Starch compositions and methods for use in papermaking

Abstract

Starch compositions, including cationic crosslinked starches, and methods of using those starches in papermaking are disclosed. In particular, a cationized crosslinked starch and use of the starch in the wet end system of a paper machine is disclosed. The starch compositions of the disclosure are particularly adapted for customization for specific wet end systems, and allow for modification to correspond to variations in the wet end of the papermaking machine.

Description

REFERENCE TO CO-PENDING APPLICATION[0001]This application is a Continuation-in-Part of application Ser. No. 09 / 635,962, filed Aug. 10, 2000 now U.S. Pat. No. 6,451,170.[0002]FIELD OF THE INVENTION[0003]The present disclosure is directed to improved starch compositions, and methods of making and using the improved starch compositions. In particular, the disclosure is directed to starch compositions for use in papermaking processes, and to methods of preparing, manipulating and using the starch compositions during manufacture of paper products.BACKGROUND[0004]Numerous paper products are manufactured from fibers. These products are often manufactured from an aqueous slurry containing modified cellulose fibers derived from various plant sources. The slurry is formed in the wet end of a papermaking machine, where paper fiber is formed into a dilute water slurry and combined with a variety of materials before being distributed onto a paper machine wire. The water is subsequently removed f...

AI Technical Summary

Benefits of technology

[0011]The starch can also be modified during production by adjusting the starch functionality in the papermaking process. By selectively changing the crosslinking level of the starch, the drainage and retention properties of the paper furnish containing the starch are altered, which permits the starch properties to be tailored to provide improved performance depending upon the characteristics of the paper furnish in which it will be used.

[0012]The starch properties can further be adjusted immediately prior to use in the wet end of the papermaking machine in order to tailor the starch to the specific conditions existing in the papermaking machine. In this manner, the starch can be tailored to improve drainage and retention. This customization occurs, for example, by modification of the temperature at which the starch composition is cooked prior to addition to the wet end, by changing the period of time for cooking the starch, by changing the pressure at which the starch is cooked, and / or by changing the solids content of the starch prior to cooking. By adjusting these parameters, either individually or in concert, the properties of the starch are altered and can be conformed to specific conditions of various papermaking processes. For example, by cooking at higher or lower temperatures the starch properties are altered, and these altered properties can be used to improve wet end performance.

Problems solved by technology

One of the challenges of using microparticles during papermaking is that the microparticles are not all retained on the web as the paper is formed.

The microparticles that are not retained often end up being discharged, which can be expensive because the particles are not used.

However, papermakers often experience drainage limitations while trying to maintain product quality, and therefore it is desirable to have high drainage values such that the paper can be made at high speeds and high quality.

Although papermakers and suppliers of paper ingredients realize that high retention and drainage are desirable, a considerable challenge in making consistent, high-quality paper has been that papermaking systems are not all alike and can show significant variation.

These variations can make it difficult to produce quality paper at high speeds due to changes in particle retention and drainage.

Unfortunately, conditions at most papermaking facilities vary over time as the ingredients and systems change.

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