United States Environmental Protection Agency Risk Reduction Engineering Laboratory Cincinnati, OH 45268 Research and Development EPA/600/SR-94/144 September 1994 <&EPA Project Summary Waste Reduction Evaluation of Soy-Based Ink at a Sheet-Fed Offset Printer Beth Simpson, Pamela Tazik, Gary Miller, and Paul Randall This Waste Reduction and Innova- tive Technology Evaluation project fo- cused on the use of soy-based inks as a substitute for petroleum-based inks in sheet-fed offset printing. The goal of the study was to evaluate the waste reduction and economic effects of us- ing soy-based inks in place of the pe- troleum-based inks traditionally used in sheet-fed offset printing. The main potential environmental benefits claimed for soy-based inks are that they are a renewable resource and emit less amounts of volatile hydrocarbons dur- ing the printing process. No published studies verify the claim of reduced air emissions or quantify other environ- mental aspects of using soy-based inks such as the amount of liquid wastes generated and cleaners required. Other reported benefits of soy-based inks are that they are biodegradable in landfills and are more conducive to cleanup with degradable and less toxic cleaners than are petroleum-based inks. This Project Summary was developed by EPA's Risk Reduction Engineering Laboratory, Cincinnati, OH, to announce key findings of the program demon- stration that is fully documented in a separate report (see ordering informa- tion at back). Introduction The impetus for developing soy-based inks initially came from the oil shortages of the 1970's that threatened the supply of petroleum-based chemicals. Now, in- creased emphasis on improving worker safety and reducing environmental emis- sions is motivating the printing industry to seek cleaner technologies. In the 1980s, soy-based inks were first used in offset web presses for printing newspapers, mainly for presumed environmental ben- efits. In the late 1980s, soy-ink formula- tions were marketed for sheet-fed offset presses. Sheet-fed soy inks are defined as those that have a minimum of 20% soy oil by volume. The soy oil replaces petroleum oils in the ink vehicle and varnish compo- nents. Use of the soy oil affects color, drying, and other operating characteristics of the inks. Soy-based inks used in sheet- fed presses still contain at least 10% pe- troleum oils. Research is continuing to increase the proportion of soy and other vegetable-based oils in these ink formula- tions while maintaining satisfactory print- ing characteristics. The Office of Printing Services (OPS) at the University of Illinois is the operating partner in this study. They are considered a medium size, in-plant printer and gross about $4.5 million annually. They agreed to enter into this cooperative project be- cause of their commitment to active re- search participation and out of a desire to be a model environmentally aware print shop. They were one of the first sheet-fed offset presses in the United States to use soy-based inks. Approach Data for this study was collected during a full-scale print run on a Miller TP104 Plus' six-color press in July 1992 at the OPS. The print job evaluated was a 4400 sheet, six-color, work-and-turn. Only four Printed on Recycled Paper ------- of the six colors were included in the study because the type of ink used for two col- ors was not changed between the runs. All inks included in the study were manu- factured by the same company, Handschy, Inc. of Bellwood, IL* In-plant measure- ments consisted of weighing the contain- ers of inks, blanket cleaners, and roller cleaners used during makeready and print- ing at each press unit before and after each print run. Cleanup rags were weighed before and after each print run. Wastes in the wash-up trays were weighed at each press unit at the end of each run. Samples of each type and color of ink and each cleaner used were analyzed at the same temperature as the press for total solids and volatile content at the Hazardous Waste Research and Information Center's (HWRIC) Hazardous Materials Laboratory. The operators at OPS use the same cleaners for both petroleum-based and soy-based inks. They had previously tried aqueous and less volatile organic clean- ers and had not found any satisfactory substitutes. Problems identified with some of the cleaners they tested were that they required more labor, dried much slower, and sometimes left a film on the presses that had to be removed in an additional step. Results Ink Use During the two print runs studied, makeready for the petroleum-based ink run was considerably more involved than that for the soy-based run. This was caused by excess moisture in the original batch of paper and not by differences in the inks. This difference in the two runs affected ink and blanket cleaner usage and waste paper generated. The excess moisture in the paper caused it to curl and wrinkle during feeding into the press. This