Screen Printing Findings & Accomplishments
The DfE Screen Printing Partnership activities focused on three main areas:
- Technical assessment of screen reclamation technologies.
- Survey of pollution prevention activities and opportunities.
- Creation of a series of publications such as case studies, bulletins, videos, and environmental accounting software to help printers prevent pollution and save money.
Half of the screen printers involved with DfE have switched to
cleaner reclamation systems. Several suppliers also have adjusted
their research and development strategies to incorporate DfE principles.
The DfE Screen Printing Partnership completed a comparison of the environmental and human health risk, performance, and cost of 16 substitute screen reclamation product systems and technologies. The project collected hazard and environmental release information (i.e., releases to air, water, land) on 72 different chemicals that were found in these screen reclamation systems. With this information, the project assessed the risks to human health and the environment posed by the substitute product systems and technologies.
Performance was evaluated in two phases:
- The Screen Printing Technical Foundation's laboratory evaluated the products under control conditions.
- Field demonstrations at volunteer printers' facilities provided performance information under "real world" production conditions.
Twenty-three screen printing shops volunteered to use a substitute product system for one month. The participating printers recorded the amount of product used, the length of time needed to reclaim the screens, and their opinion of how well the product cleaned the screen.
The information collected in the performance demonstration was used to develop cost data for each of the demonstrated product systems and technologies. The Screen Printing Project also identified simple workplace practice changes that printers can implement easily and inexpensively. In addition, new methods and technologies were examined that might help printers improve the bottom line while reducing human health and environmental impacts.
Information on the comparative risk, performance, and cost of each of the substitute product systems and technologies are contained in a summary booklet, Designing Solutions for Screen Printers, and in a full technical report, Screen Reclamation Cleaner Technologies Substitutes Assessment (CTSA).
The DfE Program conducted a national survey of 305 screen printers via telephone in 1996. Assessing the state of pollution prevention (P2) activities in the screen printing industry and identifying factors that motivated screen printers to implement these activities were the survey's primary goals. Key results are highlighted below.
Factors That Motivate Work Practice Changes:
- Worker safety was the most commonly reported reason for changing ink, haze, or emulsion removal methods; process/quality improvements was the second most common response. For example, 51 percent of small firms and 32 percent of large firms changed ink removal methods as a result of worker safety, while 31 percent and 24 percent, respectively, changed methods to improve quality.
- Product suppliers were the most useful, the most trusted, and the most commonly cited source of information for printers that had changed methods or that had considered changing methods. Specifically, 30 percent of all firms indicated that suppliers were the most trusted source of information.
P2 Opportunities in the Screen Printing Industry:
- The majority of screen printers reclaim screens on-site. Most screen printers that remove ink, emulsion, and/or haze use acceptable work practices, such as dipping a rag or a brush into a container and then wiping the screen clean. Far fewer screen printers report using more preferred methods for cleaning screens, however, such as spraying removal chemicals from a tank or bottle, or using specialized spray equipment.
- Numerous screen printers use disposable or reusable rags for loosening and removing ink from the screen. Encouraging printers to recapture the chemical residue from these rags before either disposing of them or cleaning them could reduce chemical releases into the environment.
- The majority of screen printers use ink degradents and/or screen degreasers. Degreasers are detergent-like products that are not particularly harmful, while ink degradents are solvent-based products that release volatile organic chemicals. Some environmentally preferable ink degradents do exist, however, and present P2 alternatives.
- Very few screen printers filter/distill, reuse, or recycle waste chemicals from ink, emulsion, or haze removal.
- Most screen printers use a disposal service. Although survey respondents were not questioned as to whether their service providers reprocess waste chemicals, printers could be encouraged to use services that do so.
- Worker safety, followed by quality improvement, were the most cited reasons that screen printers changed ink, emulsions, or haze removal methods and practices. Furthermore, worker health concerns, along with ecological, performance, and cost factors, were identified as the most effective incentives in persuading firms to adopt additional P2 techniques.