TURI Technical Reports
Preliminary Studies on the Plasticization of Polylactic Acid |
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| TURI Technical Report No. 63. This project was undertaken to examine the use of biodegradable additives to PLA to modify its properties such that it might eventually be considered as an alternative to certain applications where polyvinyl chloride (PVC) is presently used. Not only is PVC an undesirable oil based plastic, it is often plasticized with fugitive phthalates. On the 75th anniversary of its first preparation, polylactic acid has become a widely popular biodegradable thermoplastic. The use of additives will continue to greatly expand the properties of polylactic acid and its and its applications in the coming years. We have established a reliable laboratory method for casting films which will permit formulations to be evaluated quickly with minimum waste. Read more... | |
Blanket wash technology study. 1994.
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| TURI Technical Report No. 16. This Blanket Wash Technology Study (BWTS) provides comparative information on a group of commercially available blanket washes commonly used in sheetfed offset lithography. The study was conducted by the Toxics Use Reduction Institute (TURI) at the University of Massachusetts Lowell, in cooperation with the Printing Industries of New England (PINE) and the Graphic Arts Technical Foundation (GAIT). The BWTS is designed to evaluate functional performance as well as environmental, health, and safety characteristics of selected blanket washes and to make this information available to printers. The Institute’s primary objective in conducting this study is to provide information to printers that will assist them in their toxics use reduction (TUR) efforts. Toxics use reduction gives printers the opportunity to reduce occupational hazards and environmental pollution without compromising competitive advantage. Download PDF file (3.03 MB) |
Synthesis of silicon carbide fibers. 1993.
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| TURI Technical Report No. 17. The objective of this project is to synthesize single crystal silicon carbide fibers without the use of any toxic chemicals. This would be accomplished by following a two step procedure. The first step is to grow single crystal silicon fibers using the Czochralski technique. The second step is to diffuse carbon, from methane, into the fibers to form silicon carbide through a gas-solid reaction in a quartz-tube reactor. Several silicon fibers were grown and identified, through electron diffraction, as single crystals. The quartz-tube reactor was designed and built. Final testing of the silicon fibers was delayed because of several problems, however, at present all systems are ready for operation. Download PDF file (540.11 kB) |
Cyanide Reduction in Bright Stripping Using an Electrolytic Process. 1994.
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| TURI Technical Report No. 18. The Robbins Company, located in Attleboro, Massachusetts is a manufacturer of recognition awards. The manufacturing process involves metal plating and finishing operations for producing emblematic jewelry. One process in the metal finishing operation, bright stripping; better known in the industry as "bombing"; removes the surface oxidation and fire-scale from metal substrates. Typically, this is accomplished by immersing the substrates in a mixture of two hazardous chemicals, hydrogen peroxide and sodium cyanide, which generates a powerful, and dangerous, chemical reaction. This project investigates electrolytic bright stripping as an alternative technology to chemical stripping. It was found that using different electrolyte solutions for specific substrate compositions gave great results on gold alloys, copper, brass, and silver . We experimented mostly with a gold alloy electrolyte which after some modifications also gave us acceptable results with brass substrates as well. We are now successfully electrolytically stripping approximately 85% of the substrates that were once exclusively stripped by the use of chemicals. Worker safety has also improved due to the use of a less toxic and more controllable technology. The results of implementing this technology at The Robbins Company has proved it to be effective, economically feasible, and capable of reducing the use of hydrogen peroxide and sodium cyanide. Download PDF file (451.75 kB) |
VOC lacquer replacement for wood finishing. 1994.
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| TURI Technical Report No. 19. Smith & Wesson improved operations by eliminating the lacquer which contained volatile organic compounds (VOCs) in our Stocking Department. The substitution of carnauba wax eliminated VOC lacquer constituents: xylene, n-butanol, MIK, isobutyl isobutyrate, MEK, toluene, acetone and isopropanol. Smith & Wesson has always been interested in replacing the VOC lacquer with an aqueous-based alternative, but had never found the right product. This project was expedited in April 1993 when Smith & Wesson management challenged members of the Stocking Department to find a suitable alternative to the VOC lacquer presently in use. The project team met this challenge with an alternative process utilizing carnauba wax, a non-toxic, similarly priced product that enhances aesthetics. Download PDF file (430.02 kB) |
Cyanide-based electroplating elimination. 1994.
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| TURI Technical Report No. 20. Eliminating cyanide processes generates many benefits. The removal of extremely toxic chemicals from the workplace, and the reduction in waste treatment costs are among the most notable. This investigation demonstrates the replacement of copper cyanide based processes with a commercially available copper electroplating solution that contains no cyanides. Download PDF file (2.09 MB) |
Supercritical fluid extraction cleaner application. 1994.
