability under harsh environmental conditions.

[0006] Polypropylene film split fiber has a wide range of applications in various fields. It can be used as a reinforcing material for reinforcing composite materials, rubber products, paper, etc. In the textile industry, it can be used to make protective clothing, industrial fabrics, filter materials, etc. In addition, in the field of environmental protection, polypropylene film split fiber can be used to make adsorption materials, sound insulation materials, etc.

[0007] Silica aerogel powder is a powdery substance made of silica aerogel. It has many unique physical and chemical properties, which make it widely used in various fields, specifically as follows:

[0008] High specific surface area: Due to the extremely high porosity and microporous structure of aerogel, its specific surface area is very large. This makes the aerogel powder have strong adsorption capacity and can be used for adsorbing and removing various pollutants, harmful gases, etc.

[0009] Low density: Aerogel is a very lightweight material with extremely low density. Therefore, the powder made of aerogel also has a very low density and can be used to prepare lightweight composite materials, sound insulation materials, etc.

[0010] High heat insulation performance: Aerogel has good heat insulation performance and can effectively block heat conduction and heat convection. Therefore, aerogel powder can be used to prepare highly efficient heat insulation materials for applications in the fields of architecture, aerospace, etc.

[0011] Chemical corrosion resistance: Silica aerogel powder has good chemical stability and can withstand the corrosion of various chemical agents. This makes it widely used in the fields of chemical industry, environmental protection, etc.

[0012] Easy to process: Aerogel powder can be processed and formed by various methods, such as pressing, injection molding, spraying, etc.

[0013] Although aerogel materials are widely recognized for their excellent heat insulation and adsorption properties, there are certain challenges in processing them into flexible materials. Therefore, it is of great significance to develop new fiber materials suitable for flexible processing. Summary of the Invention

[0014] The purpose of the present invention is to provide a method for processing composite fibers of polypropylene composite silica aerogel to solve the problems proposed in the above-mentioned background technology.

[0015] To achieve the above purpose, the present invention provides the following technical solution: A method for processing composite fibers of polypropylene composite silica aerogel, comprising the following steps:

[0016] Step S1: Prepare polypropylene resin particles and silica aerogel powder of appropriate models according to requirements;

[0017] Step S2: Make a polypropylene film from the polypropylene resin particles through an extension drawing mechanism for standby;

[0018] Step S3: Uniformly adsorb the silica aerogel powder on the surface of the polypropylene film by means of an electrostatic field and a vibrating sieve;

[0019] Step S4: Double-layer laminate the polypropylene film adsorbed with silica aerogel powder and hot press it through a hot rolling roller, so that the silica aerogel powder is in the middle of two layers of polypropylene film;

[0020] Step S5: Feed the compounded film material into multiple groups of stretching components through a width expanding roller, and perform unidirectional stretching under hot stretching with an elongation rate reaching 150 - 250%;

[0021] Step S6: After the stretched film material passes through a slitting roller and is oiled, polypropylene composite silica aerogel fiber is obtained.

[0022] Preferably, the grades of the polypropylene resin particles selected in step S1 include T30S and Z30S, and the particle size of the silica aerogel powder is between 5 and 10 microns.

[0023] Preferably, the specific steps of making polypropylene into a polypropylene film in step S2 are as follows:

[0024] Step S2.1: The prepared polypropylene resin particles need to be dried first. After the polypropylene resin particles are dried, they are screened and filtered to complete the pretreatment of the polypropylene resin particles, ensuring the quality and purity of the polypropylene resin particles;

[0025] Step S2.2: After the pretreatment of the polypropylene resin particles is completed, they are heated to 160°C to 171°C in an extruder. Then, the polypropylene resin particles are passed through the heated extruder, pushed by a rotating screw, and extruded through the microporous spinneret of a spinning head to obtain a molten polypropylene filament bundle;

[0026] Step S2.3: Cool and solidify the obtained molten polypropylene filament bundle with cooling water;

[0027] Step S2.4: Feed the cooled polypropylene filament bundle into a calendering and stretching machine for stretching to obtain a polypropylene film.

