One-step breathable film and preparation method thereof

Abstract

The invention discloses a one-step breathable film and a preparation method thereof. The one-step breathable film is prepared by one-step film blowing equipment, and the preparation method comprises the following steps: A, inorganic powder is activated to prepare active inorganic powder; B, mixed breathable film plastic particles and the active inorganic powder form a mixed melt in a double-screwextruder, and the mixed melt sequentially passes through a first metering pump and a melt pressure buffer area, then enters a feeding port of a single-screw extruder, and then enters a film blow molding machine through a second metering pump to be subjected to extrusion blow molding to prepare a primary film; then, longitudinal stretching is performed; and thickness measurement control, corona treatment, film deviation rectification, thick edge cutting and rolling are carried out to prepare the one-step breathable film. The one-step breathable film is high in water vapor transmission rate, good in breathability, high in first-hour water vapor transmission rate and high in water vapor transmission efficiency; the one-step breathable film is high in static water pressure resistance and doesnot leak liquid water during use; and the one-step breathable film is degradable and does not cause any pollution to the environment.

Description

Technical field[0001]The invention relates to the field of film materials, in particular to a one-step gas permeable film and a preparation method thereof.Background technique[0002]A breathable film material used in the production of sanitary products such as diapers, sanitary napkins and medical disposable products such as medical protective clothing, sanitary care pads, etc., is made of polyethylene or polypropylene and other plastics by casting or blow molding. The film is then made by the longitudinal stretching process. Polyethylene or polypropylene materials are petroleum refining products. After use, they are hard to be degraded as solid waste in the environment, and therefore have an adverse impact on the environment.[0003]In addition, the currently used breathable film materials still have the following problems:[0004]1. The traditional two-step method of manufacturing breathable film is traditionally used. Because the twin-screw extruder is directly used as a cast film, it...

AI Technical Summary

Problems solved by technology

[0004] 1. The traditional two-step breathable film manufacturing method is traditionally used. Because the twin-screw extruder is directly used to make cast film, it is easy to cause uneven thickness of the film. On the one hand, because the twin-screw is forced to feed, as long as the material is not uniform , it is easy to cause uneven extrusion. On the other hand, because the particle size and specific gravity of PE particles and calcium carbonate powder are too different, uneven feeding will inevitably occur, and calcium carbonate powder with a large specific gravity is easy to discharge. The sinking is faster, and the feeding of PE particles with small specific gravity is slow, and it is easy to appear that the feeding will be more for a while and less for a while

The two factors together lead to poor uniformity of extrusion volume of the twin-screw extruder. It is very intuitive that the melt pressure fluctuation of the twin-screw extruder is relatively large.

One-step method must solve this puzzle to complete;

[0005] 2. The air permeability is poor, the water vapor transmission rate is low, and the water vapor transmission efficiency is low;

[0006] 3. Easy to leak liquid water;

[0007] 4. The breathable membrane is difficult to degrade, and the mechanical properties of the breathable membrane product are poor, easy to be damaged, or the shelf life is short

[0008] That is, the existing breathable film has poor overall performance

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