DE112021002391T5 - barrier mask - Google Patents

Abstract

A barrier mask or face mask is provided that includes a mask body that includes a filter portion, an upper elastic portion, and a lower elastic portion, the mask body including at least one meltblown layer. The face mask also includes one or more elastic straps. A method of forming a face mask is also provided, the method including electrostatically treating the meltblown layer during formation of the face mask.

Description

Cross reference to related applications

This application claims priority over the provisional one U.S. Patent Application No. 63/028,889 with a filing date of May 22, 2020, which is incorporated herein by reference.

Background of the Invention

Face masks are used in a variety of medical, industrial, and domestic applications as they protect the wearer from inhaling dust and other harmful airborne contaminants through the mouth or nose.

However, face masks that provide protection from airborne contamination often require proper fitting, which can be difficult unless the user is a trained healthcare professional. In particular, many face masks require a user to tie an attachment portion behind their head or to properly adjust the wire or metal strip over a user's nose. This is problematic because the use of face masks outside of a hospital or medical setting (where wearers are accustomed or trained to wear such protective clothing), such as in daily life, including at work, can lead to the masks are not properly fitted, which greatly reduces their effectiveness. In addition, it is desirable, especially in a work environment, to use disposable masks as this minimizes the spread of contamination in and out of the workplace. However, this results in a user having to reattach their mask at least once per shift.

In addition, it is difficult to store large quantities of face masks because the filter quality degrades over time. However, producing large quantities of filtration face masks quickly is also difficult as line speeds are usually quite slow, allowing only about 160 masks per minute or less to be produced. Therefore, it can be difficult for employers to provide large quantities of single-use masks.

Therefore, it would be advantageous to provide a face mask that solves one or more of the above problems. In one aspect, it would be advantageous to provide a face mask that fits a variety of users without requiring the user to adjust the face mask. It would also be advantageous to provide a face mask that can be manufactured quickly. Additionally, it would be advantageous to provide a face mask that has a high degree of filtration, such as filtering about 90% or more of airborne particulates, without requiring the use of special pre-engineered components.

Summary of the Invention

The present disclosure generally relates to a barrier face mask that includes a mask body and at least one elastic strap attached to a first side and a second side of the mask body. The mask body is formed from one or more nonwoven web layers and includes a seamless filter portion, an upper elastic portion, and a lower elastic portion.

In one aspect, the mask body includes at least two layers, with one or more of the layers being formed from a nonwoven meltblown web. Additionally or alternatively, in one aspect, the meltblown nonwoven web has been electrostatically treated. In one aspect, the mask body includes a spunbonded nonwoven layer and a meltblown nonwoven layer. In another aspect, the mask body includes a spunbond-meltblown-spunbond layer and a nonwoven meltblown layer.

In one aspect, the face mask filters 70% or more of particles that are 0.65 microns or larger. Additionally, in one aspect, the face mask has an air permeability per ASTM D737 of about 20 ft ³ /m or greater. Additionally or alternatively, the upper elastic part, the lower elastic part or both the upper elastic part and the lower elastic part are arranged between a first and a second fleece layer of the mask body. Furthermore, in one aspect, the upper elastic portion, the lower elastic portion, or both the upper elastic portion and the lower elastic part is laminated with one or more nonwoven web layers. In one aspect, the at least one elastic band is formed of the same elastic material as the top elastic portion, the bottom elastic portion, or both the top elastic portion and the bottom elastic portion. In one aspect, the face mask also includes at least two straps.

In yet another aspect, the mask body has a length of from about 200 millimeters to about 350 millimeters in a stretched state. In another aspect, the at least one elastic band has a length of from about 200 millimeters to about 350 millimeters in a stretched state. Additionally, in one aspect, the at least one elastic band has a width in a stretched state of from about 25 millimeters to about 75 millimeters.

The present disclosure also generally includes a method of forming a face mask. The method includes forming a laminate by unwinding a first nonwoven web, attaching one or more elastic members in an upper region, a lower region, or both an upper region and a lower region, unwinding a second nonwoven web, and laminating the first nonwoven web, one or more elastic members and the second nonwoven web, and attaching one or more tapes to a leading edge and a trailing edge of the laminate. In the method, the one or more tapes are attached to the laminate during an in-line process.

In one aspect, the method includes cutting the one or more tapes from the laminate prior to attaching the tapes to the laminate. In one aspect, the second nonwoven web is a meltblown nonwoven web and the method includes unwinding a virgin meltblown web and subjecting the virgin meltblown web to an electrostatic treatment prior to laminating the meltblown web to the first nonwoven web and the one or more elastic members. Additionally or alternatively, the first nonwoven web is a spunbonded web or a spunbonded-meltblown-spunbonded web. In one aspect, an adhesive is applied to the one or more elastic members. Additionally, in one aspect, the one or more tapes, or both the laminate and the one or more tapes, are formed during lamination, attachment of the one or more tapes, or both lamination and attachment of the one or more tapes kept in a stretched state.

Other features and aspects of the present invention are described in more detail below.

character list

• 1 veranschaulicht eine Seitenansicht eines Aspekts einer Gesichtsmaske gemäß der vorliegenden Offenbarung;
• 2 veranschaulicht eine Vorderansicht eines Aspekts einer Gesichtsmaske gemäß der vorliegenden Offenbarung;
• 3 veranschaulicht eine Rückansicht eines Aspekts einer Gesichtsmaske gemäß der vorliegenden Offenbarung; und
• 4 veranschaulicht die Bildung einer Gesichtsmaske gemäß einem Aspekt der vorliegenden Offenbarung.

A complete and enabling disclosure of the present invention, including the best mode thereof, directed to those of ordinary skill in the art is set forth in detail in the remainder of the specification with reference to the accompanying figure, wherein:

• 1 12 illustrates a side view of an aspect of a face mask in accordance with the present disclosure;
• 2 12 illustrates a front view of an aspect of a face mask in accordance with the present disclosure;
• 3 12 illustrates a rear view of an aspect of a face mask in accordance with the present disclosure; and
• 4 illustrates the formation of a face mask in accordance with an aspect of the present disclosure.

Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention.

Detailed Description of Representative Embodiments Definitions

As used herein, the terms "about," "about," or "generally," when used to modify a value, mean that the value can be increased or decreased by 10% and remain within the disclosed aspect.

The term “fits a majority of users” as used herein is based on anthropometric data for head, face and neck dimensions according to ISO/TX 19672-2 (2015). For example, an average bigonial diameter of 132.5-144.5 millimeters (mm), an average Menton-Sellion length of 123 mm to 135 mm, an interpupillary width of 65 mm to 71 mm, and an average bitragion jaw arch of 295 mm to 315 mm are generally taken as values for an average adult head, face and neck. Thus, based on the average measurements above, a face mask according to the present disclosure can fit about 70% or more of users, like about 75% or more, like about 80% or more, like about 85% or more, like fit properly and cover the mouth and nose for around 90% or more of users.

As used herein, the term "fibers" generally refers to elongated extrudates that can be formed by passing a polymer through a forming orifice, such as a die. Unless otherwise specified, the term "fibers" includes discontinuous fibers of definite length (e.g., stable fibers) and substantially continuous filaments. Essentially, for example, filaments can have a length much greater than their diameter, e.g. B. a length to diameter ratio ("aspect ratio") greater than about 15,000 to 1 and in some cases greater than about 50,000 to 1.

As used herein, the term "nonwoven web" generally refers to a web having a structure of interwoven fibers, but not in an identifiable manner as a knitted fabric. Examples of suitable nonwoven webs include, but are not limited to, meltblown webs, spunbond webs, bonded carded webs, airlaid webs, coform webs, hydraulically entangled webs, and so on.

As used herein, the term "spunbonded nonwoven web" generally refers to a nonwoven web containing substantially continuous filaments formed by extruding a molten thermoplastic material from a plurality of fine, usually round, capillaries of a spinnerette, the diameter of the extruded fibers is then rapidly reduced, for example by eductive drawing and/or other known spunbonding mechanisms. The production of spunbond webs is described, for example, in US Patent Nos. 4,340,563 to apple. et al., 3,692,618 to Dorschner, et al., 3,802,817 to Matsuki, et al., 3,338,992 to Kinnev, 3,341,394 to Kinney, 3,502,763 to Hartman, 3,502,538 to Levy, 3,542,615 to Dobo, et al. and 5,382,400 to Pike, et al. described and illustrated.