problem was not a result of the type of ink being used for that run but because the paper had been stored in high humidity conditions before the first run. Because of this, about 25% more pages were printed using petroleum-based inks, which makes a comparison of inks and cleaners used and waste generated between the two runs difficult. These differences were com- pensated for to the extent possible in evaluating results of in-plant measure- ments. The study results showed that the pe- troleum-based ink run required larger quantities of three of the four colors of ink than did the soy-based ink print run (Table 1). The amount shown in the g/100 sheets printed column compensate for the differ- ence in the number of sheets printed dur- ing makeready. The % difference column compares the amount of petroleum-based ink used with the amount of soy-based ink used. For these specific print jobs, in to- tal, approximately 17% more petroleum- based inks were used on a per sheet printed basis. Cleaner Use The amount of blanket cleaners used is shown in Table 2. Almost 46% more blan- ket cleaners were used during the petro- leum ink run (3,455.4g compared with 2,368.0g). Some of this difference can be attributed to the larger amount of blanket cleaners used during the longer makeready that occurred during this run. The amount of blanket cleaner used during makeready was not recorded separately from that used during press cleaning at the end of the print run. The amount of additional clean- ers used for that purpose during the print- ing run could not be directly measured; it Table 1. Quantity Inks Used would not necessarily be directly propor- tional to the amount of paper printed. Therefore, an equivalent comparison can not be made between the amount of blan- ket cleaners used for each print run. At the end of each printing run, roller cleaners were used to clean up the presses. Their use was not affected by differences in makeready, but there was a difference in the way the presses were cleaned at the end of the two runs. At the end of the petroleum ink run, the ink in two of the stations was not changed. Also, since the same colors were used in the next run, each ink station was not cleaned as thoroughly as it was at the end of the second run with soy inks. The amounts of each roller cleaner used for each color and type of ink are shown in Table 3. Overall, about 30% more roller cleaners were used for the soy inks. This was ex- pected since the stations were cleaned more thoroughly at the end of the soy- based ink run. Both inks appeared to re- quire approximately the same amount of cleaners and effort to remove from the presses. On average in typical practice, Ink Color Black Blue Red Yellow Ink Type Petroleum Soy Petroleum Soy Petroleum Soy Petroleum Soy Ink Used (9) 241.8 162.7 124.8 79.5 109.7 87.1 85.8 53.6 Ink Used (9)/100 Sheets 3.8 3.2 2.0 1.6 1.7 1.7 1.4 1.1 % Difference 19 25 0 27 Table 2. Quantity (g) of Blanket Cleaners Used Ink Type Cleaner Name Cleaner Used (g) ' Mention of irada names or commercial products does nol constitute endorsement or recommendation for use. Petroleum Soy V120 Clean Quick V120 Clean Quick 1768.7 1686.7 1141.2 1226.8 ------- Table 3. Quantity of Roller Cleaners Used at Each Color Station Ink Color Black Blue Red Yellow Ink Type Petroleum Soy Petroleum Soy Petroleum Soy Petroleum Soy RBP#1(g) 40.1 78.8 44.8 75.7 29.5 97.9 35.1 40.3 RBP#2(g) 31.0 43.5 34.5 56.2 75.8 19.7 96.6 84.9 MIX(g) 12.4 27.9 33.8 52.1 19.5 24.9 61.5 71.5 the amount of cleaner used for the two inks would be expected to be about the same. At the end of the petroleum-based ink run, 663.8 g of ink and cleaner mixed waste was in the washup trays. By com- parison, there was 604.5 g at the end of the soy-based ink run. This approximately 10% difference can be attributed to the extended makeready at the beginning of the petroleum-based ink run. On average in typical practice, the amount of cleaner usage for the two inks would be expected to be the same. Volatile Components All inks had less than 6% volatile com- ponents, and there were significantly less volatile components in the soy-based inks than in the petroleum-based inks. The pe- troleum-based inks had an average of about 4.6% volatile components compared with an average of about 0.8% for the soy-based inks. Thus, on average, the soy-based inks only had about 17% of the amount of volatiles as the petroleum-based inks. The cleaners contained more than 97% volatile components except for one roller cleaner that contained about 88%. Based on these laboratory results and on the amount of inks and cleaners used (Tables 1 and 2), the amounts of solids and volatiles in the inks and cleaners were calculated (Table 4). The amounts of volatiles were used to estimate the total mass of air emissions. Over 90% of the liquid wastes originated from the inks. As for the volatiles, over 99% originated from the cleaners in both cases. Because of the difficulty