Лако-красочные материалы — производство

Density, a fundamental physical property, is an important conside­ration, as it can have a major effect on cost. In most cases, solvents are sold on a weight basis, but coatings are sold on a volume basis. In addition, the solvent is generally the lightest ingredient of the coating; therefore, density of the solvent is important with respect to the cost of the coating. Density is the mass of a unit volume of a material at a specified temperature, which is expressed in units such as grams per milliliter, grams per cubic centimeter or pounds per gallon. Specific gravity is the ratio of the mass of a unit volume of a material at a stated temperature to the mass of the same volume of gas-free distilled water at that temperature. A hydrometer is the quickest method used for measuring density of a solvent and a pycnometer is used for measuring specific gravity of the solvent. Specific gravity is a unitless quantity.