Patent Application
20230292858
The present invention relates generally to systems and methods for securing protective face coverings. More specifically, the present invention relates to systems and methods that allow a disposable respirator or face mask to be secured to the head of a user while simultaneously assuring a tight fit and high wearing comfort. Intended applications include medical and consumer-grade face masks for preventing airborne transmission of bacterial and viral pathogens and respiratory protective equipment for protection against airborne particulate matter.
For a face mask to function properly, an effective seal to the front or sides of the face must be formed. This is typically accomplished by pulling the mask body against the front and sides of the face through tensioned elements anchored at either the back of the ears or the back of the head or neck. The tensioned elements may take the form of elastic or non-elastic bands, straps, loops, strings or ties. They may be made from elastic bands, fabric-covered elastic bands, fabric straps, cotton strings, etc. Tensioning may be accomplished through tying, the elasticity of the tensioning element, or by controlling the length of the elements, or some combination, wherein shorter tensioning elements create a higher tension and a better mask seal against the face.
Gaps around the periphery of masks can be a leakage source, wherein particles may pass around filtering or covering elements unobstructed and significantly reduce the efficacy of the face mask. Many current face mask designs for medical or industrial applications may have open gaps between the mask and the wearer's face in the cheek, nose/infraorbital and chin regions. These gaps are potential direct routes to a wearer's respiratory system for undesired bioaerosols, microdroplets, or particles. In addition, leakage on the either side of a wearer's nose frequently occurs and contributes to fogging on a wearer's goggles or spectacles. Proper tensioning of the straps is essential for appropriate mask functioning.
Tensioning elements in most current face masks utilize either dual ear loops or head straps. Ear loops create tension on each side of the mask by extending from each mask side over the back of the ear on the corresponding side. These rely on the top and back sides of the ear as the anchor for tensioning. Alternatively, head straps extend from both sides of the mask and pass around the back of the head or neck. Head straps are typically either elastic bands, which must be pulled over the top of the head, or ties, which may be passed around each side of the head and tied in the back.
Masks with ear loops are popular because they are inexpensive and are relatively easy to don and doff. They do not require pulling of elastic straps over the top of the head or tying of strings at the back of the head, which may be difficult for some users with spectacles or long hair. Because of their low cost and ease of use, many inexpensive disposable masks use ear loops, including surgical masks, KN95 masks, KF94 masks, etc. There are several designs for the N95 respirator, which resemble KN95, KF94 designs, but come in different sizes for various face sizes and utilize elastic head straps. The most common N95 respirator 3M 1860 (3M, Maplewood, MN, USA) has a domed shape. All these disposable mask designs are comprised of typically at least 3 layers of material. The outer layer is hydrophobic to protect from liquid penetration, the center is a filter layer to trap microbes, aerosols, droplets, etc. and the inner layer is a soft material for comfort against the skin. For disposable masks, each of the three layers are typically made from a polypropylene material, although several other materials such as cotton, cellulose or other synthetics may be used.
In one alternative design of a disposable mask, a fourth flap layer is used as an additional layer on the inside face of the mask. This layer has a hole in the center, which encircles the mouth of the user, and is sealed, welded, or otherwise secured around the mask periphery. The function of this flap layer is to allow user exhalations through the center of the hole of the flap layer and help trap any escaping air, aerosols, droplets, etc. that might otherwise leak through gaps between the user's face and mask proximate the mask edges.
When using masks with ear loops, the constant force against the back of one's ears, over a long period of use, can cause discomfort, skin irritation, and pain on the wearer's skin. Thus, for long wearing periods, head straps are often preferred.
So called “ear savers,” for example from www.Amazon.com, can provide relief to posterior ear irritation by pulling the ear loops off the back of the ears. These are typically short fabric, elastomeric or plastic bands that are positioned behind the head and have hooks or other securing means at each of their two ends for attaching to the ear loops. By pulling both ear loops off the back of the ears, they may relieve the irritation caused by ear loop tension over extended periods of time. They also have the additional feature of making the mask more secure and less likely to fall off if the ear loops come off the back of the ears. They further allow for more convenient temporary doffing, during say eating or drinking activities. Because ear savers and similar head straps secure the mask around the back of the head, the mask may be pulled downward off the face and hang under the chin, while still being secured around the neck area. Unfortunately, ear savers require users to carry the devices with them if they are to be used with masks they may wish to don and are thus not always convenient.