As used herein, the term "meltblown" web or cover sheet generally refers to a fiber-containing nonwoven web formed by a process in which a molten thermoplastic material flows through a plurality of fine, usually circular, die capillaries as molten fibers into converging high-velocity gas streams (e.g. air jets) attenuate the fibers of molten thermoplastic material to reduce their diameter, which may be microfiber diameter. Thereafter, the meltblown fibers are entrained by the high velocity gas stream and deposited on a collection surface to form a web of randomly distributed meltblown fibers. Such a procedure is, for example, in U.S. Patent No. 3,849,241 to Butin et al. disclosed.

As used herein, the term "machine direction" or "MD" generally refers to the direction in which a material is made. The term "cross-machine direction" or "CD" generally refers to the direction perpendicular to the machine direction. Dimensions measured in the cross-machine direction are also referred to as "width" dimensions, while dimensions measured in the machine direction are referred to as "length" dimensions. As used herein, the term "extensible" generally refers to a material that stretches in the direction of an applied force (e.g., CD or MD direction) by about 50% or more, in some embodiments by about 75%. or more, in some embodiments about 100% or more, and in some embodiments about 200% or more of its relaxed length or width.

As used herein, the term "elastic" generally refers to an extensible material that is stretchable in at least one direction (e.g., CD or MD direction) upon application of a stretching force, and which recovers approximately in contracts/returns to its original dimension. For example, the stretched material can contract or recover at least about 50%, and more desirably at least about 80% of its stretched length. It should go without saying that recovery is a stretchy material properties may be absent, so it is considered an “inelastic” material. Materials can be tested for their elastic properties using a cyclic testing method, as explained below.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of the invention, one or more examples of which are described below. Each example is provided to illustrate and not limit the invention. It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment or figure may be used on another embodiment or figure to yield a still further embodiment. It is therefore intended that the present invention covers such modifications and variations.

Generally speaking, the present disclosure relates to a face mask with a tubular design that does not require the user to tie or otherwise manually fasten the straps in order to don the mask. In particular, the present disclosure has shown that by using a mask body that includes a filter portion, an upper elastic portion, and a lower elastic portion, excellent filtration of particulate matter in the air can be achieved through the uninterrupted filter portion, while the upper and lower elastic part achieves a good fit for a majority of users. In addition, the present disclosure has also revealed that a tubular face mask can be formed (e.g., completely enclosing a user's head when donned) through the use of one or more elastic straps tied to the body portion. , which has a good fit for a majority of users without the user having to tie or adjust it. Since the bands encircle the head and are formed from a wide elastic band with good comfort properties such as softness and touch while maintaining good elasticity, they also allow for long-term wear without causing fatigue or discomfort to the wearer's head or ears .

For example, with reference to 1 and 2 1, a face mask 100 is illustrated in accordance with an aspect of the present disclosure. The face mask 100 includes a mask body 102 formed of a filter portion 104, an upper elastic portion 106 and a lower elastic portion 108. FIG. As discussed in more detail below, the mask body 102 may include two or more layers. Thus, in one aspect, the upper elastic portion 106 may be generally formed by adhering an elastic member to at least one layer of the mask body 102 in an upper region 110 of the mask body 102 . Of course, in one aspect, the upper elastic portion 106 may be "embedded" between first and second layers of the mask body 102 (as discussed below with reference to FIG 4 shown and explained in more detail). Thus, in such an aspect, the elastic member can form the bond between the first layer and the second layer of the mask body 102 and, as will be discussed in more detail below, be adhered to the first layer and the second layer, as is known in the art .

Additionally, in one aspect, one or more of the first layer, the second layer, or both the first and second layers of the mask body 102 may have some elasticity or stretchability. In such an aspect, the first and/or second layer of the mask body 102 may be adhered to the elastic member in a stretched or at least partially stretched condition to provide a top elastic portion 106 having a gathered orientation when at least partially relaxed. As for example in 1 and 2 As shown, the upper elastic portion 106 can be attached to the mask body 102 such that the mask body 102 has a gathered orientation in the relaxed state. In particular, the present disclosure has demonstrated that such an orientation can result in an improved fit and can provide an improved fit for a variety of users, since the gathered orientation can result in greater contact around the user's nose and eye area without loss a wire or other clip must be used across the bridge of the nose.

Similarly, the present disclosure has shown that a lower elastic portion 108 can be formed using an elastic member as described above with respect to the upper elastic portion 106 but can be located in a lower region 112 of the mask body 102 , which is the upper region 110 opposite. Thus, in one aspect, the lower elasti cal portion 108 may be generally formed by adhering an elastic member to at least one layer of the mask body 102 in a lower region 112 of the mask body 102 . Of course, in one aspect, the lower elastic portion 108 may be "embedded" between first and second layers of the mask body 102 (as discussed below with reference to FIG 4 shown and explained in more detail). In such an aspect, the elastic member may form the bond between the first layer and the second layer of the mask body 102 and, as will be discussed in more detail below, may be adhered to the first layer and the second layer as is known in the art.

Additionally, in one aspect, as discussed above, one or more of the first layer, the second layer, or both the first and second layers of the mask body 102 may have some elasticity or stretchability. In such an aspect, the first and/or second layer of the mask body 102 may be adhered to the elastic member of the lower elastic portion 108 in a stretched or at least partially stretched condition to provide a lower elastic portion 108 having a gathered orientation. As for example in 1 As shown, the lower elastic portion 108 can be attached to the mask body 102 such that the mask body 102 has a gathered orientation in the relaxed state. In particular, the present disclosure has demonstrated that such an orientation can result in improved fit over a user's chin and jaw area and can provide improved fit for a variety of users since the gathered orientation results in greater contact around the chin and jaw area jaw area of the user without the user having to tighten or adjust the closure of the face mask.

It will be appreciated that although the foregoing aspect generally includes an elastic member of the upper and lower regions between two layers of the mask body, in an alternative aspect two or more layers of the mask body may be adhered to one another and the elastic member to one or more of those layers can be attached. Additionally, in one aspect, the mask body may be formed from a single layer, with at least one side of the layer being adhered to the elastic member of the upper and lower regions. In a further aspect, discussed in more detail below, the mask body may comprise more than two layers, and the upper and lower region elastic member may be adhered between any two layers or adhered to an outer portion of one or more of the layers.

Nevertheless, the face mask of the present disclosure, with reference to the 1-3 and also include one or more straps 114 attached to the mask body 102 as discussed above. In particular, as illustrated, the strap 114 or straps 114 may be attached to a first side 116 and an opposite second side 118 of the mask body 102 . As in 2 As can be seen particularly clearly, both the first side 116 and the opposite second side 118 intersect the upper region 110 and the lower region 112. While the face mask in FIG 2 having a generally square shape in a stretched state, the face mask 100 in a relaxed state, as shown in FIG 1 1, may have a less uniform shape while still having a first side 116 and/or an opposing second side 118 intersecting lower region 112 and upper region 110. FIG.

In one aspect, the strap or straps 114 may be formed of the same material as the elastic member of the upper elastic member 106, the lower elastic member 108, or both the upper elastic member 106 and the lower elastic member 108. Regardless of whether the elastics Where elements of the band(s) 114, upper region 106, or lower region 108 are the same or different, the elastic member(s) may have a variety of configurations. For example, the width of the individual elastic members can be from about 1 millimeter to about 100 millimeters, such as from about 10 millimeters to about 90 millimeters, such as from about 25 millimeters to about 75 millimeters, such as from about 40 millimeters to about 60 millimeters , or any range or value in between. In particular, the present disclosure has shown that tapes with such a width can further improve the comfort of the wearer while maintaining good elastic properties.

Regardless of the width of the elastic member(s), the elastic member(s) may include a single strand of elastic material, or may include multiple parallel or non-parallel strands of elastic material, or attached in a straight or curved configuration be. When the strands are not parallel, two or more of the strands may cross or be otherwise connected within the elastic member or members.

Although the elastic member(s) may be formed from any known elastic material, in one aspect one or more of the elastic members may comprise one or more elastic strands comprised of a Lycra elastomer, that of DuPont, a Wilmington, Del. company. is available. Each elastic strand may have a linear density of from about 600 decitex (dtex) to about 1200 dtex, for example from about 700 dtex to about 1100 dtex, for example from about 800 dtex to about 1000 dtex, or any range or value in between. Additionally, in one aspect, the elastic member can comprise from one strand to about 7 strands, such as from about 2 strands to about 5 strands, or any range or value in between.