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| TURI Technical Report No. 21. Texas Instruments Incorporated, Materials & Controls Group (TI), with headquarters in Attleboro, MA, has been actively pursuing alternatives to halogenated solvent vapor degreasing since 1984. Aqueous, semi-aqueous, and "no-clean" technologies have been implemented to reduce solvent usage by more than 60%. However, several manufacturing production units have been unable to find a technically feasible and cost-effective alternative to vapor degreasing. In 1990, TI qualified the use of supercritical carbon dioxide as a solvent capable of cleaning mineral oil residue from temperature sensitive metal parts. The conceptual design of the cleaner equipment included a large cleaning chamber capable of meeting TI'S cleaning requirements for an entire shift. The high capital cost of such a system prevented TI from employing supercritical fluid extraction technology in its routine cleaning operations. In 1992, TI engaged with CF TECHnologies (CF TECH) to evaluate the application of a smaller scale SFE technology to clean organic residues from metal parts assembled into motor protectors. Download PDF file (607.48 kB) |
Alternative fire extinguishing agents. 1994.
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| TURI Technical Report No. 23. Our group has prepared many non-volatile precursor (NVP) agents which have been shown to generate hydrobromofluorocarbon and olefinic bromofluorocarbon fire extinguishing agents when heated to temperatures typical of those encountered near a fire zone. The liquid NVP agents proved to be as effective as the most efficient Halon agents now in use. Solid polymer NVP agents are now being prepared for possible use in the prevention of fires in small enclosed areas. All NVP agents show greatly reduced emissions to the atmosphere, and would be predicted to have no ozone depletion, global warming or toxic vapor problems. Lower vapor pressures in the case of liquid NVP agents results in less of the agent evaporating en route to the fire zone. In addition, the greater streaming characteristics of the liquid NVP agents greatly reduces the agent requirements and increases the throw ranges, which results in increased safety for firefighting personnel. Solid NVP agents would have zero vapor pressure and thus no loss to the atmosphere due to evaporation. The chemical nature of all of the NVP agents prepared so far suggests that gradual hydrolysis to yield relatively innocuous materials would prevent extended environmental contamination. Download PDF file (277.65 kB) |
Reclamation of nitric acid from solder strip. 1995.
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| TURI Technical Report No. 26. The manufacture of printed circuit boards is a complex, multi-step process. As part ofthe process, a tin/lead solder coating is applied to copper circuitry in order to protect the pattern from the subsequent ammoniacal etching process. After the unwanted copper is etched from the surface ofthe printed circuit board, the solder coating is stripped from the remaining circuitry with a proprietary aqueous solution ofnitric acid, iron salts, and various inhibitors and adjuncts. When the speed at which stripping occurs drops below the PCC specified limit, the solder strip solution is considered "spent" and the entire solution is replaced. However, if the metals can be separated from the stripping solution, it is possible that the solution could be reused continuously, with adds made only to replace dragout. In order to reduce the nitric acid by-product generation PCC has implemented a diffusion dialysis acid recycling process developed by Pure Cycle Environmental Technologies, Inc. This proprietary design features an extended membrane area configuration that efficiently promotes the removal and concentration of the acid up to 95% ofits original strength with very little power consumption. The purified acid is directed back to the process tank, while the contaminant-laden spent acid stream goes to metal recovery or waste treatment for further processing. Download PDF file (389.96 kB) |
Toxics use reduction through process improvement, substitution & integral recycling. 1996.
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| TURI Technical Report No. 31. With the goals of toxics use reduction (TUR) and pollution prevention, Cranston Print Works Company has developed innovative technologies and methodologies for traditional textile processes. The focus of some of these efforts is the reduction in the use of acetic acid and sulfuric acid at Cranston's Webster, Massachusetts facility. In order to reduce cost, worker exposure to hazardous materials,and environmental impact, Cranston Print Works has implemented programs involving the TUR techniques of process modernization, in-process recycling and operations improvements. In-process recycling for an acid ager incorporated integral acetic acid recycling in the process. Control charting and automation of the process to monitor and regulate the use of acetic acid has resulted in significant reductions through process modification and operations improvements. Input substitution for end-of-pipe treatment has also been implemented, using carbon dioxide to replace sulfuric acid as a means of treating alkaline waste in the on-site wastewater treatment facility. Download PDF file (543.32 kB) |
Nitric acid recovery using diffusion dialysis. 1996.
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| TURI Technical Report No. 32. Danaher Tool Group, operating under SIC Code 3423, is a manufacturer of high quality steel ratchets for a variety of distributors. The cleaning of racks used in the electroplating process requires the use of nitric acid, a toxic chemical listed under the Toxics Use Reduction Act (TURA). As a result of toxics use reduction (TUR) planning, Danaher Tool Group implemented nitric acid recycling using an integral diffusion dialysis system in its Springfield, MA facility in 1994. Nitric acid can cause injury to plant personnel through inhalation, ingestion, or skin contact. The implementation of the diffusion dialysis system has reduced worker exposure, operating costs, and environmental impact. This report illustrates the successful implementation of diffusion dialysis technology including technical and economic feasibility. Download PDF file (506.93 kB) |
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