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Semelhante a New Era Converting Machinery – Gravure Coating Webinar
Semelhante a New Era Converting Machinery – Gravure Coating Webinar (20)
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New Era Converting Machinery – Gravure Coating Webinar
- 1. Gravure Coating: Webinar – April 26, 2012 John Looser New Era Converting Machinery P.O. Box 377 Hawthorne, NJ 07506 Phone: 973-413-4605 E-mail: john.looser@neweraconverting.comwww.neweraconverting.com 1 One of the Most Versatile Methods in the Industry
- 2. Webinar Outline • Classic Gravure Coater – Section Details • Improvements – Enclosed Applicator – Sleeve System – Cartridge Systems • Variations – Reverse Gravure – Offset Gravure – Differential Offset Gravure – Process Handles: • 2-Roll and 3-Roll Gravure – Pressurized Gravure – Two-side Coating • Versatility – Application Range – Coating Types – Products 2
- 3. Classic Gravure Coater • Sections: – Coating Reservoir (Pan) – Gravure Roll (Etched Metal) – Doctor Blade – Impression Roll (Rubber) • Process: – Coating Pick-up • Fill Cells – Wipe (Doctor) Excess – Transfer Coating • “Empty” Cells (Transfer Efficiency) • Film Split Impression / Back-up Roll Gravure Roll Doctor Blade Coating Pan Coated Web Incoming Web 3
- 4. Classic Gravure Coater Impression / Back-up Roll Gravure Roll Doctor Blade Coating Pan Coated Web Incoming Web 4 • Terminology: – Direct Gravure – Forward Application • Synchronous Rotation – Pan Fed
- 5. Classic Gravure Coater • Coating Reservoir – Enclosed Applicator Shown • Gravure Roll – Motor Driven – Pneumatically Positioned • Doctor Blade – Integral to Enclosed Applicator • Impression Roll – Nip/Web Driven 5
- 6. Coating Pan • Function: Delivers Coating to Gravure Roll • Maintain Constant Level – Stand Pipe or Overflow Weir • Consistent Coating Movement – Continuous Recirculation – Foam Management – Avoid Solids Settling • Enclosure / Covers – Minimize Solvent Evaporation – Contain Slinging • Pneumatic Pan Lift Gravure Roll Doctor Blade Supply ReturnReturn Gravure Roll Doctor Blade Supply Return 6
- 7. Gravure Roll • Function: Deliver Consistent Coating – Homogeneous Transfer (Across and Down Web) • Etched / Patterned Cylinder – Determines Coat Weight and Appearance – Cell Creation: Mechanical / Laser / Electronic • Driven Roll – Tension Control – Idle Mode – Vector or Servo Controlled • Cored for Temperature Control – Heat Management – Viscosity Control 7
- 8. Cell Creation – Gravure Patterns • Cell - Coating Reservoir – BCM: Volume = Billion Cubic Micron per Square Inch • 2 – 200 BCM – LPI: Cell Density = Lines Per Inch • 10 – 1500 LPI – Release / Transfer Rate • % Coating Volume Released Onto Substrate – Patterns / Shapes • Appearance and Flow • Promote Release • Methods for Cell Creation – Mechanical Engraving – Laser Engraving – Electronic Engraving 8
- 9. Cell Creation – Mechanical Engraving • Roll Design – Steel Core with Soft Copper Layer – Chrome Plating Over Pattern • Cell Creation – Patterned Tooling Stamps/Forms Shapes – Material is NOT Removed • Surface is Re-Formed – Roll Precision Can Be Affected • Release Characteristics – Most Angles are 45o – High Surface Tension – Average Release 40-50% 9
- 10. Mechanical Engraving – Common Shapes 10 Quad Roto Flo Quadragravure ImprovingReleaseProperties Pyramid Roto-Flo Pyramid Tri-Helical Quad Channel
- 11. Cell Creation – Laser Engraving • Roll Design – Steel Core with Ceramic Covering • Cell Creation – Focused Pulses Create Shape – Laser Vaporizes Surface Material • Release Characteristics – Relatively High Surface Roughness – Medium Surface Tension – Average Release 50-60% 11 Multi-Hit Single-Hit
- 12. Laser Engraving – Common Shapes 12 ImprovingReleaseProperties 30o Channel 60o Hex Tri-Helical 30o Hex
- 13. Cell Creation – Electronic Engraving • Roll Design – Steel Core with Hard Copper Layer – Chrome Plating Over Pattern • Cell Creation – Electronically Positioned Diamond Tip Stylus – Material is Precisely Removed – Roll Precision is Maintained • Release Characteristics – Low Surface Tension – Average Release 65-75% 13
- 14. Electronic Engraving – Common Shapes 14
- 15. Doctor Blade • Function: Remove Excess Coating – Coating in Cells Only – Cell Determines Coat Weight • Angle of Attack – Trailing Blade • Low Speed / Low Viscosity • Hydraulic Forces Can Lift Blade • Traps Contaminates – Reverse Angle / Chisel / Plowing • Increased Speed and Viscosity • Hydraulic Force Helps Hold Blade • Rejects Contaminates • Loading Pressure – 0.5 – 4.0 pli Gravure Roll Coating Pan Trailing Blade 25-30o Gravure Roll Coating Pan Reverse Angle 30o 15
