An impact-resistant flash evaporation material

Abstract

This invention relates to an impact-resistant flash material, characterized in that the raw material of the flash material comprises polyethylene; the impact energy of the flash material is 3-20 J; the specific impact permeability of the flash material is 0.35-2 J / s; and the number of lint particles with a particle size of 5 μm-25 μm is no more than 70; wherein, specific impact permeability = impact energy / Gurley permeability. The flash material of this application has excellent impact resistance.

Description

Technical Field

[0001] This invention relates to the field of textile production technology, and more specifically, to the field of flash spinning technology, and to impact-resistant flash spinning materials prepared by flash spinning. Background Technology

[0002] The cushioning packaging materials used in consumer electronics components and products currently suffer from three major technical problems: poor impact resistance, easy shedding of lint, and poor air permeability. It is difficult to address all three problems simultaneously. Insufficient impact resistance: Conventional cushioning materials such as foam, EVA, ordinary non-woven fabric, and silicone have low impact energy and poor cushioning efficiency. They are difficult to provide effective protection in scenarios such as vibration during express sorting, impact during transportation, and daily drops from 1 to 5 meters. This can easily cause electronic component solder joints to fall off, internal structural damage, and screen and casing breakage. In addition, the impact resistance performance range of conventional materials is fixed and cannot meet the differentiated protection needs of the consumer electronics field that require high impact resistance.

[0003] Easy to shed lint and generate dust pollution: Most common fiber materials are short fiber structures, which are very easy to shed lint during production, packaging and transportation, including fiber shedding and dust generation; dust adhering to the surface of electronic components can directly cause fatal quality problems such as poor contact and conduction failure, seriously affecting product reliability and service life.

[0004] Poor breathability leads to dampness and dust accumulation: Although materials such as silicone and foam do not easily shed dust, their pores are closed and not interconnected, resulting in extremely poor breathability. During transportation and storage, they can easily create a damp environment. Moisture and fine dust cannot be discharged through the pores and are more likely to be adsorbed and retained on the surface of components, causing hidden pollution and performance failure.

[0005] In summary, existing cushioning packaging materials cannot simultaneously achieve a synergistic balance between high impact resistance, low shedding, and good breathability, thus failing to meet the technical pain points of the comprehensive requirements for protection, cleanliness, and breathability in cushioning packaging materials for consumer electronics components and products. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide an impact-resistant flash evaporation material.

[0007] The objective of this invention is achieved through the following technical solution: In a first aspect, this disclosure provides an impact-resistant flash material, wherein the raw material of the flash material comprises polyethylene, the impact energy of the flash material is 3 to 20 J, preferably 3 to 15 J, and the specific impact penetration of the flash material is 0.35 to 2 J / s, preferably 0.35 to 1 J / s, more preferably 0.4 to 0.8 J / s; The flash material has no more than 70 lint particles with a particle size of 5–25 μm, preferably no more than 50, and more preferably no more than 40; wherein, specific impact permeability = impact energy / Gurley permeability. In some embodiments, the specific impact permeability of the flash material is 0.35–0.4 J / s.

[0008] In some implementations, the specific permeability of the flash material is 0.4 to 0.5 J / s.

[0009] In some implementations, the specific permeability of the flash material is 0.5 to 0.6 J / s.

[0010] In some implementations, the specific permeability of the flash material is 0.6 to 0.7 J / s.

[0011] In some implementations, the specific permeability of the flash material is 0.7 to 0.8 J / s.

[0012] In some implementations, the specific permeability of the flash material is 0.8 to 1 J / s.

[0013] In some implementations, the flash material has an impact resistance of 3–6 J.

[0014] In some implementations, the flash material has an impact resistance of 6–9 J.

[0015] In some implementations, the flash material has an impact resistance of 9–15 J.

[0016] In some embodiments, the number of flocs in the flash material with a particle size of 5–25 μm is 50–70.

[0017] In some embodiments, the number of flocs in the flash material with a particle size of 5–25 μm is 30–50.

[0018] In some embodiments, the number of flocculated particles in the flash material with a particle size of 5–25 μm is 5–30.

[0019] In some embodiments, the number of flocs in the flash material with a particle size of 5–25 μm is 5–50.

[0020] In some embodiments, the thickness of the flash material is 0.1 to 0.3 mm.

