This support document is presented through the EPA Common Sense Initiative. It reflects the input of stakeholders and does not represent consensus of the participants
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The U.S. Environmental Protection Agency (USEPA) Common Sense Initiative Auto Sector Subcommittee membership is made up of a cross section of stakeholders from government, industry and associations with an interest in the automobile assembly operations. These stakeholders are represented by professionals with varied credentials from technical and non-technical fields. In the Life Cycle Management/Supplier Partnership project team, an array of manufacturing technologies are often points of discussion. This document was produced for the benefit of those not familiar with these technologies. It is intended to provide a simple, non-technical overview of the manufacturing operations performed by the automotive parts suppliers. Examples cited are for illustration only and are not intended to be all inclusive.

John O. Sparks, USEPA, Office of Air and Radiation, was the principal writer and compiler of "Identifying the Supply Chains for Automotive Assembly Plants".

Additional contributions and editing comments were received from:

• *Linda Anderson-Carnahan, USEPA, Region IV
• *Terry Cullum, General Motors Corporation
• *Gary Davis, University of TN Center for Clean Products and Clean Technologies
• *Gorton Greene, Ford Motor Company
• *Charles Griffith, Ecology Center of Ann Arbor
• *Steve Farrington, Textron Automotive Company
• *Monica Prokopyshen, Chrysler Corporation
• *Robert Kainz, Chrysler Corporation
• *Timothy (Tim) C. Hughes, Pittsburgh Plate Glass (PPG)
• *Julie Lynch, USEPA, Office of Prevention, Pesticides, and Toxic Substances
• *Keith Mason, USEPA, Office of Air and Radiation
• *Vic Young, USEPA Region IV, Waste Reduction Resource Center

This document describes the production processes associated with different categories of parts provided by automotive suppliers to assembly plants. It is intended to be a "living" document, and will be refined as new information is uncovered. For the purposes of this analysis, the automobile is segmented into the following groupings:

• Body Parts
• Engine and drive train parts
• Suspension and brake parts
• Electrical/electronic parts
• Heating, cooling and air-conditioning systems
• Glass
• Interior Parts

Typically, the manufacturing process used for each category of part is different. Similarities may occur during the execution of common, basic operations, such as painting. In general, suppliers specialize in the manufacturing processes needed for their segment. Some of the larger firms, however, are involved in several of the market segments
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BODY PARTS

This category consists of hoods, fenders, doors, fascia, roofs, and similar parts. Production takes place in two distinct phases. The first phase involves formation of the part, either by blanking and stamping (for metal parts) or injection or sheet molding (for plastic parts). The second phase involves surface finishing and coating.

Production Flow for Metal Body Parts

1. The metal coils (cold-rolled and oiled-steel or aluminum) are delivered to the facility from a steel/aluminum mill or service center (distributor).

2. The metal is then cut to size for the stamping/forming presses. Just before entering the presses, a lubricating compound is applied to help the forming process. Suppliers are increasingly replacing mineral oil lubricators with synthetics (soaps, fatty acids) because the latter can be reduced with water and are generally easier to clean before painting. Also, industry believes that synthetics are easier to treat and dispose of than mineral oils.

3. The formed metal part may then be "hung" on a conveyorized line that travels at a speed of 10 to 25 feet per minute. The parts are then chemically processed and electro-deposition primed in the following continuous sequence:

• Step 1. Aqueous cleaning to remove the processing lubricants. This step involves application of a hot, aqueous alkaline cleaning solution using a "spray washer." The spray is recovered in large tanks beneath the spray zone and reused until spent. Normally, cleaners last between one week and one month, depending on the volume and footage of metal processed. All of the lubricating compounds are concentrated during this operation, and are normally skimmed off and drummed as waste. In some systems, an immersion cleaning step follows the spray cleaning.
  
  
• Step 2. Fresh water spray rinsing. The collection tank overflows continuously into the waste treatment system.
  
  
• Step 3. Activation for zinc phosphating with a very dilute titanium phosphate solution.
  
  
• Step 4. Zinc Phosphating. This is done using phosphoric acid/nitric acid solution (pH about 2.5) containing solubilized zinc, nickel, manganese and ferrous metals. Fluorides are also present to aid in processing zinc clad (galvanize) and aluminum metals. Phosphating can be accomplished with either a spray or immersion process. Sludge is a continuous by-product of this operation, and is removed, dried, hauled and usually land filled.
  
  
• Step 5. Overflowing freshwater rinse to remove unreacted acid. Overflows are directed into the waste treatment system.
  
  
• Step 6. Chromic acid pacifying rinse. This rinse is a very dilute solution of hexavalent and/or trivalent chromic acid. Because of the chrome, it is carefully contained so it does not co-mingle with the other solutions. When spent, it is treated separately and does not seem to be a major problem for users, but involves considerable handling and disposal expense.
  
