BS ISO 21896:2020,Paper, pulp, and recycling – Decolouration test of dye coloured paper products and paper products printed using dye inks.
Large scale recycling of paper and board is now used worldwide since recycled fibres make up approximately half of the fibre resources needed for global production.
The quality of the pulp obtained is characterized by its brightness/colour, cleanliness, mechanical properties and ash content. It depends both on the type of paper and board for recycling being recycled and the treatment applied.
A very small percentage of graphic paper products is produced using dye inks and dyed papers, which are typically not able to be removed by deinking but can be brightened and decoloured in the bleaching stage(s).
BS ISO 21896:2020 provides a laboratory test method for the decolouration capability of products, thus allows assessing a dyed paper or a graphic product printed with dye inks. On industrial scale, bleaching can act as a supplement to dein king but not as a substitute. The major reason is that raw material for deinking is nearly always a mix of paper grades and printing as well as converting technologies.Bleaching is only effective for a small portion of it.