Thickening agents additives

The process of textile print coloration can be divided into three steps. First, the colorant is appHed as pigment dispersion, dye dispersion, or dye solution from a vehicle caUed print paste or printing ink, containing in addition to the colorant such solutions or dispersions of chemicals as may be required by the colorant or textile substrate to improve and assist in dye solubUity, dispersion stabUity, pH, lubricity, hygroscopicity, rate of dye fixation to the substrate, and colorant-fiber bonding. The required viscosity characteristics of a print paste are achieved by addition of natural or synthetic thickening agents or by use of emulsions. 

Poly(vinyl alcohol) will function as a non-ionic surface active agent and is used in suspension polymerisation as a protective colloid. In many applications it serves as a binder and thickener is addition to an emulsifying agent. The polymer is also employed in adhesives, binders, paper sizing, paper coatings, textile sizing, ceramics, cosmetics and as a steel quenchant. 

The polymers are of interest as water-soluble packaging films for a wide variety of domestic and industrial materials. (Additional advantages of the poly(ethylene oxide)s are that they remain dry to the feel at high humidities and may be heat sealed.) The materials are also of use in a number of solution application such as textile sizes and thickening agents. As a water-soluble film they are competitive with poly(vinyl alcohol) whereas in their solution applications they meet competition from many longer established natural and synthetic water-soluble polymers. 

Joint FAOAVHO Expert Committee on Food Additives, Toxicological Evaluation of Some Food Colours, Enzymes, Flavour Enhancers, Thickening Agents, and Certain Other Food Additives, WHO Food Series, Geneva, 6, 74, 1975. 

Natural or synthetic, mostly low-MW molecules that reduce or suppress microbe populations in plastics. Specialised products (both organic and inorganic) which tend to be used most in plasticised materials such as PVC and polyurethanes, as well as in rubber articles. The main cause of microbial growth is the additives themselves plasticisers, starch fillers, lubricants, thickening agents and oils. 

A review of uses of galactomannan thickening agents, of which some 23 000 tons were used worldwide in 1986, is available [354]. The use of borate ions to crosslink locust bean or guar mannose chains has been mentioned already. It has been shown that addition of borax... 

Evaporation can be reduced by containing the bubble in a closed bottle. It is also found that, in such a closed system, the bubbles remain stable for a very long time. The drainage of water away from the film is dependent on the viscosity of the fluid. Therefore, such additives as glycerin (or other thickening agents [polymers]) assist in maintaining stability. 

The addition of hydrocolloids (e.g. carrageenans, pectins or car-boxymethyl cellulose) as thickening agents will greatly increase the apparent viscosity of the product. The production of extracellular polysaccharides by certain bacteria will also increase the viscosity of milk products. 

Joint FAO/WHO Expert Committee on Food Additives. Specifications for Identity and Purity of Thickening Agents, Anticaking Agents, Antimicrobials, Antioxidants, and Emulsifiers. Rome, Italy FAO, UN 1978 59-71. 

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