  
• Step 7. Deionized water (DI) rinse. This is the last step before electro-deposition painting (E-coat). It is important not to use tap water in this process, as ground water salts from tap water will contaminate the E-coat tank. The DI is continuously regenerated and sometimes counter-flowed to rinses in earlier steps. Reverse osmosis membrane technology is becoming much less expensive and is beginning to challenge deionized methods that require chemically treated resin beds.
  
  
• Step 8. Cathodic electro-deposition primer. Often this is the last wet process for a supplier. The part is primed in an E-coat bath, rinsed with DI water and cured in an oven. Transfer efficiency is excellent (90%+). Although most formulations still contain lead, this process is contained and produces very limited amounts of volatile organic compounds (VOCs) and effluent. Lead free technology is now (or will soon be) available.

If no other coating occurs, the best opportunities for pollution prevention, recycling and source reduction are in the front end of the process. Several possibilities are described below.

• Eliminating or recycling the current processing lubricants. Dry film polymer lubricants have been developed by Pittsburgh Plate Glass (PPG). Steel mills, aluminum producers and/or coil coaters can apply these before the raw materials enter the supplier's plant. They provide corrosion protection en route and lubricity for forming. Precoated, dry lubricant films on coiled steels could also be an opportunity for the iron and steel CSI group. Most steel producers already have in-house expertise in prepainted coil stocks (coilcoating). This expertise is likely transferable to dry lubricants.
  
  
• Petroleum oils could be used as forming lubricants, formulated to split from aqueous solutions and recycled into the same operations. At present they are only used once, washed off, and disposed.
  
  
• The aqueous cleaners and rinses can be closed-looped to extend life and greatly reduce effluents. The zinc phosphate process can also be closed-looped, but with more difficulty.
  
  
• Non-chrome pacifying rinse agents do not perform as well as chromic acid but, the performance gap is closing.
  
  
• The zinc-bearing sludge from the zinc phosphate coating process does have some commercial value. At least one company recovers the zinc from these sludges as zinc oxide. The zinc oxide is then sold as a raw material.

1. The formation of plastic parts generally requires an injection molding machine (flexible parts) or a press (rigid parts). Some mold releases are required, but these processes are otherwise clean.

2. After molding the parts may be "hung" or placed on racks in a conveyorized system and chemically processed and painted in the following steps:

• Step 1. The molded parts have mold release, dirt and dust that have to be removed. This is normally accomplished using a phosphoric acid-based cleaner in a recirculating spray washer.
  
• Step 2. Fresh water spray rinsing.
  
• Step 3. Deionized water (DI) rinse.
  
• Step 4. Freshly generated deionized water. The overflow from this step normally counter flows into the Step 3 DI rinse.
  
• Step 5. The remaining water is evaporated in a drying oven. Water spots in this drying process must be avoided (which makes DI rinses critically important).
  
• Step 6. This is a cool down period. The parts are still on the conveyor and moving through the system.
  
• Step 7. Spray painting with plastic primer or color-coated with standard colors.
  
• Step 8. Oven curing of the painted parts. After wiring, the parts are removed from the conveyor, packed and shipped.

These operations tend to be cleaner than metal parts manufacturing. Opportunities for improvement may include the changes described below.

• Closed-looped cleaning and rinsing.
  
• VOC reductions from the spray painting operation.
  
• Improved transfer efficiency to reduce paint waste and to minimize water wash paint booth sludge.
  
• In-mold coatings could eliminate some of the coating processes and possibly all of the priming steps.

Engine and drive train parts include castings from a foundry, parts that have been machined from metal stock, tubing and springs, and an array of polymeric seals. In addition, some stamped and painted parts are used in the engine and drive train, such as pulleys, mounts, covers and oil pans. The engine and drive train segment is primarily made up of machine shops (independent and captive) that utilize metal removal techniques by machining (grinding, milling, turning and polishing). The principle processing fluids used are cutting oils, coolants, rust inhibitors and cleaners. Most of the larger shops have several machines that share coolants (metal removal lubricants) from a central sump, in addition to some specialized machines with their own small sump. The central sump coolants are continuously filtered and recirculated back to the machines. The longevity of these fluids is very important to the economical operation of the business. For this reason, the sumps are treated with biocides/fungicides to check biological growth in the fluids. Most companies employ specialized fluid maintenance equipment that filters and adds more biocide and lubricant concentrate to ensure optimal life and performance. Painting may occur but is normally a smaller operation, and with less demanding appearance requirements than body part painting. The major types of fluids used in metal removal processes are described below.

• Straight oils are mineral oils formulated with performance additives. They provide excellent lubricity, but poor cooling (heat removal from the cutting tool and part). In general, this is an old technology but some operations still require it.
  