[0021] A second aspect of this disclosure provides a method for preparing an impact-resistant flash spinning material, comprising: (1) providing a flash spinning solution; (2) flash spinning the flash spinning solution to obtain flash fibers; (3) laying the flash fibers into a web; and (4) molding to obtain a flash spinning material; wherein, in step (2), the flash fibers are obtained through a spinneret of a spinning assembly, and the stretching velocity at the outlet of the spinneret is 350 to 450 m / s; and the ratio of the spinning speed in step (2) to the web laying speed in step (3) is 1:1.1 to 1:1.3.

[0022] In some embodiments, in the method for preparing the impact-resistant flash spinning material, the flash spinning solution in step (1) can be formed by dissolving a polymer in a spinning solvent. In some embodiments, the polymer is polyethylene. In some embodiments, the polymer has a mass fraction of 8-12% in the spinning solution. In some embodiments, the spinning solvent is selected from aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, unsaturated hydrocarbons, halogenated hydrocarbons, alcohols, esters, ethers, ketones, nitriles, amides, fluorocarbons, sulfur dioxide, carbon disulfide, nitromethane, water, and mixtures of two or more of the above substances.

[0023] In some embodiments, the temperature of flash spinning in step (2) is 190–230°C.

[0024] In some embodiments, in step (4), the flash-evaporated fibers laid in step (3) are subjected to a hot rolling step. In some embodiments, the hot rolling temperature is 120–135 °C. In some embodiments, the hot rolling pressure is 7–9 MPa.

[0025] In some embodiments, step (4) may include an optional winding step after the hot rolling step to obtain the shaped flash material.

[0026] In some embodiments, the impact-resistant flash material of the first aspect of this disclosure is prepared by the preparation method of the second aspect of this disclosure.

[0027] A third aspect of this disclosure provides a packaging material comprising the impact-resistant flash material of this disclosure, or the impact-resistant flash material obtained according to the preparation method of this disclosure.

[0028] A fourth aspect of this disclosure provides the use of the impact-resistant flash material of this disclosure, or the impact-resistant flash material obtained according to the preparation method of this disclosure, in cushioning packaging.

[0029] Compared with the prior art, the positive effects of the present invention are: the present invention solves the three major technical problems of poor impact resistance, easy shedding and poor air permeability of traditional materials through the synergistic effect of flash evaporation process and parameters, and achieves a synergistic balance of high impact resistance, low shedding and high air permeability, which cannot be achieved simultaneously by the prior art, and therefore has outstanding technical innovation. Detailed Implementation

[0030] The following description of this disclosure is merely intended to illustrate various embodiments of the disclosure. Therefore, the specific modifications discussed should not be construed as limiting the scope of this disclosure. It will be apparent to those skilled in the art that various equivalents, changes, and modifications can be made without departing from the scope of this disclosure, and it should be understood that these equivalent embodiments are included herein. All references cited herein, including publications, patents, and patent applications, are incorporated herein by reference in their entirety.

[0031] This disclosure provides an impact-resistant flash material, wherein the impact energy of the flash material is 3–20 J; the specific impact penetration of the flash material is 0.35–2 J / s. In this disclosure, "flash material" refers to a material whose preparation process includes a flash spinning step. "Flash spinning" refers to a spinning method comprising mixing a polymer with a spinning solvent to form a spinning solution, conveying the solution to a spinneret assembly under a pressure higher than the solvent boiling point and the system's saturated vapor pressure, and releasing it through spinneret orifices into a low-pressure region with a temperature lower than the solvent boiling point; utilizing the flash phenomenon to cause the solvent to instantly boil and vaporize, and the polymer to cool and stretch in situ to form a network structure.

[0032] The term "specific impact permeability" is a parameter characterizing the balance between a material's impact resistance and air permeability. A higher specific impact permeability value indicates better impact energy at a normalized Gare volume, signifying a better overall balance between impact resistance and air permeability. In this disclosure, specific impact permeability = impact energy / Gare volume.

[0033] In this disclosure, the test standard for impact energy is ASTM D3420-21, "Standard Test Method for Pendulum Impact Resistance of Plastic Film"; and the test standard for Gurley permeability is ISO 5636-5:2013, "Paper and board – Determination of air permeance (medium range) – Part 5: Gurley method".

