Protective cover assembly having improved Z-strength
View Patent ↗A protective cover assembly is disclosed that comprises a porous expanded membrane having a plurality of pores, a first surface and a second surface opposite the first surface. The porous expanded membrane comprises an active area and a bonded area. The bonded area comprises an adhesive material that forms a bridge extending through the plurality of pores in the bonded area from the first surface to the second surface. The adhesive material in the bonded area improves the Z-strength and allows the porous expended membrane to be a lightweight material having a mass/area ratio of less than or equal to 3 g/m 2 .
1. A protective cover assembly comprising a porous expanded membrane having a plurality of pores, a first surface and a second surface opposite the first surface, wherein the porous expanded membrane comprises an active area and a bonded area, wherein the bonded area comprises an adhesive material that forms a bridge extending through the plurality of pores in the bonded area from the first surface to the second surface, and wherein there is no backing layer adjacent to the porous expanded membrane.
2. The assembly of claim 1 , wherein the adhesive material does not extend beyond a plane of the first surface.
3. The assembly of claim 1 , wherein a distance between the first surface and the second surface is less than or equal to 20 microns.
4. The assembly of claim 1 , further comprising at least one releasable liner adjacent to the first surface or the second surface.
5. The assembly of claim 4 , wherein a first peel strength of the bonded area is greater than a second peel strength of the active area.
6. The assembly of claim 4 , wherein a first peel strength of the bonded area is greater than or equal to 1×10 8 Pa.
7. The assembly of claim 1 , wherein the porous expanded membrane has a mass/area ratio of less than or equal to 3 g/m 2 .
8. The assembly of claim 1 , wherein the porous expanded membrane has a mass/area ratio from 0.2 q/m 2 to 3 g/m 2 .
9. The assembly of claim 1 , wherein the porous expanded membrane comprises an expanded fluoropolymer or an expanded polyolefin.
10. The assembly of claim 1 , wherein the adhesive material has a tan delta at 10 −2 rad/s of greater than or equal to 0.4.
11. The assembly of claim 1 , wherein the adhesive material comprises an acrylic, polyamide, polyacrylamide, polyester, polyolefin, polyurethane, or polysilicone.
12. The assembly of claim 1 , wherein at least 10% of the plurality of pores in the bonded area comprise an adhesive material.
13. The assembly of claim 1 , wherein the plurality of pores remain open when the porous expanded membranes is compressed.
14. An electronic device, comprising:
a housing having an opening therein,
an acoustic transducer positioned in the housing near to the opening, and
the protective cover assembly of claim 1 positioned covering the opening.
15. A protective cover assembly comprising a porous expanded membrane having a plurality of pores, wherein the porous expanded membrane comprises an active area and a bonded area, wherein at least 10% of the plurality of pores in the bonded area comprise an adhesive material, wherein there is no backing layer adjacent to the porous expanded membrane.
16. The assembly of claim 15 , wherein a first peel strength of the bonded area is greater than a first peel strength of the active area.
17. The assembly of claim 15 , wherein a first peel strength of the bonded area is greater than or equal to 1×10 8 Pa.
18. The assembly of claim 15 , wherein the porous expanded membrane has a mass/area ratio of less than or equal to 3 g/m 2 .
19. The assembly of claim 15 , wherein the porous expanded membrane has a mass/area ratio from 0.2 q/m 2 to 3 g/m 2 .
20. The assembly of claim 15 , wherein the porous expanded membrane comprises an expanded fluoropolymer or an expanded polyolefin.
21. The assembly of claim 15 , wherein the adhesive material has tan delta at 10 −2 rad/s of greater than or equal to 0.4.
22. The assembly of claim 15 , wherein the adhesive material comprises an acrylic, polyamide, polyacrylamide, polyester, polyolefin, polyurethane, or polysilicone.
23. The assembly of claim 15 , wherein the porous expanded membrane has a first surface and a second surface opposite the first surface; and the adhesive material forms a bridge from one of the first or second surface of the porous expanded membrane to the opposing surface.
24. The assembly of claim 15 , wherein at least 70% of the plurality of pores in the bonded area comprise the adhesive material.
25. The assembly of claim 15 , wherein less than 1% of the plurality of pores in the active area comprise the adhesive material.
26. An electronic device comprising
a housing having an opening therein,
an acoustic transducer positioned in the housing near to the opening, and
the protective cover assembly of claim 15 positioned covering the opening.