Non-woven material for the production of a respiratory mask as well as respiratory mask

Abstract

Nonwoven material (2) for the manufacture of a respiratory mask (1), wherein the nonwoven material comprises an outer layer (4) facing away from the face of the user of the respiratory mask, an inner layer (5) facing the face of the user of the respiratory mask, and a filter fleece (3) arranged between the outer layer and the inner layer for filtering the breathing air, characterized in that the inner layer (5) has a basis weight of 15-20 g / m² and is a fiber-based thermobond nonwoven made of polypropylene fibers, fully calendered on both sides by means of thermocalenders.

Description

[0001] The present invention relates to a nonwoven material for the manufacture of a respiratory mask according to the preamble of independent claim 1 and to a respiratory mask manufactured from a corresponding nonwoven material.

[0002] Common respiratory masks are usually made from a multi-layered non-woven fabric. This fabric typically consists of an outer layer facing away from the wearer's face, an inner layer facing the wearer's face, and a filter fleece sandwiched between the outer and inner layers to filter the breathing air. The inner layer can also be a layer of the filter fleece itself.

[0003] Commercially available respiratory masks made from the material described above are primarily used as hygiene masks to prevent or reduce the risk of droplet infection. However, they generally only offer protection to those in close proximity to the wearer. The wearer themselves is only inadequately protected from droplet infection due to air leakage.

[0004] In the course of the ongoing COVID-19 pandemic, there is a need for respiratory masks that can be manufactured inexpensively and offer reliable protection against droplet infection for both the wearer and the environment. The object of the present invention is to provide a nonwoven material for the manufacture of a respiratory mask that meets these requirements. Furthermore, it is an object of the present invention to provide a nonwoven material for the aforementioned application that is perceived as comfortable and pleasant to the touch by the wearer of the respiratory mask.

[0005] The problem is solved by the features of independent claim 1. Accordingly, in the case of a nonwoven material according to the preamble of independent claim 1, a solution to the problem according to the invention exists if the inner layer is a fiber-based thermobond nonwoven made of polypropylene fibers, which is fully calendered on both sides by means of a thermocalender to achieve a smooth surface.

[0006] The inner layer of the nonwoven material according to the invention allows for significantly higher dimensional stability of the respiratory mask compared to conventional materials. This increased dimensional stability has a particularly positive effect on the inhalation and exhalation resistances specified in DIN EN 149. Furthermore, the inner layer according to the invention exhibits very low elongation, at only about 5-20%, which ensures a proper fit and correct positioning of the respiratory mask even during use. The stability of the inner layer also results in a high level of wearing comfort. This is because the increased stability of the inner layer largely prevents the nonwoven material from momentarily pressing against the user's face, even in the area near the mouth, during inhalation, a problem that sometimes occurs with conventional respiratory masks. The smooth, calendered surface of the inner layer makes the material feel pleasant to the touch.This applies particularly to men with beards. Furthermore, the nonwoven material according to the invention can be produced inexpensively.

[0007] Advantageous embodiments of the present invention are the subject of the dependent claims.

[0008] According to a preferred embodiment of the present invention, the inner layer has a basis weight of 15-20 g / m². More preferably, the inner layer has a basis weight of 16-18 g / m². A basis weight of 17 g / m² has proven to be particularly preferred. This achieves an optimal compromise between dimensional stability and a comfortable feel, as well as low breathing resistance.

[0009] According to a further preferred embodiment of the present invention, the inner layer consists of staple fibers whose fiber titer is in the range of 2 to 5 dtex. This embodiment also serves to achieve the highest possible dimensional stability while maintaining a comfortable feel.

[0010] According to a further preferred embodiment of the present invention, the filter fleece comprises a first meltblown filter layer facing the outer layer, a second meltblown filter layer, and a spacer fleece facing the inner layer, wherein the spacer fleece is a calendered, fiber-based thermobond fleece made of polypropylene fibers and polyester fibers, and wherein the meltblown filter layers consist of polypropylene fine fibers with a fiber diameter between 0.6 and 2.5 micrometers.

[0011] The meltblown filter layers are electrostatically charged and serve as fine filters. The fine fibers of the meltblown filter layers are extremely thin. The specified fiber diameter corresponds to a fiber titer of approximately 0.03 to 0.28 dtex. The spacer fleece contributes to the separation, particularly of moisture. The interaction of the two meltblown filter layers with the spacer fleece achieves high filtration efficiency with simultaneously low breathing resistance.

