Manufacture Economically Exploit Resources

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Lindsay Gilmore
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1 Fig. 7. The workpiece carrier system positions the injection moulded part (black) at the second assembly station for insertion of the insert element (pink) (photo: Neureder) Manufacture Economically Exploit Resources Integrated Automation. The economics of manufacturing today depends essentially on creative integration of automation. On the one hand, this provides cost benefits vis-à-vis competitors in countries with lower labour rates, while, on the other, automation facilitates integration of subsequent process steps, thus assuring high quality of the goods produced. JOCHEN MITZLER THOMAS MARUFKE T oday, it is no longer enough to employ so-called pick & place solutions when implementing or planning production. Profitable automation must be capable of much more, e. g., loading inserts, joining or positioning. Value added increases noticeably only when automation performs additional functions. Moreover, broader concepts assure reliable processing and high equipment availability. Production site retention Translated from Kunststoffe 4/2005, pp and job security are achieved through high productivity and engineering creativity. In this way, cost pressures and those associated with industrial policies can be balanced. In light of the above, it is especially important to find a system partner with a wide range of technical solutions. The newest division (Automation) within Krauss-Maffei Kunststofftechnik GmbH, combines automation solutions with the three primary processing areas of injection moulding, extrusion and reaction injection moulding. The significant increase in know-how is a result of close cooperation with the automation specialists of Neureder AG, Oberding-Schwaig/Germany, which was acquired in Neureder AG concentrates its activities on automation 1

In order to fit the long, flat part between the tiebars, the robot removes the front-end module from the machine at an angle a variant for which the degrees of freedom of the articulating arm robot

2 AUTOMATION savings of about 50 eurocents/kg (30 % glass-filled PP) improves the economics considerably. The long reach of the robot permits free selection of magazine placement, thus allowing a space-saving arrangement. In order to fit the long, flat part between the tiebars, the robot removes the front-end module from the machine at an angle a variant for which the degrees of freedom of the articulating arm robot are fully exploited (Fig. 2). Synergy from Combining Injection Moulding and RIM Technology Fig. 1. The injection moulding compounder provides high value added through the MX clamping unit and the high melt quality (photo: Krauss-Maffei) for plastics processors and offers linear robots (type: CBN/LR), multi-axis robots (type: IR) and customer-specific special-purpose solutions. From a Single Source At the K 2004 in Düsseldorf/Germany, Krauss-Maffei exhibited various solutions that demonstrated the capabilities of its production systems. One example involved production of a front-end module for the VW Touareg on KM MX/IMC injection moulding compounder (IMC) [1]. An industrial robot, type IR60 L30 KS mounted to the stationary platen in a space-saving arrangement removed the finished components. From the machinery standpoint, the potential of the injection moulding compounder lies in the new MX clamping unit (Fig. 1). With the rapid traversing movements and the improved clamp force build-up times, the time required for machine motions can be reduced by about one-third. The high melt quality achieved by the IMC series is used to reduce clamp force requirements. As a result, it was possible to transfer the 4 kg frontend module, which is usually produced on a 1300 tonnes machine, to a 950 tonnes machine. This option translates into reduced investment for the same high product quality. The cost Fig. 2. The robot is mounted to the stationary platen and rotates the part through the tiebars (photo: Krauss-Maffei) Three areas developed jointly both the new SkinForm technology [2] and the golf production exhibited at the K For the golf balls, the core inserts were first supplied to an industrial robot (Fig. 3), which then placed them, from the non-operator side of the clamping unit, into the cavities of the 4-cavity mould. Integrated vacuum nozzles held the cores exactly in position. These were then overmoulded with PU in two successive steps of one half-shell each in the clamping unit from a KM 65 injection moulding machine from the C series. A second robot on the operator side removed the finished balls and simultaneously cleaned the empty mould with a brush attachment. Next, the gripper placed the balls in a separate degating station (Fig. 4). Following this, the balls were transferred to a flash trimming station, where the joint between the two half-shells was smoothed. Prior to final placement, a third station printed the two-colour logo. The sum total of the process steps is a fully automatic PU production system. Complexity in a Small Space Lear Corporation, which produces polyamide (nylon) fuse holders in Bersebrück/Germany, provided an additional example from the automotive sector. Krauss-Maffei installed a compact production cell with a KM C2 injection moulding machine, the heart of which is a linear robot installed on the stationary platen (Fig. 5). The gripper removes the basic module for the fuse holder i Manufacturer Krauss-Maffei Kunststofftechnik GmbH Krauss-Maffei-Straße 2 D München / Germany Phone +49 (0) 89/ Fax +49 (0) 89/ info@krauss-maffei.de from above and disposes of the runner system on the non-operator side. It then places the moulded part in the cooling station, which is located to save space above the overhead guarding that covers operator passage at the front of the machine. The linear robot also removes from here an already cooled part and places it properly oriented into the assembly station. Here, three locking elements are simultaneously inserted to an exactly defined position in the basic module (Fig. 6). Finally, an insert element is placed in the module and the gripper lays the completed fuse holder on the conveyor belt (Fig. 7). The dynamic linear robots equipped with highly repeatable servomotors are very well-suited for tasks that require exact approach to a specific position. The production monitoring system oversees not only the injection moulding process but also assembly and provides, for instance, a real-time display of the 2 Carl Hanser Verlag, München

Fig. 3. The core inserts are singulated by a sorter and fed to the gripper arm. The brush on the gripper cleans the mould (shuttle mould) during the PU casting operation (photo: Krauss-Maffei) Fig. 4.

prepared trays. This mounting arrangement lowers the cycle time considerably, since it was thus possible to minimise the strokes of the clamping unit in conjunction with the short mould open time.