- 16. Doctor Blade • Materials – High Carbon Spring Steel – Stainless Steel – Mylar – UHMW – ………… • Different Shapes – Most Common = Simple Bevel
- 17. • Pneumatically Loaded – On/Off Control • Angle Adjustment – Coarse: Trailing and Reverse – Fine: Attack Angle • Oscillation – Motor Driven Typical Blade Holder 17
- 18. Impression Roll • Supports Substrate – Rubber Covered Roll – 65-90 Shore A Durometer • Nip Footprint – Impression: 0.25” – 0.375” • Controls Coating Width – Undercut Roll – Lift Edges Off Gravure Roll – Unique Roll for Each Web Width Web Gravure Roll Impression Roll 18
- 19. Impression Roll • Impact on Coating Quantity and Quality – Roll Durometer Impacts Amount of Coating Transferred • Thick Soft Covering (60-70 duro) = Large Footprint = More Coating • Thin Hard Covering (80-90 duro) = Small Footprint = Less Coating – Higher Precision Leads to Better Coating Uniformity • Soft Roll = .002 - .004” TIR • Hard Roll = .0005” - .001 TIR – Thin Precision Coating • Hard Cover – Small Footprint – Precision Roll
- 20. Impression Control • Pressure Only – Pressure in Loading Cylinders Set Impression – No Position Stops Between Rolls – Difficult to Control • Cylinders Lift Roll / Pan / Motor AND Sets Impression • Pressure Changes Impact Impression • Adjustable Stops – Cylinders are Utilized for Positioning – Stop Setting Dictates Impression – High Loading Pressure = Stability – Fine / Repeatable Adjustment • Stop Configurations – Coarse Thread – Differential Screw – Taper Wedge Block 20
- 21. Improvements • Enclosed Applicator • Sleeve System • Cartridge Systems 21
- 22. Enclosed Applicator Supply Impression / Back-up Roll Coated Web Incoming Web Return • Enclosed System – No Slinging of Coating – Minimizes Solvent Evaporation – Reduced System Volume • High Rate of Recirculation – Minimizes Air Entrapment – Foam Control – Flows Out of Chamber • Easy to Clean – Simple Flushing Systems – Minimize Waste Gravure Roll 22
- 24. Impression Roll: Sleeve System • Impression Roll: – Rubber Covered Sleeve – Steel Mandrel • Drive Side – Cantilever Support • Operator Side – Removable Bearing Support • Quick Width Change – 5 Minute Task 24
- 25. Impression Roll: Sleeve System • Air Pressure Expands Sleeve – Floats Off Mandrel • Straight or Tapered Mandrel • Sleeves – Nickel – Composite 25
- 26. Cartridge System • Base Frame and Drive Stand Fixed in Web Line • Gravure Roll, Impression Roll and Coating Applicator on Cartridge • Quick Change System – Off-Line Clean-up – Coating Change – 10 Minute Change-out Time • Typical Features – Precision Rails Maintain Alignment – Quick Connects for Air and Electrical – Tool-less Quick Disconnect Drive Coupling 26
- 27. Cartridge System • Base Frame with Applicator Roll, Impression Roll and Drive Stand Fixed in Web Line • Gravure Cartridge Installed • Five Motors on Drive Stand • 5-Roll Transfer Coating – Two Rolls on Base – Three Rolls on Cartridge • Quick Change System – Switch Between Methods – Clean-up Off-Line – 10 Minute Change-out Time 27
- 28. Variations • Reverse Gravure • Offset Gravure • Differential Offset Gravure • Pressurized Applicator • Two-Side Coating 28
- 29. Reverse Gravure • Reverse Application – Speed Range: 90-120% • Benefits – Removes Cell Pattern – Film Split Avoided • Minimizes Ribbing – Adjust Coat Weight with Roll Speed • Impression Control is Critical – Light / Controlled Impression – Precision Required – Better Rolls • Driven Impression Roll – Suggested for Tension Control – Overcome Reverse Action Impression / Back-up Roll Gravure Roll Doctor Blade Coating Pan Coated Web Incoming Web 29
- 30. Offset Gravure • 3-Roll System – Gravure is Offset from Substrate – Removes Substrate from Coating Nip • Protects Sensitive Substrates • Roll Rotation – All Roll Same Direction • Synchronous Rotation – Two Film Splits – Thinner Coatings • Roll Speeds – All Rolls at 100% Line Speed – Single Drive is Possible • Gravure Roll is Typically Driven – Idle Mode • Applicator Roll is Nip Driven • Back-up Roll is Web Driven Steel Back-up Roll Gravure “Forward” Doctor Blade Coating Pan Coated Web Incoming Web Rubber Applicator Roll “Forward” Film Split 30 Film Split
