Duplex PVC/PVDC High-Barrier Film
PVC forming web with PVDC coating for elevated moisture and oxygen protection.
Duplex PVC/PVDC is the practical step up from plain rigid PVC when a product needs better shelf-life protection without moving fully to cold-form ALU ALU. The structure keeps thermoformable PVC as the mechanical backbone and adds a polyvinylidene chloride (PVDC) coating whose coat weight, expressed in gsm, sets the barrier level.
Higher PVDC coat weights reduce water-vapour and oxygen transmission. Common pharmaceutical options include 40, 60, 90 and 120 gsm. Selection follows API sensitivity, labelled shelf life and the climatic zone of the market. Many humid-market and export packs specify mid to high coat weights after stability review.
On the line, duplex film runs on the same class of thermoforming blister machines as plain PVC, with correct film orientation and modest heat-profile tuning for heavier coatings. Cavities remain clear for inspection, then seal to hard aluminium blister lidding foil under the lacquer window of the lid stock. Final PVC gauge, PVDC gsm, width and optical options are confirmed against the customer contract.
- Significantly lower MVTR and OTR versus plain rigid PVC
- Coat-weight options (40 to 120 gsm) matched to stability need
- Thermoforms on standard blister packaging lines
- Clear cavities for product visibility and line inspection
- Cost-effective barrier step before ALU ALU cold form
DB Packaging parameters & tolerances.
General product specification. Final values are confirmed against the customer contract and batch documentation.
DB Packaging supplies duplex PVC/PVDC high-barrier film for pharmaceutical blister packaging. The construction combines a thermoformable rigid PVC base with a PVDC barrier coating. Barrier level scales with PVDC coat weight. Final product specifications are made as per the agreed contract with the customer.
Duplex structure: non-plasticised rigid PVC forming film with PVDC barrier coating. PVC provides stiffness, clarity and thermoformability. PVDC provides the upgraded moisture and oxygen barrier. Optional tint or UV-filter pigments can be discussed for light-sensitive products. Where a PE interlayer is required (triplex-style builds), that is treated as a separate agreed construction.
Choose duplex when plain PVC barrier is not enough for stability, humidity or export shelf-life targets, but a full cold-form ALU ALU pack is not required. It is a widely used middle path for moisture-sensitive solid orals in tropical and subtropical markets.
PVDC coat weight is stated in grams per square metre (gsm). As coat weight rises from 40 toward 120 gsm, water-vapour and oxygen transmission fall. Exact transmission values depend on PVC gauge, coat quality, test method and conditions. Selection should follow the product stability protocol rather than a single catalogue number.
Duplex film is intended for the same thermoforming blister platforms used for plain PVC. Correct orientation (PVDC coating typically facing outward on the forming web) and small forming-heat adjustments for heavier coats help keep cavity quality and seal integrity consistent at speed.
Layer Construction & Function
| Layer | Typical Thickness | Function |
|---|---|---|
| PVDC coating | 40 / 60 / 90 / 120 gsm (typical options) | Primary upgrade for moisture and oxygen barrier. Higher gsm generally means lower transmission rates. |
| Rigid PVC base | Typically 200 to 300 碌m | Thermoformable backbone that forms the blister cavity and supports seal to aluminium lidding foil. |
A common commercial starting point is PVC 250 碌m with PVDC 60 or 90 gsm, then adjusted after stability and market-zone review. Heavier coats (90 to 120 gsm) are often considered for highly hygroscopic actives or demanding humid-zone shelf-life claims.
Process Notes
- Runs on standard pharmaceutical thermoforming blister lines used for plain PVC.
- Confirm film orientation so the PVDC coating is presented as specified for the machine and cavity design.
- Heavier PVDC coats may need a slightly higher forming-heat profile and careful cooling to avoid haze or thin spots.
- Seal to hard aluminium blister lidding foil under the lacquer and dwell conditions recommended for that lid stock.
- Barrier performance should be verified against the product stability protocol (including climatic zone), not assumed from coat weight alone.
PVDC Coat Weight Options
| PVDC Coat Weight | Barrier Direction | Typical Positioning |
|---|---|---|
| 40 gsm | Step-up from plain PVC | General tablets 路 mild barrier upgrade |
| 60 gsm | Common mid-barrier choice | Many humid-market / export OSD packs |
| 90 gsm | High barrier duplex | Moisture-sensitive APIs 路 longer shelf life |
| 120 gsm | Highest common duplex coat | Demanding barrier briefs before ALU ALU |
Key Performance Values
Configuration
Duplex PVC/PVDC is supplied in reel form for continuous thermoforming blister lines. PVC gauge, PVDC gsm, width and reel build are matched to the customer machine and stability brief.
| Product form | Duplex PVC/PVDC film reels for pharmaceutical blister thermoforming. |
| PVC thickness options | Commonly 200, 250 and 300 碌m. Other gauges against agreed specification. |
| PVDC coat weights | 40, 60, 90 and 120 gsm as standard selectable options. |
| Appearance | Clear standard. Tinted or UV-filtered options subject to approval. |
| Core | Material options: (a) Plastic (b) Cardboard. Core ID typically 76 mm +/- 0.5 mm. Core length equals web width. |
| Reel / Web Width | Cut to blister-line width requirements agreed at order stage. |
| Identification | Each reel identified with specification (including PVDC gsm), net weight, operator reference and date of manufacture as applicable. |
| Packing | Reels packed to protect coating and optical surfaces in transit. Outer markings as per shipment documentation. |
| Quality release | Supplies accompanied by test documentation covering observed values of agreed parameters for the batch. |
Recommended Operating Conditions
- Forming methodThermoforming (heat + pressure / vacuum assist as per machine)
- Line compatibilitySame machine class as plain PVC 路 orientation critical
- Heavier coatsMay need modest heat-profile fine-tuning (e.g. 90 to 120 gsm)
- SealingHeat seal to hard Alu blister lidding foil per lid lacquer window
Related products
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