JP2022040851A - mask - Google Patents

Abstract

To provide a mask which is made of inexpensive and highly available material and has certain filter effect.SOLUTION: A mask has a substantially rectangular body in which a sheet-like breathable material composed of a skin surface side layer 13, filter layers 11 and 12 and a surface layer 10 is laminated. The filter layers include sheets made of at least two layers of pulp fibers.SELECTED DRAWING: Figure 2

Description

The present invention relates to a mask.

In recent years, a disposable mask in which an ear strap or the like is attached to a mask body in which a non-woven fabric or the like is laminated is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2020-2483

Disposable masks are generally formed by laminating multiple thermoplastic polymer sheets, with a soft material on the inner layer, an environmentally resistant material on the outer layer, and a filter on the middle layer. A material that is much finer than other layers is used. However, the supply amount of the sheet for the filter layer is limited, and the availability is poor.

In order to solve the above problems, in the present application, a plurality of pulp fiber sheets are used for the filter layer.

Specifically, the present invention is a mask having a substantially rectangular body in which a sheet-like breathable material composed of an inner layer, a filter layer, and an outer layer is laminated, and the filter layer has at least two layers. Provided is a mask containing a sheet of pulp fibers.

The sheets made of the pulp fibers may be adjacent to each other and may not be adhered to each other. Further, the sheet made of the pulp fiber may be configured not to be adhered to the inner layer and the filter layer. Further, the sheet made of the pulp fiber may be tissue paper.

In addition, the inner layer and the outer layer include a cover portion made of a thermoplastic sheet, which is made of a thermoplastic sheet and covers at least two sides of the main body, and the cover portion includes the inner layer and the outer layer. May be fused to each other. The cover portion may be made of the same material as the inner layer or the outer layer, and the material constituting the cover portion may be a part of the original fabric of the inner layer or the outer layer.

According to the present invention, it is possible to realize a mask having a certain filter effect with an inexpensive and highly available material.

FIG. 1 is an external perspective view of the mask according to the embodiment. FIG. 2 is a diagram showing a sheet structure of a mask according to an embodiment. FIG. 3 is a diagram showing a sheet fixing method using a cover sheet. FIG. 4 is a diagram showing an example of a cover sheet manufacturing method. FIG. 5 is a diagram showing the permeability of the pulp fiber sheet. FIG. 6 is a table showing changes in permeability when pulp fiber sheets are laminated. FIG. 7 is a diagram showing particle capture by the stacked pulp fiber sheets.

Hereinafter, the mask according to the embodiment of the present invention will be described with reference to the drawings. The configurations of the following embodiments are examples, and the present invention is not limited to the configurations of these embodiments.

FIG. 1 is an external perspective view of the mask according to the embodiment. As shown in FIG. 1, the mask 1 has a mask body 2, ear straps 3, 4, side portions 5, 6, and a nose fitter 7. The mask body 2 is made of a sheet-like breathable material and has a size capable of covering the wearer's mouth and nose. The ear straps 3 and 4 are made of a string-shaped elastic material, and the ends are joined to the side portions 5 and 6 located on both sides of the mask body 2 so that the ear straps 3 and 4 are joined to the left and right sides of the mask body 2. Each ring is formed.

The mask body 2 has creases that can form a pleated three-dimensional shape. In such a crease, the side portions 5 and 6 are joined to the left and right end portions in a state where the mask main body 2 is folded in a fold shape, and the shape thereof is held by the side portions 5 and 6. That is, the folds are prevented from unfolding at the side portions 5 and 6 of the left and right end portions, and the creases are unfolded when the mask 1 is attached in the region near the center of the mask body 2, thereby causing the pleats of the mask body 2. Is expanded to form a three-dimensional shape. By closing the pleats when not attached, the mask body 2 can be made into a flat surface without being bulky.

The string-shaped elastic material constituting the ear strings 3 and 4 is formed of, for example, a rubber thread and cotton mixed woven band, a resin filament mixed knitted net, an elastic non-woven fabric, or the like. By joining both ends of such a string-shaped material to the side portions 5 and 6 of the left and right sides of the mask body 2, one end of the material becomes the starting point and the other end of the material ends. The loop-shaped ear straps 3 and 4 are formed on both the left and right sides of the mask body 2.

The nose fitter 7 is a member fixed to the mask main body 2 in a state in which the longitudinal direction extends in the left-right direction of the mask main body 2 in the upper part of the mask main body 2. The nose fitter 7 may be fixed to the inside of the laminated body in a state of being sandwiched between the sheet-shaped breathable materials constituting the mask main body 2, or may be fixed to the surface of the mask main body 2. May be good. The nose fitter 7 is a plastically deformable material having strength enough to be deformed into an appropriate shape by being pressed by the wearer with a finger and maintaining the shape even when released from the pressing. By providing such a nose fitter 7 on the upper part of the mask body 2, the wearer can close the gap formed between the nose and the mask body 2.

