Starches

An inspection of the chemical composition of cellulose and of similar glucose-based polysaccharides, it reveals that the bonds between individual glucose units, known as the glycosidic link (i.e. an oxygen bridge), display different positions according to the type of the polysaccharide considered.

With regard to cellulose (Fig. 1), glucose units are linked according to a rigid structural configuration, whereas this not true in other polysaccharides, such as amylose (Fig. 2), where such a bond is particularly flexible.

It is therefore possible to use as raw material affording water-soluble polymers, not only cellulose, but also starches, potato flours, or a combination of different polysaccharides, such as vegetable gums, in order to attain specific properties in the finished products. Based on such assumptions, research work at Barzaghi has been able to design complex products at a competitive price.

When a suitable mixture of polysaccharides is used as a raw material, esterification yields non-degradable products, affording solutions displaying a good fluidity, having medium to low viscosities and an excellent solubility both in hot and cold solutions as well as a stability of the solution over long periods of time.

Our production of starches, today offered with the trademark Cartagel®, Resamin® and Tabertex®, includes:

• Cationic starches
• Oxidized starches
• Cationic-oxidized starches
• Carboxymethylated starches, with different degree of esterification, in a liquid or in a powder form

CARTAGEL is a range of products specifically designed for the paper industry, made by synthetic means starting from polysaccharides. Their application includes:

• Additives for bulk paper-stock. They improve the dry mechanical properties: i.e. by improving resistance to burst, rip, pull, and superficial tear as well as by enhancing the stiffness of the sheet;
• Surface sizing. In applications such as size press they improve the printability of paper;
• Additives for coatings. They favour water retention and act as viscosity regulators;
• Co-binders for coatings and pre-coatings, affording a synergistic effect with latexes.

The TABERTEX product line is obtained by synthetic means starting from polysaccharides, chemically modified and properly formulated for the textile industry, where they are used for the warp sizing of yarns.
RESAMIN L and L1 are two anionic derivatives of polysaccharides obtained by synthetic means in water solutions, specifically designed for the ceramic industry where they are used as binders for glazes.

The RESAMIN SA3 are derivatives of oxidized-cationic polysaccharides obtained by synthetic means, specifically designed for the paper industry, where they are used for the surface treatment of paper. In fact, when used in size press they afford to the paper a glossy and closed surface, improving the printability as well as the surface resistance properties.