Solvent-free Dampner Cleaning: The Printing Office
The Printing Office (TPO) is a medium sized print shop employing 15 staff. It specialises in the production of high quality, short run jobs.
In the printing industry, the use of solvents has always been a problem. Whether it is from the point of view of workplace health and safety or from environmental concern, any reduction in the use of solvents is a welcome change. Motivated by these issues, TPO decided to trial a new dampener roller washer system that uses no solvents.
The offset printing process requires a dampening system, which comprises three cloth covered rollers that supply a thin film of moisture to the printing plate. The roller covers become ink soiled with use, and require regular cleaning to keep spoillage to a minimum.
Cleaning used to be a slow process where the dampeners were manually sprayed with solvents and hosed down in a tub. This resulted in excessive machine down-time and water usage (as much as 200 litres per wash). The rollers would then have to be wrung out to remove excess water, which resulted in excess wear to the covers. Consequently, a more cost effective and environmentally friendly method of cleaning the dampeners was sought.
For the last three months, TPO has been trialing a new process that uses high pressure water without any solvent to wash the dampeners. Water is sprayed onto the rollers at high pressure and filtered through a Dacron filterpad before being reused.
The new process uses only seven litres of water per week. The water pressure also causes the rollers to spin while they are washed, and the centrifugal force of the spinning rollers facilitates the drying of the covers after the water spraying has stopped.
The entire process takes a little more than two minutes compared with more than ten minutes required by the old method. This enables TPO to clean the dampeners more frequently to ensure consistent print quality without the incurrence of excessive production and maintenance costs.
Implementation of the project has resulted in the following outcomes:
- Reduced solvent emissions and odour resulted in a healthier and safer work environment;
- Water usage was dramatically reduced;
- Extended life of the dampeners resulted in replacement cost savings and reduced solid wastes to the landfill;
- Reduction in machine down-time required to clean the dampeners resulted in improved productivity; and
- More frequent cleaning of dampener rollers led to improved work quality and reduced spoillage.
Three of TPO’s presses use the offset process that utilises the dampener roller system. There are six rollers in all and they are washed on average three times a day. Estimated cost savings from the implementation of this project are over $31,820 per annum, in addition to an annual saving of 285,000 litres of water.
The machine can be purchased for $7,000. In the case of TPO, this resulted in a payback period of around 2.6 months.
TPO is willing to test alternative technologies as they come onto the market. Providing the quality of their work is not compromised, the potential to improve workplace health and safety as well as environmental performance is recognised as one way to increase productivity.
Other areas looked at include:
- The purchase of inks packaged in plastic lined cardboard cartons to reduce the volume of wastes going to landfill and to maximize ink usage from each container;
- Product substitution with non-alcohol based solvents such as soy bean oil have been tested; and
- Waste, energy and water walkthrough assessments carried out by the Industry Assistance Unit of the Brisbane City Council to identify other areas of improvement.