[0034] In some embodiments, the flash material of this disclosure has an impact resistance energy of 3 to 20 J, for example, 3 J, 4 J, 5 J, 6 J, 7 J, 8 J, 9 J, 10 J, 11 J, 12 J, 13 J, 14 J, 15 J, 16 J, 17 J, 18 J, 19 J, 20 J, or any range or values ​​within any two of these values. In some embodiments, the flash material has an impact resistance energy of 3 to 6 J. In some embodiments, the flash material has an impact resistance energy of 6 to 9 J. In some embodiments, the flash material has an impact resistance energy of 9 to 15 J.

[0035] In some embodiments, the specific impulse of the flash evaporation material of this disclosure is 0.35–2 J / s, for example, 0.35 J / s, 0.4 J / s, 0.45 J / s, 0.5 J / s, 0.55 J / s, 0.6 J / s, 0.65 J / s, 0.7 J / s, 0.75 J / s, 0.8 J / s, 0.85 J / s, 0.9 J / s, 0.95 J / s, 1 J / s, 1.05 J / s, 1.1 J / s, 1.15 J / s, 1.2 J / s, 1.25 J / s, 1.3 J / s, 1.35 J / s, 1.4 J / s, 1.45 J / s, 1.5 J / s, 1.55 J / s, 1.6 J / s, 1.65 J / s, 1.7 J / s, 1.75 J / s, 1.8 J / s. J / s, 1.85 J / s, 1.9 J / s, 1.95 J / s, 2 J / s, or any two of these values ​​within a range. In some embodiments, the specific permeability of the flash material is 0.35–0.4 J / s. In some embodiments, the specific permeability of the flash material is 0.4–0.5 J / s. In some embodiments, the specific permeability of the flash material is 0.5–0.6 J / s. In some embodiments, the specific permeability of the flash material is 0.6–0.7 J / s. In some embodiments, the specific permeability of the flash material is 0.7–0.8 J / s. In some embodiments, the specific permeability of the flash material is 0.8–1 J / s. By limiting the specific permeability within the above ranges, the flash material of this disclosure can simultaneously achieve high impact resistance and air permeability, rather than improving impact resistance or air permeability alone. The flash material exhibits a better overall balance between impact resistance and air permeability.

[0036] In some embodiments of this disclosure, the number of lint particles in the flash evaporation material with a particle size of 5–25 μm does not exceed 70. The test standard for the number of lint particles is GB / T 24218.10-2016 "Textiles - Nonwoven Fabrics - Test Methods - Part 10: Determination of Dry Lint Count". For example, the number of lint particles in the flash evaporation material with a particle size of 5–25 μm is less than 70, less than 65, less than 60, less than 55, less than 50, less than 45, less than 40, less than 35, less than 30, less than 25, less than 20, less than 15, less than 10, less than 5, less than 4, less than 3, less than 2, and less than 1. In some embodiments, the number of lint particles in the flash evaporation material with a particle size of 5–25 μm is 50–70. In some embodiments, the number of lint particles in the flash evaporation material with a particle size of 5–25 μm is 30–50. In some embodiments, the number of lint particles in the flash evaporation material with a particle size of 5–25 μm is 5–30. In other embodiments, the number of lint particles in the flash evaporation material with a particle size of 5–25 μm is 5–50. The flash evaporation material of this disclosure, by limiting the number of lint particles to the above levels, has the characteristics of not shedding lint and not generating dust, solving the technical pain point of existing packaging materials being prone to lint shedding, and will not cause malfunctions such as contact failure or conduction failure of electronic components.

