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