However, the elastic member(s) of the strap(s) 114 may be attached to the mask body 102 in a variety of ways that are known in the art. The elastic members may be bonded to the mask body 102 with, for example, ultrasonic bonding, heating, and pressure sealing using a variety of bonding patterns, or with hot melt adhesive sprayed or swirled patterns. Regardless, in one aspect, the band(s) 114 may be continuous (e.g., extending from the first side 116 to the second side 118 with no seam or band therebetween). In one aspect, while the straps and mask body may be formed by any of the foregoing methods, the face mask may be sized to fit a majority of users. For example, in one aspect, the face mask may have a mask body length L1 when stretched from about 200 mm to about 350 mm, such as about 225 mm to about 325 mm, such as about 250 mm to about 300 mm, or any range or value in between. Additionally, in one aspect, the band(s) can have an extended length L2 of from about 200 mm to about 350 mm, such as about 225 mm to about 325 mm, such as about 250 mm to about 300 mm, or any range or have values in between. Additionally, the band(s) can have a width W1 of from about 25mm to about 75mm, such as about 30mm to about 70mm, such as about 35mm to about 65mm, such as about 40mm to about 65mm. In a two band aspect, each band may be the same width or may have different widths corresponding to the widths discussed above. However, as defined above, the face mask according to the present disclosure can have a shape and size that fits a majority of users.

Regardless of the elastic member(s) or straps 114 used, the mask body 102 may be formed of one or more layers, as discussed above. Each layer may generally be formed from a nonwoven web, such as a spunbond web, a meltblown web, a coform nonwoven web, a bonded carded web, or a wetlaid web. In one aspect, the mask body 102 includes two layers, although three or more layers can also be used. For example, in one aspect, the mask body 102 includes a spunbonded layer and a meltblown layer. In another aspect, however, the mask body may include a meltblown layer sandwiched between two spunbonded layers, or alternatively, one or both of the spunbonded layers may be formed of an SMS (spunbond-meltblown-spunbond) fabric.

In particular, the present disclosure has shown that a mask comprising a first layer and a second layer, at least one of the first and second layers including a meltblown web, has excellent filtration properties while maintaining good elastic properties (to maintain proper fit) and offers a good wearing comfort for the wearer. Additionally, without wishing to be bound by theory, it is believed that in one aspect the filtration region has excellent filtration properties because it is not interrupted by seams or adhesive and can be further improved by subjecting the meltblown layer to one or more corona treatments is subjected to, as explained in more detail below. For example, the present disclosure has demonstrated that the face mask removes at least about 70% or more of airborne particles having a size of about 0.65 microns or larger according to EN 13274-7 (using a sodium chloride aerosol with a particle size of 0.65 microns and a velocity of 95 liters/minute over a range of 100 cm), such as 75% or more, such as 80% or more, such as 85% or more, such as 90% or more of the particles having a size of about Can filter 0.65 microns or more.

Additionally, the present disclosure has demonstrated that the face mask has excellent filtration properties while maintaining good air permeability through the face mask. For example, the face mask may have an air permeability, as measured by ASTM D737 (2020, measured on a 38 cm ² sample and a pressure of 125 Pa), of about 20 ft ³ /m or greater, such as about 25 ft ³ /m or greater such as 30 ft ³ /m or more, such as 32.5 ft ³ /m or more, such as 35 ft ³ /m or greater, such as 40 ft ³ /m or greater, or any range or value in between. Therefore, the face mask according to the present disclosure not only provides good filtration properties but also offers increased comfort.

Additionally, in one aspect, one or more of the layers used to form the mask body 102 may have a design printed on an outwardly facing portion of the layer, or may be composed of colored or patterned fibers that impart a design or pattern to the face mask to lend.

However, exemplary polymers that can be used to form one or each of the two or more nonwoven webs may include olefins (e.g., polyethylene and polypropylenes), polyesters (e.g., polybutylene terephthalate, polybutylene naphthalate), polyamides (e.g nylons), polycarbonates, polyphenylene sulfides, polystyrenes, polyurethanes (e.g., thermoplastic polyurethanes), etc. In a particular aspect, the fibers of the nonwoven web material may comprise an olefin homopolymer. A suitable olefin homopolymer is a propylene homopolymer having a density of 0.91 grams per cubic centimeter (g/cc), a melt flow rate of 1200 g/10 minutes (230°C, 2.16 kg), a crystallization temperature of 113° C and a melting temperature of 156 °C and is available as METOCENE MF650X polymer from LyondellBasell Industries of Rotterdam, The Netherlands. Another suitable propylene homopolymer that can be used has a density of 0.905 g/cm3, a melt flow rate of 1300 g/10 minutes (230°C, 2.16 kg) and a melting temperature of 165°C and is known as Polypropylene 3962 available from Total Petrochemicals of Houston, Texas. Another suitable polypropylene is EXXTRAL™ 3155 available from ExxonMobil Chemical Company of Houston, Texas.

Additionally, various thermoplastic elastomeric and plastomeric polymers can be used in the nonwoven web material in the present disclosure, such as elastomeric polyesters, elastomeric polyurethanes, elastomeric polyamides, elastomeric copolymers, elastomeric polyolefins, and so on. In a particular aspect, elastomeric semi-crystalline polyolefins are used because of their unique combination of mechanical and elastomeric properties. Partially crystalline polyolefins have or can have an essentially regular structure. For example, semi-crystalline polyolefins can be essentially amorphous in their undeformed state, but form crystalline domains when stretched. The degree of crystallinity of the olefin polymer can be from about 3% to about 60%, in some aspects from about 5% to about 45%, in some aspects from about 5% to about 30%, and in some aspects from about 5% and about 15% . Likewise, the semi-crystalline polyolefin can have a latent heat of fusion (ΔHf), which is another indicator of the degree of crystallinity, from about 15 to about 210 joules per gram ("J/g"), in some aspects from about 20 to about 100 J /g, in some aspects from about 20 to about 65 J/g, and in some aspects from 25 to about 50 J/g. The semi-crystalline polyolefin can also have a Vicat softening temperature of from about 10°C to about 100°C, in some aspects from about 20°C to about 80°C, and in some aspects from about 30°C to about 60°C. The semi-crystalline polyolefin can have a melting temperature from about 20°C to about 120°C, in some aspects from about 35°C to about 90°C, and in some aspects from about 40°C to about 80°C. Latent heat of fusion (ΔHf) and melting temperature can be determined using differential scanning calorimetry ("DSC") according to ASTM D-3417, as is well known to those skilled in the art. The Vicat softening point can be determined in accordance with ASTM D-1525.

Exemplary semi-crystalline polyolefins include polyethylene, polypropylene, and blends and copolymers thereof. In a particular aspect, a polyethylene is used which is a copolymer of ethylene and an α-olefin such as a C3-C20 α-olefin or C3-C12 α-olefin. Suitable α-olefins can be linear or branched (e.g. one or more C1-C3 alkyl branches or an aryl group). Specific examples include 1-butene; 3-methyl-1-butene; 3,3-dimethyl-1-butene; 1-pentene; 1-pentene having one or more methyl, ethyl or propyl substituents; 1-hexene having one or more methyl, ethyl or propyl substituents; 1-heptene having one or more methyl, ethyl or propyl substituents; 1-octene having one or more methyl, ethyl or propyl substituents; 1-nonen having one or more methyl, ethyl or propyl substituents; ethyl, methyl or dimethyl substituted 1-decene; 1-dodecene and styrene. Particularly desirable alpha-olefin comonomers are 1-butene, 1-hexene and 1-octene. The ethylene content of such copolymers can range from about 60 mole percent up to about 99 mole percent, in some aspects from about 80 mole percent up to about 98.5 mole percent, and in some aspects from about 87 mole percent up to about 97 .5 mole %. The alpha-oleim content can similarly range from about 1 mole percent to about 40 mole percent, in some aspects from about 1.5 mole percent to about 15 mole percent, and in some aspects from about 2.5 mole percent to about 13 mol%.

The density of polyethylene can vary depending on the type of polymer used, but generally ranges from about 0.85 g/cc to about 0.96 g/cc. For example, polyethylene "plastomers" have a density ranging from about 0.85 g/cc to about 0.91 g/cc. Likewise, "linear low density polyethylene"("LLDPE") can have a density ranging from about 0.91 g/cc to about 0.94 g/cc; "Low Density Polyethylene"("LDPE") can have a density in the range of 0.91 g/cm3 to about 0.94 g/cm3 and "High Density Polyethylene"("HDPE") can have a density in the range of from about 0.94 g/cc to about 0.96 g/cc. Densities can be measured according to ASTM 1505.

