MAINTENANCE-FREE ANTI-FOG RESPIRATOR

• US 20080271737A1
• Filed: 05/03/2007
• Published: 11/06/2008
• Est. Priority Date: 05/03/2007
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Wilson, Audra A., Facer, John M., Henderson, Christopher P.
• Granted Patent: US 9,770,611 B2
• Time in Patent Office: Days
• US Class Current: 128/205.25
• CPC Class Codes: A41D 13/11 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 Class Codes: A41D 13/1115 with a horizontal pleated pocket
• CPC Class Codes: A41D 13/1161 Means for fastening to the user's head
• CPC Class Codes: A62B 18/025 Halfmasks A62B23/02 takes precedence; surgical face masks A41D13/11
• CPC Class Codes: A62B 23/025 the filter having substantially the shape of a mask surgical face masks A41D13/11

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.

Claims

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.

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 alteration of the intrinsic structure occurs over 1 to 100% of the total surface area of the sinus region.

6. The respirator of claim 1, wherein the alteration of the intrinsic structure occurs over 2 to 50% of the total surface area of the sinus region.

7. The respirator of claim 1, wherein the alteration of the intrinsic structure occurs over 5 to 25% of the total surface area of the sinus region.

8. 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.

9. The respirator of claim 8, wherein the mask body further comprises a predetermined pattern welded into portions of the sinus region.

10. The respirator of claim 9, wherein the predetermined pattern is repeating.

11. The respirator of claim 9, wherein the predetermined pattern comprises a trademark.

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

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

14. 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.

15. 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.