Industrial Compostability Passed off as Home Compostable on Shelf
Finished packaging claims demand independent home compostability certification because industrial resin testing excludes ambient degradation and converting inks.
Substrate Thickness Limits
Caliper Constraints
Manufacturing and converting equipment are designed to operate within a specific range of material thicknesses to ensure process stability and avoid jams. Defining substrate thickness limits prevents operational failures during printing, folding, gluing, and filling. These boundaries are dictated by the physical clearances of feed rollers and gripper bars on the converting machinery.
Materials that are too thick or too thin will fail to feed properly or form weak packages. Equipment operators must check these specifications before initiating high-speed runs.
Press Runnability
Sheet-fed offset presses require precise paperboard calipers to maintain consistent ink transfer and register accuracy. Exceeding the upper thickness limit can cause severe damage to the printing blankets and impression cylinders. Conversely, substrate thickness below the minimum threshold leads to feeding errors, double-sheet detections, and press stoppages.
Maintaining board caliper within the specified tolerances ensures high-speed print runs.
Crease Formation
Automatic folder-gluers rely on uniform board thickness to achieve precise folds and strong adhesive bonds. Deviation from the thickness limits alters the score-line geometry, resulting in crooked cartons or unglued joints. Packaging lines measure caliper continuously to ensure the material remains within the tolerance window.
Adhering to these limits guarantees the mechanical functionality of the finished carton.