Testing Standard
Standardized evaluation of dynamic water absorption in paper and board depends on a defined testing protocol to provide converters with comparable surface receptivity data. This specification, known as ISO 14968, establishes the guidelines for assessing the interaction between liquid droplets and the substrate surface over milliseconds. It applies to both coated and uncoated papers intended for high-speed printing and gluing.
The resulting data help manufacturers predict how paperboard will behave when exposed to water-based inks.
Measurement Procedure
The test procedure involves depositing a droplet of a specified volume onto the paper surface and recording the change in contact angle or droplet volume over time using high-speed digital imaging. In accordance with ISO 14968, the apparatus must capture these changes at sub-second intervals to resolve the initial wetting phase. This measurement tracks both the contact angle and the wetting rate, which are critical for predicting glue adhesion in packaging lines.
Because manual measurements cannot capture these rapid changes, the standard relies on automated optical systems to maintain precision. The test must be conducted under controlled temperature and humidity to ensure reproducible results across different laboratories.
Industrial Utility
Adhesive performance in automated folding cartons depends on the dynamic wetting behavior defined by this international standard. By specifying a uniform test method, ISO 14968 allows paper mills and packaging plants to resolve quality disputes regarding ink-receptivity or gluing failures.
