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Everything robotic: molders can expect quick ROI from affordable, user-friendly robots.

Robotic automation in the plastics industry is no longer just for large processors. Robots can also help midsized and molders stay competitive through labor savings, increased throughput, improved quality, safer working conditions, and other benefits. While robots have become more sophisticated, they have also become easier to use and more affordable. Even the smallest shops can expect a quick return on an investment in robotics.

The displacement of operators by robots does not necessarily mean layoffs, molders agree, since those workers can be retrained for other jobs, including operating and maintaining the robots and handling the increased business that often results from higher yields and higher-quality parts.

The U.S. is second only to Japan in the use of robots in manufacturing. North American manufacturers ordered 19% more robots from North American suppliers last year than in 2002, reports the Robotic Industries Association (RIA). A total of 12,367 robots valued at $876.5 million were ordered in 2003. Material handling is the largest application across all industries, including plastics and rubber, according to the RIA.

More Molders Using Robots

More and more robots are finding their way into the plastics industry. "We are seeing a notable increase in demand for robots," says Joe Calomino, product manager of Tracer Robots, Husky Injection Molding Systems Ltd. "Processors are having to do more with fewer resources. They are looking for suppliers who can help them not only in the hardware selection, but also with system-type solutions. They count on suppliers for project engineering so that their staff can concentrate on production," he notes.

Husky has revamped its part handling, top-entry servo robots, offering them as the new Tracer line. Features include integrated controls with improved graphical displays, part tracking for reduced cycle times for large parts, and longer strokes for use on larger machines. Tracer robots can be configured for three payloads for a broad range of applications, says Husky. The Tracer offers dual in-line configuration, adding flexibility for stack molding and multimold carrier applications on the company's Quadloc and large Hylectric machines.

Wittmann Inc. also reports increased demand for automation and robotics in the plastics industry. "We have seen a good increase in business, and we expect that to continue this year. Molders are after the whole range of robots," says Wittmann president David Preusse. "They want to buy robots that have very flexible controls. They need to get the job up and running quickly, plus they need to be able to retool and reprogram the robot to a different mold or part configuration after the job changes."

Open Architecture

The concept of open architecture is becoming more and more important to molders, Preusse observes. "Open programming is needed when a processor wants to optimize the cycle or wants to interface to more auxiliary components in a work cell. Few robots on the market offer that open programming ability in a very user-friendly way," he says. Wittmann offers true open architecture in its controls, yet the company's training program only takes 2-1/2 days to complete, he notes. Other robot suppliers report that their training programs have grown shorter as programming controls become more user-friendly.

Wittmann has introduced new automation products in recent months, including clean-room robots to suit multiple applications. Several top-entry servo robot models, from the W621 through W633, for machines of 40 to 650 tons, meet or exceed the Class 1000 U.S. Federal clean-room standard. Clean-room applications are no longer limited to medical and pharmaceutical molding, notes Preusse. This equipment is increasingly being used for molding cellphone components and automotive parts with high-quality surface finish requirements, and for in-mold decoration and labeling.

The clean-room models offer a variety of payloads and strokes--with both the single and the patented telescopic vertical arm. Wittmann's standard TeachBox graphical hand-held teach pendant is used to program and operate the robot. Specialized custom end-of-arm tooling, safety guarding, and downstream automation can also be supplied as part of a complete workcell based on specific application requirements.

Wittmann's new Compact Series Robot features a unique self-contained microprocessor control in a drawer that slides out of the robot's horizontal beam, saving floor space. A large-cross-section beam adds stability and minimizes vibrations. Also new is the W621 UHSS (ultra-high speed servo) top-entry robot for part removal in as fast as 0.33 second. Another model, the W633 UHSS, is specifically designed for thin-wall parts and other applications requiring extremely short removal times.

Wittmann has introduced vibratory stability control (VSC) as standard on all its traversing robots for increased stability, improved precision and repeatability, and extended maintenance intervals. Dual high-precision-ground bearings were designed to absorb shock and vibration for both high-dynamic and static-load conditions. The VSC enables faster ramp-up and ramp-down of the robot, improving the speed profile for maximum speed and positioning accuracy, Preusse says.