In addition, the flexible articulating arm robot permits fast, uncomplicated conversion to alternative products and types of packaging. Reliable Production Even with Complex Sequences Fig. 5.

3 Fig. 3. The core inserts are singulated by a sorter and fed to the gripper arm. The brush on the gripper cleans the mould (shuttle mould) during the PU casting operation (photo: Krauss-Maffei) Fig. 4. The runner system and flash are removed from the golf ball at the degating/deflashing station (photo: Krauss-Maffei) the moulded parts, the gripper reorients the covers and then places them in prepared trays. This mounting arrangement lowers the cycle time considerably, since it was thus possible to minimise the strokes of the clamping unit in conjunction with the short mould open time. The robot executes all handling operations during the only 6 s long injection moulding process and is thus not a time-determining factor. In addition, the flexible articulating arm robot permits fast, uncomplicated conversion to alternative products and types of packaging. Reliable Production Even with Complex Sequences Fig. 5. The KM C2 is equipped with a linear automation line (type CB); complex assembly operations and quality assurance mesures are performed within a very limited space (photo: Neureder) slide positions. Lear Corporation can thus operate with 100 % availability starting at the conveyor belt, since any defective parts regardless of whether attributable to moulding machine or assembly will have been immediately detected by the quality assurance system and diverted from the process. All elements of the automation are synchronised with one another exactly. This increases the availability and assures reliable production; in addition, the cycle time of the injection moulding process is utilised in an optimal manner. Flexible Industrial Robot For the production system for a mobile telephone cover running at Oechsler AG in Ansbach/Germany, the designers resorted to a special type of robot assembly operation. The base of the industrial robot is installed on a welded frame mounted above and parallel to the clamping unit of the KM C2 (Fig. 8). The robot is centred in such a way as to permit removal of the moulded parts during the mould open time of about 1.2 s while occupying minimal space (Fig. 9). The pivoting motion downwards is limited to two joints and thus occurs very rapidly. After part removal, a mechanism in the gripper degates The Neureder robots are employed for highly complex insert loading operations at Eckerle GmbH in Ottersweier/Germany. Utilising a 4-cavity mould on a rotary platen installed on a Netstal type 1000/230, the company produces brush holders for the automobile industry (Fig. 10). During the first step, very fine contacts are loaded into the cavity and positioned exactly. The contacts come from a coil that runs continuously through a stamping machine. The contacts are stamped out, formed and placed in a centering unit by a feed robot (Fig. 11). The primary robot, a linear system, picks up the contacts and loads them on the stationary side. Simultaneously, the back of the gripper removes the finished parts from the opposite side. When designing the gripper system, the smallest possible opening stroke was taken as a basis, so that in spite of its two-sided, complex configuration with tight tolerances the gripper head can enter and exit without problem. Fig. 6. Fully automatic assembly of three locking elements (pink) in the PA fuse holder (black) with position monitoring (QA check) (photo: Neureder) 3

E-mail: info@neureder.de www.neureder.de from feeding from the coil to logging of all relevant steps in the process. The quality assurance system is also fully integrated.

