Flame-retardant wrapping tape based on wide-range biomass fibers and preparation process thereof

Abstract

The invention belongs to the field of cable flame-retardant material manufacturing, and relates to a flame-retardant wrapping tape based on wide-range biomass fibers and a preparation process of the flame-retardant wrapping tape. The preparation method comprises the following steps: dispersing an inorganic flame retardant and an auxiliary functional agent in water, adjusting the pH value, stirring to form aqueous slurry, mixing the aqueous slurry with biomass fibers, and carrying out negative pressure ultrasonic oscillation; continuously adding acid until the pH value is 4.8-5.3, and standing for 15-30 minutes; slowly adding acid until the pH value is 4.0-4.5, and slowly stirring until a semi-finished product gel is formed; conveying to a slit mold, setting the temperature to be 55-65 DEG C, the pressure to be 1-1.5 MPa and the shearing speed to be 1200-2000s <-1 >, and extruding a sheet-shaped strip; and spraying paraffin microspheres on the surface of the strip, heating at 65-75 DEG C for 2-3 minutes, and gradually cooling through temperature gradient to finish curing molding. The wide-range adaptive flame-retardant wrapping tape is prepared by adopting a dynamic negative pressure impregnation-slit extrusion orientation process, the material compatibility is high, the universal production is realized, and the application scene is wide.

Claims

1. A preparation process of a flame retardant wrapping tape based on wide-area biomass fiber, characterized in that: The following steps are involved: (1) Dispersing an inorganic flame retardant and an auxiliary functional agent in deionized water according to the composition of the flame retardant wrapping tape, controlling the solid content to be 25% to 30%, then adding an acid source to adjust the pH to 5.5 to 6.0, and stirring at high speed to form an aqueous slurry; mixing the aqueous slurry with biomass fibers, and ultrasonically oscillating at a negative pressure of -0.05 MPa to -0.1 MPa; (2) Continue to add acid source to adjust the pH value to 4.8-5.3, let it stand for 15-30 minutes to allow the fiber to swell; then slowly add acid source to the pH value of 4.0-4.5, stir at low speed until cross-linking forms a semi-finished gel; (3) The semi-finished gel is transported to the slit die, the temperature is controlled at 55-65 ° C, the pressure is 1-1.5 MPa, and the temperature is controlled at 1200-2000 s -1 Extrusion under the action of shear rate forms sheet-like strips; (4) spraying paraffin microspheres on the surface of the extruded tape, heating it at 65-75°C for 2-3 minutes, and then gradually cooling it through a set temperature gradient to complete the curing and molding to obtain a flame retardant wrapping tape product.

2. The preparation process according to claim 1, characterized in that The flame retardant wrapping tape comprises the following components in percentage by mass: 50-60% biomass fiber, 25-35% inorganic flame retardant and 5-15% auxiliary functional agent; The biomass fiber includes any one or more of α-cellulose, bamboo pulp fiber or straw fiber; The inorganic flame retardant includes any one or more of hydrotalcite, magnesium hydroxide, aluminum hydroxide, zinc borate, phosphogypsum, ammonium polyphosphate or aluminum hypophosphite; The auxiliary functional agent includes any one or more of expanded graphite, nanoclay, carbon nanotube or silicon carbide.

3. The preparation process according to claim 1, characterized in that The acid source includes any one or more of citric acid, phytic acid or ammonium dihydrogen phosphate.

4. The preparation process according to claim 1, characterized in that In the step (1), the rotation speed of the high-speed stirring is 80 to 100 rad / min.

5. The preparation process according to claim 1, characterized in that: In the step (1), the biomass fibers are pre-opened, mixed with the aqueous slurry, and then negative pressure is applied, and ultrasonic oscillation is performed at 20kHz to 30kHz for 5 to 10 minutes to allow the particles in the aqueous slurry to penetrate into the fiber pores.

6. The preparation process according to claim 1, characterized in that In the step (2), the rotation speed of the low-speed stirring is 10 to 15 rad / min.

7. The preparation process according to claim 1, characterized in that The slit die used in step (3) has a slit width of 0.3 to 0.8 mm, a slit length of 300 to 500 mm, an inlet expansion angle of 30° to 60°, and a surface roughness of ≤0.1 μm.

8. The preparation process according to claim 1, characterized in that In the step (4), paraffin microspheres with a particle size of 5 to 20 μm are sprayed onto the surface of the strip, and phase change penetration is triggered by infrared heating at 65 to 75° C., and then the temperature gradient is set to 43 to 47° C. for slow cooling and setting for 5 to 8 minutes, and finally cooled and stabilized at 23 to 27° C. for 3 to 5 minutes, and the strip is gradually cooled to reduce the setting shrinkage of the material.

9. A flame retardant wrapping tape based on wide-area biomass fibers, characterized in that: The flame retardant wrapping tape is prepared by the preparation method according to any one of claims 1 to 8.

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