Understanding a Four-Layer Shielding Bag
A shielding bag combines layers with different roles. Review the finished construction and test evidence rather than judging shielding from surface resistance alone.
4-layer structure of shielding bag
Swipe the table horizontally to see all columns.
The source product description lists PET, an aluminium layer, CPP and an anti-static treatment. The exact layer order and material grades should be confirmed for the proposed bag.
| Element | Role to confirm |
|---|---|
| PET film | Mechanical support and outer-surface protection |
| Metallic layer | Part of the shielding structure |
| CPP or another seal layer | Heat sealing and bag construction |
| Anti-static surface treatment | Low-charging or dissipation properties for the specified surface |
Thickness, metallic-layer continuity, seams and closure condition can all affect the finished package. Request the electrical and shielding results for that construction.
·Selection steps·
Step-by-Step Guide
- 01
Confirm shielding need
Shielding bags block external ESD fields. For internal static dissipation, anti-static bags suffice.
- 02
Pick the right resistivity range
Verify shielding bag resistivity in 10⁹–10¹¹ Ω per ANSI/ESD STM 11.11-2021 — note that industry labels can confuse this with anti-static grade.
- 03
Sealing is part of shielding
Shielding bags must be fully sealed (zip or heat seal); an open bag breaks the Faraday cage.
·Frequently asked questions·
Frequently Asked Questions
01 Is a thicker shielding bag always better?
No. Evaluate shielding, mechanical strength, seams and closures together for the actual application.
02 Does the quoted resistance range establish shielding?
No. Confirm the resistance test and the applicable shielding test separately.
03 Can shielding bags be reused?
Reuse depends on condition, contamination, seams, closures and the customer’s procedure. Inspect and requalify where required rather than assuming a fixed number of uses.
References and scope
- Aspirature ESD Product Manual 2024
- ANSI/ESD STM 11.11-2021
Discuss your packaging requirements
Send dimensions, quantities and the intended application to discuss samples and a quotation.
