HIGH SURFACE
ENERGY RETENTION

MANUFACTURING CHALLENGES:

In flexible packaging, Cast Polypropylene (CPP) metallized films face a persistent enemy: dyne decay. Corona treatment boosts surface energy to enable proper aluminum deposition, but standard films lose surface dyne levels quickly during storage.

Doping the entire matrix with Corona Treatment (CT) retention additives is expensive and often compromises core mechanical properties. The solution lies in strategic co-extrusion: concentrating CT retention compounds exclusively in the skin layer.

SUDARSHHAN SOLUTION:

Polypropylene is inherently non-polar. Corona treatment oxidizes the surface by introducing polar groups (carbonyl, hydroxyl, carboxylic acid). Over time, un-stabilized polymer chains rotate inward, and migratory additives like slip agents bloom to the surface, causing dyne decay.

CT retention masterbatches work by immobilizing surface polarity and modifying skin-layer morphology. Confining these polar functional modifiers to the outer 10–15% skin layer maximizes their density right where vacuum metallization occurs.

CORE PERFORMANCE BENEFITS:

Extended Shelf Life & Dyne Stability: Films maintain critical surface energy (≥42-44 dynes/cm) even after months of storage, ensuring consistent performance for down-stream converters.
Higher Metal Bond Strength: Enhanced surface polarity yields superior nucleation of deposited aluminum atoms, dramatically improving metal adhesion and preventing layer delamination during printing or lamination.
Cost Efficiency Without Compromise: Doping only the outer skin reduces masterbatch usage by up to 85% per ton of finished film compared to full-matrix dosing.
Zero Impact on Sealability: Because the core and sealing layers remain untreated and free of high-concentration polar additives, low heat-seal initiation temperature (HSIT) and seal integrity remain completely untouched.