Particularly useful polyethylene copolymers are those that are "linear" or "substantially linear". The term "substantially linear" means that the ethylene polymer contains long chain branches in the polymer backbone in addition to the short chain branches resulting from the incorporation of comonomers. "Long chain branching" refers to a chain length of at least 6 carbons. Each long chain branch can have the same comonomer distribution as the polymer backbone and be as long as the polymer backbone to which it is attached. Preferred substantially linear polymers are substituted with from 0.01 long chain branches per 1000 carbons to 1 long chain branch per 1000 carbons, and in some aspects from 0.05 long chain branches per 1000 carbons to 1 long chain branch per 1000 carbons. In contrast to the term "substantially linear", the term "linear" means that the polymer has no measurable or detectable long chain branching. That is, the polymer is substituted with an average of less than 0.01 long chain branches per 1000 carbons.

The density of a linear ethylene/α-olefin copolymer is a function of both the length and the amount of the α-olefin. That is, the greater the length of the alpha-olefin and the higher the amount of alpha-olefin present, the lower the density of the copolymer. Although not essential, linear polyethylene "plastomers" are particularly desirable because the level of short chain α-olefin branches is so high that the ethylene copolymer exhibits both plastic and elastomeric properties - i.e., is a "plastomer". Because polymerization with alpha-olefin comonomers reduces crystallinity and density, the resulting plastomer typically has a lower density than thermoplastic polyethylene polymers (e.g., LLDPE), but approaches and/or overlaps with that of an elastomer her. For example, the density of the polyethylene plastomer can be 0.91 g/cc or less, in some aspects from about 0.85 g/cc to about 0.88 g/cc, and in some aspects from about 0.85 g/cc to about 0.85 g/cc be about 0.87 g/cm3. Although elastomers are similar in density to elastomers, they generally have a higher degree of crystallization and can be formed into pellets that are non-sticking and relatively free-flowing.

The distribution of the alpha-olefin comonomer in a polyethylene plastomer is normally random and uniform among the various molecular weight fractions that make up the ethylene copolymer. This uniformity of comonomer distribution within the plastomer can be expressed by a Comonomer Distribution Breadth Index ("CDBI") of 60 or greater, in some aspects 80 or greater, and in some aspects 90 or greater. Further, the polyethylene plastomer may be characterized by a DSC melting point curve showing the occurrence of a single melting point peak occurring in the range of 50 to 110°C (second melt reduction).

Suitable plastomers for use in the present disclosure are ethylene-based copolymer plastomers available under the EXACT™ designation from ExxonMobil Chemical Company of Houston, Texas. Other suitable polyethylene-based plastomers are available under the designations ENGAGE™ and AFFINITY™ from the Dow Chemical Company of Midland, Michigan. An additional suitable polyethylene-based plastomer is an olefin block copolymer available from the Dow Chemical Company of Midland, Michigan under the trade designation INFUSE™, such as INFUSE™ 9807. A polyethylene that can be used in the fibers of the present disclosure is DOW™ 61800.41. Other suitable ethylene polymers are available from The Dow Chemical Company under the designations DOWLEX™ (LLDPE), ASPUN™ (LLDPE), and ATTANE™ (ULDPE). Other suitable ethylene polymers are disclosed in U.S. Patent Nos. 4,937,299 to Ewen et al., 5,218,071 to Tsutsui et al., 5,272,236 to Lai et al. and 5,278,272 to Lai et al. which are incorporated herein by reference in their entirety for all purposes.

Of course, the present disclosure is in no way limited to the use of ethylene polymers. For example, propylene polymers may also be suitable for use as the semi-crystalline polyolefin. Suitable propylene plastomeric polymers may include, for example, copolymers or terpolymers of propylene, which are copolymers of propylene with an α-olefin (e.g., C3-C20), such as Ethylene, 1-butene, 2-butene, the various pentene isomers, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-unidecene, 1-dodecene, 4-methyl-1-pentene, 4-methyl- 1-hexene, 5-methyl-1-hexene, vinylcyclohexene, styrene, etc. The comonomer content of the propylene polymer can be about 35% by weight or less, in some aspects from about 1% to about 20% by weight, and in some aspects from about 2% to about 10% by weight . Preferably, the density of the polypropylene (e.g., propylene/α-olefin copolymer) can be 0.91 grams per cubic centimeter (g/cc) or less, in some aspects from 0.85 to 0.88 g/cc and in some aspects from 0.85 g/cm3 to 0.87 g/cm3. Suitable propylene-based copolymer plastomers are commercially available under the designation VISTAMAXX™ (e.g., 2330, 6202, and 6102), a propylene-ethylene copolymer-based plastomer from ExxonMobil Chemical Co. of Houston, Texas; FINA™ (e.g. 8573) from Atofina Chemicals of Feluy, Belgium; TAFMER™, from Mitsui Petrochemical Industries; and VERSIFY™, available from Dow Chemical Co. of Midland, Michigan. Other examples of suitable propylene polymers are in US Patent Nos 6,500,563 to Datta, et al.; 5,539,056 to Yang, et al.; and 5,596,052 to Resconi, et al. which are hereby incorporated by reference in their entirety for all purposes.

A variety of known methods can generally be used to form the semi-crystalline polyolefins. For example, olefin polymers can be formed using a free radical or a coordination catalyst (e.g., Ziegler-Natta). Preferably, the olefin polymer from a complex-coordinative single-site catalyst, such as. B. a metallocene catalyst formed. Such a catalyst system produces ethylene copolymers in which the comonomer is randomly distributed within a molecular chain and distributed uniformly over the different molecular weight fractions. Metallocene-catalyzed polyolefins are, for example, in U.S. Patent Nos. 5,571,619 to McAlpin et al.; 5,322,728 to Davis et al.; 5,472,775 to Obijeski et al.; 5,272,236 to Lai et al.; and 6,090,325 to Wheat, et al. which are incorporated herein by reference in their entirety for all purposes. Examples of metallocene catalysts include bis(n-butylcyclopentadienyl)titanium dichloride, bis(n-butylcyclopentadienyl)zirconium dichloride, bis(cyclopentadienyl)scandium chloride, bis(indenyl)zirconium dichloride, bis(methylcyclopentadienyl)titanium dichloride, bis(methylcyclopentadienyl)zirconium dichloride, cobaltocene, cyclopentadienyltitanium trichloride, ferrocene, hafnocene dichloride, isopropyl(cyclopentadienyl,-1-flourenyl)zirconium dichloride, molybdocene dichloride, nickelocene, niobocene dichloride, ruthenocene, titanocene dichloride, zirconocene chloride hydride, zirconocene dichloride and so on. Polymers made using metallocene catalysts typically have a narrow molecular weight range. For example, metallocene catalyzed polymers can have polydispersity numbers (Mw/Mn) below 4, a controlled short chain branching distribution, and a controlled isotacticity.

The melt flow index (MI) of the semi-crystalline polyolefins can generally vary, but typically ranges from about 0.1 grams per 10 minutes to about 100 grams per 10 minutes, in some aspects from about 0.5 grams per 10 minutes to about 30 grams per 10 minutes and in some aspects from about 1 to about 10 grams per 10 minutes measured at 190°C. Melt flow index is the weight of polymer (in grams) that can be forced through an extrusion rheometer orifice (0.0825 inch diameter) when subjected to a force of 5000 grams in 10 minutes at 190°C and can be determined according to the ASTM test method D1238-E can be determined.

Although the elastomer has heretofore been discussed generally as a component of a fiber for a nonwoven fabric, it is to be understood that the fiber can contain both a core layer and a skin layer, with the core layer and skin layer being the same elastomer or different elastomer(s). may contain. For example, as discussed above, in one aspect, the core layer may contain a polyethylene-based copolymer elastomer (e.g., INFUSE™), while the outer layer may contain a polypropylene-based copolymer elastomer (e.g., VERSIFY™).

Additionally or alternatively, the core layer and outer layer may each be formed from either a propylene-based copolymer or an ethylene-based copolymer (or other elastomer discussed above), however, the core layer may be formed from a "medium" to "high" molecular weight elastomer while the outer layer is formed from a “low” molecular weight elastomer. In one aspect, the "medium" to "high" molecular weight of the elastomer can include, for example, a number average molecular weight of from about 10,000 g/mol to about 70,000 g/mol, such as about 12,500 g/mol to about 67,500 g/mol, such as about 15,000 g/mol. mol to about 65,000, such as about 17,500 g/mol to about 62,500 g/mol, such as about 20,000 g/mol to about 60,000 g/mol, or any ranges or values in between. In addition, a "low" molecular weight elastomer according to the present disclosure may have a number average molecular weight of from about 1,000 g/mol to about 10,000 g/mol, such as about 2,000 g/mol to about 9,000 g/mol, such as about 3,000 g/mol to about 8,000 g/mol, like about 4000 g/mol to about 7000 g/mol, such as about 4500 g/mol to about 6500 g/mol, or any range or value in between.

