How to Approach Ink – Media Problems By: Vadim Baliasny
Content Outline • Training Objectives • Introduction • Printing Technology - SB\WB ↔ UV • UV Ink in comparison to the solvent • Shipping and Storage Condition - Preface • Shipping Condition • Storage Condition • Safety working with UV inks • Media/Ink Interaction • Cross Cut Test • Problems classification • Ink Curing Problem Diagnosis • Ink-Media Interaction Problem Diagnosis • Machine Problem Diagnosis • Print Quality Problem Diagnosis • Samples • Summary
Training Objectives By the end of this module you will be able to • Separate between Machine, ink and Media problems • Tell the differences between UV ink and water base ink • Explain in which conditions the UV ink should be stored and transported • Work with UV ink while presenting safety precautions • Tell how the ink interacts with the media • Approach ink/media problem in a systematic manner
Introduction – why ink/media problem is complicated Ink/media problems are different and more complicatedthan HW problems because: • HW is well known and same at all customer sites but there are different media types on the same site and definitely different between the sites. • HW is almost not sensitive to environment conditions(temperature, humidity, static electricity, dust, sun light, etc) that cause strong effect on ink and media performance. • Storage and transportation conditions arevery important to ink and media futureperformance but not relevant to HW problems.
Introduction – why ink/media problem is complicated, Cont’d. • During HW troubleshooting SE always has a standard,good and reliable HP part to replace.Media is supplied by many different manufacturersand has a very basic standards and wide tolerances. • When SE gets DOA HP HW part – it could be discoveredexternally or by quick installation on the printer withcertain results – working/not working.Ink replacement takes time; results are not immediateand could be not certain. • Customer calls service immediately when HW problem happens. It makes investigation muchsimpler than in ink/media case when problemcould be noticed much later then occurred.
difference between UV solidification to solvent evaporation process. SB\WB ink are thinning during the process due to solvent’s evaporation. Printing Technology - SB\WB ↔ UV Heat\IR SB\WB ink Substrate 1. Printing (liquid ink) 2. Hot air causes evaporation 3. Remaining resins and pigment (solid ink) UV ink Substrate 1. Printing (liquid ink) 2. UV light causes ink solidification 3. Cured ink (solid ink) Solvent ink evaporation process UV ink curing process UV lamp
UV Ink in comparison to the solvent • Viscosity –12cP -+2cP • Surface tension – 27Dyne/cm -+1Dyne/cm • Glossiness – less them solvent • Solvent resistance – same as solvent • Can print on uncoated YUPO. • Flexibility – less then solvent • Adhesion – perception vs. reality (“all you can print”?)
Shipping and Storage Condition - Preface • How to calculate shelf life accordingly to extreme storage conditions • From the table we can conclude that high temperature diminishes significantly UV ink shelf life as an example:30 days @ 40°C will eliminate 78 days from shelf life
Shipping Condition • 10-35°C at all times with the following exceptionsExceptional cases and for single event only (no repetition is allowed): • -10°c up to 5 days Or 0°c for 1 week • 50°c up to 2 days (50°c for 2 days reduces shelf life by 18 days!) • In all exceptional cases after maximal term the temperature must return immediately to approve surrounding conditions of 10-35°C.
Storage Condition • Store at temperatures between 15°C-30°C at all time no exception allowed! • 20-25°C is optimal • Store in opaque containers • Prevent freezing • Use within the expired limitation time • Conditions to avoid • Elevated temperatures • Direct sunlight • Localized or direct heat sources • Follow all federal, state, and local regulations when disposing of materials
Safety working with UV inks • Knowledge of UV materials • Thoroughly read and understand the MSDS before using material • Personal protective equipment (PPE) • Skin protection • Gloves (Nitrile or Butyl Rubber) - do not use latex gloves • Protective clothing (apron, work clothes) • Safety shoes (leather works best) - do not wear canvas or suede shoes • Eye protection • Personal Hygiene • Remove watches, rings, etc before working with materials to avoid contamination • Wash hands after handling materials (even if gloves are used) • Frequently remove and replace contaminated PPE or clothing • DO NOT eat, drink, or smoke in work area
Media/Ink Interaction • Wetting - No wetting, Dyne level, Pens • Surface tension, flexibility, light fastness • How we test media in GBU (adhesion, scratch, flexibility, scrunch) • Flexibility tests • Impact test (manual/automatic) • Weight 20 kg test • Scrunch • What is Light fastness ?
Problems classification • Drying/curing performance • Ink not dry/cured • Media related • Adhesion, light fastness, abrasion, flexibility, etc • HW affecting • Ink system parts damaging (PH, pumps, filters, pipes, manifolds) • Quality • Color gamut, overspray, bleeding, color shift, etc
Ink Curing Problem Diagnosis • Does problem appear on specific separation or all separations? • Does problem appear on all UV lamp/dryer setups? • Does problem appear on all print modes?
Ink-Media Interaction Problem Diagnosis • Does problem appear on all media types? • Does problem appear on other ink versions? • Does problem appear on all print modes? • Does problem appear on the same media on other machines? • When problem appears – just after the print, after some time on site, while finishing/installation, in post installation period.
Machine Problem Diagnosis • Does problem appear with the same ink batch on other machines (preferably the same site machine)? • Does problem appear on the same machine and different type/batch of ink? • Does problem appear on one/few/all separations?
Print Quality Problem Diagnosis • Is problem connected to specific separation or all separations? • Is problem is connected to specific media type? • Is problem connected to specific print mode? • Does problem appear on the other machine of the same type at the same site or other sites?
Samples • Color Shift • PLM • PEEQ • Media Porosity • Duggal on canvas • Light Fastness • National Posters • Ink wetting/adhesion • Deremaux on PE 23
Samples Undercuring and flexibility Graphic House Gardners Ink Chipping PLM on Styrene Unclear problems Heads clogging (Galande) Flashing Fluid affected problems (East Asia) Adhesion problem (Masterprint, Bay Imagery, Image Option)
Summary • Now you have tools to handle ink-media problems • We saw that ink-media problems can be analyzed and handled • Don’t give up or despair of such problems • Ink has its limitations and so does the media. It is important to be familiar and cope with these limitations • When needed, tell the customer that the media he is using will not work with our ink • Only in case you cannot get clear results with your tests in the customer site, you may send us the customer’s media for testing.Nevertheless in many cases we will see the same behavior viewed in the customer site
Thank You Vadim Baliasny