Method and apparatus for increasing the thickness of microporous polypropylene film

Abstract

The invention discloses a method and equipment for increasing the thickness of a microporous polypropylene film. The method comprises the following steps: overlapping, namely, overlapping the microporous polypropylene film and interleaving paper at an interval to form a material group; warming, namely, under the condition of a filling gas under a pressure of 1MPa-3MPa, heating to a target temperature, wherein the target temperature is 60 DEG C-150 DEG C; insulating, namely, insulating for a certain time of 30min-5h; exhausting, namely, after the insulation time is out, rapidly exhausting the filling gas; and taking out, namely, taking the material group out, and after the material group is cooled to a room temperature, and increasing the thickness of the microporous polypropylene film by 20 percent-200 percent. According to the method, a piezoelectric charge coefficient d33 of the microporous polypropylene film serving as a piezoelectric electret film is effectively improved. The invention further relates to equipment for realizing the method. The method and the equipment are high in use efficiency, remarkable in effect, simple in process and suitable for batch industrial production.

Description

technical field [0001] The present invention relates to a method and a device capable of realizing the method, in particular to a method for increasing the thickness of a microporous polypropylene film and a device capable of realizing the method for increasing the thickness of a microporous polypropylene film. Background technique [0002] Polyvinylidene fluoride (PVDF) is a well-known ferroelectric polymer material, but its relatively low piezoelectric charge coefficient (d 33 ≈25pC / N and d 31 ≈28pC / N, resulting in lower sensitivity of the device), which limits its application range to a certain extent. So far, the commercial piezoelectric functional materials with high sensitivity are still dominated by some inorganic single crystal ceramics (such as barium titanate, BT), PZN-based ceramics and polycrystalline ceramics (such as lead zirconate titanate, PZT) materials. [0003] Microporous polypropylene film as a piezoelectric electret film (Piezoelectret) is a porous st...

AI Technical Summary

Problems solved by technology

[0007] The object of the present invention is to propose a kind of method for increasing the thickness of microporous polypropylene film and the equipment that can realize the method for increasing the thickness of microporous polypropylene film, solve the microporous polypropylene film produced by industry at present due to holes The size is relatively flat and the Young's modulus Y in the thickness direction is large, so that the piezoelectric charge coefficient d when used as a piezoelectric electret film 33 Low, resulting in low sensitivity as a sensor, can not meet the technical problems of production needs

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