07/21/2004

Pollution Prevention in the Printing Industry

According to a fact sheet from the (ADEM) Alabama Department of Environmental
Management's Pollution Prevention Unit, the keys to pollution prevention in the
printing industry are


  • material substitution,
  • ink recycling and
  • minimization of changeover.


With that in mind, ADEM offers printers these suggestions for minimizing the
pollution their facilities generate.


  • Segregate spent fix baths from rinse waters and developer solutions.
  • Silver recovery is more efficient on the more concentrated spent fix waste stream.
  • Optimize bath life and reduce wastewater quantity by adjusting chemical
    replenishment rates and washwater flow rates on photoprocessors.
  • Keep lids on bulk solutions to prevent oxidation and contamination while in storage.
  • Use materials on a first in, first out basis so as to not exceed shelf life
    and thus reduce waste. Do not get rid of expired products by discharging to the wastewater treatment system.
  • Purchase ink from distributors that will take back unused or spent ink.
  • Special nondrying aerosol materials can be sprayed on ink fountains to keep them from drying out overnight. Fewer ink fountain cleanings will be required.
  • Purchase new developing machines that use less rinse water and have
    squeegees or air blades to reduce dragout from chemical baths to rinse water.
  • Add acetic acid to the fix bath. This keeps the pH low, maximizing soluble complexes and extending bath life.
  • Recycle inks to make black inks, or filter out inks instead of discharging
    to the sewer.
  • Change from alcohol-based to water-based inks and aqueous-type cleaning
    agents.
  • Save rinse water and transfer to an ink-splitting device that absorbs the
    various ink pigments on a cellulose-based, porous material. Then, depending on state and local regulations, the nearly clear filtrate may be permitted to flow to the sanitary sewer, while the pigment-colored cellulose may be sent along with other wastes to the local landfill.


Benefits of water-based inks and cleaning agents


  • They reduce solvent emissions by 80 percent or more.
  • They reduce toxicity of liquid and gaseous wastes by approximately 90
    percent.
  • Wastes that were previously classified as hazardous can be recycled or
    disposed of as nonhazardous, thus saving disposal costs.
  • There is no difference in raw material costs for inks and cleaners,
    productivity may increase, no capital expenditures are required, insurance
    costs may decrease and nondisposable wiping materials provide a savings.

Further Information


AplusA-online.de - Source: Stevenspublishing