/ " ABES 94' 10th Annual Technical Business Exhibition and Symposium - May 10 11,1994 Von Braun Civic Center Huntsville, Alabama TABES Future Leaders in Science and Engineering Symposium Proceedings Paper 94-502 ENVIRONMENTALLY SOUND MANUFACTURING Larry A. Caddy NASA/Marshall Space Flight Center Ross Bowman Thiokol Corporation, Space Operations Dr. Rex A. Richards Thiokol Corporation, Interdivisional Coordinator TABES Sponsored Annually by Huntsville Association of Technical Societies P.O. Box 1964 Huntsville, Alabama 35807 Telephone: 205-837-4287 F~x:2 05-837-4275 Fw pcrmbka to copy w republirb, mtrt HATS a1 above ddrcm. TABES 94502 ENVIRONMENTALLY SOUND MANUFACTURING by Lvrry A. Caddy NASA/Marshall Space Flight Center Ross Bowmau Thiokol Corporation. Space Operations Dr. Rex A. Richards Thiokol Corporation, Interdivisional Coordinator ABSTRACT During the last three years, the NASA/ThiokoVindustry team has developed and stand implementation of an environmentally sound manufacturing plan for the continued production of solid rocket motors. NASA Marshall Space Flight Center (MSFC) and Thiokol Corporat~onh ave worked with other industry representa- tives and the U.S. Environmental Protection Agency (EPA) to prepare a comprthensive plan to eliminate all ozonodepleting chemicals from nianufacturing processes and reduce the use of other hazardous materials used to produce the space shuttle reus- able solid rocket motors. The team used a classical approach for problem-solving combined with a creative synthesis of new ap proaches to attack this challenge. INTRODUCTION The manufacturing processes that were acceptable in the early 1980s are not acceptable in the '90s. Forty--seven percent of the organizations that were Fortune 500 companies 10 years ago m - J no longer there. They were not adaptive enough to survive in the g#)~lst- _ . * .- .- J ' changing busir~ssse nvironment. As budgets become smaller and M3975%-12 competition requlies us to work smmer, faster, and more effi- Fig. 1. Sets of Bad Chemical Lists ciently. weneed tc make sure theprocessesandproductsw edevel- op in the '90s serve us aell into the 2 1st century. As our ability to Successful leaders must antiupate future reguldtlons and design gather data on the state of the Earth's environmental health in- their products and proce\ses to glve them an advantage when new creases. Enrimnn~enmllyS ound Manufacturing must become an regulations are ~rnplementedT. he dynam~cc hanges in business Integral part of the busmess dec~s~omna king process. and technology resultmg from the admin~\trat~ons'ece mingly par- adoxical goals of defic~tr eduction and tnfrastructure Investment BRIEF HIST9RY OF EN'lIRONMENTAL demand a stronger focus on the Rnanc~alc hallenges facing the REGULATORY ACTIVITY industry in the '90s. The '70s are remembered as the beginning of the . ,dative envi- This paper summarizes some of the plans and accomplishments ronmental movement with the passage of the h .tional E .;-on- . made by the NASA/T'hiokoVindustry team. New -hips. mental Policy Act (NEPA. 1969). the Clean Air and Clean .dter new techcologies, and new approaches and strategies have ken Acts, the Toxic SubstancesC onaol Act (TSCA). and the Occupa- some of the new resources employed as part of Thiokol's plan to tional Safety and Health Act (OSHA). The '80s concentrated on achieve environmentally sound manufacturing. treatment. storage, disposal, and cleanup of solid and hazardous wastes, and public involvement with the passage of the . TRADITIONAL APPROACH TO Emergency Planning and Community Right-to-Knv Act PROBLEM- SOLVING (EPCRA). The '90s have given us the Pollution Revention Act. the Oil Pollution hot. additional ngulations on hazardous air pol- Enginwing problem-solving usually consists of the following liimts (HAPS),w ater toxins. acid rain, and the production ban of step. 1) recognize a problem exists, 2) organize to deal with the ozone depleting compounds (ODCs) scheduled to take effect Ian- problem, 3) more clearly state the problem and establish a plan of uary 1. 1996. The Venn diagram, shown in Fig. I illustrates the action. 4) execute the plan, 5)a nalyzc the data and evaluate solu- interrelationships of the various lists of hazardous materials thaf tions. 6) qualify solutions into the manufacturing process, and art a pan of the regulatory picture. 