Printing Technology
Printing technology today includes flat, gravure, relief, and screen printing processes, as well as number of variations on these. Although printing processes are highly technological and are carried out on specialised printing machines, the necessary related processes can often only be carried out by hand.
Printing procedures are divided into three primary types:
• graphic printing (e. g. for newspapers),
• special reproduction (e. g. for textiles, carpets, furniture decoration and electronic circuitry) and
• package printing.
Emissions with environmental impact occur mainly on the use of printing dyes and cleaning products that contain volatile organic compounds (VOC) such as toluene, ethanol and ethyl acetate. In the manufacture of packaging, further procedural steps involving solvents, such as gluing, laminating, and lining, are involved in addition to the actual printing process.
In order to reduce diffuse and compressed VOC emissions as far as possible, the following procedures are currently considered in the industry to be particularly efficient:
• the use of residual toluene reducing printing dyes,
• the siphoning off of collection points for surplus dyes and floor cloths,
• basic cleaning with dry ice instead of solvents,
• regular process control of adsorber setting for waste gas purification and supply of adsorber-drying air for waste gas purification plants as well as
• the installation of air circulation technology.
Waste products are also accumulated through printing and related processes. Misprints (maculature) can be easily reduced with computer-supported initialisation systems. Solvent water waste materials can be cleaned by filtration and the cleaning materials recycled.
The CPG Information portal can provide interesting examples of practice and industry-specific information on this complex topic.
Electroplating pastes (Phase 2): Screens for water-soluble pastes, and their cleaning with water (Part 3)
IIntegrated Pollution Prevention and Control in selected Industrial Activities - Installations for Surface Treatment using organic solvents for Dressing, Impregnating, Printing, Coating - Printing (Part II)