Molded respirator having outer cover web joined to mesh

Patent metadata

Field	Value
Publication number	US-10245537-B2
Application number	US-201213465827-A
Country	US
Kind code	B2
Filing date	May 7, 2012
Priority date	May 7, 2012
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

A respirator 10 that has a mask body 12 and a harness 14 that is attached to the mask body 12. The mask body 12 includes a filtering structure 18 that has an inner cover web 40a, an outer cover web 40b that comprises melt-blown fibers and staple fibers, and a filtration layer 42 that is located between the inner and outer cover webs 40a, 40b. The mask body 12 also has a mesh 20 that is joined to the outer cover web 40b. A respirator having this construction is more resistant to inward collapse of the filter media during breathing and is more aesthetically pleasing.

First claim

What is claimed is:

1. A method of making a filtering face-piece respirator, which method comprises:
(a) providing filtering pre-form that comprises an inner cover web and a filtration layer;
(b) providing a combined structure that has a molded plastic mesh joined to an outer cover web; and
(c) inserting the filtering pre-form into the molded plastic mesh and welding the pre-form to the combined structure at least at the perimeter.

2. The method of claim 1 , further comprising electrically charging microfibers of the outer cover web.

3. The method of claim 1 , wherein the molded plastic mesh is laminated to the outer cover web.

4. The method of claim 1 , wherein welding the pre-form to the combined structure comprises ultrasonically bonding the pre-form to the combined structure at least at the perimeter.

5. The method of claim 1 , wherein the outer cover web is coextensive and in intimate contact with the molded plastic mesh over the whole mask body inward from the perimeter.

6. The method of claim 1 , wherein providing the filtering pre-form comprises:
disposing the inner cover web on two layers of filter media to form a three-layer laminate;
folding the three-layer laminate in half along a fold to form a six-layer stacked laminate structure, wherein the filter media provides outer layers of the stacked laminate structure;
bonding the stacked laminate structure together to form a bond and the filtration layer;
removing portions of the inner cover web and filter media between the bond and the fold; and
unfolding the stacked laminate structure to provide the pre-form.

7. The method of claim 6 , wherein the bond comprises a sinusoidal wave form bond.

8. The method of claim 1 , wherein the mesh contains cells that each have a hexagonal shape.

9. The method of claim 1 , wherein the mesh has a hexagonal or octagonal pattern.

10. The method of claim 1 , wherein the mesh has a hexagonal pattern.

11. The method of claim 10 , wherein each hexagon occupies an area of 20 to 40 square millimeters.

12. The method of claim 11 , wherein the mesh comprises strands that have an average cross-sectional area of 0.2 to 3.2 mm 2 .

13. The method of claim 1 , wherein the molded plastic mesh and melt-blown fibers of the outer cover web contain polypropylene.

14. The method of claim 1 , wherein the outer cover web comprises melt-blown fibers and staple fibers, the melt-blown fibers comprising a polymeric material that has a first melting point.

15. The method of claim 14 , wherein the plastic mesh contains a polymeric material that has a second melting point similar to the first melting point.

16. The method of claim 15 , wherein the first melting point is 130 to 170° C.

17. The method of claim 16 , wherein the second melting point is 130 to 170° C.

18. The method of claim 15 , wherein the first and second melting points are within 10° C. or less of each other.

19. The method of claim 1 , wherein the filtration layer comprises sorptive materials disposed between fibers of the filtration layer.

20. The method of claim 1 , wherein the filtering pre-form further comprises a sorptive layer.

Assignees

• Angadjivand Seyed A
• Brandner John M
• Nguyen Nhat Ha T
• 3M Innovative Properties Co

Inventors

• Angadjivand Seyed A
• Brandner John M
• Nguyen Nhat Ha T

Classifications

• B29L2031/14

  Filters {(optical filters B29L2011/0066, sieves or screens B29L2031/737)} · CPC title

• B01D2239/065

  More than one layer present in the filtering material · CPC title

• B29C66/545

  one hollow-preform being placed inside the other · CPC title

• B29L2031/4835

  Masks · CPC title

• A62B23/025

  the filter having substantially the shape of a mask (surgical face masks A41D13/11) · CPC title