Inline Breaker Bar Geometry Optimization and Reverse-Side Fluid Dampening Dynamics
Breaker bar geometry and reverse fluid dampening control film lamination curl by balancing plastic yield strain and z-direction substrate moisture gradients.
Z Direction Strain Profile
Internal Delamination Resistance
Vertical tensile forces act upon the z direction strain profile to quantify the integrity of a paper substrate through its thickness. This specific mechanical property identifies how well the internal fibre network holds together when subjected to stresses perpendicular to the plane of the sheet. It defines the maximum load a sample supports before failing under pure tension between the surfaces.
Structural Variation
Uniformity in this metric dictates how different grades of paper behave during high speed converting or offset printing. Excessive strain concentration at specific depths often points to issues with fibre bonding strength or orientation during the wet end formation process on the paper machine. Poor distribution leads to picking or surface rupture when the material encounters the adhesive tack of ink or lamination films.
Consistent measurement ensures the sheet resists localized rupture during vacuum suction or rapid mechanical handling.
Testing Parameter
Standardized laboratory procedures isolate the sheet between two metal platens bonded with a high strength adhesive to measure the load at failure. This apparatus applies force steadily until the internal structure separates completely. Precision depends upon the quality of the bond between the sample faces and the platens because adhesive failure provides an inaccurate result that masks the true material weakness.
Practitioners use this data to verify that multi ply boards maintain adhesion between layers throughout the life of the package.