Virgin and Recycled Fiber Ratio Auditing in Packaging Board Production
Paperboard fiber ratio auditing requires pairing ISO 9184 Graff C microscopic stain counts with EN 16995 chemical marker testing and mass-balance credit ledgers
PAE Resin Markers
Chemical Detection
Analytical tracing of wet strength chemicals in paperboard identifies the synthetic polymers that give the sheet its water resistance. PAE resin markers are chemical signatures, such as specific nitrogenous compounds or polymer fragments, that reveal the presence of polyamideamine-epichlorohydrin in the board’s furnish. This identification helps recyclers determine the re-pulping difficulty of the material, as papers treated with this resin require hot water and special chemical treatment to break down.
The testing is designed for diagnostic use, as it does not measure the wet tensile strength of the board itself.
Analytical Method
The tracking involves pyrolysis gas chromatography-mass spectrometry to pyrolyze the paper board and analyze the resulting thermal fragments. Using PAE resin markers, the laboratory can pinpoint the specific thermal decomposition products that belong to the cross-linked resin network. This identification allows for a precise calculation of the resin concentration, helping mills adjust their dosing to avoid using too much chemical.
Over-dosing can increase production costs and cause paper machine runnability issues.
Recyclability Assessment
Identifying these resins is essential for managing the intake of waste paper in recycling plants. Board that contains high levels of the resin can cause blockages in standard pulping equipment if it is not identified and treated with chemical dispersants. This screening ensures that recycling lines run smoothly and maintain high fiber yields.