Deinkable

Deinkable is an adjective used to describe paper, pulp, or printing materials that can have printing inks removed from the fibers during the recycling process, typically through flotation and washing steps in chemical pulps. A deinkable material yields high ink removal efficiency, resulting in pulp with low residual ink content and improved brightness and cleanliness of the recycled fiber.

Factors influencing deinkability include fiber source (virgin vs recovered), paper coatings and fillers, surface sizing and ink holdout, and the chemistry of the inks used. Uncoated or lightly coated papers and formulations designed for easy ink detachment from fibers are considered more deinkable. Inks used with deinkable papers are often water-based and formulated to detach or fragment easily under deinking conditions; inks with heavy pigment loads or durable binders may resist removal.

Industrial relevance: Deinkability affects recyclability of magazines, newspapers, packaging, and other printed paper products. Papers marketed as deinkable are intended to yield clean pulp suitable for producing new paper grades, reducing contamination, and enabling higher recycled content while meeting quality standards.

Testing and standards: Deinkability is assessed in laboratory deinking trials that simulate pulping and flotation; measurements include residual ink concentration, dirt content, and optical properties of the recycled pulp. Industry guidelines and standards provide methods for evaluating deinking performance, but specific ratings vary by region and application.

Related concepts: deinking, recycled fiber, paper coatings, printing inks.