Washable thermoplastic elastomer foam and articles incorporating same
US10940045B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Aug 2, 2016 |
| Grant date | Mar 9, 2021 |
| Priority date | — |
| Expiry date | Aug 12, 2038 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2995/0097
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A thermoplastic elastomer (TPE) foam having a soft open-cell inner layer and a washable closed-cell outer layer which surrounds and substantially seals the inner layer, and which may be used alone or in combination with other components to produce useful articles. The TPE foam includes a base resin which is a styrenic block copolymer, and a foaming agent. A process of forming and molding the TPE foam includes using a shutoff nozzle to prevent the foaming agent from activating before reaching the mold cavity, using an oversized gate to minimize shear heat, and using oversized vents. An earplug may be constructed by molding the TPE foam over a core or body formed from a material which is denser than the TPE foam. A first earplug design may employ a constrained layer damping effect, while a second earplug design may employ an adjustable sound attenuation effect.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.