[0037] It should be noted that when flash materials are used for cushioning packaging of consumer electronic components and products, a series of problems will arise if their thickness deviates from the appropriate range: Excessive thickness will result in excessively high bending stiffness and compressive modulus, reduced elastic deformation capacity, and ineffective absorption of impact energy, leading to excessively high acceleration response. This can easily cause hidden damage to fragile components such as solder joints, ceramic capacitors, or glass screens. Furthermore, excessive thickness will significantly increase packaging volume, reduce logistics loading efficiency, and increase transportation costs. It will also create difficulties for die-cutting precision, automated packaging, and heat sealing processes. Conversely, insufficient thickness will result in inadequate energy absorption due to a short compression stroke, making it prone to "bottoming out" impacts at standard drop heights. This can lead to peak accelerations far exceeding the tolerance limits of electronic components. Simultaneously, the material's puncture resistance and tear resistance will significantly decrease, making it susceptible to punctures by sharp pins or metal terminals under transport vibration or external pressure. Additionally, thin flash materials will undergo permanent deformation and loss of resilience under long-term static loads, causing widening of packaging gaps, loosening of components, and frictional damage. Moreover, it is more sensitive to environmental stresses such as humidity, and its cushioning performance is easily degraded. Therefore, properly controlling the thickness of the flash material is crucial to ensuring the cushioning and protective effect of consumer electronics products. In some embodiments, the thickness of the flash material disclosed herein is 0.1–0.3 mm, for example, 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, 0.2 mm, 0.21 mm, 0.22 mm, 0.23 mm, 0.24 mm, 0.25 mm, 0.26 mm, 0.27 mm, 0.28 mm, 0.29 mm, 0.3 mm, or any range of two values ​​or values ​​within that range.

[0038] This disclosure also provides a method for preparing an impact-resistant flash material, comprising: (1) providing a flash spinning solution; (2) flash spinning the flash spinning solution to obtain flash fibers; (3) laying the flash fibers into a web; and (4) molding to obtain the flash material.

[0039] In flash spinning, if the polymer mass fraction in the spinning solution is too low, continuous fibers cannot be formed during flash spinning; if it is too high, the viscosity is too high, resulting in loss of spinnability. Simultaneously, this mass fraction directly affects the microstructure, crystallinity, and orientation of the flash-spun fibers. Appropriately increasing the mass fraction is beneficial for increasing fiber diameter, improving crystallinity, and mechanical strength; however, exceeding the optimal range will lead to decreased structural uniformity and mechanical properties due to hindered solvent evaporation. In some non-limiting embodiments, in the preparation method of impact-resistant flash-spun materials, the flash spinning solution in step (1) can be formed by dissolving the polymer in the spinning solvent. In some embodiments, the polymer includes, but is not limited to, polyethylene. In some embodiments, the polymer mass fraction in the spinning solution is 8–12%, for example, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, or any two of these values ​​within a range.

[0040] In some embodiments, the spinning solvent is selected from aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, unsaturated hydrocarbons, halogenated hydrocarbons, alcohols, esters, ethers, ketones, nitriles, amides, fluorocarbons, sulfur dioxide, carbon disulfide, nitromethane, water, and mixtures of two or more of the above substances.

[0041] In some embodiments, step (2) involves obtaining the flash-evaporated fibers through the spinneret of the spinning assembly. In this disclosure, the term "stretching velocity (at the spinneret outlet)" refers to the velocity of the cooling or stretching airflow applied at a certain distance downstream of the spinneret outlet (typically perpendicular or inclined to the direction of the fiber movement) after the polymer / solvent system extruded from the spinneret during flash spinning has been flash-evaporated to form a filament bundle or fiber web. This airflow is used to stretch and refine the nascent fibers, promote solvent evaporation, and regulate the fiber diameter, orientation, and crystalline structure. In this disclosure, the stretching velocity at the spinneret outlet is 350–450 m / s. The high-speed airflow formed by solvent flash evaporation can be used to moderately stretch the uncured polymer filament bundle, constructing a highly oriented fiber network. This improves impact resistance while maintaining air permeability, ultimately fundamentally solving the technical defects of insufficient orientation leading to weak impact resistance or excessive stretching leading to fiber breakage. When the stretching velocity is below 350 m / s or above 450 m / s, the overall performance of the flash-evaporated material does not meet the actual application requirements. For example, the stretching velocity at the spinneret outlet can be 350 m / s, 355 m / s, 360 m / s, 365 m / s, 370 m / s, 375 m / s, 380 m / s, 385 m / s, 390 m / s, 395 m / s, 400 m / s, 410 m / s, 415 m / s, 420 m / s, 425 m / s, 430 m / s, 435 m / s, 440 m / s, 445 m / s, 450 m / s, or any two values ​​forming a range or a value within that range.