7) report solution of the problem. TABES 94-502 1. RECOGNIZE A PROBLEM EXISTS When the Montreal Pmtocol members promulgated their docu- ment outlining theendof production of ODCs, the NASA/Tliokol team realized a need to start looking at changes to Thiokol matcri- als and processes in order to be prepared for eventual elimination of OKs. In 1992. when Resident Bush moved those elimination dates to 1%. the awareness of future challenges became much more acute. A likely extens~onto the end of RSRM production added to the immediacy of the problem of ODC replacement. When a survey was completed determining the processes that used ODCs and the quantities being used by the various divisior s. we mmwa 0.0 recognized the magnitude of our problem. 0 9 B O 8 1 9 2 Q ~ 0 l 9 7 ~ S B 0 0 O l ~ M1DtSJI-11 2. ORGANIZE TO DEAL WITH THE PROBLEM Fig. 2. Actual and Projected Reduction in TCA Usage Thiokol's Corporate Sdety and Environmental Affairs director appointd an interdivisional solvent elimination coordinator in early 1991. Each Thiokol division then selected a coonlinato: and was assigneda solvent replacement task based upon highest usage. Space Operations was assigned methyl chloroform-I. I. l-trich- loroethane (TCA). Each division was eventually tasked with n- placement of the solvents peculiar to their programs. 3. MORE CLEARLY STATE THE PROBLEM AND ESTABLLSH A PLAN OF ACTION An overall corporate hazardous solvent elimination plan was pro- duced. Eachdivision submittedapreiiminary elimination plan. An overall schedule was prepared in early 1991 predicting that pro- duction phaseout would come at the end of 19%. Bonds were recognized as being critical to the reliability of the motors. ther- fore. no bonds would be changed without data to qualify equal or better margins of safety. 4. EXECUTIVE PLAN- 0 1 2 3 4 5 6 7 8 9 10 11 12 13" 32 ODC ELIMINATION STRATEGY Use No. The ThiokolflrlASAs trategy used to eliminate all ODC from solid A0397534 rocket motor production followed sound engineering principles. Fig. 3. RSRM Uses of TCA The issue was well defined. There would be a production ban of ODCs on January 1, 19%. Thiokol Spcx Operations ODC use in 1989 had been almost one million pounds in direct manufacturing operations and anotker 400,000 pounds in indirect use (Fig. 2). A detailed study of each ODC used identified 852 manufacturing llouts in official planning documents. Ova 100 different bonds in the motor were affected Ihc rebability of the motor depends on these bonds to prevent hot gases from naching metal sbuctural components. A Paretoanalysis (Fig. 3) wasconducted to prioritize the 32 major categories of use. The two biggest usen wen vapor &greasers like the one shown in Fig. 4. This analysis indicated that approximately 90 percent of the TCA use was in the top four categories. i.e.. two large TCA vapor degreasers. diluent for pre- servative grease. and as a cleaner for propellant mix and cast tooling. Possible replacement processes for the vapor depaser wen evaluated. Requalification testing myired for all of the 852 planning changes and l00plus affected bonds were identified. An ODC team sorted through all of the possible altemate solutions to the required changes and developed a plan to eliminate all ODCs from the process. Fig. 4. Case Vapor Degreasing TABES -2 Industry Survey with five of th: best cleaners from each group: five aqueous. five semiaqueous.a nd five organic-or 15 total-beforc a finaldown- As the scope of the bonding process changes became clear. NASA selection of the two best cleaners was ma&. Both an aqueous andr a7dThiokolengineers beganan mdustry survey to identify options semiaqueous cleaner produced bonds that demonstrated superior and alternative processes. Over a twc+year penod. 