Presentation on theme: "...... SAKATA INX SAKATA INX SAKATA INX (INDIA) LTD TECHNICAL TRAINING - OFFSET INKS 08.09.06 & 09.09.06 VENUE : UNITECH - I COUNTRY CLUB, GURGAON TOPIC."— Presentation transcript:
SAKATA INX SAKATA INX SAKATA INX (INDIA) LTD TECHNICAL TRAINING - OFFSET INKS & VENUE : UNITECH - I COUNTRY CLUB, GURGAON TOPIC Coatings, its applications, advantages & application process. PRESENTER : Mr. Bhupinder Singh CO – PRESENTER :Mr. Rajesh Chauhan. EXPERT :Mr. TAKASHI KIMURA
SAKATA INX SAKATA INX Coatings It is a thin protective layer applied to a surface to protect and improve its appearance.
SAKATA INX SAKATA INX Need Of Coatings in Printing Alone ink cannot act as barrier to physical and chemical abrasion. To provide more sheen or gloss. To provide better slip properties. For fast turn around on press. To provide special effects. To give advanced packaging solution. Therefore along with ink, coating are used to give desired final print or pack.
SAKATA INX SAKATA INX Coating Characteristics High gloss or matt finish Barrier property (vapor/grease) Scuff resistance Water and chemical resistance Heat resistance Blocking resistance Seal ability ( Blister Packing) Deep freeze resistance Hot foil stamping Flexibility Glue ability
SAKATA INX SAKATA INX Functions of Coatings Gloss Level 70 % and above – High gloss 55 to 70 % - Gloss 30 to 40 % - Satin or Neutral Below 20 % - Matte
SAKATA INX SAKATA INX Functions of coatings - Scuff, rub and slip properties COF or coefficient of friction – denotes slip characteristics Number of rubs with fixed weight Dry or wet Temperature and humidity conditions
SAKATA INX SAKATA INX Types Of Coatings Oil Base Varnishes Aqueous Varnishes U V Varnishes Solvent Base Varnishes
SAKATA INX SAKATA INX Oil Base Coatings Litho over print coatings are generally solutions of solid resins in vegetable drying oils. It is nothing but a colorless ink. Most economical way for providing gloss and scuff. Maximum film weight can be applied is as low as 0.8 to 1.5 g.s.m.
SAKATA INX SAKATA INX Advantages Disadvantages Does not offer instant drying and necessary to use spray powder which can cause characteristic rough feel. Gloss level and scuff resistance is lower in comparison to aqueous and U.V. Tendency to yellowish ness. Do have a distinctive odor on dried print Is the most inexpensive way to add gloss to a printed piece. Ideal means of “spot” varnishing at high speed. Greater flexibility in film and creates no problem during folding and creasing.
SAKATA INX SAKATA INX Aqueous Coatings Styrene-acrylic based resin systems pH between 8.2 to 8.6 Solid contents typically between 40 to 45 % Viscosity Tower coating – 35 to 60 seconds Flexo/Gravure – 30 to 40 seconds Dampener – 60 seconds Duct/screen – 30 +/- 10 poise
SAKATA INX SAKATA INX Advantages Disadvantages Instant drying. No spray powder and cleaner environment. Generally better than OPV in gloss and scuff. Dried coating is water white and odor less,suitable for food packaging. Can be used as primer for UV Coat. Spot varnish is difficult and possibility is only cutting blanket on non - image areas which is generally done for providing cut-outs for printing packing information on pack.
SAKATA INX SAKATA INX U.V. Varnish Is the blend of acrylates of low molecular weights which when energized by the use of powerful UV light photo-initiators within the coating, crosslink virtually instantaneously to form a dry, solid resin film. Maximum film weight applied is 3 gsm.
SAKATA INX SAKATA INX Advantages Disadvantages Produce ultimate gloss and film hardness and instant curing. Good product resistance. Fast turn around and no spray powder. Being solvent free, taint problems are reduced although it does have characteristic odor. Higher unit cost. Lesser film flexibility. Substrate and dried ink should have sufficient high surface energy to be UV receptive.
SAKATA INX SAKATA INX Precaution in doing UV and Aqueous coatings Over lithographic inks Avoid inks that contain surface lubricants (waxes) and high concentration of distillates (ultra quick setting inks). Ensure the inks are dry in offline application. Allow at least two days minimum. Avoid use of final pigments - rhodamine, reflex blue, purple and violet. In offline application spray powder should be used minimum or coated powders.
SAKATA INX SAKATA INX Drying Process Conventional or oil based Water based UV Coating Absorption and Oxidation Absorption and evaporation Photo-Polymerization