of directly mea- suring the amount of emissions from the many sources on the press, the printed papers, and the waste containers, a worst case assumption was made that air emis- sions were equal to the volatile content of the materials used. Thus, for the petro- leum-based ink run, 3,930.15 g were cal- culated to be evaporated compared with 3,004.30 g for the soy-based ink run. This was about 31% more emissions. As de- scribed above, even after adjusting for differences in makeready, about 17% more petroleum-based ink was used. In addi- tion, the petroleum-based inks had a higher volatile content (4.6% compared with 0.77%). Just in terms of ink used, there were 0.39 g/sheets of volatile emissions from the petroleum inks compared to 0.23 g/100 sheets for the soy inks. This is about 70% more emissions to the air for an equivalent amount of printing with pe- troleum inks. As shown in Table 4, the mass of volatiles estimated to be emitted from the inks is less than 1.0% of the total mass estimated to be emitted from the inks and cleaners. Since most of the air emissions were from the cleaners, less than 1% over- all reduction in air emissions resulted from using the soy-based inks. The longer the print run the greater the reduction in vola- tile emissions from using soy inks.. Liquid Components The two main liquid wastes from the printing press were from washup trays and inks and cleaners on used rags. None of these materials were spilled during the two runs. To clean the various rollers and blankets, several rags were saturated with each cleaner and were used to wipe down the press. As a result, the rags contained some highly volatile inks and cleaners. An undeterminable portion of these cleaners and inks ended up in the washup trays. Rather than determining the rapidly chang- ing amount of liquids on the rags immedi- ately at the end of the print run, the rags were dried and the amount of dried solids on the rags was weighed. About 60% more solids were on the rags used to clean the presses after the petroleum ink run. Since more inks and cleaners were used in that run, apparently much of these materials ended up on the cleanup rags. The amount of liquids in the washup trays from this study was measured di- rectly at the end of the print runs. Almost 10% more liquids were generated in the washup trays after the petroleum ink run. This liquid was a mixture of inks and vari- ous cleaners. The amount of each ink and each cleaner that ended up in these trays and the rags (less the amount evaporated and on printed product) could not be di- rectly measured. The amount of each cleaner used to saturate the rags was not metered out precisely by the press operators so that differences between the two runs in the amounts used were mostly the result of operator variability when they poured cleaners on the rags and not the results of the type of ink being cleaned. We ob- served no reason for there to be a consis- tent difference in the amount of liquid wastes generated by the two types of inks studied. Differences resulted from opera- tor variability, extended makeready during the petroleum ink run, and more thorough cleaning conducted at the end of the soy ink run. It can not be concluded that one ink generated more liquid wastes than the other. Table 4. Solid and Volatile Contents of Inks and Cleaners Used (g) Parameter Petroleum Print Run Soy Print Run Ink Solids Cleaner Solids Total Solids Ink Volatiles Cleaner Volatiles Total Volatiles 537.17 64.78 601.95 24.93 3905.22 3930,15 371.36 48.64 420.00 11.54 2992.76 3004.30 ------- Solid Waste During makeready for the petroleum- based ink run, 1375 waste sheets were generated. The reverse side of 100 waste sheets were reused during makeready for the soy-based ink print run. This is the amount of solid waste generated directly during these print runs. No other contain- ers of solid wastes were observed. Addi- tional solid waste that may be generated in printing include trimmings and excess number of pages printed to compensate for losses that may occur during folding, binding and any other final preparation steps. Because the soy inks generally spread further (by an average of about 17%), less used ink containers may be generated with those inks. The amount of the other solid wastes would be unaf- fected by the type of ink used. In this case, the difference in makeready waste resulted from moisture in the paper at the beginning of the print run and not from difficulty with using the inks. Press alignment and ink metering was automated for the press used in this study. Based on observations of manually oper- ated presses at this and other facilities, automation or efficient press set-up, rather than the choice of ink, results in less solid waste being generated during printing. Once operators are familiar with the use of either the petroleum or soy inks, then the amount of solid waste generated dur- ing makeready will not be noticeably dif- ferent. In