Previous systems have been reported that combine ear loops with an optional head band. Emery US2020/0229520 A1 discloses a strap that hooks to the ear loops of a conventional disposable surgical mask. Qu et al. US2019/0269183 A1 disclose ear straps that include an integral connector at the back of the ears. The connector allows for the latching of a separate, optional head strap which may be used to pull the ear loops off the back of the ears.
Previous systems that utilize some version of a head strap to be optionally used with a mask incorporating ear loops require users to carry a separate head strap, which may be inconvenient. None includes an optional integral head strap.
In accordance with the present disclosure, there is provided a mask and mask securing system comprising both a set of ear loops for securing the mask around the back of the ears and an integral head strap to be optionally used to secure the mask around the back of the head or neck. The present disclosure also includes integral ear loop tensioning elements.
In one embodiment, one or more layers of a mask have an extended perforated portion that may be optionally torn off to be used as a head strap. In a mask with a fourth flap layer, as previously described, the perforated head strap section may be at the bottom of the mask, thereby keeping it out of the way of the main mask body and the normal functioning of the mask. Although we describe the junction of the head strap with the mask body as being perforated, it should be recognized that any number of separable attachment systems, such as partially cut material, adhesives, welding, snaps, zippers, etc., may be used to connect the head strap feature, and thus the term “perforated” should not be considered as any specific method or geometry of separable attachment.
In another embodiment of the mask, each end of a perforated head strap ends may include a feature or device to attach to the ear loops.
In yet another embodiment of the mask, the ear loop attachment device at each end of the head strap may include a way of shortening the effective length of the ear loops, thereby increasing their tension when the head strap is placed behind the head.
In another and alternative embodiment, a device that provides way of shortening the effective length of the ear loops is attached to the mask body and separate from the perforated head strap.
In another and alternative embodiment, the ear loop attachment device may also include a tensioning feature that may be used to shorten the effective length of the ear loops while the head strap is still attached to the mask body, thereby increasing the tension of the ear loops when the ear loops are extended behind the ears and without detaching the head strap. Such a tensioning feature may have a dual function, where it may also be used to shorten the effective length of the ear loops when the head strap is detached and extended behind the neck or head.
In another and alternative embodiment, the ear loop attachment device may include a hook or similar connecting feature, allowing the user to optionally connect the attachment device to the ear loops or to choose not to connect the feature to the ear loops.
In another and alternative embodiment, the ear loop attachment device may include a channel or hole that surrounds the ear loop and requires no additional attachment steps by the user to capture the ear loops with the head strap.
In yet a further and alternative embodiment, the hook, channel or hole that secures the ear loop may include a tensioning feature that may be used to shorten the effective length of the ear loops, thereby increasing the tension of the ear loops either without detaching the head strap when the ear loops are extended behind the ears or when the head strap is detached and extended behind the neck or head.
In another embodiment, an ear loop tensioning feature may be fabricated from a thin material that includes a slit or other feature to cinch the ear loop in one or more places.
The present invention relates to a disposable mask comprised of elastic ear loops to secure the mask body over the mouth, nose and chin and an optional head strap that is integral to the mask. The present invention also relates to devices and methods for adjusting the force in tensioned elements used to secure any type of mask to the face. The terms mask, face mask, and respirator are used interchangeably herein and refer to any type of covering over portions of or the entire face. Such coverings may be fabric, plastic, rubber, paper, synthetic, etc. and may be either flexible or rigid. A mask body, as referred to herein, is the main functional area of the mask comprising the filter, covering or masking element and is not inclusive of the elements securing the mask to the face. The terms outer, outside, front, outward all refer to the surface of the mask that is facing away from the face and the terms inner, inside, rear, back and inward all refer to the surface of the mask that is facing towards the face.