• Coolants are water based lubricating fluids. The water provides the lubricant with excellent heat removal properties. The result is longer tool life, better work and reduced hydrocarbons in the fluids. Coolants are generally divided into three categories: soluble oils, synthetics and semi-synthetics. Soluble oils are actually emulsions of mineral oil, additives and water. When diluted with water, these oils become milky emulsions. Synthetics are saponified vegetable oils, fatty oils and additives. These fluids are more soluble than oils and are mostly clear. Semi-synthetics are blends of soluble oils and synthetics, but contain much less mineral oil.

For several reasons, companies are increasingly substituting synthetics for mineral oils. Most manufacturers know that grease and oil is monitored in effluents. Furthermore, anaerobic bacteria thrive in oil emulsions, which therefore require constant monitoring and treatment with biocides. Biocides are regulated, expensive, and can cause dermatitis among the workers. While synthetics have fewer of these problems, they are susceptible to fungus. In addition, they do not have the lubricity of straight oils or soluble oils in severe operations, and machining of aluminum is more difficult with synthetics.

Production Flow for Engine Parts

The manufacturing of larger engine parts (blocks, heads, pistons, valves, cam shafts, etc.) begins in a foundry, although some smaller internal parts and external "bolt-on parts" are formed from steel stock. The foundry parts are normally cast in molds and transferred to a machining facility for final finishing. The normal production flow involves the following steps.

• Step 1. Molten iron or aluminum is cast into moldings. Sand or die castings are the common processes. The sand is mixed with a bonding resin and formed into a mold. The extreme heat of the molten iron causes the resin/sand mold to break down. The remaining loose sand is removed from the part.
  
• Step 2. The molded part is cooled and transported to a machining facility.
  
• Step 3. The machining facility uses various tools to remove excess metal and further hone the parts into smooth, precision pieces.
  
• Step 4. After machining, the parts are washed in an industrial washer with aqueous cleaners to remove metal chips and various oily soils. Rust inhibitors are applied here, as either part of the washing cleaners or as a final step in the washing process.
  
• Step 5. The parts are moved to an assembly area and assembled.
  
• Step 6. The engine is shipped to the assembly plant for installation.

Opportunities for pollution prevention, recycling, and source reduction may exist in both the foundry and the machine shops. Obvious areas to explore in foundries include emissions from melting operations, VOC emissions from resin flash-off, casting sand and clay binder reclamation and effluents from the various cleaning processes.

More opportunities may exist in machining operations. In larger operations, most machining fluids are managed through the use of professional contract chemical management companies. Most of these companies also supply machining fluids and metal cleaners and have an interest in maintaining the machining fluids market. More source reduction can be implemented through the efforts of non-fluid suppliers as well. Some possibilities include:

• Dry Machining - This is being done on a small experimental scale at Ford Motor Company.
  
• Powdered Metal Forming and Sintering - Dry powdered metal is formed in "cookie cutter" molds and heated to 1100-1200 degrees Fahrenheit in sintering ovens and fused. This process eliminates metal shavings, metal chips, and machining fluids, although some final touch-up machining may be needed. This process is now used for some connecting rods and gears used in transmission and oil pumps. When mixed with resins, the powdered metal can be injection molded like plastics. This could be useful for valve bodies and other complex parts.
  
• High-Temperature Plastics and Ceramics - These materials are finding more applications in experimental engines. These technologies could nearly eliminate the need for engine block foundries and greatly reduce machining requirements.

Drive train parts are assembled into transmissions, differentials, and axles. Except for the housing and certain valve bodies that are cast aluminum or steel, most of the metal parts in these components are machined from steel stock into gears, shafts and rotors. The machining processes are similar to those used in engine manufacture.

SUSPENSION AND BRAKE PARTS

Brake parts include brake drums/discs, wheel/master cylinders, and backing plates for drums/discs. The suspension includes struts, shocks, springs and the mounting assemblies for these parts. The processes used to make suspension and brake parts include casting, forming, machining, and painting. These operations have been described in previous sections of this memo, as have pollution prevention and recycling opportunities. Brake pad manufacture is not explored in this document.

ELECTRICAL/ELECTRONIC PARTS

Automobile companies are including more electronics in standard equipment and add-on options. Standard equipment, including electronic engine controls, speed controls and air bags, contain printed circuit boards, relays and various chips. Options include upscale stereo systems and cellular phones. Electronic mapping and satellite positioning devices are also becoming available.

Since these components are used in other types of consumer equipment, it may be useful to involve the CSI electronics group in this portion of the life cycle analysis.

