Push-in earplug

Patent metadata

Field	Value
Publication number	US-9737439-B2
Application number	US-201213547177-A
Country	US
Kind code	B2
Filing date	Jul 12, 2012
Priority date	Jul 12, 2012
Publication date	Aug 22, 2017
Grant date	Aug 22, 2017

Abstract

A push-in earplug including an elongate core and outer layer is disclosed. The outer layer includes a sound attenuating portion having a first average density and a stem portion having a second average density, and the second average density is greater than the first average density.

First claim

What is claimed is:

1. An earplug comprising:
an elongate core comprising a first material and having first and second ends and an outer major surface; and
an outer layer comprising a second material and covering at least a portion of the outer major surface of the elongate core;
wherein the second material comprises expandable spheres including thermoplastic shells encapsulating a gas and the outer layer comprises a sound attenuating portion having a first average density ρ1 and a stem portion having a second average density ρ2, and |ρ2>1.2 ρ1|, and further wherein the second material of the stem portion comprises the expandable spheres including the thermoplastic shells encapsulating the gas.

2. The earplug of claim 1 , wherein |ρ2>1.5 ρ1|.

3. The earplug of claim 1 , wherein ρ1 is between 100 kg/m 3 and 180 kg/m 3 .

4. The earplug of claim 1 , wherein ρ2 is between 200 kg/m 3 and 300 kg/m 3 .

5. The earplug of claim 1 , wherein the outer layer is thermally bonded to at least a portion of the outer major surface of the elongate core.

6. The earplug of claim 1 , wherein an adhesive is not present between the outer major surface of the elongate core and the outer layer.

7. The earplug of claim 1 , wherein the second material comprises a thermoplastic.

8. The earplug of claim 1 , wherein the second material comprises styrene-ethylene-butylene-styrene (SEBS) having a molecular weight between 100,000 Daltons and 200,000 Daltons.

9. The earplug of claim 1 , wherein the second material comprises at least 2% weight of a chemical foaming agent.

10. The earplug of claim 1 , wherein the second material comprises a thermoset polymer.

11. The earplug of claim 1 , wherein the second material comprises an EPDM rubber.

12. The earplug of claim 1 , wherein the first material is selected from the group consisting of polypropylene and styrene-ethylene-butylene-styrene (SEBS).

13. The earplug of claim 1 , wherein the outer layer comprises a contiguous layer.

14. The earplug of claim 1 , wherein the outer layer extends from the first end of the elongate core to the second end of the elongate core.

15. The earplug of claim 1 , wherein the first and second ends of the elongate core are at least partially exposed.

16. The earplug of claim 1 , wherein the elongate core has a cross-section that is uniform at any location between the first and second ends of the elongate core.

17. The earplug of claim 1 , wherein the elongate core includes a channel extending from the first end to the second end.

18. An earplug according to claim 1 , wherein the elongate core comprises multiple layers, wherein at least one layer of the elongate core facilitates thermal bonding with the outer layer of the earplug.

19. An earplug comprising:
an elongate core comprising a first material and having first and second ends and an outer major surface; and
an outer layer comprising a second material and covering at least a portion of the outer major surface of the elongate core, wherein the outer layer forms a sound attenuating portion and a stem portion, wherein an average density of the stem portion is greater than an average density of the sound attenuating portion;
wherein the second material comprises thermoplastic shells encapsulating a gas at the sound attenuating portion and at the stem portion.

20. The earplug of claim 19 , wherein the second material comprises styrene-ethylene-butylene-styrene (SEBS) having a molecular weight between 100,000 Daltons and 200,000 Daltons.

21. The earplug of claim 19 , wherein the outer layer is thermally bonded to at least a portion of the outer major surface of the elongate core.

22. The earplug of claim 19 , wherein the second material comprises a thermoplastic.

23. The earplug of claim 19 , wherein the second material comprises a thermoset polymer.

24. The earplug of claim 19 , wherein the second material comprises an EPDM rubber.

25. The earplug of claim 19 , wherein the first material is selected from the group consisting of polypropylene and styrene-ethylene-butylene-styrene (SEBS).

26. The earplug of claim 19 , wherein the outer layer comprises a contiguous layer.

27. The earplug of claim 19 , wherein the outer layer extends from the first end of the elongate core to the second end of the elongate core.

28. The earplug of claim 19 , wherein the first and second ends of the elongate core are at least partially exposed.

29. The earplug of claim 19 , wherein the elongate core includes a channel extending from the first end to the second end.

30. An earplug according to claim 19 , wherein the elongate core comprises multiple layers, wherein at least one layer of the elongate core facilitates thermal bonding with the outer layer of the earplug.

31. An earplug comprising:
an elongate core comprising a first material and having first and second ends and an outer major surface; and
an outer layer comprising a second material and thermally bonded to at least a portion of the outer major surface of the elongate core;
wherein the second material comprises thermoplastic shells encapsulating a gas and the outer layer comprises a sound attenuating portion having a first average density ρ1 and a stem portion having a second average density ρ2, and |ρ2>1.2 ρ1|, the outer layer comprises a contiguous layer and extends from the first end of the elongate core to the second end of the elongate core, and wherein the thermoplastic shells encapsulating a gas are present at the sound attenuating portion and at the stem portion.

32. An earplug according to claim 31 , wherein the elongate core comprises multiple layers, wherein at least one layer of the elongate core facilitates thermal bonding with the outer layer of the earplug.

Assignees

• Endle James P
• Hamer Jeffrey L
• Seville Alan R
• Teeters Kenneth F
• 3M Innovative Properties Co

Inventors

• Endle James P
• Hamer Jeffrey L
• Seville Alan R
• Teeters Kenneth F

Classifications

• C08J2203/184

  of chemical foaming agent and physical blowing agent, e.g. azodicarbonamide and fluorocarbon · CPC title

• B29C44/08

  using several expanding {or moulding} steps · CPC title

• B29C44/022

  Foaming unrestricted by cavity walls, e.g. without using moulds or using only internal cores · CPC title

• B29K2105/04

  cellular or porous · CPC title

• B29C44/507

  extruding the compound through an annular die (in general B29C48/03) · CPC title