<p>Solenis’ portfolio of <a href="/en/products-and-services/pulp-paper/colorants/">paper colorants</a> includes the Pergasol family of direct dyes, which comprises both powder and liquid concentrate products. These direct paper dyes are highly adaptable and can be applied in papermaking furnishes to achieve precise shade and quality targets. The dye group is ideal for providing deep, lasting color in printing and writing papers, graphic and specialty papers, hygiene papers, paper board, corrugated case materials, and decorative tissue paper grades.</p>
<p>Pergasol direct dyes for paper offer a number of benefits:</p>
<ul>
<li>Available in anionic and cationic, liquid and powder products to accommodate a variety of papermaking needs and environments</li>
<li>Ability to achieve deep shades</li>
<li>“Good” to “very good” resistance to fading, bleeding and chemicals</li>
<li>High levels of fiber affinity, reducing the demand for fixatives</li>
<li>Increased productivity due to quick shade changes and corrections</li>
</ul>
<h2>How Direct Dyes Work</h2>
<p>Pergasol direct dyes for paper are water-soluble synthetic dyes. Chemically they are azo dyes or solubilized pigments.</p>
<p><strong>Anionic Dyes</strong> - Anionic Pergasol direct paper dyes contain several sulfonic or carboxyl groups to activate the dye soluble in water. In solution the dyes are dissociated into a dye anion and a colorless cation for instance sodium. The dye molecules also exhibit a linear and planar structure, which allows the dye to attach to the cellulose chains in the fiber via intermolecular bonding. Anionic Pergasol dyes are especially suitable for dyeing wood-free papers or papers containing small amounts of lignin. In most cases the use of a fixing aid is suggested.</p>
<p><strong>Cationic Dyes</strong> - Cationic Pergasol direct paper dyes have amine groups, providing a net positive charge. The combination of positive charge and relatively large, planar shape means that cationic direct dyes bond readily to fiber surfaces. Because of their more rapid uptake, cationic dyes are highly suitable for continuous application.</p>
<h2>More Information</h2>
<p>If you have a question about Pergasol direct dyes for paper or would like free technical advice on a technical challenge, <a href="/en/contact/ask-expert/">ask a Solenis expert today</a>.</p>
