📌 Core Principle of the Unidirectional Breathable Structure
The key feature of breathable aluminum foil lies in its internal one-way valve membrane (also known as a waterproof breathable membrane). This membrane is typically welded into the aluminum foil layer and is designed to allow internal gases (such as carbon dioxide) to escape under specific pressure conditions, while blocking external air, moisture, or contaminants from entering.
Unidirectional Flow Mechanism:
This principle relies on the micro-porous structure and elastic design of the membrane. When internal pressure builds up, the pores open to release gas; when external pressure is applied, the membrane automatically closes. This forms a "one-way out, no way in" protective barrier.