In one aspect, for example, the ratio of the average molecular weight of all the elastomer or elastomers in the core layer to the ratio of the average molecular weight of all the elastomer or elastomers in the outer layer can be from about 10:1 to about 1.1:1, such as 7.5:1 to about 1.5:1, such as about 5:1 to about 2:1, or any range or value in between. Without wishing to be bound by theory, the present disclosure has shown that by using a lower molecular weight elastomer in the outer layer compared to the core layer, an increase in stress forces during stretching that normally occurs when using a non-blocking outer layer can be avoided . Therefore, in one aspect, a lower molecular weight elastomer is used in the outer layer, which can further improve the elastic performance of the composition according to the present disclosure. Of course, other thermoplastic polymers can also be used to form nonwoven web material. For example, a substantially amorphous block copolymer having at least two blocks of a monoalkenyl arene polymer separated by at least one block of a saturated conjugated diene polymer can be used. The monoalkenyl arene blocks can be styrene and its analogs and homologues such as o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, p-methylstyrene, etc., as well as other monoalkenyl polycyclic aromatic compounds such as vinylnaphthalene, vinylanthrycene, and the like further, include. Preferred monoalkenyl arenes are styrene and p-methylstyrene. The conjugated diene blocks can include homopolymers of conjugated diene monomers, copolymers of two or more conjugated dienes, and copolymers of one or more of the dienes with another monomer in which the blocks consist predominantly of conjugated diene units. Preferably, the conjugated dienes contain 4 to 8 carbon atoms, such as 1,3-butadiene (butadiene); 2-methyl-1,3-butadiene; isoprene; 2,3-dimethyl-1,3-butadiene; 1,3-pentadiene (piperylene); 1,3-hexadiene; and so forth.

The amount of monoalkenyl arene blocks (e.g., polystyrene) can vary, but typically is from about 8% to about 55%, in some aspects from about 10% to about 35%, and in some aspects from about 25% to about 35% by weight of the copolymer. Suitable block copolymers can have monoalkenyl arene endblocks having a number average molecular weight of from about 5,000 to about 35,000 and saturated conjugated diene midblocks having a number average molecular weight of from about 20,000 to about 170,000. The total number average molecular weight of the block polymer can range from about 30,000 to about 250,000. Particularly suitable thermoplastic elastomeric block copolymers are available from Kraton Polymers LLC of Houston, Texas under the tradename KRATON™. KRATON™ polymers include styrene-diene block copolymers such as styrene-butadiene, styrene-isoprene, styrene-butadiene-styrene, and styrene-isoprene-styrene. KRATON™ polymers also include styrene-olefin block copolymers formed by the selective hydrogenation of styrene-diene block copolymers. Examples of such styrene-olefin block copolymers are styrene-(ethylene-butylene), styrene-(ethylene-propylene), styrene-(ethylene-butylene)-styrene, styrene-(ethylene-propylene)-styrene, styrene-( ethylene-butylene)-styrene (ethylene-butylene), styrene (ethylene-propylene)-styrene (ethylene-propylene), and styrene-ethylene (ethylene-propylene)-styrene. These block copolymers can have a linear, radial, or star molecular configuration. Specific KRATON™ block copolymers include products sold under the brand names G 1652, G 1657, G 1730, MD6673, MD6703, MD6716 and MD6973. Various suitable styrenic block copolymers are disclosed in U.S. Patent Nos. 4,663,220 , 4,323,534 , 4,834,738 , 5,093,422 and 5,304,599 which are hereby incorporated by reference in their entirety for all purposes. Other commercially available block copolymers include those available from Kuraray Company, Ltd. S-EP-S and SEEPS elastomeric copolymers available from Okayama, Japan under the trade designation SEPTON™.

Other suitable copolymers include SIS and SBS elastomeric copolymers available from Dexco Polymers of Houston, Texas under the trade designation VECTOR™. Also suitable are polymers composed of an ABAB tetrablock copolymer as described in US Pat. No. 5,332,613 to Taylor, et al. which is incorporated herein by reference in its entirety for all purposes. An example of such a tetrablock copolymer is a styrene-poly(ethylene-propylene)-styrene-poly(ethylene-propylene) block copolymer ("S-EP-S-EP") block copolymer.

Although elastomeric polymers have been described, a non-elastomeric polyolefin material, either alone or in combination with one or more of the above elastomers, can be used in the skin layer, the core layer, or in both the skin and core layers. For example, by using a non-elastomeric polyolefin material, a non-blocking outer layer can be formed which does not affect the elastic effectiveness of the composition takes. Thus, in one aspect, the non-elastic polyolefin can be generally non-elastic polymers such as conventional polyolefins (e.g., polyethylene), low density polyethylene (LDPE), Ziegler-Natta catalyzed linear low density polyethylene (LLDPE), etc., ultra low density polyethylene (ULDPE), polypropylene, polybutylene, etc.; polytetrafluoroethylene; polyester, e.g. e.g., polyethylene terephthalate (PET), etc.; polyvinyl acetate; polyvinyl chloride acetate; polyvinyl butyral; acrylic resins, e.g. B. polyacrylate, polymethyl acrylate, polymethyl methacrylate, etc.; polyamides, e.g. e.g. nylon; polyvinyl chloride; polyvinylidene chloride; polystyrene; polyvinyl alcohol; polyurethanes; polylactic acid; copolymers and blends thereof; and so on. For example, the outer layer(s) can include an LLDPE available from Dow Chemical Co. of Midland, Michigan, such as DOWLEX™ 2517 or DOWLEX™ 2047, or a combination thereof, or from Westlake Chemical Corp. of Houston, Texas. In addition, the non-blocking polyolefin material can be other suitable ethylene polymers such as those available from The Dow Chemical Company under the designations ASPUN™ (LLDPE) and ATTANE™ (ULDPE).

To form the fibers comprising the nonwoven web material, a single polymer as discussed above can be used in an amount up to 100% by weight based on the total weight of the nonwoven web material, for example from about 75% to about 99% by weight. - %, for example from about 80% to about 98% by weight, for example from about 85% to about 95% by weight. In other aspects, however, the nonwoven web material can also comprise two or more polymers from the polymers discussed above. For example, monocomponent fibers of which the nonwoven web material may include fibers composed of an olefin homopolymer in an amount ranging from about 5% to about 80%, such as about 10% to about 75%, by weight , such as from about 15% to about 70% by weight based on the total weight of the nonwoven material. Meanwhile, the fibers may also include a derivative of an olefin polymer. For example, the nonwoven web material can be an elastomeric semi-crystalline polyolefin or "plastomer" (e.g., an ethylene/alpha-olefin copolymer, a propylene/alpha-olefin copolymer, or a combination thereof), a thermoplastic elastomeric block copolymer, or a combination thereof in one Amount from about 20% to about 95%, such as about 25% to about 90%, such as about 30% to about 85% by weight based on the total weight of the Nonwoven web material include.

In additional aspects, the fibers from which the nonwoven web material is formed can be multicomponent fibers and can have a sheath-core configuration or a side-by-side configuration. For example, in a sheath-core multicomponent fiber assembly, the sheath may comprise a blend of a polypropylene and a polypropylene-based plastomer (e.g., VISTAMAXX™), while the core may comprise a blend of a polyethylene and a polyethylene-based plastomer (e.g., INFUSE™). may include. On the other hand, the sheath can include a blend of a polyethylene and a polyethylene-based plastomer (e.g., INFUSE™), while the core can include a blend of a polypropylene and a polypropylene-based plastomer (e.g., VISTAMAXX™). Furthermore, in still other aspects, the core may include 100% of a polyethylene or polypropylene homopolymer.

For example, in some aspects, the fibers from which the nonwoven web material is formed may have a sheath-core arrangement, with the sheath comprising about 20% to about 90%, such as about 25% to about 80%, by weight %, such as about 30% to about 70% by weight of an olefin homopolymer (e.g., polypropylene or polyethylene) based on the total weight of the sheath component of the multicomponent fiber. Meanwhile, the sheath can also contain from about 10% to about 80%, such as from about 20% to about 75%, such as from about 30% to about 70%, by weight of a plastomer olefin-based (e.g., a polypropylene-based plastomer or an ethylene-based plastomer) based on the total weight of the sheath component of the multicomponent fiber.

Additionally, the core can contain from about 30% to about 100%, such as from about 40% to about 95%, such as from about 50% to about 90%, by weight of an olefinic homopolymer (e.g., polypropylene or polyethylene) based on the total weight of the core component of the multicomponent fiber. Further, the core may comprise from about 0% to about 70%, such as from about 5% to about 60%, such as from about 10% to about 50% by weight of a plastomer olefin-based (e.g., a polypropylene-based plastomer or an ethylene-based plastomer) based on the total weight of the core component of the fiber.

