Drying of Ink


• Printing inks dry by different mechanisms depending on the printing method.• The common methods are penetration (absorption), oxidation, setting, evaporation and polymerization. Normally the drying is a combination of above mentioned methods.
• How the ink dries by different printing methods:
Sheet-fed offset: : By oxidation and absorption
Heatset: : By evaporation of solvent .
Offset/UV-ink : Polymerization
Gravure: evaporation
Flexo: evaporation
Drying of the Ink – Sheet-Fed Offset Printing
• Sheet-fed offset inks dry by oxidation and by absorption. The ink pigment is dispersed in medium that is a mixture of oil and resin (resin dissolved into oil). The resin stays on the top of the printing ink layer and covers the surface of oxidized oil. The solvent of printing ink penetrates into the paperboard pores. The resin hardens and the surface of printed layer gets touch resistant. After the ink has set the oxidation and further on drying can begin. The ink layer gets harder and harder while oxidation goes ahead and at last dries completely.
• If you want to speed up drying, the printed sheets can be acclimatized by turning them, either manually or using a pile turner.
• When the inks dry by oxidation it normally takes about 2…24 hours to get a”solid” ink layer.
• The common reasons for a drying problem may be:
–a) Too high humidity in the press room
–b) Temperature changes in the press room
–c) Too short a settling time of pallets before printing (the stock is cold or humid)
– d) Unsuitable ink or ink series for the stock
–e} Excessive water or ink amount
– f) Fountain solution is too acidic.
–g) IR-dryer temperature too high

Comments

  1. anil kumarSeptember 9, 2020 at 7:56 PM

    DIC India is heatset ink manufacturer in India and That ink is one type of offset ink that provides good print depth, better picture according to clarity on standard newsprint.

    ReplyDelete
  2. DirajNovember 11, 2020 at 1:17 PM

    DIC India is No.1 printing inks dealers in India and it manufacturers and supply also all types of printing ink. DIC India is also key player in laminating adhesives market in market.

    ReplyDelete

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