[0028] Preferably, the thickness of the stretched polypropylene film in step S2.4 is 0.05 - 0.08 mm.

[0029] Preferably, the mass of the silica aerogel powder attached to the polypropylene film in step S3 is 5 - 8 g / ㎡.

[0030] Compared with the prior art, the beneficial effects of the present invention are:

[0031] The polypropylene composite silica aerogel fiber prepared by the method of the present invention has excellent properties. The polypropylene composite silica aerogel fiber not only has the flexibility and chemical stability of the polypropylene film, but also has the heat insulation performance and adsorption performance of the silica aerogel powder; the processed fiber of the polypropylene composite silica aerogel fiber can be woven into a heat insulation fabric through filament weaving, or the fiber can be cut into short cut heat insulation polypropylene fibers. The fibers are carded into a web and then hot rolled or chemically bonded to obtain a warm and breathable thermal batting. Description of the Drawings

[0032] Figure 1 This is a schematic flowchart of the method of the present invention. Specific embodiments

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] In the description of the present invention, it should also be noted that unless otherwise clearly defined and limited, the terms "set", "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0035] Please refer to Figure 1 , the present invention provides a technical solution: a method for processing composite fibers of polypropylene composite silica aerogel, including the following steps:

[0036] Step S1. Prepare polypropylene resin particles and silica aerogel powder of appropriate models according to requirements;

[0037] Step S2. Make polypropylene film from polypropylene resin particles through a stretching mechanism for standby;

[0038] Step S3. Uniformly adsorb the silica aerogel powder on the surface of the polypropylene film by means of an electrostatic field and a vibrating screen;

[0039] Step S4. Stack and press the polypropylene film adsorbed with silica aerogel powder in double layers and hot-press and compound it through a hot rolling roller so that the silica aerogel powder is in the middle of two layers of polypropylene film;

[0040] Step S5. Feed the composite film material into a plurality of drafting assemblies through a width expanding roller and perform unidirectional drafting under hot drafting, and the elongation rate reaches 150-250%;

[0041] Step S6. After the drafted film material passes through a slitting roller and oiling treatment, polypropylene composite silica aerogel fibers are obtained.

[0042] Furthermore, in step S1, the grades of the polypropylene resin particles selected include T30S and Z30S, and the particle size of the silica aerogel powder is between 5 and 10 microns.

[0043] Further, the specific steps of making the polypropylene into a polypropylene film in step S2 are as follows:

[0044] Step S2.1: The prepared polypropylene resin particles first need to be dried. After the polypropylene resin particles are dried, they are screened and filtered to complete the pretreatment of the polypropylene resin particles, ensuring the quality and purity of the polypropylene resin particles;

[0045] Step S2.2: After the pretreatment of the polypropylene resin particles is completed, they are heated to 160°C to 171°C in an extruder. Then, the polypropylene resin particles are passed through the heated extruder, pushed by a rotating screw, and extruded through the microporous spinneret of a spinneret head to obtain a molten polypropylene filament bundle;

[0046] Step S2.3: Cool and solidify the obtained molten polypropylene filament bundle with cooling water;

[0047] Step S2.4: Feed the cooled polypropylene filament bundle into a calendering and stretching machine for stretching to obtain a polypropylene film.

[0048] Further, the thickness of the stretched polypropylene film in step S2.4 is 0.05 - 0.08 mm.

[0049] Further, the mass number of the silica aerogel powder attached to the polypropylene film in step S3 is 5 - 8 g / ㎡.

[0050] Specifically, the present invention will be further elaborated in detail below in conjunction with embodiments;

[0051] 1) The prepared polypropylene resin particles first need to be dried. After the polypropylene resin particles are dried, they are screened and filtered. After completing the above steps, the polypropylene resin particles are sucked into the feed hopper of the extruder. The temperature of the screw heater of the extruder is controlled in four intervals: interval 1: 120°C, interval 2: 145°C, interval 3: 165°C, interval 4: 175°C. The film extrusion speed is 15 m / min, 25 - 35 g / cm², to obtain a polypropylene filament bundle. The polypropylene filament bundle is cooled and solidified with cooling water, and then undergoes two passes of stretching by a calendering and stretching machine at a production speed of 35 m / min to obtain a polypropylene film;

[0052] 2) The silica aerogel powder is evenly adsorbed on the surface of the polypropylene film by means of an electrostatic field and a vibrating sieve, where the electrostatic field voltage is 10^5 volts to coat the aerogel powder.