Additionally, the weight percentage of the sheath may range from about 10% to about 70%, e.g., from about 15% to about 65%, e.g., from about 20% to about about 60% by weight based on the total weight of the fiber. Meanwhile can the weight percentage of the core in a range from about 30% to about 90% by weight, for example from about 35% to about 85% by weight, for example from about 40% to about 80% by weight .- % based on the total weight of the fiber. Additionally, the fibers from which the nonwoven web material is formed can have a side-by-side arrangement in which two fibers are coextruded adjacent to one another. In such an aspect, the first side may include a polyethylene and a polyethylene-based plastomer, while the second side may include a polypropylene and a polypropylene-based plastomer. The polyethylene may be present in the first side in an amount ranging from about 30% to about 90%, such as about 35% to about 80%, such as about 40% by weight. up to about 70% by weight based on the total weight of the first side. Meanwhile, the polyethylene-based plastomer can be present in the first side in an amount ranging from about 20% to about 80%, such as about 25% to about 70%, such as about 30%, by weight .-% to about 60% by weight based on the total weight of the first side. Additionally, the polypropylene in the second side can be present in an amount ranging from about 30% to about 90%, such as about 35% to about 80%, such as about 40% by weight. % to about 70% by weight based on the total weight of the second side. Meanwhile, the polypropylene-based plastomer can be present in the second side in an amount ranging from about 20% to about 80%, such as about 25% to about 70%, such as about 30%, by weight .-% to about 60% by weight based on the total weight of the second side.

In such fiber configurations as discussed above, in some aspects, a propylene-ethylene copolymer can be used in either the sheath and/or the core, or on the first side and/or the second side to act as a compatibilizer and the to improve the bond between the mantle and the core. For example, the propylene-ethylene copolymer can be present in the sheath in an amount ranging from about 0.5% to about 20%, such as about 1% to about 15%, such as 2% to about 10% by weight based on the total weight of the sheath. Alternatively, the propylene-ethylene copolymer may be present in the core in an amount ranging from about 0.5% to about 20%, such as about 1% to about 15%, such as 2% to about 10% by weight based on the total weight of the core.

Other additives may also be added to the nonwoven web material such as melt stabilizers, processing stabilizers, heat stabilizers, light stabilizers, antioxidants, heat aging stabilizers, whitening agents, antiblock agents, viscosity modifiers, etc. Viscosity modifiers such as polyethylene wax (e.g., EPOLENE™ C-10 from Eastman Chemical) be used.

Phosphite stabilizers (e.g., IRGAFOS available from Ciba Specialty Chemicals of Tarrytown, N.Y. and DOVERPHOS available from Dover Chemical Corp. of Dover, Ohio) are exemplary melt stabilizers. In addition, hindered amine stabilizers (e.g., CHIMASSORB from Ciba Specialty Chemicals) are exemplary heat and light stabilizers. In addition, hindered phenols are commonly used as antioxidants in the manufacture of films. Some suitable hindered phenols include those available from Ciba Specialty Chemicals under the tradename IRAGANOX™, such as IRGANOX™ 1076, 1010 or E 201. If used, such additives (e.g., antioxidants, stabilizers, etc.) each in an amount of about from 0.001% to about 25%, in some aspects from about 0.005% to about 20%, and in some aspects from 0.01% to about 15% by weight of the Nonwoven web material may be present.

If desired, a fatty acid derivative can also be used in the polymer composition, such as in a blend of ductile and rigid polymers, to achieve the desired level of ductility. Suitable fatty acid derivatives for use in the composition may include, for example, fatty acid amides, fatty acid esters, fatty acid salts, and so on. In a particular embodiment, the fatty acid derivative can be a fatty acid amide, for example. The fatty acid amide can be any suitable amide compound derived from the reaction between a fatty acid and ammonia or an amine containing compound (e.g. a compound containing a primary amine group or a secondary amine group). The fatty acid can be any suitable fatty acid, such as a C ₈ -C ₂₈ saturated or unsaturated fatty acid or a C ₁₂ -C ₂₈ saturated or unsaturated fatty acid. In certain embodiments, the fatty acid may be erucic acid (ie cis-13-docosanic acid), oleic acid (ie cis-9-octadecenoic acid), stearic acid (octadecanoic acid), behenic acid (ie docosanoic acid), arachidic acid (ie arachidic acid or eicosanoic acid), palmitic acid (ie hexadecanoic acid) and mixtures or combinations thereof. The amine containing compound can be any suitable amine containing compound such as fatty amines (e.g. stearylamine or oleylamine), ethylenediamine, 2,2'-iminodiethanol and 1,1'-iminodipropan-2-ol.

wobei
R₁₃, R₁₄, R₁₅, R₁₆ und R₁₈ unabhängig voneinander aus C₇-C₂₇-Alkylgruppen und C₇-C₂₇-Alkenylgruppen und in einigen Ausführungsformen aus C₁₁-C₂₇-Alkylgruppen und C₁₁-C₂₇-Alkenylgruppen ausgewählt sind;
R₁₇ ausgewählt ist aus C₈-C₂₈-Alkylgruppen und C₈-C₂₈-Alkenylgruppen und in einigen Ausführungsformen aus C₁₂-C₂₈-Alkylgruppen und C₁₂-C₂₈-Alkenylgruppen; und
R₁₉ ist -CH₂CH₂OH oder -CH₂CH(CH₃)OH.In particular, the fatty acid amide may be a fatty acid amide having the structure of one of formulas (I)-(V):

whereby
R ₁₃ , R ₁₄ , R ₁₅ , R ₁₆ and R ₁₈ are independently selected from C ₇ -C ₂₇ alkyl groups and C ₇ -C ₂₇ alkenyl groups and in some embodiments from C ₁₁ -C ₂₇ alkyl groups and C ₁₁ -C ₂₇ - alkenyl groups are selected;
R ₁₇ is selected from C ₈ -C ₂₈ alkyl groups and C ₈ -C ₂₈ alkenyl groups and in some embodiments from C ₁₂ -C ₂₈ alkyl groups and C ₁₂ -C ₂₈ alkenyl groups; and
R ₁₉ is -CH ₂ CH ₂ OH or -CH ₂ CH(CH ₃ )OH.

For example, the fatty acid amide may have the structure of formula (I) where R ₁₃ -CH ₂ (CH ₂ ) ₁₀ CH=CH(CH ₂ ) ₇ CH ₃ (erucamide), -CH ₂ (CH ₂ ) ₆ CH=CH( CH ₂ ) ₇ CH ₃ (oleamide), -CH ₂ (CH ₂ ) ₁₅ CH ₃ , -CH ₂ (CH ₂ ) ₁₉ CH ₃ or -CH ₂ (CH ₂ ) ₁₇ CH ₃ . In other embodiments, the fatty acid amide may have the structure of formula (II) where R ₁₄ is -CH ₂ (CH ₂ ) ₁₀ CH=CH(CH ₂ ) ₇ CH ₃ and R ₁₅ is -CH ₂ (CH ₂ ) _{I 5} CH ₃ , or where R ₁₄ is -CH ₂ (CH ₂ ) ₆ CH=CH(CH ₂ ) ₇ CH ₃ and R ₁₅ is -CH ₂ (CH ₂ ) ₁₃ CH ₃ . Also, in still other embodiments, the fatty acid amide may have the structure of formula (III) wherein R ₁₆ is CH ₂ (CH ₂ ) ₁₅ CH ₃ or -CH ₂ (CH ₂ ) ₆ CH=CH(CH ₂ ) ₇ CH ₃ . The composition can also contain a mixture of two or more such fatty acid amides.

