IMM Focus: Automotive:Automotive molding, OEM-style, at Honda

A small cosmetics molder serves big customers by using the right design tools.

Pulling into the colossal, 3.6-million-sq-ft Honda of America manufacturing facility in Marysville, OH, this intrepid reporter manages to locate every off-limits area and friendly-but-firm security guard before finally making it to the right parking lot. Shortly before our tour, Honda is rolling out its all-new 2004 Acura TL model, so the place is abuzz with media and suppliers. This facility produces 440,000 cars every year, including the Accord Sedan and Accord Coupe, in addition to the TL. Once the rollout presentation is over, officials clear a path to Honda’s Marysville Plastics Operations (MPO) for the long-awaited IMM tour.

Before we make our way to the plant, however, our guides Jack Mullaney, manager of MPO, and Jack Bilotta, assistant manager, want to clarify the way Honda operates. They explain that the company relies on competence and skill in its workforce, not exotic equipment. “Respect for the individual is the basis for all systems,” says Mullaney.

Employees, called associates, have daily opportunities to comment on ways to improve operations. Many take advantage of this feature, enabling Honda to implement continuous improvement projects on a regular basis. A Wall Street Journal article in 2002 explained that associates were given the authority to stop the assembly line to make sure that defects were corrected before a car was completely assembled. “We firmly believe that our associates are our greatest assets, rather than the buildings and equipment,” adds Mullaney.

True to this philosophy, the MPO operations appear to be staffed by dedicated and involved workers. Engineers spend a good deal of time getting their hands dirty, so to speak, on the shop floor by participating in production teams. Operators are cross-trained to handle multiple job functions. Managers and team leaders don’t sit in glass-encased offices, but rather in a bullpen arrangement that facilitates communication. While you might expect to see only automation and machines, you’re greeted instead by well-crafted workcells that optimize space and focus on human ergonomics.

This is not to say that MPO hasn’t invested in its equipment. Three years ago it began a strategy of updating/replacing older molding machines, and two years later the installation was complete. Three Mitsubishi 4400-tonners form the cornerstone of this program, and serve to mold bumpers for both Accord and Acura models assembled at the Marysville plant.

A Honda Original

When Marysville first began producing cars in 1982, plastics manufacturing was tucked into a relatively small area of the plant. By 1987, the number and scope of plastic parts on Honda vehicles had grown tremendously, and management decided to add a separate building next to the main plant for molding, bumper painting, toolmaking, and quality engineering operations.Our guides begin the tour by heading toward the original plastics operations in the main plant, which specialize in producing instrument panels. We pass through a just-in-time material services department that began life with kaizen and kanban systems that continue today.

Purchased components, such as windshields and seats, are matched up together as kits along with a computer printout identifying the vehicle on which the parts will be assembled. The parts are then sent on an elaborate overhead conveyor system to the assembly area.

A large welding area closer to molding operations is almost entirely robotic, reminiscent of a field of animatronic dinosaurs. As the sparks fly, car bodies move slowly through each station and are then conveyed to an underground buffer zone. Returning to the main floor, the bodies-in-white undergo final inspection before moving to the body painting area.

When we arrive at the original plastics area, three machines (a 1500-ton Farrell and two HPMs, 2200 and 3000 tons) are busy churning out the upper and lower portions of Accord instrument panels. The upper portion of the IP is produced on the Farrell, while the HPMs are responsible for the lower halves. Each workcell features a six-axis robot that combines takeout and trim operations. Parts are removed from the mold, degated, and then placed on a conveyor for cooling and quality checks. The two-cavity upper IP molds and one-cavity lower molds are injected with TPO material.

Materials are stored outside the facility in silos, fed through trenches below the stamping department, and then loaded into a Conair materials handling system with automated hopper/feeders. Colors are gray, brown, beige, and black, and there are multiple color changes per day. “From the beginning in 1982, we implemented lean manufacturing, and have manufactured just in time,” says Bilotta. “This isn’t exactly order-to-assembly sequencing, but comes very close.”

Making IPs

To produce a complete Accord IP, three other post-molding operations take place—vacuum forming, vibration welding, and painting with soft-touch paint.

