Slip and Antiblock Additives Migrating into a Sealed Film
Excess primary amide migration depresses hot tack and seal peel strength; control with secondary amides or non-migrating siloxanes verified via ATR-FTIR.
Surface Energy Reduction
Meaning
Polymer treatment lowering the molecular attraction at a solid boundary is surface energy reduction, governing ink wetting and adhesive bonding on molded parts. The phenomenon applies strictly to the boundary layer of the finished substrate rather than the bulk polymer matrix. Exceeding the operational threshold during corona discharge or plasma activation creates microfissures that degrade the mechanical strength of the component.
Tooling Cavity Pressure
Tool engineers regulate melt temperature and injection velocity to prevent premature skin freezing before the gas exchange occurs inside the mold. Injection pressure profiles must hold steady because thermal degradation alters the viscosity of virgin feedstock. Scrap rates multiply when regrind ratios exceed established limits because degraded polymer chains consume active sites intended for oxidation.
Adhesion Boundary Defect
Poor dyne level retention causes delamination when secondary painting operations apply pigmented coatings over polyethylene substrates. Operators adjust transformer wattage on the treating station to counteract ambient humidity shifts that damp the discharge arc. Datasheet values assume laboratory atmospheres that differ from factory floors where cooling water temperature fluctuates across a production run.
Material Specification Standard
Quality inspectors verify surface tension values against purchase orders before releasing molded enclosures to assembly lines. Part specifications mandate a minimum dyne level across complex geometries where robot spray guns dwell briefly near sharp corners. Economic pressures favor high regrind percentages despite the drift in wettability that complicates downstream bonding processes.