Opportunities for pollution prevention and recycling include solvent substitution in cleaning and conformal coatings, substitution for heavy metals in solder and chip manufacture, and development of closed loop aqueous cleaning systems. The manufacturing of most electronic parts requires in-process cleaning at various points in the process. Until recently, most companies used CFC-113 or methyl chloroform (MCF) solvents. The Montreal Protocol and the U.S. phase-out of Class I ozone depletors, effective January 1, 1996, has forced companies to find acceptable substitutes. U.S. EPA's Significant New Use Policy (SNAP) program has published several manuals on alternative products and methods. Additional pollution prevention and recycling opportunities may come from other programs and offices within EPA (e.g., CSI, DFE, SNAP, and ORD) that have focused on this area. For this reason, electronics suppliers may need a catalog of existing pollution prevention, recycling, and source reduction research and literature.

Electrical part manufacturing is a mature technology sector. Starters, alternators and small electric motors for electric windows, windshield wipers and wiring harnesses are typical electrical parts, and have not changed much in recent years. Opportunities for pollution prevention and recycling may come from machining operations (described previously) or in the coating of cast iron housings and stamped steel covers. Both captive and independent parts suppliers have already started electro-deposition painting. Some are using auto-deposition coating, a newer technology that is applicable for parts where color (normally black) and appearance are not particularly important. Auto-deposition (or autophoretic) coating is an immersion process that is chemically driven and far less energy intensive than electro-deposition. Auto-deposition coatings provide corrosion protection, but to a lesser degree than electro-deposition.

COOLING, HEATING AND AIR-CONDITIONING SYSTEMS

This sector includes finned heat exchangers (radiators, heater cores, evaporators for air conditioning, condensers for air-conditioning systems and oil coolers), compressors for air conditioning systems, and tubing. The compressor is an assembly of castings and machined parts. These processes have been discussed previously in this memo and are not repeated here. Conversely, heat exchanger manufacturing is a unique operation that might offer pollution prevention and recycling opportunities.

Most automobile heat exchangers are made of aluminum or brass components. Aluminum products are more widespread, and so this section focuses on aluminum heat exchangers used in radiators, condensers and evaporators.

Production Flow for Aluminum Heat Exchangers

The major components of heat exchangers are the aluminum fins, aluminum internal tubing, and in the case of radiators, reservoir tanks.

Aluminum Fins

1. Aluminum roll stock is unrolled, lubricated and corrugated, normally in a continuous line. This process is either performed in-house or by an outside supplier that specializes in this process.

2. The corrugated aluminum is cut to size for assembly.

Aluminum Tubing

1. In a continuous operation, aluminum roll stock is unrolled, lubricated, shaped into tubing in a "roll mill" machine, welded, and cut to size for assembly or shipping. As with fins, this process can be done in-house or through an outside contractor.

2. The tubing is assembled together with the fins in a temporary rack for cleaning, fluxing, and brazing.

3. Before fluxing and brazing, it is important to have a very clean assembly, as poor brazing can cause leaks in the final product. Cleaning ensures that all processing oils are removed. In the past, vapor degreasing with CFC-113 or methyl chloroform was the preferred cleaning technique. With the pending CFC phaseout, most manufacturers have installed aqueous cleaning alternatives.

4. Immediately following the cleaning process, the part is fluxed and brazed. Normally, the "braze" is a soft aluminum alloy laminate that was applied earlier in the process. The original aluminum roll consists of three alloy laminates. The first laminate ends up on the inside of the tube and is corrosion-resistant, because of its exposure to the engine coolant. The middle layer is the base aluminum that provides rigidity to the part, and the third and final laminate is the "braze".

5. Immediately following the fluxing operation, the part enters the brazing oven where the outer alloy fuses the "racked" parts together into a single unit.

6. For radiators, the next and final step is to attach the nylon reservoir tanks. The other heat exchangers undergo additional, minor processing and are transferred to assembly or shipping. The lone exception is the air-conditioning evaporator, which is treated with corrosion-resistant chromate conversion coatings. These evaporators condense moisture during use and therefore require additional corrosion protection.

Pollution Prevention and Recycling Opportunities

The processes are Original Equipment Manufacturer (OEM) "state of the art" and incorporate pollution prevention and recycling activities. Vapor degreasing with CFCs and other chlorinated solvents has been replaced with substitutes (mostly aqueous cleaners). Mineral oil lubricants used in the corrugating and tube forming process have been replaced with synthetic fluids or vanishing oils. Alternative chromate conversion technology has improved substantially in recent years, and is starting to be used by some OEMs. A technology transfer of these pollution prevention and recycling advances to OEM suppliers would promote lifecycle management to the supplier chain.

Because vanishing oils consist in part of volatile hydrocarbons and VOCs, they may pose air pollution risks. A "closed loop" system that recaptures the volatiles would be a definite improvement and could make this approach more viable. Another approach may be to develop "dry film" technology to replace the hydrocarbons altogether.

