A facemask having one or more nanofiber layers

Abstract

Facemasks and methods utilizing nanofibers are provided. The facemask and methods provided reduce pressure drop and enhance filtration of airborne particles. In one embodiment there is a facemask, comprising: an inner layer comprising non-woven fiber material configured to contact a wearer's nose and mouth; a middle layer disposed on the inner layer and comprising a nanofiber material; an outer layer disposed on the middle layer and comprising nonwoven fiber material, the facemask having upper and lower edges and at least one pleat configured to fit over a chin of the wearer when unfolded, the at least one pleat configured for folding and unfolding the facemask such that when folded the facemask is configured to assume a generally flat storage configuration and when unfolded the facemask is configured to cover at least the nose and mouth of the wearer.

What is claimed is: 
     
         1 . A facemask, comprising: an inner layer comprising nonwoven fiber material configured to contact a wearer's nose and mouth; a middle layer disposed on the inner side of the outer layer and comprising a nanofiber material; an outer layer disposed on the middle layer and comprising nonwoven fiber material, the outer layer configured to contact an external environment, the facemask having upper and lower edges and at least one pleat disposed between at least the upper and lower edges and configured to fit over a chin of the wearer when unfolded, the at least one pleat configured for folding and unfolding the facemask such that when folded the facemask is configured to assume a generally flat storage configuration and when unfolded the facemask is configured to cover at least the nose and mouth of the wearer. 
     
     
         2 . A facemask according to  claim 1 , wherein the nanofiber material of the middle layer is coated on the inner layer and/or outer layer in one or more discrete coatings. 
     
     
         3 . A facemask according to  claim 1 , wherein the nanofiber material is disposed on a nonwoven, spunbond fiber layer of the middle layer. 
     
     
         4 . A facemask according to  claim 1 , wherein each nanofiber of the nanofiber material has a diameter comprising at least about 150 times smaller than the diameter of each fiber of nonwoven fiber material. 
     
     
         5 . A facemask according to  claim 1 , wherein the nanofibers layer comprises a metal organic framework disposed on the nanofiber layer. 
     
     
         6 . A facemask according to  claim 1 , wherein the nanofiber material is hydrophilic or hydrophobic and draws moisture away from the inner and/or outer layer. 
     
     
         7 . A facemask according to  claim 1 , wherein the outer, middle, and/or inner layer comprises an antimicrobial agent. 
     
     
         8 . A facemask according to  claim 1 , wherein the nanofiber material increases in hydrophilicity or hydrophobicity in a direction from the inner layer to the middle layer such that a moisture concentration gradient is formed between the inner layer and middle layer with the inner layer having the least moisture and the middle layer having the most moisture when the mask is worn. 
     
     
         9 . A facemask according to  claim 1 , further comprising a malleable stiffening member attached to or within the facemask proximate to the upper edge, the malleable stiffening member configured to conform the inner layer to at least a nose portion and a cheek portion of the face of the wearer. 
     
     
         10 . A facemask according to  claim 9 , wherein the malleable stiffening member comprises a bend portion indicating at least the inner layer and the nose portion of the facemask by having a portion of the facemask elevated when the facemask is in the folded storage configuration and the facemask comprises a means for securing the facemask to the wearer's face. 
     
     
         11 . A facemask according to  claim 9 , further comprising a second malleable stiffening member attached to or within a lower edge of the facemask, the second malleable stiffening member configured to conform the facemask to at least a chin portion and a jaw portion of the face of the wearer, the second malleable stiffening member being smaller in length than the malleable stiffening member. 
     
     
         12 . A facemask according to  claim 11 , wherein the second malleable member comprises a bend portion indicating at least the inner layer and the chin and/or jaw portion of the facemask by having a portion of the facemask elevated when the facemask is in the folded storage configuration. 
     
     
         13 . A facemask according to  claim 12 , wherein the malleable stiffening member is pre-crimped to conform to the nose and cheek portion of the wearer, and the second malleable stiffening member is pre-crimped to conform to the chin and jaw portion of the face of the wearer. 
     
     
         14 . A facemask according to  claim 1 , wherein the facemask comprises a temperature, moisture, and/or pathogen collector disposed on the outer, inner, or middle layer. 
     
     
         15 . A facemask according to  claim 5 , wherein the facemask comprises an antimicrobial disposed in or on one or more layers. 
     
     
         16 . A facemask according to  claim 14 , wherein the collector comprises a removable nanofiber strip. 
     
     
         17 . A method of reducing pressure differential in a facemask, the method comprising: providing an inner layer comprising nonwoven fiber material configured to contact a wearer's nose and mouth; a middle layer disposed on the inner layer or inner side of outer layer and comprising a nanofiber material; an outer layer disposed on the middle layer and comprising nonwoven fiber material, the outer layer configured to contact an external environment, the facemask having upper and lower edges and at least one pleat disposed between at least the upper and lower edges and configured to fit over a chin of the wearer when unfolded, the at least one pleat configured for folding and unfolding the facemask such that when folded the facemask is configured to assume a generally flat storage configuration and when unfolded the facemask is configured to cover at least the nose and mouth of the wearer. 
     