New for Wittmann top-entry robots with CNC6 and higher controls is PartTrack, a system that facilitates synchronized operation between the robot and parts in motion on conveyors or during mold opening to reduce cycle time by up to 15%, the company estimates. PartTrack is said to offer advantages in thermoforming and injection molding applications that require parts to be handled by the robot while traveling along conveyors. It assists in removing/stripping parts from the mold and eliminates the need for adding downstream equipment and labor.

More Flexibility Demanded

John Mallon IV, president of Yushin America, Inc., observes that molders are looking for more flexibility in robots, more mechanical capabilities, more networking capability, and open, expandable controls that allow processors to perform more value-added operations. Yushin has developed a new web-enabled E-Touch controller, based on Windows XP and .net technology, that is expandable and easy to program. E-Touch enables the networking of robots, communication, and remote maintenance.

"Molders are trying to do more with fewer people--including support and maintenance people. They need robots that can help with troubleshooting and provide the ability to connect with the factory to fix problems remotely," Mallon says. "They want to be able to network robot to robot and robot to the front office so they know what is happening in the plant from anywhere in the world."

Yushin recently introduced the VSX series of value-priced, all-servo traverse robots for machines from 30 to 300 tons. Also new is the SX-mini I, a 2-axis, servo-driven, side-entry extraction robot, designed for micromolding with machines of 5 to 15 tons. The company manufactures the NCR Series of linear servo robots, which reportedly operate as much as 20% faster than conventional servos, offering extraction times of 0.3 second. Yushin recently re-released the RA servo traverse line as the RA Alpha Series. It features steel-beam construction and reportedly is easier to reconfigure for extended strokes.

More Than Simple Extraction

According to Jim Healy, Conair VP, Automation, robotics in the plastics industry has been moving away from simple extraction of parts and toward the integration of robotic automation into the manufacturing process. He describes an insert molding operation involving manual placement of inserts that went from an 80-second cycle to 45 seconds by automating the operation. Inserts are automatically fed to the robot, which places them into the mold before taking out the finished parts.

"Processors are looking to suppliers for total solutions to help them compete better in their markets," says Healy. "That involves not only the robot and the tooling, but also other equipment such as insert feeders, conveyors, part-finishing equipment, vision systems, and stacking and palletizing equipment. Robot buyers want controls that are easy to program and use, plus more speed to reduce cycle time, costs, and labor."

Conair has introduced the Generation IV family of beam-mounted robots, designed for small to midsized molding applications. The newest and largest model, the SR4040, has a vertical stroke of almost 80 inches with an optional telescoping arm. It also features two new servo wrist rotations that allow the robot to more easily manipulate parts in the machine clamp area and for post-mold fixturing, reports Healy.

All Generation IV robots are equipped with the new user-friendly Visual Control Package, a touch-screen graphical controller that is very powerful, but at the same time very simple to use, he notes. Able to control up to 8 axes and execute up to three parallel subroutines simultaneously, the controller features a large graphic touch-screen interface that presents only information that is relevant to the user, reducing clutter and confusion. Day-to-day setup can be handled by unskilled operators with no special training, Healy says.

Conair also recently started delivering the new Axess robot for pick-and-place applications on machines under 200 tons. "It's a simple, 3-axis servo robot, without as many bells and whistles as others, but it's economical," says Healy. "The affordable price enables smaller molders to put automation on their presses." The icon-driven control panel enables robot cycles to be created from previously written source programs stored in memory. The Axess control also supports direct programming and step-by-step creation of a robot cycle from scratch, he notes.

Automated Robot Trimming

FANUC Robotics has developed and patented AccuDeflash [TM] for robotic deflashing and trimming of plastic parts. The fully automated system utilizes either a contoured knife or a rotary contoured cutter attached to a compliance device that maintains a highly sensitive contact force. As the robot moves AccuDeflash around the part, the cutter locates, adapts to, and follows the parting line. The system enables a robot to deflash and trim plastic parts that vary in size and shape.

Fanuc recently introduced the latest addition to its line of Toploader 6-axis articulated gantry robots, the M-16iB/20T. Like other Toploader models, it has an overhead rail-mount and is electric servo-driven. With a payload rating of 20 kg, it is suited for light to medium material-handling applications, machine tending, and secondary operations such as degating, deflashing, labeling, quality assurance, packaging, and palletizing. The design reduces floor space and ceiling height requirements.

