Clariant offers papermakers new deposit control solutions with the addition of Cartaspers SCH and Cartabond DST.01 to its range.The extended portfolio has been developed specifically to improve machine cleanliness and runnability when wastepaper is used as a raw material in the papermaking process.
Cartaspers SCH makes use of nano-technology to introduce trillions of tiny polymer particles into the wet-end of a paper machine system. The emulsion particles, which are hydrophobic in nature, are derived from a very hard (high melting point) polymer. In a typical wet-end environment, the tiny polymer spheres associate themselves with other hydrophobic components in the pulp slurry.
Cartaspers SCH works through a mechanism of passivation, combining with pressure sensitive adhesives, latex binders, pitch and all other potential “stickie” contaminants, to give them a hard protective shell, which prevents agglomeration and reduces the tendency of stickies to foul machine clothing. The increased softening point of the passivated stickies helps prevent “picking” in the drying section and the transfer of contaminant to the hot cylinders is significantly reduced. Addition levels of Cartaspers SCH are aligned with the degree of stickie contamination and the product is applicable to mills using wastepaper but also virgin fiber as a raw material.
Cartabond DST.01 is a low charge cationic polymer solution designed to reduce turbidity in the wet-end circuits, without impacting on backwater or fiber charge. Micro-stickies are transferred onto fibers without significantly increasing particle size, unlike the traditional high-charge polyamine coagulants which are known for creating agglomerated secondary stickies; much larger particles responsible for machine contamination and sheet quality problems. Primarily, but not exclusively, for Tissue grades, the Cartabond DST.01 polymer is rich in hydrogen bonding groups and has been proven as a dry strength additive. The product therefore provides dual functionality and replaces both the coagulant and dry strength resin.
These new products join the patented and recently launched Cartaspers PSM in Clariant’s Deposit Control range. Cartaspers PSM provides protection for machine wires and felts, in the form of a hydrophilic coating, which prevents the adhesion of stickies. Added to the shower water, Cartaspers PSM modifies the surface energy of the fabric monofilaments and ensures a continuous hydrophilic barrier, so that stickies are rinsed away before they can build up on machinery. With this new technology, solvent cleaning of machine clothing is hardly ever required.
The complementary additions to Clariant’s range of deposit control solutions, with the launch of Cartaspers SCH and Cartabond DST.01, address a key challenge facing papermakers; the efficient use of wastepaper, in the papermaking process.
