Paper Applications for Selvol Polyvinyl Alcohol
SEKISUI Specialty Chemicals offers a complete line of polyvinyl alcohol (PVOH/PVA) resins for paper applications. Our manufacturing facilities in Calvert City, Kentucky; Pasadena, Texas; and Tarragona, Spain, employ advanced computer-controlled production technology to provide the highest-quality PVOH. All plants are ISO 9002 certified.
As part of our commitment to the paper industry, we maintain a fully staffed paper applications laboratory in Houston, Texas. The lab is equipped with state-of-the-art analytical instruments to support applications and customers across global paper markets.
Paper Machine Applications at the Wet End
At the wet end of the paper machine, polyvinyl alcohol (PVOH/PVA) improves papermaking efficiency by controlling stickies, pitch and other deposit issues.
Stickies Control
Manufacturers use PVOH to control the deposition of stickies associated with secondary fiber. PVOH encapsulates stickies and forms a multilayer shield that effectively covers the surface, rendering it nontacky. U.S. Patent 4,886,575 (assigned to Betz Laboratories, Inc.) may cover this technology.
PVOH may also be effective in controlling pitch deposition in Kraft, acid sulfite and ground wood papermaking systems. U.S. Patent 4,871,424 (assigned to Betz Laboratories, Inc.) may cover this technology.
Note. These applications may be subject to certain U.S. patents and equivalents issued in other countries. No license is granted with the purchase of Selvol™ Polyvinyl Alcohol. Contact your SEKISUI Specialty Chemicals sales representative for more information.
Paper Machine Applications at the Size Press
At the size press, PVOH enhances paper performance by adding surface strength, barrier properties and improved print quality.
Clear Sizing
Manufacturers widely use PVOH at the size press to improve surface strength and barrier properties. In this role, it often upgrades the performance of starch. PVOH is stronger and more resistant to oils, greases, waxes and solvents than many other surface sizing agents.
Pigmented Surface Sizing
Manufacturers can formulate PVOH at lower levels than other binders because of its superior strength, optimizing pigment brightness and opacity.
Ink Jet Papers
PVOH is the preferred binder for ink jet size press coatings with silica pigments. Its high binding strength controls dusting better than starch. As a hydrophilic polymer, PVOH works with silica pigments to absorb water-based ink quickly, reducing wicking, mottling and bleeding.
Optical Brightener Carrier
Compared with starch, PVOH delivers 2.0–2.5 more UV brightness units. This means lower levels of expensive fluorescent dye can achieve the same brightness, improving cost efficiency.
Oil and Grease Resistance
PVOH exhibits excellent barrier properties to oils, greases, waxes and solvents. Manufacturers use it alone or blended with starch to meet vanceometer, turpentine, K&N ink holdout and other specifications. It is also a highly effective fluorochemical carrier. PVOH–fluorochemical blends can achieve high 3M kit ratings at significantly lower cost.
Hydrophobicity
Surface applications of PVOH and alkyl ketene dimer (AKD) blends improve Cobb and Hercules sizing values on both acid and alkaline papers, with little size loss over time. Unlike starch, PVOH applications do not degrade the internal sizing effect of AKD or alkenyl succinic anhydride (ASA).
Plybond Adhesion
Thanks to its strength, PVOH is an effective means of achieving plybond adhesion in multiply paperboard.
Paper Machine Applications at the Coater
At the coater, PVOH functions as a cobinder and dye carrier, improving coating strength, brightness, gloss and print quality.
Cobinder
With superior strength, PVOH allows coatings to use lower binder levels while still delivering better brightness, gloss and opacity. Its water retention properties mean manufacturers can formulate coatings with little to no hydrocolloid. Unlike some natural cobinders, PVOH does not require ammonia for solubilization.
Ink Jet Dyes
PVOH is an ideal binder for ink jet coatings with silica pigments. Compared with typical latex binders, it offers superior binding strength and improved print quality. (See “Ink Jet Papers” above.)
Optical Brightener Carrier
Manufacturers recognize PVOH as the most efficient carrier for fluorescent dyes. Adding 0.5–2.0 parts (dry) PVOH per 100 parts pigment can boost brightness by 4+ units. It also provides binding strength and water retention, helping reduce latex and hydrocolloid levels.
Selvol PVOH 203S, a fine-grind version of Selvol PVOH 203, is a noncook carrier. Manufacturers can add it directly to pigment dispersions or pigmented formulations under high shear agitation for at least 15 minutes. (U.S. Patent 5,057,570 [SEKISUI Specialty Chemicals] covers Selvol PVOH 203S in coating color formulations as a “non-cook” product.)
Find the Right Selvol PVOH Solution for Paper Applications
Contact SEKISUI to learn more about PVOH for paper applications, or request samples. Our specialists partner with paper manufacturers worldwide to help optimize performance, reduce costs and expand the possibilities of PVOH in paper formulations.