[0012] It has proven further advantageous if the spacer fabric has a basis weight of 40-60 g / m², preferably 50 g / m², and consists of 40-60% by weight of polypropylene staple fibers with a fiber titer in the range of 2 to 5 dtex and 40-60% by weight of polyester staple fibers with a fiber titer in the range of 4 to 8 dtex. The polyester staple fibers are preferably polyethylene terephthalate staple fibers. The spacer fabric is consolidated by thermocalendering, with the consolidation in the calender occurring only at specific points according to a repeating pattern in the form of dots, diamonds, ovals, or similar shapes. The pressing area in the thermocalender is preferably about 9% to 14%. Most preferably, the spacer fabric is consolidated at specific points in the thermocalender according to a diamond pattern, resulting in a relatively voluminous nubbed structure.This allows the spacer fleece to optimally fulfill its function as a spacer between the meltblown filter layer and the inner layer.

[0013] According to a further preferred embodiment of the present invention, the meltblown filter layers each have a basis weight of 22-28 g / m². This achieves an optimal compromise between high filter performance and low breathing resistance.

[0014] According to a further particularly preferred embodiment of the present invention, the outer layer has an air permeability of 2000 - 4500 l / m². 2 / s, with each meltblown filter layer having an air permeability of 350 - 450 l / m² 2 / s exhibiting an air permeability of 3000 - 4800 l / m². 2 / s, wherein the inner layer has an air permeability of at least 3500 l / m 2 / s. All the aforementioned air permeabilities are specified according to WSP 70.1 at a differential pressure of 200 Pascals.

[0015] According to a further preferred embodiment of the present invention, the outer layer is a polypropylene spunbond nonwoven fabric with a basis weight of 30-50 g / m², selectively calendered by a thermocalender. Preferably, the basis weight is 40 g / m². As with the spacer fabric, the consolidation of the outer layer in the calender also occurs only selectively according to a repeating pattern in the form of dots, diamonds, ovals, or similar shapes. The pressing area in the thermocalender is preferably about 22% to 30% of the total area. The fiber titer of the polypropylene fibers of the outer layer is preferably 5-12 dtex.

[0016] The present invention further provides a respiratory mask made from a nonwoven material according to the invention. The individual layers of the nonwoven material according to the invention can be manufactured separately. They are all inherently stable and can be joined together during the manufacture of the mask, for example, by ultrasonic welding.

[0017] According to a particularly preferred embodiment of the present invention, the respiratory mask is designed as a beak-shaped mask. This allows both the desired dimensional stability and the low desired leakage rates to be achieved.

[0018] An embodiment of the present invention is explained in more detail below with reference to the drawings.

[0019] They show: Fig. 1: A respiratory protection mask according to the invention in a perspective view, Fig. 2: a material cut for the respiratory mask according to the invention made of Fig. 1, and Fig. 3: the layer structure of the nonwoven material used.

[0020] In the following explanations, identical parts are designated by the same reference numerals. If a figure contains reference numerals that are not further explained in the corresponding figure description, reference is made to preceding or subsequent figure descriptions.

[0021] Fig. Figure 1 shows a perspective view of a respiratory mask 1 according to the invention. The respiratory mask 1 is designed as a beak-shaped mask and consists of a nonwoven material 2 according to the invention, the structure of which is described below with reference to Fig. 3 will be explained in more detail.

[0022] To manufacture the respiratory mask 1, the non-woven material is first used to create the following: Fig. 2. Material cutout 9 shown. The individual layers of the nonwoven material are welded together at suitable points using ultrasonic welding. The weld seams are in the Fig. 2 and Fig. 1 is designated with reference numeral 10. To shape the mask, the cut piece is sewn accordingly or welded again at the corresponding butt joints. In the illustrated embodiment, the mask is manufactured using conventional seams 11. Two elastic retaining bands 12 are also attached at suitable attachment points 13, which fix the mask to the wearer's head. In the upper area of ​​the nose, an adjustable metal nose clip is preferably incorporated between the corresponding welds 10.

[0023] The layer structure of the nonwoven material 2 according to the invention is in Fig.Figure 3 shows the mask. It consists of an outer layer 4 facing away from the wearer's face, an inner layer 5 facing the face, and a filter fleece arranged between the outer and inner layers for filtering the breathing air. According to the invention, the inner layer 5 consists of a fiber-based thermobond fleece made of polypropylene fibers, which is fully calendered smooth on both sides using a thermocalender. The basis weight of the inner layer is in the range of 15 to 20 g / m², preferably 17 g / m². The fiber titer of the polypropylene staple fibers used is in the range of 2 to 5 dtex.

