Recycled Content
Paper mills apply the cepi test method to quantify the proportion of fibre originating from recovered paper sources within a finished sheet. This protocol establishes the technical requirements for detecting the presence of markers added to recycled pulp batches. It functions by isolating specific chemical tracers that paper manufacturers introduce during the secondary fibre preparation phase.
The application of this procedure remains limited to paper grades containing at least five percent recovered content. Mill quality control teams use the findings to verify claims regarding circularity in production chains. Accuracy in this measurement provides the foundation for environmental labeling and compliance with industry standards concerning material origin.
Measurement Protocol
Analysts perform this assessment by extracting fibre samples from the manufactured product before subjecting the material to a controlled laboratory digestion process. The cepi test method relies on the detection of inert dyes or synthetic particles added to waste paper bales at the sorting facility. Lab personnel dissolve the substrate in a solvent that releases the markers without altering their molecular structure.
Spectroscopic analysis identifies the concentration of these markers to derive the final percentage of recycled material present in the sample. This quantification process excludes additives or mineral fillers that might interfere with optical detection sensors. Converting facilities demand this level of precision to ensure that packaging substrates align with specific sustainability targets.
Proper identification of recovered fibre ensures that the paperboard meets the structural and chemical criteria required for food grade applications while maintaining the integrity of the recycle stream.
Market Compliance
Paper converters require documentation generated by the cepi test method to validate input claims before accepting shipments into high speed production lines. Brand owners use these quantitative results to support public statements regarding the environmental performance of their secondary packaging. The procedure mitigates the risk of mislabeling during the transition from recovered materials to finished sheets.
Any variation in the testing results triggers a review of the supplier quality agreements to maintain internal inventory standards. This verification mechanism ensures the audit trail remains transparent throughout the entire converting process. Reliable quantification of recovered fibre composition remains the primary technical safeguard for maintaining trust in recycled paper products.