GLASS

Glass is expected to continue to be the preferred material for making automotive windows for many years to come. Automobiles consist of side and rear glass that is solid tempered, and windshields that are laminated. All automotive glass is fabricated from plates of flat glass shipped to the fabricating plants. The flat glass plants (or primary plants) manufacture flat plates of glass from raw materials and recycled cullet. Batches are made into various tinted, solex and clear substrates. Like the aluminum industry, the glass industry has long found it feasible to reuse and recycle waste cullet internally at the primary plants and ship waste cullet back to the primary plants from the fabricating plants.

With increasingly more aerodynamic installation angles in windshield designs and more aerodynamic contours and bends/wraps in side and rear windows, glass is making up a greater percentage of the surface area in cars, mini-vans, and recreational vehicles.

Production Flow for Automotive Glass

Side and Rear Tempered Glass

The process begins at the Cold End by cutting and grinding the edges of the flat glass to give the part its two dimensional shape. Next, a black ceramic frit is silk screened along the perimeter of the glass to give each part a paint band designed to mask the interior molding of an assembled vehicle. The ceramic paint contains very fine cullet frit that augments adherence to the glass when heated in the ovens. For back windows, this ceramic frit includes silk screening the defroster with electrically conductive silver paint. At the Hot End, the tempered glass is then formed into a three dimensional shape by heating it and pressing it with a full surface press.

Laminated Windshields

The laminated windshield process also begins at the Cold End where windshield parts are cut and the edges ground into their two dimensional shapes. Because a windshield includes two plates of glass, the part passes through the silk screen room with an inner and outer plate. A black ceramic paint band is silk screened along the perimeter of the inner plate to create the window mask. Using a gravity pressing method, the glass is heated and formed into a three dimensional shape on bending irons. Each windshield is then assembled by adding a sheet of cut vinyl between the two plates of glass. The windshield is reheated and pressed with sack rolls to melt the vinyl. After application of a rear view mirror button, the windshields are sent to an autoclave where positive pressure is applied to give them their high quality transparency. Excess vinyl is then scraped off before being packed and shipped to an automotive assembly plant.

Pollution Prevention and Recycling Opportunities
General Multimedia: Air, Water, and Solid Waste

Fabricating plants are minor sources of criteria pollutants such as Nitrogen Oxides (NOx) and VOCs. The tempering plants have a process involving some Sulfur Dioxide (SO2) that the laminating plants do not have. Levels of other air pollutants are very low. Waste water issues are effectively controlled in-house, and effectively monitored by local sewer authorities. National Pollutant Discharge Elimination System (NPDES) permits are storm water-only permits. Most pollution prevention and recycling opportunities continue to be in the area of solid waste minimization, although additional recycling of waste water and additional energy conservation may provide additional opportunities as well.

Substituting Lead (Pb) with Zinc and Bismuth

A very successful source reduction strategy in automotive glass has been the elimination of lead (Pb) compounds used in the inks to make the ceramic frit. Since 1990, lead (Pb) has been substituted with zinc compounds and bismuth compounds. All fabricating plants have or are in the process of eliminating hazardous cullet from the waste stream.

Recyclable Stretch Wrap in Raw Glass Receiving

Steel racks with lash boards, steel bands, and heavy grade plastic are being replaced with stretch wrap (or shrink wrap) in the raw glass receiving area. The long term strategy is for PPG primary plants to package all raw flat glass on steel racks with one hundred percent stretch wrap. A stretch wrap bailer has been installed to reuse and recycle stretch wrap. The market for this product is not yet developed.

Returnable Steel Racks in Finished Product Shipping

Reusable steel racks are replacing wood and cardboard boxes for finished products shipped to auto assembly plants. Chrysler requires glass suppliers to ship products in returnable racks with returnable glass separators. Other manufacturers have not yet adopted this requirement. With an up-front investment, waste minimization and cost savings opportunities can be enormous.

Onsite Recycling of Waste Water and Offsite Recycling of Its Waste Materials at the Cold End

A plan is in place to increase on-site recycling of Cold End process waste water for use in the cooling towers. In addition, a gravity sludge drying process that recycles glass grindings will soon be implemented. Glass grindings are washed off with water at the Cold End, settle at the bottom of a Henry Separator tank, and are conveyored into the gravity drying bin. The dried glass sludge is sent to a cullet recycling company where it is blended in with batches to make cullet. In addition, the Henry Separator electrostatically separates lubricants used in grinding the glass edges at the Cold End process.

Recycling Clean Cullet Substrates: Solex, Tinted, and Clear

All clean cullet wastes are segregated by their substrate and shipped for reuse at the primary plants. Mixed cullet is sent to an outside cullet recycling firm.

