What FSC and PEFC Certification Actually Prove about Paper
FSC and PEFC prove auditable timber origin and mass-balance fiber accounting; they do not prove food safety, chemical purity, repulpability, or EUDR compliance.
DIN 55619
Measurement Scope
Fibre content determination involves the quantitative analysis of multi-component textiles through the systematic removal of specific chemical constituents. The din 55619 protocol establishes the methodology for separating these fibres using solvents to isolate individual polymer classes. Analytical precision depends on the initial removal of non-fibrous substances such as finishes or sizing agents prior to the extraction process.
Laboratories apply this sequence to confirm the accuracy of labelling for consumer goods and industrial fabrics.
Process Requirements
Gravimetric analysis governs the separation of mixed fibre populations within this framework. Analysts determine the mass of the original specimen after conditioning to a constant weight in a controlled environment. Solvent immersion follows, where specific reagents target the solubility of one component while leaving the other intact.
Weighing the residue after drying allows for the calculation of the mass loss attributed to the dissolved fibre. Drying cycles proceed until the difference between two successive weighings remains below a defined threshold to ensure the complete removal of all solvent traces.
Technical Boundary
Chemical selectivity defines the limit of applicability for these separation procedures. The solvent must effectively dissolve the target fibre without damaging the secondary component, a condition that restricts the number of viable fibre combinations. Mixed blends containing unknown fibre types require preliminary qualitative identification to avoid the selection of an inappropriate reagent.
Incorrect solvent selection leads to the degradation of the non-target material, which invalidates the mass calculation for the sample. Accuracy in the final fibre percentage relies entirely upon the complete solubility of the designated component during the prescribed chemical treatment.