If appropriate, fatty acid esters can also be used. Fatty acid esters can be obtained by oxidative bleaching of a raw natural wax and subsequent esterification of a fatty acid with an alcohol. The fatty acid may be a C ₈ -C ₂₈ fatty acid or a C ₁₂ -C ₂₈ saturated or unsaturated fatty acid as described above. The alcohol can have 1 to 4 hydroxyl groups and 2 to 20 carbon atoms. When the alcohol is multifunctional (e.g. 2 to 4 hydroxyl groups) a carbon number of 2 to 8 is particularly desirable. Particularly suitable multifunctional alcohols can be dihydric alcohol (e.g. ethylene glycol, propylene glycol, butylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol and 1,4-cyclohexanediol), trihydric alcohol (e.g. glycerin and trimethylolpropane), tetrahydric alcohols (e.g. pentaerythritol and erythritol), and so on. Furthermore, aromatic alcohols can be suitable, such as o-, m- and p-tolylcarbinol, chlorobenzyl alcohol, bromobenzyl alcohol, 2,4-dimethylbenzyl alcohol, 3,5-dimethylbenzyl alcohol, 2,3,5-cumobenzyl alcohol, 3,4,5-trimethylbenzyl alcohol, p-cuminyl alcohol, 1,2-phthalyl alcohol, 1,3-bis(hydroxymethyl)benzene, 1,4-bis(hydroxymethyl)benzene, pseudocumenyl glycol, mesitylene glycol and mesitylene glycerol. Fatty acid salts, such as are formed by deesterification of a fatty acid, can also be used to neutralize excess carboxylic acids and form a metal salt. The de-esterification can be carried out with a metal hydroxide, such as an alkali metal hydroxide (e.g. sodium hydroxide) or an alkaline earth metal hydroxide (e.g. calcium hydroxide). The resulting fatty acid salt typically comprises an alkali metal (e.g., sodium, potassium, lithium, etc.) or an alkaline earth metal (e.g., calcium, magnesium, etc.).

Regardless of the polymer(s) chosen, the material can be formed into monocomponent or multicomponent fibers and extruded or spun to form a nonwoven web used in a nonwoven web of the present disclosure. Monocomponent fibers can be formed from a polymer or a blend of polymers plus optional components that are blended and then extruded from a single extruder. Meanwhile, multicomponent fibers can be formed from two or more polymers (e.g., bicomponent fibers) extruded from separate extruders with one or more of the polymers blended with a tackifier may be used, although this is not required if one of the polymers has inherent tackiness, e.g. B. VISTAMAXX™ polymers and INFUSE™ polymers. The polymers can be arranged in substantially constantly positioned discrete zones across the cross-section of the fibers. The components can be arranged in any desired configuration, e.g. shell-core, side-by-side, pie-shape, island-in-a-sea, three-island, porthole, or various other arrangements known in the art, and so on. Various methods of forming multicomponent fibers are described in US Patent Nos 4,789,592 to Taniguchi et al. 5,336,552 to Strack et al., 5,108,820 to Kaneko, et al., 4,795,668 to Kruege, et al., 5,382,400 to Pike, et al., 5,336,552 to Strack, et al., and 6,200,669 to Marmon, et al. described in their entirety by reference for all purposes. Multicomponent fibers can also be formed with various irregular shapes as disclosed in US Patent Nos 5,277,976 to Hogle, et al., 5,162,074 to Hills, 5,466,410 to Hills, 5,069,970 to Largman, et al. and 5,057,368 to Largman, et al. , which are incorporated by reference in their entirety for all purposes. In addition, hollow fibers are also contemplated in the present disclosure. Such fibers can reduce the amount of polymer required as well as the basis weight of the resulting nonwoven web material. In addition, one or more nonwoven web layers may be post-bonded after formation. Typically, a patterned bonding technique (e.g., thermal point bonding, ultrasonic bonding, etc.) is used in which the nonwoven web material is fed into a nip defined by at least one patterned roller. For example, in thermal point bonding, a nip is typically formed between two rolls, at least one of which is patterned. In contrast, ultrasonic bonding typically involves forming a nip between a sonotrode and a patterned roller. Regardless of the technique chosen, the patterned roll includes a plurality of raised bonding elements to bond the nonwoven web material.

The size of the bonding elements can be specifically tailored to facilitate the formation of apertures in the nonwoven web material and to improve bonding between the fibers contained in the nonwoven web material. For example, the length dimension of the binding elements can be between about 300 and about 5000 microns, in some aspects between about 500 and about 4000 microns, and in some aspects between about 1000 and about 2000 microns. The width dimension of the binding elements can also range from about 20 to about 500 microns, in some aspects from about 40 to about 200 microns, and in some aspects from about 50 to about 150 microns. In addition, the "element aspect ratio" (the ratio of an element's length to its width) can range from about 2 to about 100, in some aspects from about 4 to about 50, and in some aspects from about 5 to about 20. The pattern of bonding elements is typically chosen such that the nonwoven web material has a total bond area of less than about 50% (as determined by conventional optical microscopic methods), in some aspects less than about 40%, and in some aspects less than about 25% . The bond density is also generally greater than about 50 bonds per square inch, and in some aspects from about 75 to about 500 needle bonds per square inch. A suitable weave pattern for use in the present disclosure is known as an "S-weave pattern" and is described in US Pat U.S. Patent No. 5,964,742 to McCormack, et al. which is incorporated herein by reference in its entirety for all purposes. S-weave patterns typically have a bond element density of from about 50 to about 500 bonds per square inch, and in some aspects from about 75 to about 150 bonds per square inch. Another suitable binding pattern is known as "rib knit" and is described in U.S. Patent No. 5,620,779 to Levy, et al. which is incorporated herein by reference in its entirety for all purposes. Rib knit patterns typically have a bond element density of from about 150 to about 400 bonds per square inch, and in some aspects from about 200 to about 300 bonds per square inch. Another suitable pattern is the "wire mesh" pattern, which has a bond element density of from about 200 to about 500 bond elements per square inch, and in some aspects from about 250 to about 350 bond elements per square inch. Other bond patterns that can be used in the present disclosure are in US Patent Nos 3,855,046 to Hansen et al., 5,962,112 to Haynes et al., 6,093,665 to Sayovitz et al., D375,844 to Edwards et al., D428,267 to Romano et al. and D390,708 to Brown, which are incorporated herein by reference in their entirety for all purposes.

Choosing an appropriate bonding temperature (e.g., the temperature of a heated roll) helps melt or soften the nonwoven web material in the regions adjacent the bonding elements. The softened nonwoven web material can then flow and be displaced during bonding, for example by the pressure exerted by the bonding elements. Bonding temperature and pressure can be selectively controlled to achieve bonding without significant softening of the polymer(s) of the nonwoven web material. For example, one or more rollers heated to a surface temperature of from about 50°C to about 160°C, in some aspects from about 60°C to about 140°C, and in some aspects from about 70°C to about 120°C. Likewise, the pressure exerted by the rollers during thermal bonding ("nip pressure") can range from about 75 to about 600 pounds per linear inch (about 1339 to about 10,715 kilograms per meter), in some aspects from about 100 to about 400 pounds per linear inch (about 1786 to about 7143 kilograms per meter), and in some aspects from about 120 to about 200 pounds per linear inch (about 2143 to about 3572 kilograms per meter). It is understood that the dwell time of the materials can have an impact on the parameters used for binding.

Regardless of the polymers or process chosen, the filter portion of the mask body with two or more layers can have a basis weight of from about 5 g/m ² (ie, grams per square meter) to about 100 g/m ² . For example, the seamless web material of the filter portion may have a basis weight in the range of about 10 g/m ² to about 75 g/m ² , such as about 15 g/m ² to about 70 g/m ² , such as about 20 g/m ² to about 60 g/m ² , such as about 25 g/m ² to about 50 g/m ² , or any range or value in between.

Regardless of the material chosen, the top elastic portion, the bottom elastic portion, the first mask body layer, and the second mask body layer can be laminated together. Lamination can be accomplished using a variety of techniques such as adhesive, thermal point bonding, ultrasonic bonding, and so on. The particular bonding pattern is not critical to the present invention. A suitable weave pattern is known, for example, as an "S-weave pattern" and is described in U.S. Patent No. 5,964,742 to McCormack, et al. described. Another suitable binding pattern is known as "rib knit" and is described in U.S. Patent No. 5,620,779 to Levy, et al. described. Another suitable pattern is the "wire mesh" pattern, which has a bond density of from about 200 to about 500 bond sites per square inch, and in some embodiments from about 250 to about 350 bond sites per square inch. Of course, other bonding patterns can also be used, as described in US Patents Nm. 3,855,046 to Hansen et al.; 5,962,112 to Haynes et al.; 6,093,665 to Sayovitz et al.; D375,844 to Edwards, et al.; D428,267 to Romano et al.; and D390,708 to Brown. Additionally, a bond pattern similar to the spunbonded web described above and containing bond regions generally oriented in the machine direction and having a size, aspect ratio, and/or configuration as described above may also be used. For example, the binding regions can have an aspect ratio of from about 2 to about 100, in some embodiments from about 4 to about 50, and in some embodiments from about 5 to about 20.

As discussed above, the present disclosure may further include a method of forming a face mask according to the present disclosure. In particular, the present disclosure has shown that a face mask can be formed in a highly efficient manner and it is therefore possible to produce about 400 or more face masks per minute, such as 450 face masks or more, such as 500 face masks or more, such as 550 face masks or more such as 600 face masks or more, such as 650 face masks or more, such as 700 face masks or more, such as 750 face masks or more, such as 800 face masks or more per minute.