4 AUTOMATION Fig. 8. Ergonomically optimised side mounting of the industrial robot on a welded frame permits the greatest possible action radius for the robot (photo: Neureder) The automation solution encompasses complete automation of the cell. All robot systems are synchronised and integrated with each other, i Manufacturer Neureder AG Möslstraße 19 D Oberding-Schwaig Germany Phone +49 (0) 81 22/ Fax +49 (0) 81 22/ info@neureder.de from feeding from the coil to logging of all relevant steps in the process. The quality assurance system is also fully integrated. This includes, for instance, cavity-specific placement of the brush holders. The automation solution increases the availability of the system considerably and reduces the technical risk. Krauss-Maffei also supplied Johnson Controls in Wuppertal/Germany with a complete production line for fabric-covered back-moulded pillars for an auto interior (Fig. 12). A control system coordinates a line comprising one linear and three industrial robots that interconnect the individual system components, the injection moulding machine, two fabric cutting stations and a conveyor. The KM DF injection moulding machine forms the core of the extensive production system. All peripheral equipment was synchronised to it in order to eliminate any dead times and ensure that no component waits for another. The economics and availability of the system assure the continued existence of this production site. is polypropylene (PP). A sandwich nozzle connects the two injection units, which are mounted in a piggyback arrangement on the KM /55 CZ machine, to a common nozzle. In view of the short cycle times, the part removal robot was designed as a high-speed component with short strokes. The supplier offered a high-speed side-entry concept based on a lightweight LR variant. Early participation of all partners in the project from the beginning made it possible to coordinate other variables. For instance, compressed-air nozzles that blow the food containers into the gripper were integrated into the mould and in this way shorten the strokes and associated times. The mould opening stroke was matched to the size of the gripper, so that only the minimum required opening / closing strokes had to be executed (Fig. 13). Fig. 10. Production unit for stamping contacts out of a coil and loading them into a 2-cavity mould (photo: Neureder) The stacker was oriented horizontally in order to eliminate unnecessary rotating motions by the gripper. These factors played a decisive role in achieving a take-out time of only 0.5 s. Krauss-Maffei offers an extensive range of equipment for individual solutions especially in the area of high-speed applications. With regard to machinery, the high-performance machines of the CAP series (C-Advanced Packaging) and the packaging machines of the CX and MX series present ideal prerequisites for rapid yet highly precise, reproducible machine operation. Carefully Matched Components For companies that are increasingly outsourcing their engineering, the large pool of process-related know-how and the close cooperation among the individual areas within Krauss- High-performance Systems for Packaging From the packaging sector, Krauss-Maffei exhibited production of a 3-layer container that contains as a barrier a thin layer of ethylene vinyl alcohol (EVOH) copolymer at the K The outer skin Fig. 9. As a result of the gripper design, only a minimal opening stroke is required for the clamping unit. Part take-out time is 1.2 s (photo: Neureder) 4 Carl Hanser Verlag, München

Fig. 11. The prepared metal strip is unwound from the coil and fed to the stamping die in the automation cell (photo: Neureder) Maffei represent a good foundation for technological advancement.

a solution tailored to the customer s requirements.

A specific example can be found in operation of the automation, which is tailored to the control system of the injection moulding machine.

5 Fig. 11. The prepared metal strip is unwound from the coil and fed to the stamping die in the automation cell (photo: Neureder) Maffei represent a good foundation for technological advancement. Time-consuming communication with numerous component suppliers is replaced by dialogue with a single partner who assumes overall responsibility, which permits a logical, multi-discipline approach to a solution tailored to the customer s requirements. The basis for this lies in the continuous development of the processes available, machine standards, machine sizes and software components from various departments that are matched to one another. A specific example can be found in operation of the automation, which is tailored to the control system of the injection moulding machine. Basic operation of a complete cell can be accommodated with only five additional pushbuttons on the operator interface. The LR series makes interfaces to robot control systems superfluous; the machine control system provides this functionality. The robot program is entered at the operator interface of the injection moulding machine. Customer-specific solutions can be developed for all branches, including automotive, packaging, IT & communications, housewares, leisure goods, medical and electrotechnical/electronics. Multi-axis industrial and linear robots that can be configured in a modular manner to the specific requirements are available for each machine size and type. Starting with standard solutions, the supplier can offer even hybrid solutions based on a combination of several robots and robot types in order to fulfil the customer s request. Usually, the processor must expend a great deal of time and expense to have the production cell that it puts into operation tested for CE conformity. Upon request, Krauss-Maffei assumes responsibility for this, since the close cooperation among the individual departments within the company simplifies, for instance, selection of suitable cabinetry for particular requirements. The appropriate technical data and the required CE specifications are known and need not be communicated to various suppliers. The individual components fit together from the very beginning: time and costs for CE certification can be reduced significantly. REFERENCES 1 Bürkle, E.; Sieverding, M.; Mitzler, J.: Injection Moulding of Long-glassfibre-reinforced PP. Kunststoffe plast europe 93 (2003) 3, pp Mitzler, J.; Bauer, G.; Emig, J.; Ammon, S.; Rady, M.: High-quality Surface by Injection Moulding and Reaction Technique. Kunststoffe plast europe 94 (2004) 10, p. 186 THE AUTHORS DIPL.-ING. (FH) JOCHEN MITZLER, born in 1973, is Head of Product Managment Injection Moulding Machines at Krauss-Maffei Kunststofftechnik GmbH, Munich. DIPL.-ING (TU) THOMAS MARUFKE, born in 1967, is Head of Sales and Marketing at Neureder AG, Oberding-Schwaig. Fig. 12. Unattended production in the injection moulding and automation cell. The fabrics are backmoulded and then trimmed, edged and deposited in the downstream stations (photo: Krauss-Maffei) Fig. 13. Thanks to the gripper basket design, the parts are positioned accurately and removed in only 0.5 s (photo: Krauss-Maffei) 5

T he injection coining process invariably. Limitless Coining

T he injection coining process invariably. Limitless Coining Injection coining helps reduce residual stresses in optical components; such part stresses can be tested right on the injection molding machine using polarizing films or 3-D glasses (photos/grafics: Arburg)