Maintenance-free anti-fog respirator

Patent metadata

Field	Value
Publication number	US-9770611-B2
Application number	US-74371607-A
Country	US
Kind code	B2
Filing date	May 3, 2007
Priority date	May 3, 2007
Publication date	Sep 26, 2017
Grant date	Sep 26, 2017

Abstract

A respirator 10 that includes a harness 14 and a mask body 12 that is air permeable. The mask body 12 has a sinus region 40 and a primary filtering region 44 and comprises at least one nonwoven fibrous webs, which web includes a layer of filter media. The sinus region 40 of the mask body 12 exhibits a resistance to airflow that is greater than the primary filtering region 44 . This resistance to airflow is achieved through an alteration of the intrinsic structure of the plurality of nonwoven fibrous layers in the sinus region 40 without adding additional material to the mask body. The alteration of the intrinsic structure assists in preventing eyewear fogging.

First claim

What is claimed is:

1. A maintenance-free respirator that comprises:
(a) a harness; and
(b) a mask body that includes a sinus region and a primary filtering region and that comprises at least one nonwoven fibrous web, the at least one nonwoven fibrous web including a filtration layer, wherein at least a portion of the sinus region of the mask body has had an alteration to its intrinsic structure to significantly increase the pressure drop across the sinus region, the increase in pressure drop being achieved through an alteration to the intrinsic structure of the at least one nonwoven fibrous web without adding additional material or items to the mask body in the sinus region, and wherein the alteration of the intrinsic structure occurs over 5 to 25% of the total surface area of the sinus region and does not occur substantially outside the sinus region.

2. The respirator of claim 1 , wherein the alteration of the intrinsic structure comprises a series of spot welds.

3. The respirator of claim 2 , wherein the spot welds are created through application of heat and pressure to the nonwoven fibrous web(s) in the sinus region.

4. The respirator of claim 2 , wherein the spot welds are evenly spaced in a predetermined arrangement.

5. The respirator of claim 1 , wherein the mask body comprises a plurality of layers, and the intrinsic structure of the mask body is altered by bonding the plurality of layers together.

6. The respirator of claim 5 , wherein the mask body further comprises a predetermined pattern welded into portions of the sinus region.

7. The respirator of claim 6 , wherein the predetermined pattern is repeating.

8. The respirator of claim 6 , wherein the predetermined pattern comprises a trademark.

9. The respirator of claim 6 , wherein the predetermined pattern is symmetrical about a plane that bisects the mask body.

10. The respirator of claim 1 , wherein the pressure drop across the sinus region is greater than the pressure drop across the primary filtering region.

11. The respirator of claim 1 , wherein the pressure drop across the sinus region or a part thereof has been increased from about 10 to 100% by altering the intrinsic structure.

12. The respirator of claim 1 , wherein the alteration to the intrinsic structure in the sinus region causes the sinus region to exhibit a pressure drop greater than the pressure exhibited in the primary filtering region.

13. A mask body that comprises a sinus region and a primary filtering region and that comprises at least one nonwoven fibrous web, the at least one nonwoven fibrous web including a filtration layer, wherein at least a portion of the sinus region of the mask body has had an alteration to its intrinsic structure to significantly increase the pressure drop across the sinus region, the increase in pressure drop being achieved through an alteration to the intrinsic structure of the at least one nonwoven fibrous web without adding additional material or items to the mask body in the sinus region, and wherein the alteration of the intrinsic structure occurs over 5 to 25% of the total surface area of the sinus region and does not occur substantially outside the sinus region.

14. A maintenance-free respirator that comprises:
(a) a harness; and
(b) a mask body that includes a plurality of panels, including an upper panel, and has a sinus region in the upper panel and a primary filtering region and that comprises at least one nonwoven fibrous web, the at least one nonwoven fibrous web including a filtration layer, wherein at least a portion of the sinus region of the mask body has had an alteration to its intrinsic structure to significantly increase the pressure drop across the sinus region, the increase in pressure drop being achieved through an alteration to the intrinsic structure of the at least one nonwoven fibrous web without adding additional material or items to the mask body in the sinus region, and wherein the alteration of the intrinsic structure occurs over 5 to 25% of the total surface area of the sinus region.

15. The respirator of claim 14 , wherein the alteration of the intrinsic structure comprises a series of spot welds in the upper panel.

16. The respirator of claim 15 , wherein the spot welds are created through application of heat and pressure to the nonwoven fibrous web(s) in the sinus region.

17. The respirator of claim 16 , wherein the spot welds are evenly spaced in a predetermined arrangement.

18. The respirator of claim 14 , wherein the mask body further comprises a predetermined repeating pattern welded into portions of the sinus region of the upper panel, and wherein the predetermined pattern is symmetrical about a plane that bisects the upper panel.

19. A maintenance-free respirator that comprises:
(a) a harness; and
(b) a mask body that includes a plurality of panels, including an upper panel, and has a sinus region in the upper panel and a primary filtering region and that comprises at least one nonwoven fibrous web, the at least one nonwoven fibrous web including a filtration layer, wherein at least a portion of the sinus region of the mask body has had an alteration to its intrinsic structure to significantly increase the pressure drop across the sinus region relative to the primary filtering region, the increase in pressure drop being achieved through an alteration to the intrinsic structure of the at least one nonwoven fibrous web without adding additional material or items to the mask body in the sinus region, wherein the alteration of the intrinsic structure causes the sinus region to exhibit a pressure drop greater than the pressure drop exhibited by the primary filtering region, and wherein the alteration of the intrinsic structure occurs over 5 to 25% of the total surface area of the sinus region.

Assignees

• Facer John M
• Wilson Audra A
• Henderson Christopher P
• 3M Innovative Properties Co

Inventors

• Facer John M
• Wilson Audra A
• Henderson Christopher P

Classifications

• A41D13/11 Primary

  Protective face masks, e.g. for surgical use, or for use in foul atmospheres (eye-masks A61F9/04 {; hoods affording protection against heat or harmful chemical agents A62B17/04}) · CPC title

• A41D2400/52

  Disposable · CPC title

• A62B18/02

  Masks (gas-masks for animals A62B18/06; masks for welders A61F9/06) · CPC title

• A41D13/1115

  with a horizontal pleated pocket · CPC title

• A41D27/245

  made by welding or gluing (joining of plastics by welding or gluing B29C65/00; sewing machines for concurrently making thread and welded seams D05B17/00; thermal or chemical fixing of seams and hems D06M) · CPC title