     
         18 . A method according to  claim 17 , wherein each nanofiber of the nanofiber material has a diameter comprising at least about 150 times smaller than the diameter of each fiber of nonwoven fiber material. 
     
     
         19 . A method according to  claim 17 , further comprising a malleable stiffening member attached to or within the facemask proximate to the upper edge, the malleable stiffening member configured to conform the inner layer to at least a nose portion and a cheek portion of the face of the wearer. 
     
     
         20 . A method according to  claim 19 , further comprising a second malleable stiffening member attached to or within a lower edge of the facemask, the second malleable stiffening member configured to conform the facemask to at least a chin portion and a jaw portion of the face of the wearer, the second malleable stiffening member being smaller in length than the malleable stiffening member. 
     
     
         21 . A method of enhancing filtration efficiency of airborne particles in a facemask, the method comprising: providing an inner layer comprising nonwoven fiber material configured to contact a wearer's nose and mouth; a middle layer disposed on the inner layer and comprising a nanofiber material; an outer layer disposed on the middle layer and comprising nonwoven fiber material, the outer layer configured to contact an external environment, the facemask having upper and lower edges and at least one pleat disposed between at least the upper and lower edges and configured to fit over a chin of the wearer when unfolded, the at least one pleat configured for folding and unfolding the facemask such that when folded the facemask is configured to assume a generally flat storage configuration and when unfolded the facemask is configured to cover at least the nose and mouth of the wearer. 
     
     
         22 . A method according to  claim 21 , wherein each nanofiber of the nanofiber material has a diameter comprising at least about 150 times smaller than the diameter of each fiber of nonwoven fiber material. 
     
     
         23 . A method according to  claim 21 , further comprising a malleable stiffening member attached to or within the facemask proximate to the upper edge, the malleable stiffening member configured to conform the inner layer to at least a nose portion and a cheek portion of the face of the wearer. 
     
     
         24 . A method according to  claim 23 , further comprising a second malleable stiffening member attached to or within a lower edge of the facemask, the second malleable stiffening member configured to conform the facemask to at least a chin portion and a jaw portion of the face of the wearer, the second malleable stiffening member being smaller in length than the malleable stiffening member. 
     
     
         25 . A method of making a facemask, the method comprising providing an inner layer comprising nonwoven fiber material configured to contact a wearer's nose and mouth; disposing a middle layer on the inner layer, the middle layer comprising a nanofiber material; disposing an outer layer on the middle layer, the outer layer comprising nonwoven fiber material, the outer layer configured to contact an external environment; and forming at least one pleat disposed between upper and lower edges of the facemask, the at least one pleat configured to fit over a chin of the wearer when unfolded, the at least one pleat configured for folding and unfolding the facemask such that when folded the facemask is configured to assume a generally flat storage configuration and when unfolded the facemask is configured to cover at least the nose and mouth of the wearer. 
     
     
         26 . A method according to  claim 25 , further comprising attaching a malleable stiffening member to or within the facemask proximate to the upper edge, and conforming the malleable stiffening member to at least a nose portion and a cheek portion of the face of the wearer. 
     
     
         27 . A method according to  claim 26 , further comprising attaching a second malleable stiffening member to or within the lower edge of the facemask; conforming the second malleable stiffening member to at least a chin portion and a jaw portion of the face of the wearer, the second malleable stiffening member being smaller in length than the malleable stiffening member; and packing the facemask. 
     
     
         28 . A stack of facemasks, each face mask comprising: an inner layer comprising nonwoven fiber material configured to contact a wearer's nose and mouth; a middle layer disposed on the inner layer and comprising a nanofiber material; an outer layer disposed on the middle layer and comprising nonwoven fiber material, the outer layer configured to contact an external environment, the facemask having upper and lower edges and at least one pleat disposed between at least the upper and lower edges and configured to fit over a chin of the wearer when unfolded, the at least one pleat configured for folding and unfolding the facemask such that when folded the facemask is configured to assume a generally flat storage configuration and when unfolded the facemask is configured to cover at least the nose and mouth of the wearer. 
     
     
         29 . A stack of facemasks according to  claim 28 , wherein each face mask further comprises a malleable stiffening member attached to or within the facemask proximate to the upper edge, the malleable stiffening member configured to conform the inner layer to at least a nose portion and a cheek portion of the face of the wearer and each facemask is stacked so that each malleable stiffening member is stacked substantially parallel to each other so that the inner layer of the facemasks all face in the same direction. 
     
     
         30 . A stack of facemasks according to  claim 29 , wherein each face mask further comprises a second malleable stiffening member attached to or within the facemask proximate to the lower edge, the second malleable stiffening member configured to conform the inner layer to at least a chin portion and a jaw portion of the face of the wearer; and each facemask is stacked so that each second malleable stiffening member is stacked substantially parallel to each other so that the inner layer of the facemasks all face in the same direction. 
     
     
         31 . A stack of facemasks according to  claim 29 , wherein each malleable stiffening member comprises a concave portion that is stacked on top of one another so that the inner layer of the facemasks all face in the same direction. 
     
     
         32 . A stack of facemasks according to  claim 30 , wherein each second malleable stiffening member comprises a concave portion that is stacked on top of one another so that the inner layer of the facemasks all face in the same direction.