Although many of the embodiments above describe the integrated head strap as being a perforated portion of a fourth layer of a mask, it should be understood that integrated head straps may be part of any layer of a mask, or several layers that have been combined together, as long as the head-strap portion of the mask may be separated across a perforation or other means of detachment.
An objective of the current invention is to allow a user to choose the method of anchoring a mask to the user's face through ear loops or a head strap without the need for auxiliary devices. It is another objective of the current invention to provide a simple, low-cost system for altering the tension of mask ear loops. It is a further objective to provide a single tensioning system that may be used to both adjust the tension when the mask is anchored behind the ears, or adjust the tension when anchored behind the head or neck. It is yet another objective to allow a user to transition from a mask anchored from behind the ears to a mask anchored from behind the head or neck without requiring the user to perform a connection step between the ear loops and a head strap.
The present invention overcomes the limitations of previous systems and incorporates an optional head strap into the design of an ear-loop-based mask as a single element, thereby enabling users to choose between modes of mask anchoring without auxiliary devices.
The present invention also describes an integral ear loop tensioning element, which does not require ancillary devices.
Other details of the face mask with ear loops, ear loop tensioning devices and an integral head strap providing dual methods of mask securing as well as methods of tensioning ear loops of any mask are set forth in the following detailed description and the accompanying drawings wherein like reference numerals depict like elements.
The current invention involves a face mask 10 that comprises a mask body 11, two ear loops 12, an integral and separable head strap 13 and two ear-loop-tension adjusters 14. It is an improvement over other currently available mask systems which are anchored by either a set of ear loops or a set of head straps, but do not give the user a choice of one or the other without an auxiliary device.
The lowest cost and most widely used mask today is the disposable surgical style mask. This style of mask typically has three layers of thin polypropylene material with a weight of about 20-30 grams per square meter (gsm). The outer layer is a non-woven spunbond layer, the middle layer is a melt blown, electrically charged filter layer and the outside is another non-woven spunbond layer.
The primary method for fabricating a disposable surgical mask involves the use of high-speed automated machinery. The manufacturing steps using such machinery is typically broken into multiple modules. The mask body 11 is initially formed from continuous webs of material, welded to secure the multiple layers, then cut to singulate the mask bodies 11 from the continuous webs. In a subsequent automated machinery module, the ear loops 12 are cut from a continuous length of elastic material, then ultrasonically welded to the four corners 20 of the mask body 11. The ear loop 12 ends may be welded to either the inside surface or outside surface of the mask body 11.
An additional layer 22 may be added to the mask body 11 in a subsequent step to the body 11 being formed and welded. The additional layer 22 may have a number of functions including serving as a flap to help trap droplets and aerosols during exhalations. The addition of the additional layer 22 may occur prior to or subsequent to the addition of the ear loops 12 to the mask body.
In addition to connecting the integrated head strap 23 to the ear loops 12, the trapping pieces 31 shown in
When attached to a mask, tensioners 40, 45 should be placed proximate the upper or lower edges of the mask near the corners. If the tensioners 40, 45 are placed too far from these edges, for example towards the center of the side edges, then passing the ear loops 12 or head straps through the tensioners 40, 45 may distort the shape of the mask and not allow it to sit flush to the face.
Although described as a system for adjusting the tension of ear loops, the tensioners may also be used as a way to adjust the tension of any type of securing band, such as conventional elastic head straps that are incorporated into masks, such as an N95-style mask. A “securing band” is defined as any type of tensioning element, band, loop, ear loop, string, strap, etc. used to secure a face mask against the face.
There has been provided a face mask system with ear loops and integral head strap providing dual methods of mask securing. While the mask system has been described in the context of specific embodiments thereof, other unforeseen alternatives, modifications, and variations may become apparent to those skilled in the art having read the foregoing description. Accordingly, it is intended to embrace those alternatives, modifications, and variations which fall within the broad scope of the appended claims.
