Solvents play an important role in pigments and herbal extracts. The performance attributes of paints are multiplied manifold with the use of solvents and for herbal extracts solvents act as the medium through which the herbal properties are extracted from the plant material.
Choosing the right solvent for extracting from plant material is essential if you want to obtain the full benefits and who knows this better than the herbal extracts manufacturers. If the herbal extract has to be used orally for medicine formulations then the solvent will be different than the one used for isolating secondary plant compounds. Normally, in the first case vinegar, alcohol and vegetable glycerine are made use of while extracting the herbal compounds and in most cases, alcohol is the popularly chosen medium. It is highly effective in the breakdown of tough herbs such as berries and barks and helps in extraction of waxes, fats, resins, few volatile oils and many alkaloids from herbs. Food-grade vegetable glycerine is another solvent type that helps in the extraction of some alkaloids, tannins, acids and few minerals from plant material. Herbal extracts prepared using vinegar are called as herbal vinegars. However, secondary plant compounds are extracted by means of solvents other than those used above. Pure acetone, ethanol at a rather upper boiling point, methanol at a rather lower boiling point or water/acetone mixtures is normally used in these cases. For extraction of lipophilic compounds, solvents such as chloroform or petrol are resorted to.
In the paint industry, solvents play an important role in dispersing or dissolving the resin or pigments for paint formulations. It enables the paint to arrive at the required consistency so that it can be applied smoothly and evenly. Evaporation of the solvent takes place after application of the paint enabling the pigment and the resin to develop a coat of paint that dries rapidly. Solvent based paints are a preferred choice due to the performance advantages provided by them and account for a large percentage of industrial applications. Superior finishing and flexibility of use are the two major benefits offered by them and in some applications as in case of architectural coatings it is the best option due to high performance requirements. There are different solvents used in industrial applications depending upon the purposes. Mineral spirits, VM&P naphtha, denatured ethyl alcohol, lacquer thinner, toluene, xylene are just to name a few of them. However, the solvents in the paint industry are regulated by governments due to environmental concerns. But with advancements in science and technology, modern hydrocarbon and oxygenated solvents help to economically address environmental issues besides offering durability and high product performance.
As far as reactive dyes are concerned they form an important ingredient for the textile industry. With regard to textile processing, there are three types of solvents that are being used; namely Tri-chloro Ethylene, Methyl Chloroform and Per-chloro Ethylen. Among the three, however, tri-chloroethylene is most suited. Though several advantages are obtained by solvent dyeing reactive dye manufacturers however, attribute high production costs to solvent dyeing in textile processing.