31 different fracture toughness and tensile adhesion test data, with acceptabk companies were surveyed todetermine how they were responding to the production phaseout of TCA. Forty-nine technical papers results in all other areas tested. A typical set of data for steel tensile adhesion strength is shown in Fig. 5. presented at seminars, workshops. and NASA-sponsored work- ing groups were evaluared. Data were summarized and a report was published in March of 1993. A matrix was prepared listing the substrates, preferrcdcleaners. an4 the person leading the project at each company. A distribution analysis was made of usage for cleaners selected by two or more organizations. From this survey, a list of factors to consider in the selection of replacement solvents and cleaners was created: Industrial safety considerations 8 Flammability, toxicity. allowable exposure Environmental release requirements Ozone-depleting and global-warming poten- tial. volatile organic compound level 8 Product safety Cleaning effectivity as measured by bond test results. residue on substrate, effect on metallur- gical properties. material compatibility, corro- sion potential, shelf-life (aging) capability Cleaning efficiency Material and labor cost. availability, evapora- tion rate, soil loading capacity. stability. recy- clability. d~sposacl ost. energy cost, versatility Capital investment Wlthout Grtl Blast Wlth Grtl Blast Floor space required. capital expenditures, esti- A03975361 Fig. 5. Nozzle Bondline- mated life-cycle cost for equipment Tensile Adhesion Test Data THE MAIN CONCLUSION OF THE INDUSTRY SURVEY WAS THAT WHILE MUCH CAN BE LEARNED FROM OTHER COMMNIES' EXPERtENCES AND DATA. EACH COMPAlVY 6. QUALIFY SOLL'TIONS INTO PROCESS-- .MLIST TAILOR CLEANING PROCESSES TO THE t?4RTICL/- DESCRIPTION OF PHASE I-ELIMINATE LAR SOILS. SUBSTRATES AND PERFORMANCE REQL'IRE- 90 PERCENT OF TCA MENTS OF THE PRODUCT BEING MANUFACTURED. The Phase I plan to elimmate 90 percent of the TCA was focused first on eliminating the four b~pgestu srr. i.e.. the solvent in two Hierarchy of Suitable Cleaning Alternatives large vapor degreasm. cleaner for propellant tooling once it is Time and money are saved when permanent solutions ans elected out of the propellant mix and cast buildings. and d~luentu sed to rather than short-term fixes. Dr. Katy Wolf. the executive director thin the preservative grease. This effort is tune-phased: Step I- of the Institute for Research and Technical Assistance (IRTA). was replace the Refurbishment Center's vapor degreaser with a high- very helpful in suggesting that companies follow her low-risk pressure water wash system and implement greaseless storage and hierarchy of alternate cleaners, i.e.. no clean, water, aqueous, shipment of hardware: Step 2- -replace the Manufacturing Car- semiaqueous, combustible solvents, and flammable solvents in ter's vapor degreaser with a spray-inair precision cleaner and decreasing order of desirability qualify tool cleaning process for propellant mix and cast tooling. The master schedule for this effort is shown in Fig. 6. 5. ANALYZE DATA-PRELlMINARY TEST PROGRAM The Step 1 effort is 30 percent complete. Components for the In the early stages of selecting a replacement cleaner for TCA at high-pressure water wash system are in the procurement cycle. Thiokol, all potential cleaners were considered. Idtial screening tests favored organic cleaners because the hardware's preservative The Step 2development and qualificatione ffort iscor~tinuingw ith grease is soluble in organic cleaners. If all aqueous cleaners had the selection of a final cleaner to be made by mid-1994. The been eliminated because the grease preservative was not soluble in designing of the spray-in-arr system will begin in Octobcrof 1994 them. the best cleaners would have been missed as measured by and will beoperation-'bj early 19%. At thattime.TCA usage will fracture energy. tensile adhesion, and residue after final rinse. have been reduced by 90percmt from 1989 levels and TCA anis- Fortunately, the test program was structured to continue testing sions by 95 percent. TABES 94-502 Conwrvltkn - - All Schedub Am Met and Essential Urn Exmptlon Omntml M397UcB Fig. 6. Master Schedule for Replacement of ODC Phase 11--Eliminate Remaining 10 Pemnt of TCA, Stockpile, and Obtain Essential Use Waiver The Phase 11 plan eliminates the remaining 10 percent of TCA usage by the end of 1999. Critical uses of TCA associated with hand cleaning. rubber activation, and equipment cleaning that A c.kndrY"r could affect critical bonds and processes essential in propellant Y m r k nE #mtbl UU mix and cast areas where a flash fire could be catastrophic are M39753a-3 included in Phase U. The rernaming 10 percent TC'A use affects Fig. 7. ODC Program-TCA Usage approximately 80 percent of the bonds (78 of the 101) critical to the reliability of the Space Shuttle system. An approach was estab- lished to