Innovative Technology for Multi-PUR Sound Deadening Components for Large Engines: Combining Innovative Processes to Develop a Turnkey Solution

Transcription

1 Innovative Technology for Multi-PUR Sound Deadening Components for Large Engines: Combining Innovative Processes to Develop a Turnkey Solution MAX TAVERNA BARRY PILE Cannon SpA Cannon USA Via C. Colombo Freedom Road Trezzano sul Naviglio, Milan Italy Cranberry Twp., PA ABSTRACT This paper describes an innovative, automated concept to produce complex noise absorbers which must be bolted onto large engines. Produced with two different types of polyurethanes, these parts absorb a considerable amount of vibrations and noise. Requested to quote a "normal" production cell, the equipment supplier ended up providing a complete, large-scale plant based on the patented Foam & Film technology, which eliminates the release agent, its application and extraction, and all mold cleaning operations. In addition, it provides an encapsulated PUR part, which delivers better resistance to chemical aggression and moisture. THE CUSTOMER Based in USA, the customer is a supplier to the automotive industry providing over forty years of superior noise control solutions. They design and produce simple and complex laminates in various shapes, thicknesses and weights, based on three types of noise control applications: sound barriers, sound absorbers and vibration dampers. They provide their customers with everything from custom-engineered rolls and die-cuts to molded and cast-in-place materials. Their most typical product applications include floor systems, dash and front of dash barriers, composite parts, engine tunnels, HVAC (Heating, Ventilation and Air Conditioning) elements, and interior trim panels. PROJECT BACKGROUND One of the most successful products is a series of acoustic side shields for engines, which provide a substantial reduction of the noise generated by the motors conventionally installed on vehicles. These shields have a two-part foam: a semi-rigid part and a back foamed part with flexible foam. The customer used to produce the parts with a classic, logical sequence of manual operations: the production of the skin included tool cleaning, spraying of release agent in the tool, positioning of inserts, manual open-mold pouring of the first polyurethane formulation, a curing phase of approximately 3-4 minutes, manual unloading of part and roughing of the skin, to eliminate release agent in order to achieve a good adhesion between skin and foam. The back-foaming operations included the loading of the previously made part in another tool, manual open mold pouring with a soft foam polyurethane formulation, curing of approximately 2 minutes, unloading of the finished part and its final manual trimming. The next cycle of production required the tool to be manually cleaned followed by manual application of the release agent. This was a labor-intensive sequence of operations, prone to errors and to intensive handling of unfinished items. In view of a new large order coming from a major engine manufacturer, the customer identified a process solution and an equipment supplier. However, before issuing a purchase order, they decided to entertain other ways of meeting their production requirements.

2 THE SOLUTION Cannon USA (the chosen equipment supplier) has more than forty years of experience focused on providing an innovation value to its customers. These innovations help to: Reduce labor costs via automation. Produce parts at a faster rate to increase capacity. Reduce the amount of steps required to produce a part. Improve part quality while reducing the overall cost of the part. Allow for future expansion of capacity. This recipe worked fine for so many projects, why not apply it again in this case? The equipment supplier reviewed the customer s suggested scenario and then developed four different solutions designed to meet the requirements. Solution 1 was similar to the customer s proposed arrangement while solutions 2, 3 and 4 were progressively more automated systems utilizing the Foam & Film technology in lieu of applying mold release. Employing the Foam & Film solution also promised to eliminate the need for some other manual functions as well. To complete the total turnkey aspect, the customer was provided with the following options: Mold design Testing and fine tuning of the molds Production of prototype parts Racetrack system with four mold carriers and Pit-Stop system Foam & Film system System integration to supply two different films to the part surface, auto change between rolls and, depending on what mold is in the carrier, the ability to run three to four carriers with the film from Roll 1 and two to three carriers with the film from Roll 2 Two metering machines for two different PU formulations Two 6-axis robots for automatic pouring functions Vacuum system for each trolley to assist in forming the film into the mold Mold heaters Automatic quick connect/disconnect system for pneumatic mold carrier functions such as air bag inflation Control system All safeties including fences, doors and laser scanner for the manual operation station Installation and start-up Main advantages of the Pit-Stop racetrack design: 1. High flexibility; each mold carrier is mounted on an independent self-powered trolley 2. The stop time of each trolley at every station can be optimized and individually adapted 3. Mold carriers can exit without production interruption (e. g. for maintenance, periodic cleaning or mold change) 4. Modularity; the line can be expanded or contracted as called for in the future FOAM & FILM TECHNOLOGY: CREATIVE APPROACH BRINGS RESULTS! The Foam & Film system works in the following sequence: 1. Film is unrolled automatically with the gripper system. An external frame grabs the film and the film is cut. The film is heated via medium wave length IR heaters. The external frame transfers the film from the heating station to the forming station. The mold frame takes the film from the external frame and moves the film over the mold surface. The film is vacuum formed onto the mold surface (Fig. 1). In this application, the Foam & Film station film is applied simultaneously to three mold surfaces - the bottom mold, the A side of the upper mold and the B side of the upper mold (Fig. 2).

