Cationic (positively charged) Starch is used in early phase of paper making process known as Wet End Process.

To completely understand why cationic (positively charged) starch is used in wet end process, we need to understand how wet end process works in paper mills. Wet end refers to the early stage of paper making process which contains cellulose pulp fiber, cellulose fine, fillers, and other components dispersed as dilute suspension of fiber (0.5-1%) in a large volume of water. In the paper making process, a dilute suspension of fiber (0.5-1%) and chemicals are pumped to the head box which feeds the fiber suspension evenly onto the moving wire conveyor belt. Large amount of water is drawn away as the fiber suspension moves along with the wire conveyor belt. At the end of the conveyer belt, a wet sheet of paper is formed. It is then passes through a series of pressing cylinders where more moisture is removed. The remaining water in the paper sheet is further removed in the drying section where the sheet is passed over a large number of steam-heated drying cylinders. At this point, the sheet is almost dry.

Now, if you get clear understanding of how wet end process works in paper making, let me explain you why cationic starch is used in wet end process. cationic starch is commonly added in the wet end of the paper machine to serve as a retention and dewatering aid. Because of its positively charged property, cationic starches have been preferred as the wet-end starch additives. They are attracted to the negatively charged cellulose fiber and the negatively charged fillers. This increases fiber-to-fiber and fiber-to-filler bonding; thus, promoting a high degree of filler retention as well as strength increases at the early stage of paper making compare to native starch.

There are mainly two types of cationic starches commercially available in the market. They are the tertiary amino type of cationic starch and the quaternary ammonium type of cationic starch. The main problem with tertiary amino type of cationic starch is that they are only cationic in the acid range. Therefore their possibilities of application are limited. The quaternary ammonium type of cationic starch carry a cationic load in all pH ranges. Because of the progressive conversion from an acid to an alkaline operation in the manufacturing of paper and the increased use of calcium carbonate (Ash) in the wet end system, the use of tertiary amino type of cationic starch is diminishing. The quaternary ammonium type of cationic starch is gaining more popularity. This is the main reason we carry quaternary ammonium type of cationic starch grade.

If you are looking for specific grade of modified Paper Grade starch for your application, please visit our website iTradeIMEX – a Chicago based Import Export Trading company to get more information and product samples.

This article will provide just an overview of the different processes in the paper manufacturing where starch is used and their basic functionality. Please read my other blogs to learn more specific details on each starch application in the paper industry.

Paper manufacturing is one of the largest application of starch. Almost 70% of the total starch produced in the world is used by paper industries. The content of the starch in paper depends on the type of paper needs to be produced. The use of starch may be as high as 10-15% by the paper weight.

The Starch is used in three different stages in paper manufacturing for three different applications. These applications are wet end process, surface sizing and Coating application. Each application uses different grade of modified starch to achieve different functionality.

The Wet End Process mainly uses Cationic Starch which contains positive charge to retain the negatively charged cellulose fibers and fillers during the wet end process. The amount of Cationic Starch used in paper industry is less than 1-2% of the total content.

The surface sizing process uses modified starch to improve the surface properties, to give a better writing and printing surface and to minimize linting. There are several types of grades of modified starch such as oxidized starch, acetylated starch and hydroxyethylated starch (HES) can be used for surface sizing. The largest quantity of starch by volume is used in surface sizing application. The total volume of starch in surface sizing could be as high as 10-15% of the total content.

The paper coating application can use the same type of starch as surface sizing application. The paper coating starch needs less viscosity because the paper coating application uses starch as an adhesive or binder in the form of a coated film on the paper to bind the pigment particles to each other as well as to the paper itself.

If you are looking for specific grade of modified Paper Grade starch for your application, please visit our website iTradeIMEX – a Chicago based Import Export Trading company to get more information and product samples.

Why Modified Food Starches Are Used?
Modified Food Starch has an important functional ingredient for numerous food systems. Modified Food Starch can be used in numerous frozen and ready to use processed foods which needs to improve the quality and texture of the processed food.

There are several grades of modified food starch to improve specific functional properties including adhesion, anti-staling, binding, clouding, dusting, emulsion stabilization, encapsulation, flowing aid, foam strengthening, gelling, glazing, moisture retention, molding, shaping, stabilizing and thickening.

For example, modified food starch can be used on fried fish where it binds the breading to the fish piece, in processed meats where starch binds the juices, in orange soda where it provides emulsion stability, in candy where starch provides structure, and in numerous other applications where starch is used as a thickener.

How to Choose the Correct Modified Food Starch?
To select the right grade of modified starch for the specific processed food application some basic questions should be answered:

First, what are the properties of the targeted food system? Is it cook-up or instant? Will it be frozen or canned? What is the desired shelf life? In what physical form will the starch be used?

Second, what ingredients are present in the system: sugar? acid? fats? proteins?
How will these affect the starch and its functionality?

Finally, what are the processing conditions such as time, temperature and shear, and what type of modified food starch is needed to tolerate these conditions?

If you are looking for specific grade of modified food starch for your application, please visit our website iTradeIMEX – a Chicago based Import Export Trading company to get more information and product samples.