request an Essential Use Exemption from the Solvents, dancy. The NOET provides excellent opportunities for coop- Coatings, and Adhesives Technical Options Committee of the erative efforts among NASA centers, other federal agencies. United Nations Environmental Program. This approach would subcontractors. educational institutions. and private industry. allow time to address schedule and cost toensurechangescould be The NOET team leader is NASA's Robert (Bob) J. Schwing- qualified prior to useon flight motors. Discussrons were held with hamer, deputy director of Science and Engineering at MSFC. the Environmental Protection Agency (EPA),N ASA, andThiokol NASA: Assured Shuttle Availability regarding the approach, and positive indications were received. The Montreal Protocol criteria for an exemption were obtained. In 1992. Johnson Space Center (JSC) and MSFC provided and a final request to purchase 125.000 pounds of TCA per year funding to allow Thioko~to conduct testing of alternate hard- was submitted to the EPA on June 24, 1993. The United Nations ware preservation and shipprng techniques at the refurbish- committee met in October of 1993 and reviewed the exemption ment facility. The Assured Shunlc Availability (ASA) pro- request with final decision on the exemption to be made in the fall gram demonstratd a process flow that eliminated the need for of 1994. If the exemption request is approved and scbeduies ar? the three vapor degrease cycles and proved preservative met. we will not require stockpiling of TCA (Fig. 7). grease is not required if the hardware is protected from the weather and high humidity conditions (less than 45 percent Creative Synthesis of New Resources relative humidity ). Thrs program generateddata to support the concept of "clean wce and keep rt clean." and v.111 redt in Theexecutron of our plans rnvolved a bringing-together of a num- wbstantial cost savings andenvironmental benefit5 uhen qu- ber of nem resources: 1) new partnershrps. 2) new te~hnologies. alified for production. An env~ronmentallyc ontrolled trarler and 3) new approaches and strategies. has been procured to ship segments 60 miles between plants New Partnerships. Ou; efforts benefitted greatly from the new without preservative grease diluted with TCA (Fig. 8). partnerships fonned with governmental organizations, profes- Environmental Rotection Agency sional groups, indushy associations. and academia. The EPA Stratospheric Ozone Protection Division and the a. NASA Operational Environmental Team United Nations So:vents. Coatings. and Adhesives Technical The NASA Operational Environmental Team (NOET) was Options Committee arc providing orr-going s u mto the established in April 1992 to provide the entire NASA team a amspace industries' efforts to find acceptablea lternatives for central resource to pursue replacement technology. The focus ozonc-dcpleting chemicals.T his partnershiph as provided ac- of this team is environmentally questionable materials and cess to foreign and domestic experts and has helped avoid related processes involved in the design, development, test. duplication of effon while increasing confidence in the per- and manufacture of NASA hardware. The two elements of the formance of selected alternate materials and processes. Dr. NOET, the Replacement Technology Team (RT2)a nd the Pro- Stephen 0. Andersen is the deputy director of the U.S. EPA pulsion Technology Team (ITZw).o rk through the existing Stratospheric Protection Division and chairman of the United program structure to emphasize resource prioritization and Nations Solvents, Coatings, and AdhesivesT echnical Opaons trade studies. to address technical issues, and to avoid dun- Committee. TABES -502 a. Higb&ssure Water Wash Thiokol has used high-pressure water systems in the 10.W to IS.OO&psi range to remove insulation fnnn metal pans since the mid-1960s. A new application of ultrahigh-pressure water up to 36,000 psi is planned as a replacement process for TCA vapor degreking and grit blast with zirconium silicate. This environmentally superior process will eleminate TCA use, reduce process cycle times, and increase hardware life because metal removal rates with water arc an order of magin- tude less than with grit blast media. 