Grantee Research Project Results
Final Report: Office Paper De-Copying
EPA Contract Number: 68D98120Title: Office Paper De-Copying
Investigators: Bhatia, Sushil
Small Business: Imagex Technologies Inc.
EPA Contact: Richards, April
Phase: I
Project Period: September 1, 1998 through March 1, 1999
Project Amount: $69,950
RFA: Small Business Innovation Research (SBIR) - Phase I (1998) RFA Text | Recipients Lists
Research Category: SBIR - Pollution Prevention , Pollution Prevention/Sustainable Development , Small Business Innovation Research (SBIR)
Description:
1.1 DeCopier TechnologyPrinting inks are generally classified as impact and non-impact inks. Impact inks are used in conventional printing processes, including letterpress, flexography, and lithography. Impact inks are composed of carbon black or a dye and are either water-based or solvent-based. They are pressed onto the surface of the paper and leave images on the paper, but do not fuse with it. The paper industry has little trouble recycling paper imprinted with impact inks.
Non-impact inks consist of carbon black, pigments and resins cross-linked with thermoplastic polymers. These inks are variously called laser ink, xerographic ink, and toner. At the high temperatures involved in non-impact printing, the resins fuse into themselves and into paper. This bonding makes toner difficult to remove in a de-inking process because polymers used in the binding process are highly resistant to chemical and mechanical action. Consequently, few paper recycling mills use waste paper imprinted with toner. The result is congestion in landfills and incinerators. It has been estimated that in 1995 waste paper imprinted with toner accounted for 80 percent of all waste paper. Furthermore, it constitutes 24 percent by weight and 40 percent by volume of all domestic and industrial waste in the United States. The adverse effects of large quantities of paper in landfills and incinerators cannot be overemphasized. However, it is equally important to emphasize the impact on forests. More and more wood is being consumed because toner printed waste paper cannot be effectively recycled.
The few paper recycling mills that utilize waste paper imprinted with toner do so employing elaborate, combined mechanical/chemical techniques. These processes are energy intensive, expensive and polluting.
Most research has been focused on improving the de-inking process by developing new chemicals and by designing better re-pulping plants. The effort has been relatively successful, but the difficulty of separating dissolved toner from sludge persists. The number of chemicals used is still large; the energy consumed is high; the cost of waste disposal is also high; and fiber yield is only 70 percent.
DeCopier Technologies, Inc., formerly Imagex Technologies, Inc., is developing a process that takes a simple approach. It is also a combined mechanical/chemical process, but at low temperatures. Great care has been taken to ensure that all components are environmentally safe.
We have used this method to decopy and reuse about 10,000 sheets of paper. Microscopic examinations do not reveal any leftover toner particles. The technical feasibility of this process has thus been established. We encountered difficulties in getting rid of dye traces left behind by some types of toner. We are now embarked on automating the process by building a machine. Called the "DeCopier," the machine will function as the reverse of a photo copier.
1.2 Phase I Program
The objectives of the Phase I program were fourfold:
- Measure, analyze, and improve the chemistry and kinetics of toner removal from paper.
- Test and quantify the mechanical removal of toner from paper and the subsequent drying and calendering by laboratory methods in order to establish decopied paper quality in terms of brightness, shrinkage and reusability.
- Measure the change in, and expenditure of, decopying fluids during the above process tests.
- Use the results obtained to better define the design parameters and, hence, the projected cost of operation of decopying units.
Infrared spectroscopy was used to analyze the formulations before and during the decopying process. Results show that the base components of the formulations do not react chemically with one another. During decopying at a given temperature, decopying fluid simply dissociates into its original components. Thus, there are no by-products of decopying. Since the base components are known to be environmentally safe, we have concluded that the fluids are environmentally safe.
Experience has shown that in decopying, soaking and rinsing are favored by a high flow of fluids, but economics dictate low rates of fluid replenishment and waste generation. We have shown that this conflict can be resolved by recycling the fluid. Fluid residue was collected and separated from toner particles by filtration. Water was added to readjust its composition. Reconstituted fluid was subsequently used in more decopying. We have thus shown that decopying fluid can be inexpensively recycled, while resultant toner particles can be collected and stored separately for possible reuse in other ways such as road surfacing. We shall include a filter loop in the future DeCopier machine so that waste collection and required fluid replenishment can be better quantified over many decopying cycles, under real operational conditions. The final results will provide justified prediction of fluid supply to, and waste collection from, a decopying machine installation at a given throughput.
Decopying thus promises to be a zero waste operation.
A number of different brushes were tried, but an optimum design is yet to be established. The brush design must necessarily be integrated with the paper transport system of the DeCopier machine.
1.3 Breadboard Prototype DeCopier Machine
DeCopier Technologies, Inc., has self-funded the development of a "breadboard" prototype DeCopier capable of continuously decopying 60 sheets of paper per minute. This "breadboard" formed the platform for conducting some of the tests in this Phase I program. It will be used as the test platform for design improvements and further testing in Phase II of this program.
1.4 Conclusions and Recommendations
It is clear that the DeCopier process is effective in returning copied paper to reusable quality, and the chemical, thermal, and mechanical aspects of the process are understood at a general quantitative or empirical level. However, handling and gentle brushing of fluid-soaked paper in a continuous machine process appears initially to be more difficult than expected. The primary task of Phase II will be to develop the prototype machine process with respect to fluid application, paper transport control, and paper brushing; these functions are linked.
The second task of Phase II will be to demonstrate fluid recycling in the continuous process, including measurement of DeCopier fluid constituents discharged with decopied toner (ink) sludge. Once the equipment and process conditions for these functions are well-defined, we can proceed to integrate the other machine functions into a complete prototype automatic DeCopier machine.
1.5 Prospects for Commercialization
Development and commercialization of the DeCopier technology will create a new industry segment that combines the benefits of information security and recycling.
DeCopier Technologies has identified three potential types of customers for the proposed products:
- Entities that are concerned primarily with document security and want to decopy confidential printed information to prevent its dissemination (and interested in the secondary benefit of being able to immediately reuse the sheets).
- End-users of sheets of paper and transparencies who want to reduce waste and save money.
- Paper and paper recycling mills that are interested in using the DeCopier fluid as an environmentally safe and less expensive alternative to decopying the toners from paper slurry.
DeCopier Technologies is currently in discussions with two large utility companies on the East Coast regarding the establishment of decopying service facilities in their headquarters. DeCopier Technologies has a letter of intent from Boston Edison to this end.
We have been invited by the City of Boston and Boston Edison to participate as one of the anchor companies in "The Sustainable Economic Development Partnership in Boston."
DeCopier Technologies management has spoken with a major East Coast bank with regard to providing a decopying service for it that, in turn, would be used to service the bank's customers. Bank customers already send papers in for scanning. The staff has to remove the staples and paper clips to feed the paper into the scanner. Once scanned, these sheets, which often contain confidential information, are ready for decopying.
Supplemental Keywords:
Economic, Social, & Behavioral Science Research Program, Scientific Discipline, Sustainable Industry/Business, cleaner production/pollution prevention, Chemistry, Technology for Sustainable Environment, New/Innovative technologies, Engineering, Economics & Decision Making, in-process recycling, De-copying, economic benefits, in process recycling, recycling, innovative technology, pollution preventionThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.