[0053] 3) The polypropylene film adsorbed with the silica aerogel powder is double-layer laminated and hot-pressed and compounded via a hot-rolling roller, so that the silica aerogel powder is in the middle of the two polypropylene films. Among them, a high-temperature steel roller and a rubber roller are compounded and pressurized, S-shaped coated and wound, and the linear pressure is 30 kg.

[0054] 4) Feed the compounded film material into multiple groups of drawing assemblies through a width expanding roller, and conduct unidirectional drawing under hot drawing. Specifically, use 3 - 4 hot drawing units, with a drawing ratio of 150 - 250% and a width shrinkage of 60 - 80%.

[0055] 5) Cut the drawn film material into fibers, wind it onto a bobbin, or twist and cut it through a chopper to obtain polypropylene composite silica aerogel fibers.

[0056] The present invention realizes the uniform distribution of silica aerogel powder on the surface layer of the polypropylene film through electrostatic adsorption, and obtains film split fibers through processes such as laminating, drawing, and splitting, achieving a good combination of polypropylene fibers and silica aerogel powder. The product overcomes the defect that aerogel materials cannot be flexibly processed, realizes the processing of fibrous aerogel materials, and its fiber products can be widely used in making protective clothing, thermal insulation materials, industrial fabrics, filter materials, etc.

[0057] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for processing composite fibers of polypropylene and silica aerogel, characterized in that, It includes the following steps: Step S1: Prepare appropriate types of polypropylene resin particles and silica aerogel powder according to requirements; Step S2: Use the polypropylene resin particles to make a polypropylene film through an extension drawing machine for standby; Step S3: Uniformly adsorb the silica aerogel powder on the surface of the polypropylene film by means of an electrostatic field and a vibrating sieve; Step S4: Double-stack and hot-press the polypropylene film adsorbed with silica aerogel powder through a hot rolling roller, so that the silica aerogel powder is in the middle of two layers of polypropylene film; Step S5: Feed the composite film material into multiple groups of drawing assemblies through an expanding roller, and perform unidirectional drawing under hot drawing, with an elongation rate reaching 150-250%; Step S6: After the drawn film material passes through a slitting roller and oiling treatment, polypropylene composite silica aerogel fiber is obtained.

2. The method for processing composite fibers of polypropylene composite silica aerogel according to claim 1, wherein: The grades of the polypropylene resin particles selected in the step S1 include T30S and Z30S, and the particle size of the silica aerogel powder is between 5 and 10 microns.

3. A method for processing composite fibers from polypropylene composite silica aerogel according to claim 1, characterized in that: The specific steps for making the polypropylene film from polypropylene in the step S2 are as follows: Step S2.1: The prepared polypropylene resin particles need to be dried first. After the polypropylene resin particles are dried, they are screened and filtered to complete the pretreatment of the polypropylene resin particles, ensuring the quality and purity of the polypropylene resin particles; Step S2.2: After the pretreatment of the polypropylene resin particles is completed, they are heated to 160°C to 171°C in an extruder, and then the polypropylene resin particles are pushed through the heated extruder by a rotating screw and extruded through the microporous spinneret of a spinneret head to obtain a molten polypropylene filament bundle; Step S2.3: Cool and solidify the obtained molten polypropylene filament bundle with cooling water; Step S2.4: Feed the cooled polypropylene filament bundle into a calendering and stretching machine for stretching to obtain a polypropylene film.

4. A method for processing composite fibers of polypropylene composite silica aerogel according to claim 3, characterized in that: In the step S2.4, the thickness of the stretched polypropylene film is 0.05-0.08 mm.

5. A method for processing composite fibers of polypropylene composite silica aerogel according to claim 1, characterized in that: In the step S3, the mass number of the silica aerogel powder attached to the polypropylene film is 5-8 g / ㎡.

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