[0042] In the flash spinning process, if the spinning temperature (i.e., the temperature of the polymer solution before spinning) deviates from the optimal process window, it will significantly affect the fiber morphology and material properties: when the temperature is too high, the vaporization rate of the solvent at the moment of depressurization is too rapid, which leads to the uncontrolled polymer precipitation process, forming a large number of fine microfibers or powders, destroying the fiber network structure, reducing the mechanical strength and uniformity of the material, and at the same time, high temperature may trigger the thermal oxidative degradation of the polymer, making the product brittle and causing yellowing or odor, and the excessively fast curing speed leads to poor interlayer adhesion; when the temperature is too low, the solution viscosity increases, the flash driving force is insufficient, the solvent cannot fully and instantaneously vaporize, the polymer precipitation is slow and uneven, and it is easy to form coarse fibers, melt fracture or insufficiently stretched clump structure, and even the spinneret hole blockage. The resulting flash material has a rough surface, uneven porosity distribution, and significantly reduced buffer performance and puncture resistance. In some embodiments, in the flash material preparation method of this disclosure, in step (2), the flash spinning temperature is 190-230 °C.

[0043] In this disclosure, the term "spinning speed" refers to the linear velocity of a fiber or fiber bundle moving in its direction of travel during a spinning process, usually expressed in m / min, which is the initial linear velocity of the spinning solution when it is extruded from the spinneret.

[0044] The term "web laying" refers to the process by which fiber bundles or networks, after being subjected to stretching airflow, are deposited, spread, stacked, and entangled on the surface of a receiving device (such as a web-forming curtain, collecting drum, or conveyor belt), thereby forming a continuous fiber web layer or nonwoven fabric precursor with a predetermined width, uniform thickness, and pore distribution. In flash spinning, the web laying device is generally located downstream of the spinneret orifice. The web laying device is used to capture and support the filaments formed by the ejected fibers, causing the fibers to settle into a web.

[0045] In this disclosure, the term "web-laying speed" refers to the linear speed of the receiving surface (such as the receiving surface of a web-forming curtain, accumulation belt, or web-laying trolley) when the ultrafine fibers or fiber web formed after spinning, stretching, and opening are deposited on the web-laying receiving device to form a continuous fiber web during the flash spinning process. It is usually expressed in m / min. The web-laying speed directly affects the bulk density, uniformity, and unit area mass of the fiber web, and is one of the core process parameters for controlling the quality and productivity of flash spinning products.

[0046] In some embodiments, the ratio of the spinning speed in step (2) to the web-laying speed in step (3) is 1:1.1 to 1:1.3. This disclosure, by precisely controlling the speed ratio to 1:1.1 to 1.3, can adjust the fiber packing density on the web-laying screen, constructing a dense and suitable fiber network. This ensures the structural support required for impact resistance while avoiding excessive density that would obstruct air permeability. It primarily addresses the technical contradiction between excessively dense packing resulting in poor air permeability and excessively sparse packing leading to weak impact resistance. When the speed ratio is lower than 1:1.1 or higher than 1:1.3, the overall performance of the flash material does not meet the actual application requirements. For example, the ratio of the spinning speed in step (2) to the web-laying speed in step (3) of this disclosure can be 1:1.1, 1:1.15, 1:1.2, 1:1.25, 1:1.3, or any range formed by two values ​​or values ​​within that range.

[0047] In this disclosure, the preparation method of the flash material further includes, in step (4), a hot rolling step on the flash fibers laid in step (3). "Hot rolling" is a key post-processing step that imparts the final application performance of the flash material. By heating and pressurizing, the laid fiber network layers undergo partial melting and bonding, thereby transforming the loose, unfixed fiber web into a nonwoven material with sufficient mechanical strength and structural stability. Specifically, hot rolling can form a molten bond at the fiber cross contact points while maintaining the original three-dimensional porous structure of the fiber web, significantly improving the tensile strength, tear strength, and interlayer bonding force of the material. At the same time, by adjusting the temperature, pressure, and gap of the rollers, the area ratio and distribution of the hot rolling points can be precisely controlled, thereby adjusting the thickness uniformity, surface flatness, air permeability, and buffering performance of the material, avoiding problems such as delamination, fuzzing, or insufficient strength during subsequent processing or use. In addition, appropriate hot rolling parameters can also partially close the large pores on the surface of the material, improving the flash material's ability to block fine dust or liquids, without excessive compaction leading to loss of buffering and energy absorption performance. In some embodiments, the hot rolling temperature is 120–135 °C, for example, 120 °C, 121 °C, 122 °C, 123 °C, 124 °C, 125 °C, 126 °C, 127 °C, 128 °C, 129 °C, 130 °C, 131 °C, 132 °C, 133 °C, 134 °C, 135 °C, or any two of these values. In some embodiments, the hot rolling pressure is 7–9 MPa, for example, 7 MPa, 7.5 MPa, 8 MPa, 8.5 MPa, 9 MPa, or any two of these values. In this disclosure, the method for preparing the flash material further includes, in step (4), an optional winding step after the hot rolling step, to obtain the shaped flash material. Through the winding operation, the hot-rolled flash material can be collected and wound into a regular roll, which is beneficial for subsequent processing.