In the first operation, crush pads (laminate foam sheets) are vacuum formed onto the molded IP halves four at a time. Prior to the 2003 Accord, glue was sprayed onto the sheet for adhesion, but MPO now uses preglued sheets. The sheets are also TPO for recyclability.

After trimming, the parts are loaded into a simulation oven that heats them up to determine if any defects are present. (The oven simulates a car’s interior on a hot summer day.) “Any imperfections caused by heat will show up here. This is an example of how Honda attempts to eliminate potential problems before any cars roll off the line,” Mullaney says.

Parts are then inspected and sent to the next operation: vibration welding. This area features a large carousel with several different workstations and two vibration welding machines. Workers add ductwork at the carousel stations, and then load the IP upper and lower halves into the vibration welders. “Vibration welding the IP saves us from installing 39 screws by hand for each unit,” says Bilotta.

Continuous ergonomic improvement at the carousel and vibration welding stations have helped eliminate squeaks and rattles, according to Bilotta. These changes include moving the fixtures at the carousel to a height more suitable for associates. “We made the switches in August 2002, during the 2003 Accord introduction,” he explains.

Another improvement, a visual counter at the top of each vibration welding press, shows associates where they are in terms of the day’s production. This area can produce up to 1800 IPs for the Marysville plant and 120 per day for Mexico, for a total capability of 1920 per day. It takes only 1 hour from the time the parts are molded until they are vibration welded.Color changes affect this area as well, and are based on the needs of the assembly line. “In vibration welding, we may run 120 brown [IPs] to cover two lots that assembly will need today, and then change to gray and run 240,” says Mullaney. “For finished inventory, six total lots or three per line is our target, which is 180 units per line. That works out to about 3 hours’ worth of assembly time. If we don’t produce instrument panels, the line shuts down, but we have never had to do this so far,” he adds.

MPO takes a different attitude toward downtime. “We look at this as an opportunity to make our system more robust,” Mullaney explains. “We study it intensely to find out how to make the area better.”

Painting instrument panels with soft-touch paint is the next operation. Soft-touch paint is applied in a single booth operation in one of three colors—gray, beige, or black. Color changes can be done in the time one panel is painted. Certain areas are masked off prior to painting with “pack masking,” an ingenious use of recycled/scrap material from bumper and IP molding operations. Bumpers are also masked with the recycled pack masking prior to painting.“While we have always recycled unpainted scrap bumpers, we now recycle painted scrap bumpers that would normally be sent to a landfill because we are unable to use them in our process,” says Mullaney. “Recycling them into masking material not only creates a usable product for us, it also helps us maintain our goals of operating in an environmentally sound way.”Plastics Ops CentralFive years after the Marysville plant started up, a separate plastics facility was built for MPO. Most large parts are molded here, as well as any Class A-surface parts that could be damaged by handling. In addition to molding operations, bumper painting facilities, and the large, open office that is home to MPO managers, this facility also houses Honda Engineering North America, or EGA, which produces injection molding tools.

EGA also develops body welding equipment, stamping dies, and in-house automation, but for MPO, the beauty of having the toolmaker in the shop becomes apparent during mold trials. When EGA finishes a mold, for example, it is sent to the molding area on a crane that serves both operations. “Working together with the tooling engineer, operations associate, and injection engineer, we’re able to determine if any changes need to be made, and then send it back to EGA for the required work. Even if it takes several iterations, having the toolmaking facility next door, so to speak, makes it a relatively quick operation,” says Mullaney.

Honda’s MPO keeps a list of concern items from everyone involved with the part while they’re trialing molds, and a countermeasure activity list is developed that same day. “We don’t keep them to address in a week, we do it that day,” says Bilotta.

Molds for the new 2004 Acura TL bumper were developed this way. (A unique design for Honda, the bumpers feature a grille area that is able to remain unpainted because the base polymer contains metallic flake.) Injection engineering, EGA, and associates who produce the part were all there to make sure that everyone knew the part requirements, how to manufacture it, and what the molding parameters would be.