'Ibis equipment is being demonstrated in the NASA Technology and Roductivity En- hancement Laboratory at MSFC. Reduction equipment is on order and is scheduled for installation and checkout during the first quarter of 1995. A sketch of the new equipment is shown in Fig. 9. Fig. 8. RSRM Case Shipping System ODC Phase Zero d. NASA Headquarters (Environmental Engineering) The Chief Environmental Engineering Office at the Office of Space Flight (OSF), NASA Headquarters. has taken an aggressivea pproach to protecting theenvironment. This small staff has opened channels of communication between the EPA. NASA, and contractors to provide the free exchange of information. Mr. Steven Newman is OSF's chief environmen- tal engineer. e. Aerocpace Industr~esA ssoc~at~on Th~okolCorporat~on.asmae mber of the A-rospace Indusmes Association (AIA), has participated on the Environmental Ac- rivities Committee. Members include the major air frame manufacturers and their suppliers. the solid rocket motor man- Fig. 9. Ultrahigh-pressure Water Wash System ufacturers. and other aerospace organizations. Meetings have provided valuable contacts with knowledgeable senior ex- b. Spray-m-Air With Aqueous and Semiaqueous perts where information is exchanged in many areas of envi- Cleaners ronmental concern. Mr. Glynn Rountree is the AIA chairman of this committee. Aqueous and semiaqueousc leaners had been used in dip tanks followed by a rmse and drying of the mled part. Thiokol t Academia proposed using a \pray-ln-a~r method that would be cheaper Br~ghamY oung Un~versity was glver! a study cdntract to and glve a cleaner pan. Data gathered are shown in Fig. 5. evaluate improved shipping and preservation methods. Their study supported the ASA Project conclusions which were to c. Low-Emission Vapor Degreasing get the hardware clean at the refurbishment facility and pro- The first consideration in finding a replacement for TCA used vide shipping containers to keep it clean during the bile in the vapor degreasers was to evaluate a switch to perchlore transportation trip to the main plant. ethylene. It does pose health risks, and, therefore, has a low (50 ppm) permissible exposure limit. An alternative to ope~op The University of Alabama was conaactcd to develop and vapordegreasers is an airtight system known as low-cmission demonstrate a single strand fiber optic system capable of pro- vapor degreasers (LEVDs). Two manufacturers were con- viding quantitative information on the nature of contaminants tacted and several meetings held to understand how the LEVD on steel, aluminum, and phanolic systems. The principal in- system works. The process was determined to be a viable vestigators on this study are Mr. Roy Mam of Thiokol and Dr. alternative, but was not selected because of relatively little Gary Workman of University of Alabama at Huntsville. demonstrated use in US.i ndustry on parts the size of RSRM New Technologies.The team implementedplans for solvingenvi- cases. Also, the potential for future legislation on exposure ronmental problems. We benefitted from the application of new and use of perchloroethylene was a concern. Thc two leading technologies and provided additional processing benefits. Some suppliersofthisequipment are DUrr Industries, Inc., and Bamn of those arc described below. Blakeslet. TABES 94-502 Surface Cleanliness Measurements reserved for use just prior to bonding operations at the Man- ufactunng work center. High-pressure water could remove The question of "How clean is clean?" has been with us for a paint and adhesive residue faster and better thm the existing long time. Much has been accomplished to quantify the mea- grit blast process. The life of the flight hardware could be sure of cleanliness. NASA developed an optically stimulated extended with the h~gh-pressurew ater wash because less met- electron emission (OSEE) device called ConScan that mea- al would be removed than with grit blast. The change to ultra- sures surface cleanliness levels and oxides and plots them for high-pressure cleaning at the Refurbishment Centa was ac- acceptance analyr*is.'3 iokol has been using the system since cepted and eventually proved to be the best plan, once again 1988 toensureacceptable surfacecleanliness prior to bonding demonstrating that "the user knows more about the real pm- andcoatinued reliab~lityo f motor performance. The principle cess than anybody else." contact at NASAWSFC is