CN114290719A - Casting breathable film for sanitary products and preparation method thereof - Google Patents

Abstract

The invention discloses a casting breathable film for a hygienic product and a preparation method thereof. The air permeable membrane is a casting membrane, and a low air permeability area and a high air permeability area are integrally arranged on the air permeable membrane. The breathable films with different air permeability can be prepared according to the needs, so that the breathable amount of a local area of the absorbing article is larger, and the breathable amount of other areas is extremely small; therefore, the air permeability of different areas of the air permeable membrane can be adjusted according to needs, so that the use comfort of the sanitary ware is improved.

Description

Casting breathable film for sanitary products and preparation method thereof

technical field

The present invention relates to a cast air permeable film for sanitary products and a preparation method thereof.

Background technique

As the bottom film, breathable film is widely used in sanitary products such as sanitary napkins/diapers. The main stretching preparation process of breathable film is cast film stretching and blown film stretching, which has the characteristics of waterproof and vapor permeability. Due to the limitation of the existing manufacturing process, the air permeability of the air permeable film is basically the same in the entire width range during production. However, during the use of the breathable film, due to the particularity of the human body structure, after the body fluids are discharged, the air permeability in some areas of the absorbent article is often large, and the air permeability in other areas is very small; while the conventional breathable film is in order to take into account the hydrostatic pressure and physical machinery. Performance, etc., the overall air permeability of the breathable film is low, which greatly affects the comfort of sanitary products.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned defects, the purpose of the present invention is to provide a cast breathable film for sanitary products and a preparation method thereof.

In order to achieve the above purpose, in the cast air permeable film for sanitary products of the present invention, the air permeable film is a cast film, and the air permeable film integrally has a low air permeability area and a high air permeability area.

Further, the high air permeability area is integrally provided in the low air permeability area continuously or intermittently.

In order to achieve the above object, the preparation method of the above-mentioned cast air permeable film for sanitary products of the present invention, the method comprises the following steps:

Prepare low air permeability masterbatch and high air permeability masterbatch;

The low air permeability masterbatch and the high air permeability masterbatch are extruded simultaneously through a die through different screw extruders.

In order to achieve the above purpose, the preparation method of the above-mentioned cast air permeable film for sanitary products of the present invention, the method is: adjusting the gap of the discharge die, so that the thickness of the air permeable film in the low air permeability area is greater than that of the high air permeability The thickness of the breathable membrane in the volume area.

In order to achieve the above-mentioned purpose, the preparation method of the above-mentioned cast air permeable film for sanitary products of the present invention, the preparation method of the cast air permeable film comprises at least a stretching step, and during the stretching process at least comprises: : The cast air permeable film in the stretching step is stretched by pulsating stretching force, so as to form low air permeability regions and high air permeability regions arranged at intervals in the cast air permeable film.

In order to achieve the above purpose, the preparation method of the above-mentioned cast air permeable film for sanitary products of the present invention, the preparation method of the cast air permeable film comprises at least a stretching step, and in the stretching step, spaced The cast gas permeable film in the stretching step is heated to form low and high gas permeation regions at intervals in the cast gas permeable film.

The breathable film of the present invention can be made into air-permeable films with different air-permeability as required, so that the air-permeability of the absorbent article can be larger in local areas, and the air-permeability in other areas is extremely small; thus, the air-permeability of different areas of the air-permeable film can be adjusted as required. , in order to improve the comfort of hygiene products.

Description of drawings

FIG. 1 is a schematic structural diagram of Embodiment 1 of the breathable membrane of the present invention.

FIG. 2 is a schematic structural diagram of Embodiment 2 of the breathable membrane of the present invention.

FIG. 3 is a schematic structural diagram of Embodiment 3 of the breathable membrane of the present invention.

FIG. 4 is a schematic structural diagram of Embodiment 4 of the breathable membrane of the present invention.

FIG. 5 is a schematic structural diagram of Embodiment 5 of the breathable membrane of the present invention.

FIG. 6 is a schematic structural diagram of Embodiment 6 of the breathable membrane of the present invention.

Figure 7 is a schematic diagram of the arrangement of multiple screw extruders.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

1 is a schematic structural diagram of an embodiment of the breathable film of the present invention. In this embodiment, the low air permeability area 2 is located in the middle of the high air permeability area 1, and the high air permeability area 1 in the breathable film is continuous along the length direction.