In particular, with reference to 4 , a roll 200 may be unwound in the machine direction (MD) to provide a first layer 202 of the two or more layers that make up the mask body 102. FIG. It is understood that the layer 202 can also be formed linearly in one aspect. However, as illustrated, the elastic members 204 can be unfolded and placed in a top region 206 and a bottom region 208 of the first layer 202 such that the elastic members 204 are generally parallel to the machine direction. It is understood that, as mentioned above, the elastic elements 204 can also be used in a non-linear arrangement. Adhesive 210 can be applied to the elastic members 204 and/or to the first layer 202 . However, the second layer 212 can be unwound from the roll 214 in the machine direction. Of course, as mentioned above, the second layer 212 can also be formed linearly. However, an adhesive 210 may be applied to the second layer 212 which may be the same as or different from the adhesive applied to the elastic members 204 .

In one aspect, the second layer 212 is the meltblown layer and may be subjected to an electrostatic charging step 216 . In particular, as discussed above, the present disclosure has shown that the filtration properties of the face mask can be further improved by subjecting the meltblown layer to a corona treatment. Surprisingly, however, the present disclosure has shown that the meltblown layer is linear (e.g. after unwinding but before lamination). Heretofore, it has been assumed that the corona treatment must be performed prior to web winding, for example during formation of the meltblown web. Therefore, in one aspect, the method of the present disclosure includes taking an untreated meltblown or SMS nonwoven web, linearly unwinding the web during formation of the face mask, and electrostatically treating the nonwoven web during formation of the mask. However, it will be appreciated that in one aspect the meltblown web or SMS web may have been previously electrostatically treated.

Nevertheless, as in 4 As shown, the first layer 202, the elastic members 204, and the second layer 212 are laminated together during the laminating step 218. FIG. As previously discussed, in one aspect, the first layer 202 and second layer 204 can be stretched during lamination with the elastic members 204 such that the resulting composite is considered "stretch-bonded" and a laminate 218 has a gathered appearance. Regardless, thermal bonding techniques can be used to laminate the first and second layers to the elastic members. For example, one or both of the rollers may be used, which may contain a plurality of raised bonding elements and/or may be heated. In one aspect, upon lamination, the layers may be fusion bonded at a plurality of regions, as described above.

In one aspect, as in 4 1, the band(s) 222 may be formed adjacent the top region 206 of the mask body 102 and subjected to a slitting step 220, however, cuts are made in the laminate generally parallel to the machine direction to form the one or more bands 222 from the laminate 218 that will form the mask body 102. However, it should be understood that in one aspect, the tape(s) 222 may be formed separately and inserted during the seaming step 224. FIG.

Still, as in the second line of 4 1, the mask body laminate 218 and the tape(s) 222 are combined by one or more seaming steps 224, wherein the seams are formed generally perpendicular to the machine direction. As discussed above, seaming may include pressure bonding, ultrasonic bonding, thermal bonding, or the like. However, as previously discussed, the tape(s) 222 and laminate 218 may enter the seaming step 224 in a stretched configuration (e.g., stretched in the machine direction by one or more rollers or other stretching mechanism) to provide good stretch and fit to achieve. For example, the present disclosure has shown that such a method results in a tension of the strap(s) of about 100 grams*force (gf) or greater, such as 110 gf or greater, such as 120 gf or greater, as measured in accordance with STM-00070. such as 130 gf or greater, such as 135 gf or greater, or any range or value in between.

Regardless of the seam formed, a seam may be formed at a leading edge of each mask and at a trailing edge of each mask, the leading edge and/or the trailing edge corresponding to a first side 116 or a second side 118, as described above in 1-3 described. In this way, the seams can be formed in the laminate while the laminate is running through the line in the machine direction.

Additionally, the present disclosure has demonstrated that the seaming step 224 forms a seam having a bond strength measured in accordance with STM-00090 of about 1 kilogram*force (kgf) or greater, such as 1.25 kgf or greater, such as 1.5 kgf or more, such as 1.75 kgf or more, such as about 2 kgf or more, such as up to about 3 kgf, or any ranges or values in between. In particular, the present disclosure has demonstrated that such a bond strength allows the strap or straps of the face mask to be stretched over the user's head without disturbing the seams, but also allows the user to unpick the seam when removing the face mask e.g. if the face mask should not be put on again after it has been removed.

Regardless, the face mask 100 may then undergo bonding 226 and cutting 228 (e.g., cutting generally perpendicular to the machine direction) to separate the individual face masks 100 from the laminate. Although the invention has been described in detail with reference to specific embodiments, it is understood that those skilled in the art, once aware of the foregoing, would readily suggest modifications, variations, or equivalents to these embodiments can think up. Accordingly, the scope of the present invention should be evaluated as that of the appended claims and any equivalents thereof.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US63028889B[0001]
• US4340563 [0019]
• US3849241A [0020]
• US4937299 [0046]
• US6500563 [0047]
• US5571619A [0048]
• US4663220 [0053]
• US4323534A [0053]
• US4834738A [0053]
• US5093422A [0053]
• US5304599A [0053]
• US5332613A [0054]
• US4789592 [0068]
• US5277976 [0068]
• US5964742A [0069, 0072]
• US5620779A [0069, 0072]
• US3855046 [0069]

Claims (20)

Barrier face mask comprising: comprising a mask body formed from one or more nonwoven web layers a seamless filter part, an upper elastic part, and a lower elastic part; at least one elastic band, each elastic band being attached to a first side and a second side of the mask body. face mask after claim 1 wherein the mask body further comprises at least two layers, and wherein one or more of the layers is formed from a nonwoven meltblown web. face mask after claim 1 or 2 wherein the meltblown nonwoven web has been electrostatically treated. A face mask according to any one of the preceding claims, wherein the face mask filters 70% or more of particles 0.65 microns or larger in size. A face mask according to any one of the preceding claims wherein the mask body comprises a spunbonded nonwoven layer and a meltblown nonwoven layer. The face mask of any preceding claim, wherein the mask body comprises a spunbond-meltblown-spunbond layer and a nonwoven meltblown layer. A face mask as claimed in any preceding claim, wherein the upper elastic portion, the lower elastic portion or both the upper elastic portion and the lower elastic portion are sandwiched between first and second nonwoven layers of the mask body. The face mask of any preceding claim, wherein the top elastic portion, the bottom elastic portion, or both the top elastic portion and the bottom elastic portion are laminated to the one or more nonwoven web layers. A face mask according to any one of the preceding claims, wherein the at least one elastic band is formed from the same elastic material as the upper elastic part, the lower elastic part or both the upper elastic part and the lower elastic part. A face mask according to any one of the preceding claims, wherein the face mask comprises at least two straps. A face mask according to any one of the preceding claims, wherein the mask body has a length of from about 200 millimeters to about 350 millimeters when stretched. The face mask of any preceding claim, wherein the at least one elastic band has a length of from about 200 millimeters to about 350 millimeters when stretched. The face mask of any preceding claim, wherein the at least one elastic band has a width of from about 25 millimeters to about 75 millimeters when stretched. A face mask according to any one of the preceding claims, wherein the face mask has an air permeability according to ASTM D737 of about 20 ft ³ /m or greater. A method of forming a face mask, comprising: forming a laminate comprising unwinding a first nonwoven web, arranging one or more elastic members in an upper region, a lower region, or both an upper and lower region, unwinding a second nonwoven web, and laminating the first nonwoven web, one or more elastic members and the second nonwoven web; attaching one or more tapes to the laminate, each tape attached to a leading edge and an opposite trailing edge of the laminate; wherein the one or more tapes are attached to the laminate during an in-line process. procedure after claim 15 wherein the one or more tapes are cut from the laminate before the tapes are attached to the laminate. Procedure according to one of Claims 15 or 16 wherein the second nonwoven web is a meltblown nonwoven web and the method includes unwinding a virgin meltblown web and subjecting the virgin meltblown web to an electrostatic treatment prior to laminating the meltblown web to the first nonwoven web and the one or more elastic members. Procedure according to one of Claims 15 until 17 wherein the first nonwoven web is a spunbonded web or a spunbonded-meltblown-spunbonded web. Procedure according to one of Claims 15 until 18 wherein an adhesive is applied to the one or more elastic members. Procedure according to one of Claims 15 until 19 wherein the laminate, the one or more tapes, or both the laminate and the one or more tapes during lamination, attachment of the one or more tapes, or both lamination and attachment of the one or more tapes in be kept in a stretched state.

Images