Another new Fanuc product is the 6-axis P-50i coating robot, described as an affordable solution for general industrial coating applications, dispensing, and painting. The compact robot was designed to be easy to set up, use, and maintain. It features Accuflow [TM] closed-loop fluid delivery, which automatically maintains programmed flow rates for consistent material delivery and high finish quality.

Fanuc also offers SimPro[TM] off-line 3-D robot simulation software, which provides tools to develop and test a complete robotic application without the expense of time and money associated with creating a prototype workcell. CAD models of existing parts, fixtures, and grippers can be imported directly into SimPro to build system layouts and evaluate system operation.

Added Value Saves Jobs

Norton Kaplan, product marketing director for Automated Assemblies Corp. (AAC), believes that traditional plastics processors have to start adding more value to the parts they produce or risk losing that business to some lower-cost supplier, whether in North America or elsewhere. Value can be added through in-mold decorating and labeling, insert molding, secondary assembly, and primary packaging by molders, in addition to improved quality, he says.

Verifying the quality of parts has become an important part of the process. "Online integrated vision inspection provides a consistent and unbiased way to check dimensions, features, color, surface finish, and other criteria," Kaplan says. "All of those things add up to ensuring that the quality of the parts being produced is acceptable to the customer or end user. With vision inspection, the same quality inspection criteria can be transferred from plant to plant and operation to operation, enabling global suppliers to ship good parts no matter where they are produced."

AAC has developed the Raptor[R] Vision System, the industry's first multiple-camera integrated robot/workcell vision inspection system for injection molded parts. Easy to set up and program with Raptor's graphical user interface, the system enables processors to automatically check and verify critical dimensional variances, surface finish, gate vestige, and flash, as well as edge finish. The vision system can also be used for inspecting mold cavities, checking insert molding part presence and position, and other functions.

In addition to Raptor Vision, the company produces the Raptor line of robots and an integrated Raptor Controller to develop and control workcells. "We use only one programming language, one set of hardware, and one environment that shares all information within the workcell." A graphical, icon-based controller platform enables the user to program everything, even vision applications, Kaplan adds.

Revolution in Workcells

Sterltech Robotics has introduced the Revolution[TM] Series flexible downstream automation cell, which is built around a high-torque, direct rotary servo-drive robot. A programmable, multipurpose motion platform enables processors to perform secondary operations such as labeling, assembly and packaging, vision inspection, cooling, degating, and laser marking. A PC-based controller features a Windows color touch-screen and microprocessor that can run up to 32 realtime PLC and 255 motion control programs in parallel, says Mauro Apostoli, product manager for the Automation Division.

"The Revolution is easy to program and reconfigure, essentially because it's plug and play," he says. Even short runs can be automated. All stations bolt up with pre-located interchangeable tooling plates around the modular base. Reconfiguration simply involves changing rotary plates to meet the needs of the new part or application, Apostoli explains. The cell can interface with a press-mounted robot or run stand-alone, providing one system that can be used with multiple applications for added flexibility, cost savings, and minimal downtime, he adds.

The SR-SB Series Transverse robot, a low-cost 3-axis servo unit, is a popular addition to Sterltech's line of robots. It is suited for lighter payloads and simpler applications for which a full servo controller is more than required, says Apostoli. He characterizes it as a good, basic robot that can handle 75% of the robotic automation found in plastics applications. Also new is the SR-RA model, a full-sized, highly flexible, 3-axis servo robot that is networkable and web-based.

Staubli Corp. recently introduced a value-priced, simplified control system for plastics applications. Called PlasticsAssistant, the software is said to be easy to learn and use in programming its 6-axis RXplastics robots. The software is available as an alternative to the existing high-level graphics-based system. All programming can be directly executed from a manual control pendant, avoiding the need for a PC monitor and keyboard.

Staubli manufactures the RXplastics robots specifically for the plastics industry. Four models are available--RXplastics 60, 90, 130, and 170--with load capacity up to 60 kg. An entry-level RXplastics package includes the RXplastics robot, CS8 controller, electrical interface, software, and connections, ready for integration with the molding machine.