Offsite Recycling of Reject Windshields

In the past couple years, a proprietary engineering process has been developed by a cullet recycling company that physically separates vinyl from the windshields. This engineering process allows PPG windshield plants to recycle fabricated windshields that have been rejected for quality reasons. Previously, all reject windshields were land filled. This process could be implemented at automotive salvage yards throughout the country.

Offsite Recycling of Vinyl Waste, Cardboard, Scrap Metal, and Office Paper

The recycling market is very dynamic for these waste streams. Decisions are based on revenues and environmentally preferred product usages. Clean vinyl scraps can be made into floor tile. Clean cardboard, scrap metal, and office paper are recycled locally.

Implementing Employee-Based Management Systems

A key to successfully implementing pollution prevention and recycling opportunities involves the effective use of employee knowledge of manufacturing processes. From the design engineer to the on-line operator, the pollution prevention or recycling process can be effectively implemented with the right management systems and paradigms. PPG is using two management systems to continuously improve safety, health, and environmental affairs for the glass fabricating facilities: (1) The Quality Improvement Process and (2) the Environment, Health and Safety Implementation Process. These systems are used to develop facilitator/teamwork strategies for implementing source reduction and recycling strategies. For example, quality improvements that reduce the number of rejects in the on-line fabricating process support our waste minimization objectives. There are many examples that document the ability of these approaches to improve product quality, employee health and safety, and support efforts to implement and maintain a multimedia, environmental source reduction strategy.

INTERIOR PARTS

Interior trim parts consist of instrument panels, consoles, door panels, quarter trim panels, and numerous smaller panels. Several forming processes are used. They include injection molding, foaming, slush molding (liquid or powder), and vacuum forming. The forming processes are followed by painting, and assembly. There are three types of trim parts, characterized as hard, semi-soft, and soft.

Production flow for plastic interior trim parts

Hard parts

Resin is received as pellets. The pellets may be precolored, or the pellets may be natural and the color received as a concentrate. The resin is injection molded in a grained tool. The injection molded part is placed on a conveying system. If the part is not to be painted, it goes directly to assembly.

If the part is to be painted, it is washed in a power washer or similar piece of equipment. For some polyolefin parts to be painted, treatment for paint adhesion by flame treatment, corona treatment, plasma treatment, or application of wet adhesion promoter may be carried out. The part is spray painted with a special low gloss coating. Either clearcoat, one coat color, or a color/clearcoat combination is used.

Components in an instrument panel assembly may consist of the instrument cluster, HVAC controls, radio, glove compartment, trim panels, HVAC ducts and airflow control devices, passenger SIR door and module, supporting brackets, and a cross-car beam. The assembly components may also be manufactured within the Instrument panel manufacturing plant, but they are more often purchased. The assembled part is then packaged for shipment and shipped to the assembly plant for installation.

Semi-soft parts

Resin for the retainer, or substructure of the trim component is received as pellets. The resin is usually received as a standard black or as a natural color material. Foam-backed cover material is received as a roll or as pre-cut blanks. It has been painted for color and gloss and back-coated for adhesion by the supplier.

There are three alternative process sequences for molding the skin and substrate:

In alternative 1, the resin is injection molded, cover material is vacuum formed to shape, and the cover is adhesively bonded to the injection molded structure.

In alternative 2, the cover material is suspended across an injection mold and the resin is injected using a low pressure process. The cover material may either be preformed to shape or it may be formed during the injection molding process. The cover material is bonded to the substrate during the injection molding step.

In alternative 3, the resin is injection molded into a mold which contains pins which leave holes in the substrate. Adhesive is then applied to the substrate and the cover material is vacuum formed directly onto the substrate.

From this point on, the process is the same for all three options. Excess foam backed sheet material and retainer are trimmed from the part using water jet, die cutter, hot knife, or similar trimming method. Components are assembled to the part, the part is packaged for shipment, and the part is shipped to the assembly plant for installation as with the hard instrument panels listed earlier.

Soft parts

Resin for the retainer, or substructure of the trim component is received as pellets. The resin is usually received as a standard black or as a natural color material. The substrate is molded by injection molding.

There are two alternatives for forming the cover. For alternative 1, vacuum forming, the cover material is received as a roll or as pre-cut blanks. It has been painted for color and gloss and back-coated for adhesion by the supplier. The cover material is vacuum formed to shape.

For alternative 2, slush (powder slush) molding, the cover material is received as a precolored powder. The cover material is molded by heating a mold and melting, or fusing a layer of the powder against the hot mold. The molded part is then cooled, removed from the mold, washed and optionally, painted.

The process for both alternative one and two are the same from this point on. The substrate and cover are placed in a foam mold and polyurethane foam chemicals are mixed and introduced. The foamed part is removed from the foam mold.

From this point on, the process is the same for both options. Excess substrate, foam, and cover materials are trimmed from the part using water jet, die cutter, hot knife, or similar trimming method. Components are assembled to the part the part is packaged for shipment, and the part is shipped to the assembly plant for installation as with the hard instrument panels listed earlier.