both cases, more waste paper might be generated on some jobs be- cause of difficulties in obtaining accept- able colors or other print quality factors. In this regard, neither ink appears to have a clear advantage over the other. Costs The main cost factor considered was that of raw materials. No equipment ex- penditures were required by OPS to switch from using petroleum to soy inks. There was a difference in the amount of labor involved in the two print runs but that was due to the problems with paper at the beginning of the first run and the fact that cleanup was more rigorous at the end of the second run. Neither of these differ- ences was due to the type of ink being used. The operating conditions of the press, such as temperature and speed, were the same for each ink so there was no difference in overall rate of production or utilities used because of the type of ink used. Insurance, monitoring requirements, reporting and recordkeeping, and permit requirements are the same for each type of ink. Any differences in future costs for remediation or property damage would be minimal. Employee health costs would slightly favor the use of soy-based inks because of reduced employee exposure to breathing released chemicals. All the quantified cost factors are for the Miller TP 104 press only and not for the entire facility at OPS. The purchase prices of raw materials (inks, cleaners, and paper) for this print job are approximately the same for both types of ink. Generally soy inks cost about 10% more. The average purchase price for both the soy inks and petroleum inks is about $8.00/lb (or $0.018g). Actual costs, depending on the color, range from about $4.00 to $12.00/lb. Costs do vary, how- ever, when the amount of materials used for petroleum inks is compared with the amount of materials for soy inks. On an equivalent basis of ink used during print- ing and typical makeready, the overall cost savings in ink used for the soy-based ink print run was estimated to be $1.17. This cost difference is not a major factor in ink selection. Higher costs are involved in printing including labor, materials such as paper, equipment amortization, and utili- ties. The portion of total printing costs allocated to inks is usually very small. When adjusted to the amount of accept- able product printed, the difference be- tween cleaner costs for the petroleum and soy-based ink runs for this print job was only 5 cents. This difference would be greater if the cleaning after the petroleum- based ink run had been more thorough. Because the same cleaners were used for both inks and on average there would be no difference between the two inks in the amount of cleaner needed, costs for cleaning would not be expected to differ. Discussion Overall, about 17% less soy ink com- pared with petroleum ink was used for the print job studied. Because less amounts of volatile hydrocarbons are emitted from the soy-based inks, air emissions were less. Since the inks and cleaners continu- ously evaporate during use and the waste inks and cleaners end up mixed together in washup trays and on the cleanup rags, it was difficult to determine the proportion that evaporated during the actual printing process. Ultimately, most if not all of the volatiles in the inks and cleaners will ei- ther evaporate, be discharged to the wa- ter (such as from a commercial laundry) or be containerized and sent to a landfill. Some of these emissions will occur at the print shop, some perhaps after shipment of the printed product, and some at waste management facilities. The proportion of volatilization that will occur in any one place will vary depending on how the waste materials are managed. For comparison purposes, it was assumed in this study that all the air emissions occurred at the print shop. An important factor that influences the amount of waste generated per unit of production is the length of the print run. Some uses of ink (and resulting wastes generated) in the printing process are fairly consistent among print jobs. For instance, the amount of ink required to coat the rollers and plates for each revolution is relatively consistent. A certain amount of waste is expected for every print job, but a higher proportion of waste is produced per raw material input on shorter print jobs, such as the one monitored here. With longer print jobs, a greater percent- age of the ink used would be applied to acceptable product. To most printers, there are little or no perceived differences in the cost of using soy-based inks because the raw material cost is slightly higher or equivalent to pe- troleum-based inks. The cost difference is more than offset by the fact that the soy inks spread almost 20% further and do not release as much volatile organic chemi- cals. Less tangible benefits of using soy inks (company image as being environ- mentally friendly, improved employee re- lations due to a perceived healthier working environment, and customer preference