R&D Insights: Substituting PVC with PVC/PE Composite Films in Blister Packaging

10/30/2026

Originally Published: May 6, 2017
Last Updated & Revised: October 30, 2026

Historically, pharmaceutical blister packaging machines have predominantly utilized PVC films due to their low cost and excellent thermoforming properties. However, PVC presents significant drawbacks, including poor barrier performance against moisture and oxygen, alongside environmental concerns regarding its chlorine content. While high-barrier alternatives like PVDC are cost-prohibitive, and materials like PP or PET require extensive equipment upgrades due to poor processability, PVC/PE composite films offer a compelling and practical compromise.

In a PVC/PE composite, the inner PE layer is in direct contact with the pharmaceutical product (eliminating direct PVC exposure) while simultaneously ensuring reliable heat-sealing with the PTP aluminum foil. While common in liquid dosages, its application as a forming material in solid dosage blister packaging remains underutilized. This paper explores the theoretical testing and practical machine application of PVC/PE composite films to validate their feasibility for mass production.

1. Test Materials & Methodologies

- Material Specifications: The PVC/PE composite film utilizes a total thickness of 0.3mm (PE: 0.05mm; PVC: 0.25mm).

- Crucial Adhesive Modification: To ensure proper sealing with the PE layer, the traditional VC adhesive on the PTP aluminum foil was replaced with a hot-melt adhesive composed primarily of water-borne polyurethane and polyolefin.

- Testing Equipment: Standard JORNEN Blister Packaging Machine and a universal tensile testing machine.

2. Evaluation Protocols

- Barrier Integrity: Oxygen and water vapor permeance tests conducted on cut PVC/PE samples.

- Thermal Sealing Strength: 100mm × 260mm samples sealed at 150°C (±5°C) and 0.4 MPa for 1 second. After resting for 12 hours at room temperature, 15mm wide strips were subjected to a 180° peel test.

- Tightness (Negative Pressure) Test: 30 blister sheets were subjected to a negative pressure of -0.08 MPa for 30 seconds to check for water ingress, simulating high-to-low altitude transportation stress.

- Machine Operation Capability: A continuous production test of 15,000 sheets was executed on the Blister Machine to verify dynamic feeding, tracking, and thermal stability.

3. Results & Critical Engineering Adjustments

The tests confirmed that PVC/PE composite films meet stringent pharmaceutical standards, achieving an oxygen permeance of 30 cm³/(m²·24h·0.1MPa) and water vapor permeance of 2.5 g/(m²·24h). The thermal sealing strength reached 9.5 N/15mm, significantly exceeding the ≥ 7 N/15mm regulatory requirement.

However, achieving these results in continuous production requires strict equipment calibration:

- Differential Temperature Control: Because PVC and PE possess different softening points, the thermoforming station requires differential heating. The upper heating plate (facing the PE side) must be reduced, while the lower heating plate (facing the PVC side) must be increased to prevent melting or material degradation.

- Mechanical Tension Calibration: The shift to polyolefin adhesive increases the friction factor of the aluminum foil. Consequently, all PTP foil guide rollers on the machine must be adjusted for maximum flexibility and reduced operational friction.

- Sealing Temperature Offset: Field tests indicate that polyolefin adhesives require a slightly higher sealing temperature compared to traditional PVC-to-VC adhesive applications.

4. Conclusion & Feasibility

Through precise equipment calibration and adhesive substitution, replacing standard PVC with PVC/PE composite films is highly feasible for mass production on existing blister machinery. This upgrade significantly improves drug safety by utilizing the PE layer as the contact surface. Manufacturers must, however, factor in the slightly increased material costs (due to the lamination process) and a marginal reduction in blister transparency when transitioning to this superior packaging solution.