UV & EB Technology for Flexible Packaging Presented by: Don P. Duncan Director of Research Wikoff Color Corporation
Is That All There Is? Chemistry: UV(100) EB(100) EB(<100) UV/EB(100) Printing: Litho Flexo Gravure Ink Jet Print Structure: Surface Reverse 1 st /Last White Finishing: Lamination UV/EB Coated None Application: Food Not Food Substrate: Paper Plastic
UV/EB Flexible Packaging Examples (Ink and/or Coating) Pet Food Frozen Food Laundry Detergent Snack Foods Gravy Bags Retort Pouches Paper Bags (Goldfish) Shrink Wrap Dry Food Pouches Tea Bag Packets Prepared Food Pouches
Why Use UV/EB for Flexible Packaging? Lamination Replacements Save $ High Chemical Resistance High Rub/Scuff Resistance Sharper Printing Excellent Adhesion to Films Low Emissions a Green Story No Hot-Air Driers Easier Permitting for New Presses
UV vs. EB vs. UV/EB UV EB - Interstation Curing (Many Lamps) - No Inerting (Nitrogen) - Lamps Create Heat - Inks Require Photoinitiator - ~100% Solids - Web or Sheetfed (Web for Flex. Pkg.) - Cure at the End/Wet Trap (One Beamer) - Nitrogen Inerting - Little/No Heat - No Photoinitiator - Inks <100% Solids Have Some Evaporation/Emission - Web only (so far)
UV vs. EB vs. UV/EB UV/EB - Interstation Pinning (Many Lamps) - Lower Photoinitiator Levels? - ~100% Solids - No Nitrogen Purging - EB at the End for Final Cure - High Cure/Low Extractables with Proven Technology - Must Buy Lamps AND a Beamer - A Proposed Solution for Flexo, Not for Litho
UV/EB vs. Water vs. Solvent UV/EB WATER SOLVENT EC Odor Ammonia Odor Solvent Odor Stay-Open ----------Evaporative Dry ---------- Skin Irritant Caustic Irritant Skin Dry Irritant Temp. Sens.(Cure) --Temp. Sensitive (Evaporation)-- O 2 Stabilizes ---------No Oxygen Effect--------- More $ -----------------Less$----------------- Higher Visc. -----------Low Viscosities----------- Lower Dot Gains ---------Higher Dot Gains---------
Flexible Packaging with UV/EB Litho Clear Film - Process and Line Colors - White, usually last-down Laminates - Process and Line Colors - Often UV/EB Coated Paper Bags - Process and Line Colors - Always Coated, Usually with UV/EB
Flexible Packaging with UV/EB Litho UV - Dry Trap / Interstation Curing - Many Lamps - Ink/Cure/Coat/Cure - Can t Cure Through a White EB - Wet Trap / Cure at the End - One EB Unit, After the Coater - EB Can Penetrate White
Flexible Packaging with UV Flexo In-Line or CI Presses (Heat Management on Wide Web) Typically 400-700 ft./min. Full Interstation Curing Cure 1 st -Down White Before Colors Cure Inks Before Last-Down White Lamination Bond Strengths Often Less than Solvent ~100% Solids Inks & Coatings Low Emissions Low Extractables/Migratables
Flexible Packaging with UV Flexo/EB Coating Inks Still Printed UV Flexo Ink/Lamp/Ink/Lamp (etc.)/coat/beam Can Run Much Faster Requires Lamps AND a Beamer ~100% Solids Inks & Coatings LowER Emissions LowER Extractants/Migratables
Flexible Packaging with Solvent Inks/ EB Coating Standard Solvent Printing (Modified Inks) Needs Very Low Residual Solvent for Coating Adhesion Purpose: To Replace Lamination and Save $ Requires Separate Coating Unit & a Beamer Can Only Replace SOME Lamination Very Successful Where Lamination is Overkill
Flexible Packaging with EB Flexo/EB Gravure Not Really Commercial Yet Presses Have Been Sold EB Cure at the End, Wet Trap Flexo & Gravure are Inherently Dry-Trapping Processes Build Tack by Evaporation Impressive Short Runs at DRUPA (EB Flexo) Much Activity in EB Flexo, Some Activity in EB Gravure
Flexible Packaging with EB Flexo/EB Gravure Trapping Can Be Tricky Wet in Anilox/Cylinder, Dry on Substrate, Cure Downstream Flexo (Raised Plate) vs. Gravure (Cylinder) Short, Successful Runs at 1500 ft./min. Typically No Interstation Drying Equipment (Flexo) Typically Low Dot Gain, thus Sharp Printing
Flexible Packaging with UV/EB Flexo Positives: Low Residual Extractables Possible for CI & In-Line Presses Proven UV Flexo Ink Formulations Able to EB Cure Without Nitrogen Should Be Very Good for Food Packaging Negatives: Still Have Some Photoinitiator Buy UV & EB Equipment Photo Levels Not Yet Defined Photo Types/Costs Not Yet Defined Cost/Value Proposition Not Yet Defined
Food Packaging So-Called Indirect Food Contact Functional Barrier Suitably Pure Principle Requires Partnership Between Printer & Ink Manuf. Properly Applied & Dried Cured All Technologies Can Be Suitable Oil, Water, Solvent, UV, EB Litho, Flexo, Gravure, Screen Ink Jet All Technologies Can Be FUBARed
The Food Packaging Partnership Ink Manufacturer s Responsibility: Ask if job is for food packaging Clarify: Not for food contact Ask if job will be coated Don t use raw materials that will migrate Don t use raw materials that will cause odor Formulate inks to dry/cure with printer s equipment Provide optimum balance of performance & cost
The Food Packaging Partnership Printer s Responsibility: Tell if job is for food packaging Tell if job will be coated Ensure drying/curing equipment is maintained & working Measure print density Not Too Much Ink! Suitable, low-odor Fountain Solution (litho) Minimal F. S. levels (litho) Test print before shipping Standard Specs., Obvious Flaws
Food Contact Strict Formulation Guidelines FDA Approved List Expensive Extraction Testing Much Higher Risk Limited Technologies Available Water-Based Oil-Based Litho Solvent-Based EB Coating Ink Jet Not Available At All* in UV Inks EB Inks *Without Individual Extraction Studies
Food Contact Other Issues Residues from Fountain Solutions (litho) Contamination from Press Washes Limited Press-Side Adjustments Possible Complete Drying/Curing is Critical
UV & EB For Flexible Packaging Not Everywhere, but is Every Day Suitable for Food Packaging Litho & Flexo Tend to Give Lower Dot Gains Very Low Emissions You Need to Need It Will the Job Pay for the Ink?
UV & EB Technology for Flexible Packaging Thank you PRESENTED BY Don P. Duncan Director of Research Wikoff Color Corporation don.duncan@wikoff.com Please remember to turn in your evaluation sheet...