FIG. 2 is a diagram showing a sheet structure of a mask according to an embodiment. The mask main body 2 according to the embodiment is configured by laminating each sheet of the surface layer 10, the filter layers 11 and 12, and the skin surface layer 13. A non-woven fabric made of a thermoplastic polymer is used for the surface layer 10 and the skin layer 13. In the present embodiment, the number of sheets serving as the filter layer is two, the filter layers 11 and 12, but the number of sheets may be further increased while considering the air permeability.

Since the skin surface layer 13 comes into direct contact with the skin, a non-woven fabric that is particularly soft to the touch is used. The surface layer 10 may be made of the same material as the skin layer 13, or may be a sheet of another standard having excellent breathability and resistance to the external environment. In order to prevent erroneous mounting, the color of the material can be changed between the surface layer 10 and the skin layer 13. The filter layers 11 and 12 are made of pulp fiber sheets, and tissue paper is used in this embodiment.

FIG. 3 is a diagram showing a sheet fixing method using a cover sheet. FIG. 3 is a cross section of the mask body 2 viewed from above in the lateral direction. For masks in which all sheets are made of thermoplastic polymer, it is possible to prevent the sheets from scattering by joining the four sides of the sheets by methods such as high frequency welding, ultrasonic welding, and heat welding. However, in the mask according to the present invention, since the filter layers 11 and 12 do not have thermoplasticity, the entire sheet cannot be welded. Therefore, in the present embodiment, a cover sheet 14 made of a thermoplastic polymer is further provided at the longitudinal end portion of the mask, and the longitudinal end portion is wrapped with the cover sheet 14. In the welding step, the cover sheet 14 and the surface layer 10 are welded, and the cover sheet 14 and the skin surface layer 13 are welded, respectively. With such a configuration, the filter layers 11 and 12 are housed in a bag formed of the surface layer 10, the skin layer 13, and the cover sheet 14.

Further, the lengths of the filter layers 11 and 12 in the lateral direction are shorter than those of the surface layer 10 and the skin surface layer 13 and arranged on the center side, and the end portions in the lateral direction are the surface layer 10 and the skin surface layer 13. Only may be welded. With such a configuration, the filter layers 11 and 12 are fixed by the thermoplastic polymer sheet having a bag shape in all directions, and the filter layers 11 and 12 do not scatter unless one of the sheets is severely broken.

FIG. 4 is a diagram showing an example of a cover sheet manufacturing method. It is preferable that the cover sheet 14 is made of the same material as at least one of the surface layer 10 and the skin layer 13. If these sheets are made of the same material, they are more firmly welded to each sheet in the heat welding step, so that each sheet is less likely to be scattered due to insufficient welding by the cover sheet 14.

The cover sheet 14 made of the above-mentioned material can be obtained during the mask manufacturing process by a method as shown in FIG. 4, for example. In the mask manufacturing process, each sheet constituting the mask body is unwound from the roll sheet, laminated by the roller 22, folded, and heat-welded to form the mask body. In the example of FIG. 4, the surface layer 10 is made wider by the cover sheet 14 than the width in the lateral direction of the mask body at the stage of the roll sheet. The surface layer 10 is pulled out from the roll sheet, cut out by the cutter 20 with a width corresponding to the width of the cover sheet 14 before being laminated with other sheets by the roller 22, and the short side of the mask body 2 is cut out by the cutter 21. It is cut out in the direction width.

The cover sheet 14 cut out in this way is arranged on the side portions 5 and 6 at the end of the manufacturing process of the mask main body 2, and is fixed by heat welding. In this way, the cover sheet 14 made of the same material as the surface layer 10 can be incorporated into the mask. The sheet for cutting out the cover sheet 14 may be the skin surface layer 13. Further, the cover sheet 14 can be formed by separately incorporating a cover material of the same material as either the surface layer 10 or the skin surface layer 13 without taking such a step.

FIG. 5 is a diagram showing the permeability of the pulp fiber sheet. Unlike non-woven filters, pulp fiber sheets have many defects. In FIGS. 5A and 5B, different tissue papers are sandwiched between glass plates and read with a transmissive scanner at 16 bits and 1200 dpi gray scale, and the transmittance is 70 when only the glass plate portion is 100%. It is expressed by binarizing the defective portion with% as a threshold value. The white part is the defective part of the sheet, which is the part through which the particles easily pass. In the case of one pulp fiber sheet, it can be seen that such a defective portion is very conspicuous and sufficient filter performance cannot be expected.