2 is a schematic structural diagram of another embodiment of the breathable film of the present invention. In this embodiment, two high-air-permeability regions 1 are spaced on the breathable film, and the high-air-permeability regions 1 in the breathable film are continuous along the length direction.

3 is a schematic structural diagram of another embodiment of the breathable film of the present invention. In this embodiment, the low air permeability area 2 is located in the middle of the high air permeability area 1, and the high air permeability area 1 in the breathable film is discontinuous along the length direction.

4 is a schematic structural diagram of another embodiment of the breathable film of the present invention. In this embodiment, two high-air-permeability regions 1 are spaced on the breathable film, and the high-air-permeability regions 1 in the breathable film are discontinuous along the length direction.

The above-mentioned gas-permeable membranes can also be similarly deformed to meet the different needs of different users, which will not be listed one by one here.

Preparation method 1

The preparation method of the cast air permeable film used for the above-mentioned sanitary article, the method comprises the following steps:

Prepare low air permeability masterbatch and high air permeability masterbatch;

The low air permeability masterbatch and the high air permeability masterbatch are extruded simultaneously through a die through different screw extruders. As shown in Figure 7, it includes three screw extruders, the left and right screw extruders are filled with low air permeability masterbatch, and the middle screw extruder is filled with high air permeability masterbatch; The three screw extruders are all extruded through a die to form a film; this method can make the embodiment shown in FIG. 1 , and the embodiment shown in FIG. 2 can also be made by increasing the number of screw extruders. Now, the embodiment shown in FIG. 1 is taken as an example for description. When making the embodiment shown in Figure 1, three screw extruders with the same die are used for extrusion, wherein two screw extruders are filled with low air permeability masterbatch; and the middle screw extruder is filled with High air permeability masterbatch.

Using the above direction, a multi-layer extruder can also be used to manufacture the embodiment shown in FIG. 3 and FIG. 4 ; now, the embodiment shown in FIG. 3 is taken as an example for description. When making the embodiment shown in Figure 3, four screw extruders with the same die are used for extrusion, wherein two screw extruders are filled with low air permeability masterbatch; and two layers of screw extruders are used in the middle. , one layer is filled with high air permeability masterbatch, and the other layer is filled with low air permeability masterbatch. The embodiment shown in FIG. 3 can be realized by controlling the two-layer screw extruder in the middle to work alternately in different time periods during production.

Preparation method 2

As a variant, the preparation method of the above-mentioned cast air-permeable film for sanitary products of the present invention can also be: adjusting the gap of the discharge die, so that the thickness of the air-permeable film in the low air-permeability area is greater than the thickness of the air-permeable film in the high air-permeability area. thickness.

Now, the embodiment shown in FIG. 1 is taken as an example for description. When making the embodiment shown in Figure 1, increase the gap on both sides of the discharge die, and/or reduce the gap between the middle discharge die, so that the thickness (gram weight) on both sides of the breathable film is greater than the thickness in the middle of the breathable film (gram weight), so that the air permeability on both sides of the breathable film is less than that in the middle.

Preparation method 3

As a variant, the preparation method of the above-mentioned cast air permeable film for sanitary products of the present invention at least comprises the step of casting, and the step of casting comprises:

Prepare low air permeability masterbatch and high air permeability masterbatch;

The low air permeability masterbatch and the high air permeability masterbatch are extruded through different screw extruders respectively;

The masterbatch extruded from the screw extruder is arranged according to the predetermined requirements (for example, arranged according to the pattern of Example 1), and then cast through the casting machine. After the casting is completed, it can be casted through the subsequent steps.

Preparation method 4

The preparation method of the cast air permeable film for sanitary products of the present invention further includes: in the preparation method of the cast air permeable film, at least a stretching step is included, and the stretching process at least includes: using a pulsating The stretching force stretches the cast breathable film in the stretching step, so as to form regions of low air permeability and regions of high air permeability arranged at intervals in the cast breathable film.

