Building Materials Paints and Distempers
Paints Paint is any liquid, liquefiable, or mastic (المصطكي) composition which after application to a substrate in a thin layer is converted to an opaque solid film Types of paints
Composition of Paints Base (قاعدة للدهان) binder (vehicle) pigment and solvent. Base (قاعدة للدهان ) Is usually a metallic oxide Principal constituent of the paint Eg. White lead, red lead, zinc white, aluminium powder, iron oxide Not recommended for final coats To reduce the shrinkage cracks in paint films
Composition of Paints Binders/ vehicle (مادة تساعد على التماسك) is a polymeric substance (مادة البوليمر), and is either dissolved in the paint or suspended in it by emulsifiers hold the pigment to the surface. Eg. Drying oils, Alkyd resins, Vinyl and acrylic emulsions Pigments give the paint its colour and finish, protect the surface from corrosion and weathering hold the paint together.
Composition of Paints Solvent (مذيب) must be chosen that dries evenly in which the binder is soluble but not so soluble that it won't polymerize. For emulsion paints the solvent is simply water, and for resin-based paints a variety of organic compounds are used with the most common being mineral turpentine.
Characteristics of Paints Wearability: resistant to the wear and tear of the atmosphere and should maintain its color, smoothness and finish for a long time. Covering ability: cover the body uniformly and homogeneously on which it is applied and the finish should be smooth and uniform Ease of cleaning: clean the paint, it shold be easy to remove Environmentally Friendly: Paint should be water based and must not have any plasticizers or biocides as solvents. Aesthetic: It should provide a comfortable room climate and must not allow moulds and algae to grow on it. Practical and cost effective: cheap, ready to use, long lasting and should color fast
Types of Paints Distemper Distemper is actually a kind of paint – made with base as chalk and the solvent as water and glue is the binding agent
Types of Paints Enamel paint Are paint that air dries to a hard, usually glossy, finish and washable can be oil-based or alkyd-based, which dry slower and harder than water-based enamels. Water-based (also called latex or acrylic) paints are easier to use, dry faster and have a fairly low odor
Types of Paints Emulsion paint (مستحلب) Emulsions are a mixture of two substances that do not mix. One of the substances is dispersed in the other with the aid of an emulsifier (مستحلب) Emulsions have a clouded look due to the various substance boundaries that scatter light rays passing through them. Emulsion paints can be applied as a gas (aerosol) or as liquids Direct applications of emulsion paints are possible by means of brushes, paint rollers, blades and other instruments.
Enamels and Varnish Enamels (طلاء) consists of bases like zinc oxide ground in varnish (طلاء). They dry quickly and furnish a hard glossy surface Generally recommended for application on wood Varnish is a transparent, hard, protective finish or film primarily used in wood finishing but also for other materials.