High Barrier Film Sampling Across Roll Width

High Barrier Film cannot be represented by one center specimen when a commercial web is slit into several lanes. Edge, center and machine-direction samples are needed to reveal localized coating or handling variation.

A Metallized Film Supplier should receive a labelled sample map showing roll number, unwind direction, left and right edges, meter position and conversion stage.

Separate Cross-Web and Down-Web Variation

Take specimens from both edges and the center at defined roll positions. Preserve the parent-roll lane identity after slitting. Use the same conditioning, specimen size and OTR or WVTR method for every position.

Repeat after Conversion

Incoming results establish a baseline. Repeat sampling after printing, lamination and relevant flexing. Keep appearance, adhesion and barrier results separate because a visual streak may not equal transmission loss.

Use the Pattern

Lane-specific failures direct attention to guides, nips or slitting. Depth-related failures point toward winding or storage. Send Cailong the map, structure, conditions and retained samples.