Auditing Virgin and Recycled Fiber Ratios in Paperboard Packaging
Auditing fiber ratios combines ISO 9184 furnish microscopy and ash testing with strict FSC and PEFC invoice-level mass balance chain of custody reconciliation.
WLC
Material Classification
Multi-ply packaging grade manufactured primarily from recovered paper and finished with a white mineral coating on one or both sides. Common production of wlc features a grey or brown core composed of mixed recycled fibres such as newsprint and corrugated waste. It provides a cost-effective solution for retail packaging where high brightness is required for graphics but the interior appearance is less critical.
Ply Construction
Production of wlc involves multiple forming sections on a paper machine to build up the thickness and stiffness of the board. The top layer consists of high-quality bleached recycled pulp or virgin fibre to ensure a clean surface for the white coating. Below this, the filler plies provide the bulk of the material, using lower-cost recovered stocks that are cleaned and de-inked to varying degrees.
The total weight and stiffness of the board are controlled by the number and composition of these internal layers.
Market Application
Common applications for this grade include cereal boxes and household product packaging. While it lacks the ultimate strength of virgin kraft boards, it offers excellent printability and sufficient protection for lightweight consumer goods. Converters must manage the moisture content of the board to prevent curling, as the different plies can react differently to environmental changes.
The use of recycled content makes this grade a standard choice for brands focusing on circular economy goals.