# Vacuum packaging Remove air using a controlled process while separately specifying barrier film, seals, product support, and moisture or corrosion protection. Reviewed: 2026-11-01 Tags: delivery, packaging, moisture-control **Illustrative pressure load.** assume ambient pressure is 100 kPa absolute and the sealed interior initially reaches 10 kPa absolute. The initial differential is 90 kPa. Acting uniformly over an idealized supported area of 0.01 m², `force = pressure difference × area` gives `90,000 Pa × 0.01 m² = 900 N`. Real bag contact, product geometry, deformation, and changing internal pressure determine the actual load distribution. This calculation flags a load to evaluate; it is not a strength rating or allowable vacuum for a part. Henkovac's **04-series V2019 manual** separates chamber evacuation, sealing and return toward ambient pressure. The pressure history, bag, seal and contents determine the load and finished package performance. [Henkovac, *Vacuum Packaging Machines User Manual*, V2019](https://henkovac.com/wp-content/uploads/2019/12/9606-041EN-HV-V2019.pdf) This reference concerns industrial parts and assemblies. It does not establish food shelf life, sterilization, medical-device packaging suitability, or a universal storage duration. ## Define what evacuation must achieve State the objective before choosing a setting: reducing trapped air, making a compact package, supporting a specified dry-pack system, or preparing an enclosure for a qualified corrosion-protection method. Evacuation alone is not a specification for all those outcomes. Henkelman's Boxer documentation distinguishes **sensor control**, which ends evacuation at a preset vacuum level, from **time control**, which ends it after an elapsed interval. The latter does not directly measure whether the same final pressure was reached. Record the control mode and relevant machine configuration with the recipe rather than transferring a cycle time between machines or loads. [Henkelman, *Boxer*](https://henkelman.com/en/products/table-top-models/boxer) For pressure records, distinguish absolute pressure from gauge pressure or a displayed vacuum percentage. An absolute-pressure value is referenced to zero pressure; a gauge difference is referenced to the specified surrounding pressure. State the instrument's convention and units. A percentage without its definition is insufficient for comparing two packaging processes. ## Air removal and barrier properties are different An evacuated bag still needs an appropriate barrier. ASTM F1249-25 measures water-vapor transmission through flexible film and sheet; it does not certify the entire bag-and-seal system. ASTM cautions against assuming simple proportional relationships between transmission, film thickness, and vapor-pressure difference. Compare data with their specified temperature, humidity, area, time units, and specimen condition. [ASTM F1249-25, updated November 10, 2025](https://store.astm.org/standards/f1249) A named example is **SCS Dri-Shield 3700**, whose September 2019 drawing describes a polyester/foil/polyethylene laminate, electrical shielding, heat sealing, and suitability for vacuum packaging. It also specifies puncture and moisture-transmission properties separately. Vacuum compatibility therefore does not replace the material's other selection criteria, nor does it imply that a generic vacuum pouch provides ESD shielding. [SCS, *Dri-Shield 3700 drawing*, September 2019](https://www.descoindustries.com/pdf/Dri-Shield-3700-Moisture-Barrier-Bag.pdf) For oxygen-sensitive work, specify the required oxygen-barrier performance and any residual-oxygen requirement separately. A vacuum display measures the evacuation process, not the package's future oxygen ingress or the chemistry of every gas remaining around the product. Retain the applicable material and finished-package requirements rather than claiming that vacuum means oxygen-free. ## Sharp edges, fragile parts, and venting Henkovac warns that rapid chamber aeration makes the bag conform quickly and can puncture film on sharp edges. Its optional **Soft-Air** function slows air admission so conformity occurs more gradually. This is a named machine function with configuration limits, not a guarantee that any sharp part becomes safe to vacuum-pack. The manual also distinguishes sealing systems for different packaging materials. [Henkovac V2019, sections 10.6 and 10.8](https://henkovac.com/wp-content/uploads/2019/12/9606-041EN-HV-V2019.pdf) Henkelman likewise describes gradual air return for sharp or soft products, including electronic components. That feature controls the transition; it does not itself define the final pressure differential or the product's resistance to compression. [Henkelman, *Soft Air*](https://preview.henkelman.com/index.php/en/soft-air-p) For a proposed industrial pack, evaluate edges, protruding pins, unsupported thin walls, delicate finishes, and cushioning compression under the actual cycle. Consider compatible edge protection or supports and confirm that their contact does not damage the product or defeat its cleanliness requirements. Check during evacuation, after venting, and after handling. These are package-design checks; there is no single pressure appropriate for all parts. ## Seal quality and material-machine compatibility Keep evacuation and sealing controls distinct. A successful vacuum cycle cannot compensate for an unsuitable seal. Henkovac's troubleshooting guidance identifies contaminated bag openings, dirty sealing beams, damaged sealing components, poorly formed seams, and burnt seams as causes requiring different corrections. [Henkovac V2019, section 12.3](https://henkovac.com/wp-content/uploads/2019/12/9606-041EN-HV-V2019.pdf) For the Dri-Shield 3700, the supplier lists product-specific sealing temperature, dwell, and pressure conditions. Use the selected bag's requirements with a compatible sealer and verify the resulting seal; do not apply one laminate's settings to another simply because both packages retain a vacuum initially. [SCS drawing](https://www.descoindustries.com/pdf/Dri-Shield-3700-Moisture-Barrier-Bag.pdf) Define acceptance for seal continuity, leakage, product condition, and retained performance over the intended exposure. A visibly tight bag is an observation at inspection time, not proof of an assigned moisture level or a transport/storage lifetime. Investigate loss of conformity against the package and product conditions rather than automatically increasing vacuum. ## Desiccant and VCI combinations Desco's **TB-2031, September 2026**, describes electronics dry packaging using a moisture-barrier bag, desiccant, and humidity indicator card, with procedures tied to IPC/JEDEC J-STD-033D. Desiccant lowers moisture within the enclosure, while the bag limits ingress and the card indicates humidity. Evacuation does not substitute for these system elements or establish that a previously moisture-exposed component is ready for reflow. [Desco, TB-2031](https://www.descoindustries.com/pdf/TB-2031.pdf) A separate corrosion example is **Cortec VpCI-126 Vacuum Bags**. The data sheet, revised **05/06/21 as printed**, combines vacuum-packaging suitability, moisture/oxygen barrier properties, and vapor-phase corrosion inhibition for its listed metals. Its two-year shelf-life statement appears under packaging and storage of the bag product; do not turn it into a universal two-year protection claim for packed assemblies. Compatibility with the actual metals, coatings, residues, and other packaging materials remains a selection question. [Cortec, product data sheet](https://www.cortecvci.com/Publications/PDS/VpCI-126-Vacuum-Bags.pdf) A useful packing instruction identifies the item, bag grade and revision, support layout, machine/control mode, approved cycle, seal criteria, accessories, inspection, and action after opening or damage. Qualify the assembled package under its intended handling and exposure conditions. Related: [Delivery guides](../index.md) · [Barrier bags](barrier-bags.md) · [Interleaving sheets](interleaving-sheets.md).