ACTEGA Kelstar Technical Bulletin Alcohol Free Dampening Solutions

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ACTEGA Kelstar Technical BulletinAlcohol Free
Dampening Solutions

• In recent years to improve air quality, printers
  have had to reduce their Volatile Organic
  Compounds (VOC) emissions. The first major area
  of reduction was eliminating the use of isopropyl
  alcohol in dampening solutions. The function of
  isopropyl alcohol in the dampening system is to
  improve the rheological properties of the ink and
  promote faster ink setting and drying.
• The advent of alcohol substitutes replacing
  isopropyl alcohol has resulted in specific
  problems on press and at UV finishing houses.
  After the sheets are printed and the aqueous
  primer is applied, the ink becomes sealed beneath
  the primer. The emulsified ink and the alcohol
  substitutes which have a high vapor pressure are
  then trapped which significantly slows the drying
  of the ink, requiring two to three times the
  normal drying time.
• When UV coating is applied over wet inks, or inks
  that have not properly dried, poor intercoating
  adhesion will result between ink, primer and UV
  coating. The glycols and glycol ethers that are
  used in alcohol substitutes act as plasticizers,
  softening both the ink and the UV coating,
  resulting in unacceptable adhesion. To minimize
  adhesion problems, pressmen should run with the
  lowest water settings possible and use fountain
  solutions which contain minimal levels of glycol
  and glycol ethers. The selection of the aqueous
  primer will greatly affect adhesion with the UV
  coating.
• The printer and converter must allow a greater
  time interval between printing and coating.
  Incoming jobs should be examined to determine wet
  or soft inks, and sample sheets should be coated.
  If poor intercoating adhesion results then the
  sheets should sit an additional 24 hours before
  being coated.
• Although the EPAs requirement for dampening
  solution substitution was well intended, it has
  caused nationwide / industry-wide problems that
  can be easily resolved with cooperation and ample
  lead times between printers and converters.
• Contact ACTEGA Kelstar at 856 829 6300 or
  info.actega.kelstar_at_altana.com for additional
  information or technical assistance.