Space Savers

Ranger Automation has introduced the new 5-axis Ultra-Compact Wide-Body series for machines of 1000 tons and more. It features a 3-stage telescopic arm designed for extracting large parts in tight quarters. Also available is the F-series 3-axis servo robot series for machines of 100 to 3000 tons, which can operate in low-overhead areas. Ranger manufactures a high-speed, double-arm 5-axis robot for stack and three-plate molds for machines of 200 to 1000 tons. Another model is available for machines of 1000 to 5000 tons. The robot can be converted with a servo wrist flip to operate with 7 axes for additional flexibility. Controls for Ranger's servo robots feature quick-teach software designed to step operators through robot programming.

Motoman Inc. has introduced the DX1350, a compact, lightweight, 6-axis robot for material removal and part-finishing applications. The robot body was designed to be resistant to airborne particles and water, and the wrist can tolerate temporary immersion. Maximum payload is 35 kg, and the robot is said to offer the highest twist torque in its class. It features the advanced XRC 2001 Controller, which can control up to four robots at a time. The latest addition to Motoman's World Solutions line of integrated systems is ProcessWorld, a modular package of components designed for secondary operations. Also new from Motoman is the HS (high-speed) Series of 4-axis robots and the PX Series 6-axis robots for paint applications.

The new 7-axis Mitsubishi Heavy Industries PA10 robot is available from Rixan Associates, the exclusive distributor for Mitsubishi robots in North America. The powerful yet compact robot weighs only 40 kg but has a payload rating of 10 kg. It can be mounted to the floor, ceiling or wall. Controls are PC-based, and a digital I/O board enables easy configuration with peripheral devices. Also available is the Mitsubishi RV-S Series vertically articulated, high-speed, 6-axis robot, which the company describes as the fastest, most affordable and most precise 6-axis robot ever built by Mitsubishi. With a standard pick-and-place cycle time of 0.37 second, the RV-S Series reportedly runs faster than most SCARA robots.

Sailor USA Inc. offers the new low-profile RZ-V Series of traverse beam servo robots with 3 or 5 axes for high-speed extraction applications. Features include vibration suppression control for more precision during extraction, a regenerative power-saver system, and voice guidance. A 12-inch color LCD touch-screen and "Walk-Through Teach" are featured for easy operation and fast robot setup without extensive training, reports Sailor. Six models are available for machines ranging from 50 to 850 tons. The RZ-50V model for 50-ton machines provides a 0.8-second take-out.

Priced for Affordability

Adept Technology is offering the new value-priced Cobra PLC600 and PLC800 robots, featuring high-performance 4-axis SCARA robots that can be programmed directly from the customer's Allen-Bradley PLC. Target applications include pick-and-place, part transfer, and screwdriving. The SCARA robot system supports flexible dropoff and reject locations as well as multiple pick-and-place locations. Because the PLC server integrates directly with existing PLCs, plant-floor personnel familiar with PLCs can develop and support robot applications without being robot experts, the company says.

Battenfeld Injection Molding Technology offers cost-efficient automation with its Unirob R8 system, which is synchronized with the molding machine through a common control platform. With a payload rating of 8 kg, the compact, entry-level robot is designed for pick-and-place applications. It is fitted with standardized peripheral interfaces to connect it to a conveyor belt, safety barrier, and other peripherals. For in-mold decoration, Battenfeld has developed IMCmore technology, which produces two-component parts with material backing. Robocut A 300 laser robots trim the material inside the mold all in one cycle.

AEC Inc. manufactures the AE-SB Series Servo 3-axis traverse robot, which offers smooth, fast, and accurate part removal, stacking, and inspection at an attractive price, says the company. A multi-language, hand-held control pendant includes teachable programs with up to 100 steps each and 10 motion sequences per step. Servomotor technology offers a high level of accuracy and safety.

CBW Automation has developed new 2-level and 4-level side-entry robots for molds with multiple parting lines. A 2-level system hailed as the latest in lid-handling technology is designed to extract and stack lids in machines of up to 300 tons at a cycle time of under 3.5 sec. The robots run 30% faster than previous CBW models and feature regenerative servo power for a 30% energy savings, the company says. CBW's new PC-based Lumera Control System, designed to be operator-friendly, displays screen shots of parts on a monitor to help troubleshoot problems.

