Small Details in Medical Device Packaging and Lid

Optimal Design for Medical Device Packaging

In medical device packaging, the combination of blister trays and lidding films is one of the most common sterile barrier systems. Blister trays are typically made from materials such as PETG, APET, PP, and HIPS, with forming methods including pre-formed cavities and roll-fed thermoforming (FFS). Blister trays can be categorized into designs with or without flanges, with flanged designs being particularly favored for their superior sealing performance.

Clean Peel Characteristics

In practical applications, when opening medical packaging consisting of blister trays and lidding films, the ideal scenario is for the adhesive layer to fracture cleanly, leaving a uniform white adhesive residue on the blister tray, indicating a clean peel. However, fiber tearing in the lidding film sometimes occurs, primarily due to improper placement or incorrect sizing of the film. Modern sealing machines equipped with alignment pins can effectively address placement misalignment, but scientifically optimized sizing is even more critical at the design stage.

DuPont's Experimental Findings

DuPont's experimental data revealed that when the lidding film was the same size as the blister tray, 26 out of 32 samples exhibited varying degrees of fiber tearing. However, when the lidding film was designed to be at least 1mm larger than the blister tray, all samples achieved a perfect clean peel. This is because the additional margin prevents adhesive from penetrating the Tyvek® substrate's edge fibers, avoiding tearing during peeling.

Design Recommendations

Therefore, to ensure reliable clean peeling, it is recommended to use flanged blister trays and, most importantly, to partner with a reliable medical blister tray manufacturer who can preemptively address potential issues. Additionally, the lidding film should be designed to be at least 1mm larger than the blister tray. These small but crucial optimizations significantly enhance the opening experience and safety of medical device packaging.