Vacuum storage bags are typically constructed from multiple components, with an overall design centered on three core functions: sealing, pressure resistance, and air extraction. The outer layer generally consists of a thick PE or PA composite plastic film; these materials offer the necessary toughness and tensile strength to withstand repeated vacuuming or the pressure of stacking without rupturing.
The bag opening is a critical structural element, usually featuring a dual-track or multi-track sealing zipper. Pressing the sealing strip firmly shut creates an initial airtight seal, preventing air from re-entering after the vacuum process. Some products also incorporate a sliding clip outside the zipper to reinforce the seal, ensuring greater stability and reliability.
The air extraction valve is another core component; it typically employs a one-way design that allows air to be drawn out of the bag while preventing backflow. When connected to a suction device-such as a hand pump or vacuum cleaner-the valve facilitates the rapid expulsion of air, creating a negative-pressure environment that compresses the contents.
Structurally, the bag body is usually formed through a multi-layer lamination process, balancing flexibility with airtightness. High-end models may also incorporate puncture-resistant or thickened materials to enhance long-term durability, meeting the demands of repeated storage and multiple vacuum cycles.