Bleekproces

Bleekproces is a Dutch term for the chemical or enzymatic treatment that removes color from materials to achieve whiteness or brightness. It is widely used in the pulp and paper industry, textiles, and other products. Bleaching typically involves oxidation or reduction reactions that break color-causing chromophores while aiming to preserve the substrate.

In pulp and papermaking, bleaching targets lignin and other impurities that give brown or yellow tones. Historically, chlorine gas or hypochlorite was used; modern practice emphasizes chlorine-free or reduced-chlorine methods. The main strategies are chlorine-dioxide-based sequences (ECF) and total chlorine-free (TCF) processes. ECF uses ClO2 and other oxidants in staged steps; TCF relies on oxygen, hydrogen peroxide, ozone, and sometimes enzymes. The goal is sufficient brightness with minimal environmental impact and preserved fiber strength.

In textiles, bleaching removes natural pigment to improve dye uptake and uniformity. Natural fibers such as cotton and linen are commonly treated with hydrogen peroxide or stabilized sodium hypochlorite, under controlled pH and temperature; subsequent washing removes residual chemicals. Synthetics may require different chemistries, with peroxides offering gentler options and better colorfastness.

Bleaching creates effluents containing oxidants, chlorinated compounds, and by-products. Therefore, bleaching plants rely on effluent treatment, water recirculation, and process optimization. Regulations increasingly favor chlorine-free or low-chlorine approaches and safer alternatives. Enzymatic or catalytic bleaching is an area of ongoing development to reduce chemical load.

The term is primarily used in Dutch-speaking contexts.