FIG. 5 (c) is a stack of FIGS. 5 (a) and 5 (b). The white part is a defective part that both sheets have in common, but it can be seen that it is significantly improved as compared with FIGS. 5 (a) and 5 (b) alone. As described above, it can be seen that even with tissue paper having many defective portions, the defective portions are almost eliminated by stacking them, and a considerable degree of filter performance can be expected.

FIG. 6 is a table showing changes in permeability when pulp fiber sheets are laminated. FIG. 6 is a numerical value of the superposition of different tissue papers and the change of the defective portion, which are visually shown in FIG. With one piece of tissue paper, the defective part is about 5%, and sufficient filter performance cannot be expected, but when two different tissue papers are overlapped, the defective part becomes 0.3% or less. It can be seen that the defective part decreases exponentially each time the tissue paper is overlapped, and the filter performance is improved.

The actual number and types of pulp fiber sheets to be stacked should be carefully determined by considering the air permeability of the mask as well as the filter performance.

FIG. 7 is a diagram showing particle capture by the stacked pulp fiber sheets. In the present embodiment, as described above, the filter layers 11 and 12 are made of pulp fiber sheets and are stored in a bag-shaped thermoplastic polymer sheet, so that they are not fixed to each other and the filter layers 11 are not fixed to each other. , There is an air layer between the twelve. As described above, each pulp fiber sheet has a defect portion, but the defect portion penetrating the two pulp fiber sheets is extremely small. Therefore, most of the gas passing through the filter layers 11 and 12 enters between the filters from the defective portion of the first filter, moves through the air layer between the filters, and exits from the defective portion of the next filter. Become.

On the other hand, it is known that a specific pathogen attaches to and moves to an aerosol which is a droplet particle containing saliva. The gas passing between the filter layers comes into contact with the sheet surface as indicated by the arrows while moving between the defective portions of the pulp fiber sheet. Since it can be expected that a certain amount of aerosol is collected on the sheet while passing through the filter layer in this way, the hygienic effect of the mask can be further enhanced.

In addition, even if there is a defect in the same place of each filter layer by chance and a defect hole penetrating the filter layer is formed, if there is an air layer between the filter layers, fine particles may invade the air layer. do. Therefore, the possibility that the fine particles are captured by the filter layer can be increased.

Although the embodiment of the mask in the present invention has been described above, the content of the present invention is not limited to the above embodiment. For example, in the above embodiment, the cover sheet 14 is arranged only at the longitudinal end of the mask, but the cover sheet is arranged on all four sides of the mask and welded between the surface layer 10 and the skin layer 13. You may. By doing so, the filter layer can be arranged on the entire surface of the mask main body 2, so that a mask with higher performance can be realized.

Further, in the above embodiment, the filter layer is a full-thickness pulp fiber sheet, but in addition to this, a filter layer made of a non-woven fabric may be added. With such a configuration, it is possible to realize a mask having higher performance, which obtains both the filter effect of the nonwoven fabric sheet and the filter effect of the pulp fiber sheet described in the embodiment.

The embodiments and application examples disclosed above can be combined.

1 ・ ・ Mask 2 ・ ・ Mask body 3,4 ・ ・ Ear straps 5, 6 ・ ・ Side 7 ・ ・ Nose fitter 10 ・ ・ Surface layer 11, 12 ・ ・ Filter layer 13 ・ ・ Skin layer 14 ・ ・ Cover Sheet 20 ... Cutter 21 ... Cutter 22 ... Roller

Claims (7)

A mask having a substantially rectangular body in which a sheet-like breathable material composed of an inner layer, a filter layer, and an outer layer is laminated.
The filter layer is a mask comprising a sheet consisting of at least two layers of pulp fibers. The sheets made of the pulp fibers are adjacent to each other and are adjacent to each other.
The mask according to claim 1, which is not bonded to each other. The sheet made of the pulp fiber is not adhered to the inner layer and the outer layer.
The mask according to claim 2. The mask according to any one of claims 1 to 3, wherein the sheet made of the pulp fiber is tissue paper. The inner layer and the outer layer are made of a thermoplastic sheet.
A cover portion made of a thermoplastic sheet that covers at least two sides of the main body is provided.
The cover portion is obtained by fusing the inner layer and the outer layer, respectively.
The mask according to any one of claims 1 to 4. The cover portion is made of the same material as the inner layer or the outer layer.
The mask according to claim 5. The material constituting the cover portion is a part of the original fabric of the inner layer or the outer layer.
The mask according to claim 5 or 6.

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