for products) are major factors considered by printers. If customer response to product quality is negative, printers will not adopt a new ink. At OPS, their experience has been that customers find the quality of the product to be acceptable, and many pre- fer to have their job printed with soy-based inks. A company also must consider the will- ingness of its workers to switch to and use soy inks and the time it takes for operators to become skilled in using these inks. Understandably there may be some excess waste generated during such a change. At OPS, there was some initial resistance to the new inks. Formulations of soy inks in sheet-fed offset presses were new. In the past few years, these formulations have improved and the press operators at OPS have gained the experi- ence necessary to produce high quality images. Presently, the employees prefer to use soy-based inks on this particular press. A major reason for this is that the soy inks are very similar to petroleum- based inks to work with and clean from presses. If an alternative cleaner was used that took the operators longer or required more effort for the soy inks then there would be considerable resistance and cost. ------- In addition to using soy-based inks, there are other strategies printers can use to reduce wastes from the sheet-fed offset printing. Since most emissions were from use of the cleaners, these emissions could be reduced if aqueous or less volatile cleaners were used. The press operators at OPS have not found any of the alterna- tive products they tried to be acceptable. It should be kept in mind that the use of less volatile cleaners may increase liquid wastes. Another strategy to reduce waste would be to reduce the use of cleaners and inks. This can be done in two ways; both may involve additional capital for equipment. One way is to recover or reuse waste inks and cleaners. Installing a solvent still to recover chemicals from the washup tray wastes and possibly reusing those chemi- cals in formulating cleaners might be fea- sible. Some large printers have reportedly adopted this approach. A second way to reduce cleaner and ink usage would be to purchase auto- matic blanket washers and ink roller train systems. Literature from one manufacturer of this equipment claims that as little as 220 to 275 ml of cleaning solvent can be used during a print run when the auto- mated systems are in use. Although this would not eliminate the need for hand cleaning, it could greatly reduce the amount of cleaner used and, thus, the emissions from the cleaners. It could also reduce employee exposure to potentially harmful substances. An automatic blanket washer could reduce cleaner use by up to 90%. It should be noted that on some presses where these systems have been installed the operators actually increased use of the cleaners because, even during a print run, the blankets can be cleaned without stopping the press. Automatic ink handling systems allow this type of press to be operated with about 80% less ink in the fountain. The automatic blanket washer and ink handling systems also reduce makeready and cleanup times, saving the press crew time and exposure to volatile compounds. At OPS, it was estimated that such a system would have a payback of about 3 yr. Most cost savings would be expected in the cost of cleaners and in reduced cleanup time. Overall, soy inks have some environ- mental and other advantages for sheet- fed offset printers. The main environmental advantage with soy inks is that they re- lease less than 20% of the mass of vola- tile organic chemicals compared to petroleum inks. The soy inks also spread about 15% further, which offsets the small difference in cost that currently exists. Re- portedly, recycling of soy ink printed pa- per also has some advantages. In this study all other factors including makeready time, appearance of printed product, and cleanup effort were essentially equivalent between the two types of inks. The full report was submitted in fulfill- ment of Contract No. CR-815829 by the Hazardous Waste Research and Informa- tion Center, University of Illinois at Urbana- Champaign under the sponsorship of the U.S. Environmental Protection Agency. 5 ------- ------- ------- Beth Simpson. Pamela Tazik and Gary Miller are with the Hazardous Waste Research and Information Center, Champaign, IL 61820. Paul Randall is the EPA Project Officer (see below). The complete report, entitled "Waste Reduction Evaluation of Soy-Based Inks at a Sheet-Fed Offset Printer," (Order No. PB95-100046/AS; Cost: $17.50, subject to change) will be available only from: National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Risk Reduction Engineering Laboratory U.S. Environmental Protection Agency Cincinnati, OH 45268 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati, OH 45268 Official Business Penalty for Private Use $300 BULK RATE POSTAGE & FEES PAID EPA PERMIT No. G-35 EPA/600/SR-94/144 ------- |