[0048] This disclosure also provides a packaging material comprising the impact-resistant flash material of this disclosure, or the impact-resistant flash material obtained according to the preparation method of this disclosure.

[0049] This disclosure also provides the use of the impact-resistant flash evaporation material of this disclosure, or the impact-resistant flash evaporation material obtained according to the preparation method of this disclosure, in cushioning packaging.

[0050] Example To enable those skilled in the art to better understand the present disclosure, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present disclosure, and not all embodiments.

[0051] Example 1: A method for preparing an impact-resistant flash evaporation material, comprising the following specific steps: (1) The polymer is dissolved in a spinning solvent to form a flash spinning solution; wherein the polymer is polyethylene; the mass fraction of the polymer in the spinning solution is 8%; the spinning solvent is a mixed solvent of dichloromethane and cyclohexane, with a mass ratio of 4.5:0.5; (2) First, the flash spinning solution is flash spun, and flash fibers are obtained through the spinneret of the spinning assembly. The stretching wind speed at the outlet of the spinneret is controlled to be 350 m / s. Second, the flash fibers are laid into a web in sequence, and the ratio of spinning speed to web laying speed is controlled to be 1:1.1. After web laying, hot rolling is performed. Finally, the hot-rolled flash material is wound up to obtain the impact-resistant flash material E1.

[0052] The flash spinning temperature is 210 ℃; the hot rolling temperature is 125 ℃; and the hot rolling pressure is 7 MPa.

[0053] Example 2: Referring to the preparation method of Example 1, wherein the mass fraction of polymer in spinning solution is adjusted to 10%, the stretching air velocity at the spinneret outlet is 400 m / s, the ratio of spinning speed to web laying speed is 1:1.2, the flash spinning temperature is 220 ℃, the hot rolling temperature is 130 ℃, and the remaining methods and conditions are the same as in Example 1, to obtain flash material E2.

[0054] Example 3: Referring to the preparation method of Example 1, wherein the mass fraction of polymer in spinning solution is adjusted to 12%, the stretching air velocity at the spinneret outlet is 450 m / s, the ratio of spinning speed to web laying speed is 1:1.3, the flash spinning temperature is 230 ℃, the hot rolling temperature is 135 ℃, and the hot rolling pressure is 9 MPa, and the remaining methods and conditions are the same as in Example 1, to obtain flash material E3.

[0055] Comparative Example 1: Referring to the preparation method of Example 1, wherein the mass fraction of polymer in spinning solution is adjusted to 10%, the stretching air velocity at the spinneret outlet is 300 m / s, the ratio of spinning speed to web laying speed is 1:1.2, the flash spinning temperature is 220 ℃, the hot rolling temperature is 130 ℃, and the remaining methods and conditions are the same as in Example 1, to obtain flash material C1.

[0056] Comparative Example 2: Referring to the preparation method of Example 1, wherein the mass fraction of polymer in spinning solution is adjusted to 10%, the stretching air velocity at the spinneret outlet is 500 m / s, the ratio of spinning speed to web laying speed is 1:1.2, the flash spinning temperature is 220 ℃, the hot rolling temperature is 130 ℃, and the remaining methods and conditions are the same as in Example 1, to obtain flash material C2.