- 31. Differential Offset Gravure • 3-Roll System • Roll Rotation – Gravure: Forward / Reverse – Applicator: Forward / Reverse • Roll Speeds – Gravure: Variable – Applicator: Variable – Back-Up: Controls Tension – All Rolls are Driven • Roll Function – Gravure: Coat Weight Control – Applicator: Appearance Control Doctor Blade 31 Steel Back-up Roll Gravure Fwd / Rev Coating Pan Coated Web Incoming Web Rubber Applicator Roll Fwd / Rev Film Split Film Split
- 32. Differential Offset Gravure • Cartridge Coater • All Driven Rolls – Additional Drives for 5- Roll Coating • Wide Range of Set-ups – Gloss Top Coat • Gravure = 100%, Applicator = 100% – Silicone Coating • Gravure = 5%, Applicator = 95% 32
- 33. Process Handles: 2-Roll Gravure Coat Weight and Appearance • Direct Gravure - Forward Application 1. Gravure Roll Selection 2. Gravure / Back-up Roll Nip Footprint • Direct Gravure – Reverse Application 1. Gravure Roll Selection 2. Gravure / Back-up Roll Nip Footprint 3. Gravure Roll Direction 4. Gravure Roll Speed 33
- 34. Process Handles: 3-Roll Gravure Coat Weight and Appearance • Offset Gravure 1. Gravure Roll Selection 2. Gravure / Applicator Roll Nip Footprint 3. Applicator / Back-up Roll Nip Footprint • Differential Offset Gravure 1. Gravure Roll Selection 2. Gravure / Back-up Roll Nip Footprint 3. Applicator / Back-up Roll Nip Footprint 4. Gravure Roll Direction 5. Gravure Roll Speed 6. Applicator Roll Direction 7. Applicator Roll Speed 34
- 35. Pressurized Coating Applicator Pressurized Applicator Tri-Helical Gravure Roll 35
- 36. Pressurized Coating Applicator Conventional Applicator: No Pressure Pressurized Applicator: Low Pressure Pressurized Applicator: Higher Pressure 36
- 37. Pressurized Coating Applicator Pressurized Applicator • Adjustable Coat Weight with a Single Cylinder – 50-100% Weight Increase – Reduced Gravure Roll Inventory • Extended Coat Weight Range – Thicker Coatings • Constant Coat Weight with Increasing Speed – More Efficient in Filling Gravure Cells – Less Recirculation and Foam Generation • Higher Viscosity and % Solids 37
- 38. Simultaneous Two-Side Coating Gravure Roll Gravure Roll • Very Cost Effective – Coat Both Sides at One Coating Station – Single Dryer vs. Dual Dryers – Reduced Overall Line Length • Direct Application (Kiss Coating) – Forward or Reverse Apply – Coat Weight is Susceptible to Tension Variations • Limited Range of Applications – Thinner Coatings – Same / Similar Functional Coatings on Both Sides
- 39. Two-Side Coating • Offset “Kiss” Coat – Unsupported Applicator Roll Gravure Roll Gravure Roll Applicator Roll • Offset Coat – Supported Applicator Roll Applicator Roll Gravure Roll Gravure Roll
- 40. Versatility • Application Range – Speeds: 0 - 2000+ fpm – Widths: 0 - 200+ inches • Substrates: – Papers – Boards – Films – Foils – Wovens / Non-wovens – ……… • Coating Types: – Water Based – Solvent Based – 100% Solids (UV and E-Beam Cure) – Hot Melt: Adhesives and Waxes – ……… 40
- 41. Versatility • Viscosity and Wet Coating Thickness: – 2-Roll Gravure: • 10-1000 cps • 0.0005” – 0.0015” – 3-Roll Gravure • 50 – 2000 cps • 0.0001” – 0.001” – Pressurized Gravure • 100 – 5000 cps • 0.0005” – 0.005” • Coatings: – PSA’s: Solvent, Aqueous and Hot Melt – PVDC and other Barrier Coatings – Primer Coats – Topcoats: High Gloss and Protective – Laminating Adhesives – Silicones: Solvent, Aqueous, 100% Solids – ……….. 41
- 42. 42 • Top Coats for Wear Resistance on Magazines • Gloss / Color Snap Coatings for Automotive Brochures • Adhesives for Wood Grain Patterned Coverings on Furniture • Gas Emissive Coatings for Medical Packaging • Protective Coatings on Appliance Overlay • Optically Clear Adhesives for Protective Window Films • Silicone Based Release Liners for Medical Bandages • Pressure Sensitive Adhesives for Medical Bandages Versatility • Lamination Adhesives for Medical Drapery • Primer Coatings for Aluminum Layer in Cigarette Packaging • Optically Clear Adhesives for Bottle Labels • Adhesives on Masking Films • Reactive Coatings on Thermal Papers • Pre-Paste on Wall Coverings • Tinting of Decorative Fabrics • Laminating Adhesives for Lottery Tickets • Bonding Layer for Foam / Fabric Headliners
- 43. Questions? Thank You! Graphic References • Doctor Blades – Benton Graphics • Gravure Roll Slides: – Zecher – Pamarco • Enclosed Applicator – Harris and Bruno 43 John Looser New Era Converting Machinery P.O. Box 377 Hawthorne, NJ 07506 Phone: 973-413-4605 E-mail: john.looser@neweraconverting.comwww.neweraconverting.com