3 A side of upper mold B side of upper mold Bottom mold FIGURE 1: The film is vacuum formed onto the mold surface. FIGURE 2: Film is applied to three mold surfaces 2. In operation, after the film is applied to the mold surface, the trolley then moves to the inspection station where the mold surfaces are inspected for proper film placement as well as any tears in the film (Fig. 3). 3. The trolley is then transferred to the first pouring station where a 6-axis robot is utilized in conjunction with the cylinder type metering machine to apply an open pour of PU to the bottom mold. The mold is closed and the trolley proceeds toward the second pouring station (Fig. 4). 4. Once the trolley reaches the second pouring station, the mold is opened and the top mold is rotated 180 degrees to present the B side of the upper mold. Another 6-axis robot working in conjunction with an axial piston metering machine pours the second PU formulation onto the top the part located in the bottom mold (Fig. 5). 5. The mold then closes and the trolley is transferred toward the demold area (Fig. 6). 6. In the demold area the part is automatically dropped onto a take-away conveyor (Fig. 7). 7. The part is then removed from the line and taken to an automatic trimming area. This particular turnkey solution employs several innovative features which dramatically reduced the amount of manpower to produce a part while increasing the production rate and the parts' appeal for the end user (Fig. 8). The use of the Traction Drive Pit-Stop carousel allowed independent movement of the trolleys so if a function in any of the work stations takes a little longer than normal, the entire line is not necessarily held up. FIGURE 3: Inspection Station FIGURE 4: Robot open pours the first PU formulation onto bottom mold. FIGURE 5: Robot open pours the second PU formulation over the film which covers the first foam

4 FIGURE 6: The mold then closes and the trolley is transferred toward the demold area FIGURE 7: The part is automatically dropped over a take-away conveyor FIGURE 8: The part is removed and taken to an automatic trimming area. The design of this type of line also lends itself well to accommodate future growth with minimal disruption and downtime not to mention a lower capital expenditure. The Foam & Film feature not only allowed for the elimination of mold release and all of its associated costs, such as sprayguns and tanks, ventilation and explosion proofing of electrical components, but also eliminated mold cleaning functions and made automatic demolding effortless. The Foam & Film system includes an auto change feature between two film rolls depending on what tool is in the carrier. Both the HE-60 Cylinder style metering machine for the first foam system and the A-40 rotary pump style metering machine for the second foam system are integrated with a 6-axis pour robot to insure repeatable and consistent pour patterns. The HE-60 is equipped with Allen Bradley's Control Logix processor with a PanelView Plus 1250 operator interface while the A-40 features an Allen Bradley MicroLogix PLC and a Maple System operator interface. To complete the system, all safeties such as fencing, lockout doors, light curtains, safety mats and e-stops were included in the scope of supply to insure operator safety. CONCLUSION What did the equipment supplier achieve for the customer? A lot: A cycle time reduction of approx. 20%, with a cost reduction of 35% versus the original cost. Their capacity increased due to shorter cycle times, decreasing their staff. Quality of their parts highly improved for high standard adhesion. They were able to eliminate several manual process steps. This approach once more provided a win-win solution. The customer produces quality parts with a substantial savings and Cannon supplied another innovative production system.

5 BIOGRAPHIES Max Taverna Max was born in Buenos Aires, Argentina, in 1949 and has an educational background in Industrial Chemistry. He worked for Upjohn's Polyurethanes Division in Italy and joined Cannon Afros as the European Sales Manager in Since 1986 he has coordinated the Group s communications activities and currently serves as the Corporate Director of Communications. Barry Pile Barry is currently an Industry Manager at Cannon USA specializing in plastic processes for automotive interior part production. He has been with Cannon for fifteen years bringing with him a Mechanical Engineering degree from the University of Pittsburgh and a Business Management degree from Indiana University of Pennsylvania.