Pollution prevention opportunities

Opportunities for improvement include the changes described below.

• VOC reductions from the painting operation. Examples could be the expanded use of water-based coatings and to replace painting with mold-in color.
• Reduction and/or recycling of part trim waste.
• Reduction in types of materials used to facilitate material recovery for recycling/reuse.
• Expand the use of reusable, returnable or recyclable packaging materials.
• Specify materials that can reduce hazardous emissions (HAPS) or use of hazardous materials in supply chain.
• Specify post consumer content to reduce use of new raw materials (source reduction).
• Simplify attachment to vehicle to enhance removal and recycling.
• Optimize utilization of lighter weight materials to reduce emissions and energy consumption in the "use stage."

1. Tennessee Hazardous Waste Management Assistance: Automobile Body Repair and Paint Shops, EMPE, Inc., 31 August 1986. ARSG 0003. 7500/Automobile/Paint/Body/Repair.

2. California Department of Health Services. Waste Audit Study: Automotive Paint Shops, January 1987. ARSG 0005. 7500.

3. Alaska Health Project. Waste Reduction Assistance Program On-Site Consultation Audit Report: Automobile Body Repair and Paint Shop, 14 August 1987. ARSG 0019. 7500.

4. Kirsch, F. William. Waste Minimization Assessment for a Bumper Refinishing Plant (ENVIRONMENTAL RESEARCH BRIEF), July 1991. Waste min./source reduction options for bumper refinishing operation. Economics discussed. ARSG 0064. 7500/Bumper Refinishing/Automotive/Stripping/Painting/Plating.

5. Waste Minimization Assessment for a Metal Parts Coating Plant - Environmental Research Brief, F. William Kirsch, and Looby Gwen P., July 1991. This paper discusses waste minimization for a metal parts coating facility. The coating lines and rework operations were evaluated to determine the locations, types, and quantities of waste. The facilities examined were small to medium-sized businesses. ARSG 0065. 7500/Automotive Parts/Coating/Metal Parts/Paint stripping.

6. Hazardous Waste Minimization Fact Sheet for Auto Paint Shops, California Department of Toxic Substances Control., June 1992. This fact sheet discusses the minimization of solvents, paint wastes, catalysts, freon, and antifreeze generated by automotive paint shops. ARSG 0082. 7500/Automobiles/Paint shops/Hazardous wastes/Waste minimization.

7. Hazardous Waste Minimization Checklist & Assessment Manual for Auto Paint Shops, July 1992. This handbook discusses the major waste streams generated in automotive paint shops: solvents, paint wastes, catalysts, freon, antifreeze, etc. A waste minimization checklist, economic analysis worksheet, and a technical options worksheet are included. ARSG 0083. 7500/Automobiles/Paint shops/Hazardous wastes/Waste minimization.

8. Davis, Jack, and William Reichert. Reducing Risk in Paint Stripping, 1991. This case study describes the search for a substitute for methylene chloride for an uncured paint booth. CLM 818 is used as a replacement. FMP 0654. 3500/methylene chloride substitute/automotive.

9. EPRI. TechApplication (1989): This report discusses how Chrysler Motors implemented electric infrared (IR) drying at its Belvidere, Illinois, automobile assembly line. The advantages and costs are presented. FMP 0846. 3400/Coating/Technologies.

10. Foley, John S. Industrial Laser Review (August 1991): This article discusses the effectiveness of laser paint stripping, and how it can be used to reduce waste. Rates & quality issues are discussed. FMP 0887. 3400/Paint Stripping/Carbon Dioxide Laser/Chemical Stripping Alternative.

11. Hoechst High Chem Magazine 10. This article outlines the use of water-based binders and the electrodipcoating process used in the auto industry. A case study on Volkswagen is provided. FMP 1260. 3400/Automobiles/Painting/Coating/Water-based.

12. California Department of Health Services. Waste Minimization Opportunities for Selected City of Los Angeles Hazardous Waste Generating Operations, November 1989. The City of Los Angeles and the California Department of Health Services jointly assessed opportunities for waste minimization in several small businesses within the city. Automobile repair shops, vehicle body paint shops, general service print shops, and wastewater treatment facilities are all reviewed. MISC 0207.9999/Automotive/Repair/Paint/Shops/Printers/Wastewater/ Treatment/Laboratories.

13. Waste Reduction Resources for Industrial Process Wastewaters, Office of Waste Reduction, Pollution Prevention Program, NCDEHNR., January 1993. This is a compilation of documents published by EPA and other authorities on waste reduction resources. MISC 0225. 9999/Audits/Automotive Repair/Auto Body Shops/Airports/Car Washes/Food Processing/Hospitals & Medical Offices/Laundromats/ Metal Fabricating/Machine Shops/Painting/Photo processing/ Printing/Screen Printing/Radiator Repair Shops/Restaurants/Food Preparation/Slaughter Houses/Meat Packing/Textiles/Hazardous Waste.