The pulsating tensile force is now described with an example:

Example 1: The cast breathable film is placed in the front stretching roll, the rear stretching roll and the winding roll for stretching, wherein the rotation speed of the stretching roll is increased in the pulsation, for example, it is repeated at a time of 0.1 seconds to 0.5 seconds. Increase the rotation speed of the rear stretching roll to 1.1-1.3 times that of the front stretching roll; this is equivalent to stretching the cast air-permeable film section between the front stretching roll and the rear stretching roll in a shorter time. The force is increased to increase the air permeability of this segment of the cast breathable film relative to the unaccelerated segment of the cast breathable film segment. Thus, a breathable film similar to that shown in FIG. 5 is formed, even though the low-air-permeability regions 2 and the high-air-permeability regions 1 alternate. In this way, by adjusting the interval between the front stretching rolls and the rear stretching rolls and the time of the accelerated speed, the predetermined cast air permeable film can be achieved.

Example 2, as a modification of Example 1, a top roll can also be set between the front stretching roll and the rear stretching roll, and the top roll of the pulsating will top the front stretching roll and the rear stretching roll to cast a breathable film. Segments can also have a similar effect.

Example 3, as a modification of Example 1, the diameter of the stretching roll after the adjustment of the pulsation can also produce a similar effect.

Preparation method 5

The preparation method of the cast air permeable film for sanitary products of the present invention further comprises: heating the cast air permeable film in the stretching step at intervals in the stretching step, so that the cast air permeable film is formed at intervals in the cast air permeable film. Low air permeability areas and high air permeability areas. That is, a tubular heating device is placed transversely on the cast air permeable film in the stretching step, and the heating device is heated and cooled at intervals, so that the air permeability of the cast air permeable film section in the heating part is reduced, while the unheated cast air permeable film is not heated. The air permeability of the film segment remains unchanged, thereby forming a breathable film similar to FIG. 5, even though the low air permeability areas 2 and the high air permeability areas 1 alternate.

Preparation method 6

As a further improvement of the present invention, the method of preparation method 1, 2, 3 or 4 can also be combined with preparation method 5 to form a new form of cast air-permeable film, as shown in FIG. 6 .

Claims (9)

1. The casting breathable film for the sanitary products is characterized in that the breathable film is a casting film, and a low-air-permeability area and a high-air-permeability area are integrally arranged on the breathable film.

2. A cast breathable film for hygiene articles according to claim 1, wherein said regions of high air permeability are integrally provided in said regions of low air permeability continuously or intermittently.

3. A method of making a cast breathable film for use in hygiene articles according to claim 1, comprising the steps of:

preparing a master batch with low air permeability and a master batch with high air permeability;

and respectively extruding the master batch with low air permeability and the master batch with high air permeability by using different screw extruders through a die orifice in an alternating arrangement mode.

4. A method of making a cast breathable film for use in hygiene articles according to claim 1, wherein said method comprises at least a step of casting a sheet comprising:

preparing a master batch with low air permeability and a master batch with high air permeability;

extruding the master batch with low air permeability and the master batch with high air permeability respectively through different screw extruders;

arranging the extruded master batch of the screw extruder according to the preset requirement, and then casting the master batch by a sheet casting machine.

5. A method of making a cast breathable film for use in hygiene articles according to claim 1, wherein said method comprises: and adjusting the gap of the discharge die so that the thickness of the breathable film in the low air permeability area is larger than that of the breathable film in the high air permeability area.

6. A method of making a cast breathable film for use in hygiene articles according to claim 1, wherein said method of making said cast breathable film comprises at least a stretching step, wherein said stretching step comprises at least: and stretching the cast breathable film in the stretching step by using a pulsating stretching force so as to form a low-air-permeability area and a high-air-permeability area which are arranged at intervals in the cast breathable film.

7. A method of producing a cast breathable film for hygiene articles according to claim 1, wherein said method of producing a cast breathable film comprises at least a stretching step in which the cast breathable film in the stretching step is heated at intervals to form a low air permeability region and a high air permeability region at intervals in the cast breathable film.

8. A method of producing a cast breathable film for hygiene articles according to claim 3, 4 or 5, wherein said method of producing a cast breathable film comprises at least a stretching step, comprising at least: and stretching the cast breathable film in the stretching step by using a pulsating stretching force so as to form a low-air-permeability area and a high-air-permeability area which are arranged at intervals in the cast breathable film.

9. A method of producing a cast breathable film for hygiene articles according to claim 3, 4 or 5, characterized in that the method of producing a cast breathable film comprises at least a stretching step in which the cast breathable film in the stretching step is heated at intervals to form a low air permeability region and a high air permeability region at intervals in the cast breathable film.

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