Tementina solvent

Q5) Material protective coatings

a) Vehicle -

• fluid material in which the paint Hardens

• Polymerisation – reaction with the Air film forming – oil paints

• Evaporation of a solvent – volatile & flammable

Pigment -

• Fine insoluble particles which Produce the colouring and main body of the paint

• Primers and undercoats have more Pigments than the finish coats

• Maximum covering capabilities with Minimum thickness

Extenders -

• Control the flow & gloss of the Liquid paint

• Particle size is larger than the pigment

• Reduce the cost & increase area Of cover

b) Cellulose paints -

• Solvent based (cellulose dissolved in Acetone solvent)

• Plasticisers added to enhance Elasticity

• Synthetic resins produce gloss finish

• Flammable

Powder epoxy coatings -

• These are relatively new and Are shop applied by electrostatic methods

• Excess materials can be Recovered and re-used

• Uniform coating hardened by Baking