Evaluating Surface Energy Decay in Thermal Polyurethane Film Lamination
Evaluating surface energy decay in thermal TPU lamination requires measuring polar force components to ensure bond strength before heat and pressure passes.
Packaging Delamination
Layer Separation
Structural failures involving the detachment of bonded materials in a multi-layer structure compromise the safety and appearance of a product. Through packaging delamination, the adhesive or the thermal bond between a film and a paperboard fails, leading to the formation of air pockets or peeling. This defect can occur during the converting process or while the package is in use by the consumer.
Adhesive Failure
Inadequate bond strength is often the result of poor surface preparation or the incorrect application of a laminating agent. If the surface energy of the substrate is too low, the adhesive cannot wet the surface effectively, which creates a weak interface. Stress from mechanical folding or temperature changes during transport can then cause the layers to pull apart.
Chemical interactions between the contents of the package and the adhesive can also weaken the bond over time. This is a common issue in the packaging of greasy foods or liquid chemicals that can penetrate the paper layers.
Barrier Loss
The functional performance of a package is destroyed when the barrier layers are no longer in contact with each other. This separation allows oxygen and moisture to bypass the protection, which shortens the shelf life of the product. Quality control teams use peel tests to measure the force required to separate the layers and ensure it meets the minimum specification.
Regular monitoring of the lamination line prevents the distribution of defective batches.