14. Paint Waste Reduction and Disposal Options - Executive Summary, Center for Economics Research, Research Triangle Institute. Waste reduction is discussed in relation to paint manufacturers and users (original equipment manufacture, auto body repair shops, household painting). MISC 0251. 9900/Manufacturing/Paint/Waste reduction/Disposal.

15. Reinke, Daniel et al. 15th AESF/EPA Conference on Environmental Control for the Surface Finishing Industry, Von Duprin, Inc., located in Indianapolis, Indiana, is the market leader in supplying door exit hardware (panic bar devices). In 1989 and 1990, Von Duprin joined together with Capsule Environmental Engineering Inc., an environmental consulting firm specializing in process waste reduction, to develop and implement a project designed to reduce wastewater sludges from plating operations by 90 percent. Von Duprin's plating operations included automated hoist rack plating of copper cyanide, satin and bright nickel, decorative chromium, brass cyanide, and also barrel plating of alkaline non-cyanide zinc. Von Duprin's waste reduction efforts addressed methods to minimize and recover drag out from each of these process baths. FMP 1448. 3400/3500/Cyanide copper/Nickel/Chrome/Brass/Non-cyanide alkaline zinc/Recovery/Reverse osmosis/RO.

16. The Largest Captive Chrome Plater in Nebraska is the First in the State to Meet Typical California Air Standards, Monroe Auto Equipment Company. Chrome plater installs collection system to capture emissions from plating baths. System exceeds standards for capture of chromium emissions. MISC 0566 AAAB. 3472/Chrome plating/Air emissions reduction/Hazardous waste reduction/Emissions reduction system.

17. Source Reduction and Recycling of Halogenated Solvents in the Adhesives Industry (Technical Support Document), Jacobs Eng. Group. This technical support document focuses on the adhesives industry. Source reduction option such as; vapor recovery by condenser or adsorber, water-borne adhesives, high solid adhesives, mechanical fasteners or welds, hot melt adhesives, radiation curable adhesives, powder adhesives, 100% liquid reactors, use of high transfer efficiency spray equipment, use of flow coater, dip or brush, use of alternative solvents on cleanup and solvent waste recovery systems are all discussed. CAP 0053.2800/Adhesives/Source/Reduction.

18. CASE STUDY #4 - Solvent for Parts Washer, EOEML, and Georgia Pollution Prevention Assistance Division. This case study presents evaluations by several vendors of parts washer solvents used by Clear-Loc Fastener Company, with recommendations for alternative cleaning agents. FMP0403.3400/3500/Cleaning/Solvents.

19. Designing the Modern Automobile for Recycling, Richard L. Klimisch, The Greening of Industrial Ecosystems, National Academy Press, Washington, DC, 1994. This Article points out that Life-Cycle waste management and Pollution Prevention are similar, both based on practices that are already in place in the automotive industry. The Vehicle Recycling Partnership(recently formed by GM,, Ford & Chrysler) is focusing its efforts on Shredder Residue, Disassembly, and Design Guidelines. One approach under consideration in Germany and US is to require suppliers to retrieve and recycle materials in their products. The role of the OEM would be to use some or all of the recycled materials. VRP is developing simple design preference guidelines considering recyclability, cost, and performance which are extremely complex.

20. Car Recycling and Environmental Improvement in Western Europe, Univ. of Tennessee Center for Clean Products and Clean Technologies, Gary Davis & Lori Kincaid, 2/94.

21. Automotive Applications for Powder Coatings,Paint & Powder Coatings Industry Magazine, September 1994. Article describes usage of powder coatings for interior and exterior trim parts and wheels.

22. Body Panel battles marked by niche warfare, Joseph J. Innace, Modern Plastics Magazine, 10/94 Article describes the various automobile body parts, with probable materials to be used: Thermoset SMC(sheet molding compounds), amorphous nylons, aluminum, etc.

23. Automotive Coatings, Joe Schrantz, Modern Paint and Coating magazine, July, 1994. Article contains info on several new technologies for the auto industry including "UV-curable coatings for automotive plastics", "Big three to build $20 Million Powder Clearcoat test facility", "Compliance options for Auto Assembly Paint Operations", Water-Based Coatings for automotive plastics", etc.

24. Pollution Prevention Assessment for a Manufacturer of Electroplated Truck Bumpers, EPA/600/S-95/019, Richard Jendrucko, et al.

25. Pollution Prevention Assessment for a Manufacturer of Combustion Engine Piston Rings, EPA/600/s-95/015, Richard Jendrucko, et al.