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# Basic Science - (Chemistry) (MSBTE - I Scheme) 3-6 ## Paints, Varnishes, Insulators, Polymer, Adhesives & Lubricants ### Spirit Varnish - The loss of heat can take place by conduction, convection, or radiation, and thermal insulators prevent this loss. ### Oil Varnish - Thermal insulators act a...

# Basic Science - (Chemistry) (MSBTE - I Scheme) 3-6 ## Paints, Varnishes, Insulators, Polymer, Adhesives & Lubricants ### Spirit Varnish - The loss of heat can take place by conduction, convection, or radiation, and thermal insulators prevent this loss. ### Oil Varnish - Thermal insulators act as barriers or retarders in the passage of heat. Due to this property, the use of thermal insulators are very important in various industrial and engineering operations. - For example, boilers, ovens, steam-carrying pipes, brine pipelines, refrigerators, etc. all need thermal insulators. - For example, wood, plastic, glass, and rubber are good insulators. ## Syllabus Topic: Difference between Paint and Varnishes ### Difference Between Paint and Varnishes | Sr. No. | Paints | Varnishes | |---|---|---| |1 | Paints are a mechanical dispersion mixture of one or more pigments in a vehicle. | Varnish is a homogenous colloidal dispersion solution of resins in oil or thinner or both. | |2 | Paint contains pigments | Varnish do not contain pigments. | |3 | Paint produces opaque (non-transparent) film | It produces transparent film | |4 | Paint obscure (i.e. hide) the surface on which it is applied | Varnish do not obscure the surface on which it is applied. | |5 | In paint, the resins can not be used instead of oil. | In varnish, resins can be used instead of oil. | |6 | Painted surface reflects heat and light nicely. | Varnished surfaces do not reflect heat and light. | ## Syllabus Topic: Characteristics of Insulator ### Characteristics of Good Insulating Materials - The materials to be used as insulators should possess the following important characteristics: - It should have very low thermal and electrical conductivity. - It should have low density. - It should be fire-proof. - It should be cheap. - It should withstand the effects of shock and vibrations. - It should be water-proof and hence it resist absorption of moisture. - It should not give any odour while use. - It should be physically and mechanically stable at the service temperature i.e., it should not crack or suffer any deformation at working temperature. - It should be capable of bearing the load applied on it during working. ## Syllabus Topic: Insulators ### Insulating Materials (or Insulators) - What are insulators? - Why the use of Insulator is very important in various industries? - **Definition of Insulators** - "The materials or substances which are used to retard (or prevent) the flow of heat, electricity (or sound) are known as insulators".