Injection engineers are Honda’s term for process engineers. They have degrees from Penn State and other large engineering schools. “Then we turn them into Honda engineers,” says Bilotta, “which adds a new facet to their profession.” He’s referring to the training that designers get on the shop floor, where they are part of the production team. They are responsible for the part, and the training is not only hands on. “They also share the same schedule, complete with lunch breaks, as the operations associates,” says Bilotta.

Design at Honda is a team effort between sales (American Honda), engineering/manufacturing (HAM), and R&D (Honda R&D Americas). During Honda’s self-termed Digital Prototype Modeling phase, R&D engineers (responsible for styling and part design) and manufacturing engineers resolve problems together with an eye toward manufacturability. At weekly meetings, the team focuses on developing engineering drawings that reflect this goal. Mullaney explains that even after a part is in production, R&D maintains a close relationship with the shop floor. “If there are problems, they are right there to suggest design changes, and they’re very flexible.”

Flexibility Built In

Molding operations in the plastics facility are responsible for bumpers, Civic instrument panels, and ancillary components for VTX motorcycles and Honda all-terrain vehicles. The new TL bumpers were not running during our visit, but will likely be molded on a Mitsubishi 4400-tonner for the front bumper, and an HPM 3500-tonner for the rear bumper.

According to Bilotta, however, machines are not dedicated to specific molds. “All of our molds need to have the flexibility to be run in any machine that we have in this area. Before we put a mold into production, we have a primary and backup machine targeted to run it. Beyond that, we expect it to run in any of the machines here as long as it is not limited by tonnage.” Setups are often transferred via floppy disk, and machines are maintained regularly so that molding parameters remain equivalent from one to the other.

“For example, if we had a problem with an instrument panel mold running in the main plant, we could bring it here to the plastics facility and run it in one of these presses. We can and have done this,” says Mullaney, “to keep from shutting the line down.” This focus on flexibility is a major consideration throughout MPO.

A 3500-ton HPM produces both Civic IPs and VTX motorcycle parts. A second, identical press runs Civic IPs and bumper fascia, all without changing robotics because MPO uses the same trim cell for whatever part it’s running. It is simply a matter of changing the EOAT on the robotics and selecting the next program.

Another workcell molding bumpers contains a 4400-ton Mitsubishi press and a Mitsubishi takeout robot incorporated with an ABB robot for trimming. This design was done in-house. Gate and sprue trimming is done robotically, after which an associate looks for defects and performs any minor trimming needed. Specifications for this workcell have been transferred to plants in Alabama and East Liberty (OH) to produce bumpers for Accords, Odysseys, Elements, and Acura TLs.

For new model changes and equipment changeovers, all of the switching is done while running full production. For example, when an HPM machine was being replaced by a Mitsubishi, the new press was set in its place easily because Honda specified the machine base to fit the existing pad. The new press was totally installed and brought to full production with no drop in output. Five machines were replaced in the same way with no interruption to production. “It definitely improves your project management skills,” says Bilotta. “We can’t stop for tooling changes, new model startups, or equipment changes, or we would stop the assembly line—something we’ve never done,” Mullaney emphasizes.

Another pair of molding machines demonstrates the flexibility ethos in action. A 3500-ton HPM is producing a PP Civic instrument panel, while a 4400-ton Mitsubishi is running a TPO Accord front bumper next to it. These two molds can be switched at any time to fill assembly line needs within a minimum time frame, according to Bilotta.

Scheduling molds and machines is done at each shift. Production teams have a list of primary machines along with backups and a history of where the mold has run most recently. Decisions are made in sync with assembly line requirements for that shift.

Staying flexible with presses and molds helps to ward off defects. “There are two Accord front bumper molds,” says Mullaney. “If bumpers start coming off the press with defects, we can switch to the second mold, run it in another press, and keep up with production requirements.” All molds are maintained to be production ready.

Typically, MPO molds parts 2 to 3 hours ahead of the bumper paint department. It takes 2.5 hours for a bumper to get through the paint stage and be added to inventory on the floor, where it is loaded directly onto an overhead conveyor to go to the assembly line. Molding and painting operations are synchronized with assembly. Between the final operation in MPO, which is bumper painting and assembly, there is no more than 3 hours of production sitting on the floor. “So when we do have a problem, we have to react quickly,” says Bilotta. “That’s when flexibility pays off.”