[0057] Comparative Example 3: Referring to the preparation method of Example 1, wherein the mass fraction of polymer in spinning solution is adjusted to 10%, the stretching air velocity at the spinneret outlet is 400 m / s, the ratio of spinning speed to web laying speed is 1:1, the flash spinning temperature is 220 ℃, the hot rolling temperature is 130 ℃, and the remaining methods and conditions are the same as in Example 1, to obtain flash material C3.

[0058] Comparative Example 4: Referring to the preparation method of Example 1, wherein the mass fraction of polymer in spinning solution is adjusted to 10%, the stretching air velocity at the spinneret outlet is 400 m / s, the ratio of spinning speed to web laying speed is 1:1.4, the flash spinning temperature is 220 ℃, the hot rolling temperature is 130 ℃, and the remaining methods and conditions are the same as in Example 1, to obtain flash material C4.

[0059] The thickness, impact energy, Garey permeability, and number of lint particles in the 5-25 μm range of the flash material obtained by the above method were measured, and the specific impact permeability was calculated. The testing methods for impact energy, Garey permeability, and the number of lint particles, as well as the calculation method for specific impact permeability, are as described in the detailed implementation section. The test results are listed in Table 1 below.

[0060] Table 1

[0061] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the concept of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

[0062] By incorporating via reference The full contents of every patent and scientific document mentioned in this article are incorporated herein by reference for all purposes.

[0063] Equivalence This disclosure may be embodied in other specific ways without departing from its spirit or essential characteristics. Therefore, the above embodiments should be considered illustrative in all cases and not as limiting of the invention described herein. Consequently, the scope of this disclosure is defined by the appended claims rather than by the foregoing description and is intended to be encompassed therein by all variations within the equivalent meaning and scope of the claims.

Claims

1. An impact-resistant flash evaporation material, characterized in that, The raw material for the flash evaporation material includes polyethylene; The impact resistance energy of the flash evaporation material is 3-15 J; The specific permeability of the flash material is 0.35–0.6 J / s; and, The number of lint particles in the flash evaporation material with a particle size of 5-25 μm shall not exceed 70. Wherein, specific impact permeability = impact resistance energy / Gurley air permeability.

2. The impact-resistant flash evaporation material as described in claim 1, characterized in that, The specific permeability of the flash material is 0.35–0.4 J / s.

3. The impact-resistant flash evaporation material as described in claim 1, characterized in that, The specific permeability of the flash material is 0.4 to 0.5 J / s.

4. The impact-resistant flash evaporation material as described in claim 1, characterized in that, The specific permeability of the flash material is 0.5 to 0.6 J / s.

5. The impact-resistant flash evaporation material as described in claim 1, characterized in that, The impact energy of the flash material is 3-6 J.

6. The impact-resistant flash evaporation material as described in claim 1, characterized in that, The impact energy of the flash material is 6-9 J.

7. The impact-resistant flash evaporation material as described in claim 1, characterized in that, The impact energy of the flash material is 9-15 J.

8. The impact-resistant flash evaporation material as described in claim 1, characterized in that, The flash evaporation material has 50 to 70 lint particles with a particle size of 5 to 25 μm.

9. The impact-resistant flash evaporation material as described in claim 1, characterized in that, The flash evaporation material has 30 to 50 lint particles with a particle size of 5 to 25 μm.

10. The impact-resistant flash evaporation material as described in claim 1, characterized in that, The flash evaporation material has 5 to 30 lint particles with a particle size of 5 to 25 μm.

11. A method for preparing an impact-resistant flash evaporation material as described in any one of claims 1-10, characterized in that, The method includes: (1) Provide quick-spinning solution; (2) Flash spinning is performed on the flash spinning solution to obtain flash fibers; (3) Laying the flash-evaporated fibers into a web; and (4) Molding to obtain flash-evaporated material; In step (2), the flash-evaporated fiber is obtained through the spinneret of the spinning assembly, and the stretching velocity at the outlet of the spinneret is 350–450 m / s; and The ratio of the spinning speed in step (2) to the web laying speed in step (3) is 1:1.1 to 1:1.

3.

12. The preparation method according to claim 11, characterized in that, In step (4), the flash-steamed fibers after web laying are subjected to a hot rolling step, and optionally a winding step.

13. A packaging material comprising the impact-resistant flash material according to any one of claims 1-10.

14. Use of the impact-resistant flash material according to any one of claims 1-10 in cushioning packaging.

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