Mr. Billy Nerren. TheThiokol-de- veloped SurfMapTMin frared contamination detection device usesdiffuse. back-scattered light in the mid-infrared region to 7. REPORT SOLUTION OF PROBLEM monitor a surface for the presence of hydrocarbons. The con- tact at Thiokol is Mark Walker. An engineering and environmentalc hallenge was presented to the NASAmiokoVindustry team when the international dec~sion Surface Chemistry Analysis was made to stop the production of ODCs. The team used aclassi- Thiokol has made extensive use of laboratory surface chemi- cal approach for problem-solving combined with a creative cal analysis methods in the evaluation of replacement cleaning synthesis of new approaches to attack the challenge. processes for methyl chloroform vapordegreas~ngo f steel and Summary of Lessons Learned aluminum bonding surfaces. Techniques include electron spectroscopy for chemical analysis (ESCA). auger electron Establishing clear selection criteria for daisions at spectroscopy (AES), and static secondary ion mass spectrom- the beg~nningk eeps the program on m k etry (static SIMs). ESCA, AES, and static SIMS are sensitive Industrial safety considerations must be evaluated to changes in the topmost atomic layers of a surface which are when selecting alternate cleaners directly ~nvolvedi n bonding. The principal investigator at Thiokol is Dr. Mike Lesley. Examination of current process and minor changes reduced TCA useage by 50 percent bond strengths depend on cleanliness and surface New Approache*a nd Strategies chemistry a. Pollution Prrvent~on Listening to the people who will have to ~mplement The 1990s approach to enhancing the environment is prsvent- the plan improves results ing pollut~ona t the source by better. smarter planni,~oT~ t he Cost considerat~onasr e important and can be a posi- product design and the manufacturing process. The EPA h3s wec ompetition factor published a document (Facilih. Pollution Pmrntion Guide. While much information can be learned from other EPA/600/R-92 088) May 1992. that provides excellent in- companies' experience. each company must tailor structions on how to establish and maintain a successful pollu- the cleaning procesb to the part~cular\ oh. wb- tion prevention program. The document may be obtained \trates and performance requirements of the prod- from: U.S. EPA, OMce Research & Development, Wash- uct being manufactured ington. D.C. 02460. CONCLUSION Most large organizat~onsh ave a cupply system that Issues S~ncem any of the proces\e\ that were ~cceptabkIn the early materials to the production line. On controlled programs. the 1980s are no longer environmentally acceptable In the 1990s. quality of the material is assured by the seal on the container. companies need to make drastic changes to their thinking, materi- Once it is broken, and residual material cannot be returned to als, processes, and manufacturing in order to stay competitive. Stores. If the smallest unit of issue is a gallon and the user only Companies are basically concerned with how to get the best envi- needs a pint, the result is scrap material, which is wasteful and ronmental program while under tight budget constraints. Mating expensive to dispose of. By understanding the needs of the environmental requirements necessitates making changes to the production line, material can be issued in quantities actually way products are manufactured. The requirement to make changes used, avoiding waste and expense. to processes can be an opportunity rather than a burden. Since all companies must make changes at this time, leaders can make c. Listen to the User changes in a manner that will give them a competitive edge. They A significant change in direction occurred in kcember of have an opportunity to examine their manufacturing paradigms 1992 when Manufacturing Center directors responsible for and incorporate better ones. New cleaning methods should make the cleaning operations made several suggestions that com- operations more economical where possible. These new environ- pletely changed the direction of the ODC replacement pro- mental requirements give companies an opportunity to modcmk warn. They suggested that high-pressure water be used for while making the workplace safer and reducing emissions of haz- refurbishment operations and the final precision cleaning be ardous materials.