Downgauging Board Caliper through High Bulk Furnish Chemistry Mechanics
High-bulk BCTMP cores maintain boxboard bending stiffness during caliper downgauging while chemical wet-end additives prevent delamination under score creasing.
Surfactant Debonding
Chemical Modification
A process applied to wood pulp during the formation of absorbent tissue and paper products alters the interfibre hydrogen bonding to reduce the energy required for sheet disintegration. The surfactant debonding technique achieves this reduction through the introduction of specific molecular agents that hydrophobicize fibre surfaces during the drying phase. These molecules position themselves at the interface between cellulose chains, effectively interrupting the natural formation of physical cross-links.
Mechanical strength suffers as a consequence of this interference, yet the resulting substrate gains significant softness and improved fluid intake rates.
Molecular Mechanism
Fatty acid derivatives and quaternary ammonium compounds act as the primary additives during this treatment. These agents possess both a polar head group that attaches to the hydrophilic fibre surface and a non-polar tail that extends outward. This configuration prevents the fibre surface from establishing strong bonding sites with adjacent fibres as water leaves the web in the dryer section.
The reduction in inter-fibre bonding force depends heavily on the concentration of the chemical agent and the retention efficiency within the fibre matrix. Higher concentrations push the boundary of softness until the tensile strength falls below the threshold required for high-speed conversion.
Quality Impact
Tissue manufacturers utilize this procedure to create premium feel in facial and bathroom products while balancing the loss in geometric strength against the gains in bulk and drape. Print stock producers avoid such methods because the loss in structural integrity degrades surface stability during high-speed offset printing cycles. Converting equipment requires specific tension settings to handle webs treated this way to prevent web breaks during the rewinding phase.
A sheet treated through this method exhibits lower density and increased void volume between fibres compared to untreated stock of similar grammage.