Download - Coating Processes Development
Coating Process Coating Process DevelopmentDevelopment
John GlenningJohn Glenning
January 15, 2010January 15, 2010
Coating Process Coating Process DevelopmentDevelopmentCoating is a complex operation
• Integration of materials, equipment and processes• Coating Formulation• Coating Equipment and Process• Surface of the film to be coated• Transportation of the film through
the process• Drying/Curing of the coating
Coating Process Coating Process DevelopmentDevelopmentCoating Formulation
• Uniform coating formulation within a batch, batch-to-batch & over time
Coating Process Coating Process DevelopmentDevelopmentCoating Formulation
• Uniform coating formulation within a batch, batch-to-batch & over time• Understand the nature of the coating
Coating Process Coating Process DevelopmentDevelopmentCoating Formulation
• Uniform coating formulation within a batch, batch-to-batch & over time• Understand the nature of the coating• Newtonian Fluid: The viscosity of the fluid is independent on the forces acting on the fluid (water)
Coating Process Coating Process DevelopmentDevelopmentCoating Formulation
• Uniform coating formulation within a batch, batch-to-batch & over time• Understand the nature of the coating• Newtonian Fluid: The viscosity of the fluid is independent on the forces acting on the fluid (water)• Non-Newtonian Fluid: The viscosity of the fluid is dependent on the forces acting on the fluid (polymers)
Coating Process Coating Process DevelopmentDevelopmentCoating Formulation
• Uniform coating formulation within a batch, batch-to-batch & over time• Understand the nature of the coating• Newtonian Fluid: The viscosity of the fluid is independent on the forces acting on the fluid (water)• Non-Newtonian Fluid: The viscosity of the fluid is dependent on the forces acting on the fluid (polymers)
• Thixotropic: Viscosity decreases with increasing rate of shear over time (ketchup)• Pseudoplastic: Viscosity decreases with increasing rate of shear independent of time (paint)• Rheopectic: Viscosity increases with increasing rate of shear over time (pastes)• Dilatant: Viscosity increases with increasing rate of shear independent of time (corn starch and water)
Coating Process Coating Process DevelopmentDevelopmentCoating Formulation
• Uniform coating formulation within a batch, batch-to-batch & over time• Understand the nature of the coating• Newtonian Fluid: The viscosity of the fluid is independent on the forces acting on the fluid (water)• Non-Newtonian Fluid: The viscosity of the fluid is dependent on the forces acting on the fluid (polymers)
• Thixotropic: Viscosity decreases with increasing rate of shear over time (ketchup)• Pseudoplastic: Viscosity decreases with increasing rate of shear independent of time (paint)• Rheopectic: Viscosity increases with increasing rate of shear over time (pastes)• Dilatant: Viscosity increases with increasing rate of shear independent of time (corn starch and water)
• Impact process equipment that manufactures a wide range of products
Coating Process Coating Process DevelopmentDevelopmentCoating Equipment & Process • Extrusion coating process shears the polymer coating
Coating Process Coating Process DevelopmentDevelopmentCoating Equipment & Process • Extrusion coating process shears the polymer coating• Shearing applies stresses to the coating material• Coating performance depends on the type of coating
Coating Process Coating Process DevelopmentDevelopmentCoating Equipment & Process • Extrusion coating process shears the polymer coating• Shearing applies stresses to the coating material• Coating performance depends on the type of coating
• Control the coating process and equipment• Uniform & proper gap in space and time• Uniform & proper vacuum in space and time• Uniform & proper flow rate in space and time • Uniform & proper coating temperature in space and time• Uniform & proper solids concentration in space and time
Coating Process Coating Process DevelopmentDevelopmentCoating Equipment & Process • Extrusion coating process shears the polymer coating• Shearing applies stresses to the coating material• Coating performance depends on the type of coating
• Control the coating process and equipment• Uniform & proper gap in space and time• Uniform & proper vacuum in space and time• Uniform & proper flow rate in space and time • Uniform & proper coating temperature in space and time• Uniform & proper solids concentration in space and time
• Season change impacts coating processes
Coating Process Coating Process DevelopmentDevelopmentMaterial To Be Coated • Surface conditions are critical• Low and uniform surface tension• Surface tension too high: Delamination• Uniform surface tension: Uniform coating thicknesses
Coating Process Coating Process DevelopmentDevelopmentMaterial To Be Coated • Surface conditions are critical• Low and uniform surface tension• Surface tension too high: Delamination• Uniform surface tension: Uniform coating thicknesses
• Prepare the surface: Cannot “over clean” or “over dry”• Remove oils• Remove debris• Remove oxides• Dry the surface• How fast do oxides reform
Coating Process Coating Process DevelopmentDevelopmentMaterial To Be Coated • Surface conditions are critical• Low and uniform surface tension• Surface tension too high: Delamination• Uniform surface tension: Uniform coating thicknesses
• Prepare the surface: Cannot “over clean” or “over dry”• Remove oils• Remove debris• Remove oxides• Dry the surface• How fast do oxides reform
• Coat immediately after the surface is dried
Coating Process Coating Process DevelopmentDevelopmentMaterial To Be Coated • Surface conditions are critical• Low and uniform surface tension• Surface tension too high: Delamination• Uniform surface tension: Uniform coating thicknesses
• Prepare the surface: Cannot “over clean” or “over dry”• Remove oils• Remove debris• Remove oxides• Dry the surface• How fast do oxides reform
• Coat immediately after the surface is dried• Does the material being coated out-gasses: Delamination
Coating Process Coating Process DevelopmentDevelopmentMaterial To Be Coated • Surface conditions are critical• Low and uniform surface tension• Surface tension too high: Delamination• Uniform surface tension: Uniform coating thicknesses
• Prepare the surface: Cannot “over clean” or “over dry”• Remove oils• Remove debris• Remove oxides• Dry the surface• How fast do oxides reform
• Coat immediately after the surface is dried• Does the material being coated out-gasses: Delamination• Microetch the surface-Increasing the surface area
Coating Process Coating Process DevelopmentDevelopmentMaterial Handling • Material handling is a critical component of coating
Coating Process Coating Process DevelopmentDevelopmentMaterial Handling • Material handling is a critical component of coating• Uniform and proper tension• Coating Uniformity• Coating Adhesion
Coating Process Coating Process DevelopmentDevelopmentMaterial Handling • Material handling is a critical component of coating• Uniform and proper tension• Coating Uniformity• Coating Adhesion
• Uniform and proper line speed• Coating Thickness• Coating Uniformity
Coating Process Coating Process DevelopmentDevelopmentMaterial Handling • Material handling is a critical component of coating• Uniform and proper tension• Coating Uniformity• Coating Adhesion
• Uniform and proper line speed• Coating Thickness• Coating Uniformity
• Uniform and proper tracking• Coating Thickness• Coating Uniformity• Coating Adhesion
Coating Process Coating Process DevelopmentDevelopmentDrying/Curing Oven • More of an art form than a science
Coating Process Coating Process DevelopmentDevelopmentDrying/Curing Oven • More of an art form than a science• Surface “skinning”• Trap solvents• Slow down drying• Surface damage due to “blistering”• Heat from the bottom up
Coating Process Coating Process DevelopmentDevelopmentDrying/Curing Oven • More of an art form than a science• Surface “skinning”• Trap solvents• Slow down drying• Surface damage due to “blistering”• Heat from the bottom up
• Air Flow• Coating damage due to air flow: Turbulent Flow• Break-up the boundary layer: Laminar flow• Rapid air exchange in the oven• No eddy currents in the oven• Counter-current air flow
Coating Process DevelopmentCoating Process Development
End of Presentation