[0024] The outer layer 4 is a polypropylene spunbond nonwoven fabric with a basis weight of 30-50 g / m², selectively calendered using a thermocalender. Preferably, the basis weight is 40 g / m². The spunbond nonwoven fabric is bonded using a thermocalender. The bonding of the outer layer in the calender occurs only selectively, following a repeating pattern of dots, diamonds, ovals, or similar shapes. The pressing area in the thermocalender is approximately 22% to 30% of the total area. The fiber titer of the polypropylene fibers in the outer layer is between 5 and 12 dtex.

[0025] The filter fleece 3 comprises two meltblown filter layers 6 and 7, as well as a spacer fleece 8, which faces the inner layer 5. The spacer fleece 8 is a bulky, fiber-based thermobond fleece that has been calendered only at specific points using a thermocalender. It consists of 50% by weight of polypropylene staple fibers with a fiber titer between 2 and 5 dtex and 50% by weight of PET staple fibers with a fiber titer between 4 and 8 dtex. Its basis weight is approximately 50 g / m². The two meltblown filter layers 6 and 7 serve for fine filtration and consist of extremely thin polypropylene fine fibers. Their basis weight is 22–28 g / m² each.

[0026] The outer layer 4 has an air permeability of 2000 - 4500 l / m² 2 The meltblown filter layers 6 and 7 each have an air permeability of 350 - 450 l / m². 2The spacer fleece 8 has an air permeability of 3000 - 4800 l / m². 2 / s. And the inner layer 5 has an air permeability of at least 3500 l / m². 2 / s. All the aforementioned air permeabilities are specified according to WSP 70.1 at a differential pressure of 200 Pascals.

Claims

[1] Nonwoven material (2) for the manufacture of a respiratory mask (1), wherein the nonwoven material comprises an outer layer (4) facing away from the face of the user of the respiratory mask, an inner layer (5) facing the face of the user of the respiratory mask, and a filter fleece (3) arranged between the outer layer and the inner layer for filtering the breathing air, characterized by , that the inner layer (5) is a fiber-based thermobond fleece made of polypropylene fibers, which is fully calendered on both sides using a thermocalender. [2] Nonwoven material (2) according to claim 1, characterized by , that the inner layer (5) has a basis weight of 15-20 g / m², preferably of 16-18 g / m², particularly preferably of 17 g / m². [3] Nonwoven material (2) according to claim 1 or 2, characterized by , that the inner layer (5) consists of staple fibers whose fiber titer is in the range between 2 and 5 dtex. [4] Nonwoven material (2) according to any one of claims 1 to 3, characterized by, that the filter fleece (3) comprises a first meltblown filter layer (6) facing the outer layer (4), a second meltblown filter layer (7), and a spacer fleece (8) facing the inner layer (5), wherein the spacer fleece (8) is a calendered, fiber-based thermobond fleece made of polypropylene fibers and polyester fibers, and wherein the meltblown filter layers (6, 7) consist of polypropylene fine fibers with a fiber diameter between 0.6 and 2.5 micrometers. [5] Nonwoven material (2) according to claim 4, characterized by , that the spacer fleece (8) has a basis weight of 40-60 g / m², preferably of 50 g / m², and consists of 40-60% by weight of polypropylene staple fibers with a fiber titer in the range between 2 and 5 dtex and 40-60% by weight of polyester staple fibers with a fiber titer in the range between 4 and 8 dtex. [6] Nonwoven material (2) according to claim 4 or 5, characterized by, that the meltblown filter layers (6, 7) have a basis weight of 22-28 g / m². [7] Nonwoven material (2) according to any one of claims 4 to 6, characterized by , that the outer layer (4) has an air permeability of 2000 - 4500 l / m 2 / s, wherein the meltblown filter layers (6, 7) each have an air permeability of 350 - 450 l / m 2 / s exhibit, wherein the spacer fleece (8) has an air permeability of 3000 - 4800 l / m 2 / s, wherein the inner layer (5) has an air permeability of at least 3500 l / m 2 / s, where all the aforementioned air permeabilities are specified according to WSP 70.1 at a differential pressure of 200 Pascals. [8] Nonwoven material (2) according to any one of claims 1 to 6, characterized by , that the outer layer (4) is a polypropylene spunbond nonwoven fabric with a basis weight of 30-50 g / m², preferably 40 g / m², which has been spot-calendered by thermocalender. [9] Respirator (1), characterized by, that the respiratory mask is made of a nonwoven material (2) according to one of claims 1 to 8. [10] Respiratory protective mask (1) according to claim 9, characterized by , that the respirator (1) is designed as a beak mask.

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