Specifying Your Robot

The list of factors to consider in specifying a robot starts with the general type or design required for the application. Robots fall into several categories. Most common is the Cartesian type (known as gantry, traverse, and beam robots), having 2, 3, or 4 degrees of freedom called axes. The other main type is the articulated robot, with 6 or more axes, providing more flexibility and adaptability.

A 6-axis robot provides X, Y, and Z location capability, as well as yaw, pitch, and roll orientation--the same flexibility as the human arm. This type of robot can perform multiple tasks very quickly, including insert placement, demolding, deflashing, degating, in-mold decoration, painting and coating, assembly, inspection, and packaging.

The SCARA (Selective Compliant Assembly Robot Arm) robot is suited for high-speed, precision operations such as sealing, dispensing, parts insertion, and assembly applications. Other factors to consider include payload rating--not just for the current molding job but also others the robot may encounter in the future. Payload is the weight of the end-of-arm tooling and the work-piece.

Available space around the molding machine dictates whether the robot can be mounted to the floor, wall, or ceiling. Some robots are compact for space savings; some are designed for use in restricted spaces. Robots that move along a gantry or beam to tend multiple molding machines are also available. The reach of the arm, axis speed and moments of inertia are other specs to consider.

As with computers, prices of robots continue falling as the machines become more powerful. The movement toward a Windows-based PC interface has made robots more user-friendly and easier to program. Some robots can be networked and monitored from remote locations. Remote troubleshooting and maintenance by factory specialists is growing in popularity as a way to save labor costs.

People vs. Robots

Robots are not a panacea for plastics processors, observes Joseph Portelli, plastic industry program manager for Fanuc Robotics. "People are better at jobs that involve creative judgment. But if the process is repetitive and does not involve judgment, a robot can probably do it faster and better."

When a person tends a molding machine, it might sit 30% of the time waiting for parts to be extracted manually. When a robot does the job, that downtime drops to about 5% because the robot is always waiting to extract the part, he relates. The machine becomes the bottleneck.

Machine extraction is the most common use of robots in the plastics industry today, Portelli notes. "But that is not good enough anymore. The best use of the robot is multitasking," he says. "Instead of having the robot simply pull out the part, drop it on a conveyor, and remain idle while the molding machine cycles the next part, it can be doing other secondary operations."

In a tub-molding operation with a 45-sec cycle time, for example, a 6-axis articulated robot, with all the functionality of a human arm, can easily perform multiple tasks within the cycle time. After extracting the part, it can run it around a degating nipper, around a deflashing tool, over a routing head, next to a labeling machine, and then stack it on a pallet, Portelli explains. The robot can accomplish all five of those post-extraction tasks in the time it takes the press to cycle.

"Simply extracting parts is not good enough because the molder's customer or his competitor can go to China, where 10 people can be thrown at those six operations," says Portelli. "Using robots to their best I advantage is a good way to stay competitive and keep work here at home."

For More Information

Adept Technology

3011 Triad Drive

Livermore, CA 94551


AEC Inc.

801 AEC Drive

Wood Dale, IL 60191


Automated Assemblies Corp.

25 School Street

Clinton, MA 01510


Battenfeld of America

James P. Murphy Industrial


West Warwick Industrial Park

West Warwick, RI 02893


CBW Automation Inc.

3939 Automation Way

Fort Collins, CO 80525


Conair Group Inc.

One Conair Dr.

Pittsburgh, PA 15202


FANUC Robotics America, Inc.

3900 W. Hamlin Rd.

Rochester Hills, MI 48309


Husky Injection Molding Systems


500 Queen St. South

Bolton, Ontario, Canada L7E 5S5

905- 951-5000

Motoman Inc.

805 Liberty Lane

West Carrollton, OH 45449


Ranger Automation Systems Inc.

820 Boston Turnpike Rd.

Shrewsbury, MA 01545


Rixan Associates Inc.

7560 Paragon Rd.

Dayton, OH 45459


Robotic Industries Association

P.O. Box 3724

Ann Arbor, MI 48106


Sailor USA Inc.

981 Via Rodeo

Placentia, CA 92870


Sterltech Robotics

5200 W. Clinton Ave.

Milwaukee, WI 53223


Staubli Corp.

201 Parkway West

Duncan, SC 29334


Wittmann Inc.

One Technology Park

Torrington, CT 06790


Yushin America Inc.

35 Kenney Drive

Cranston, RI 02920

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Author:Stewart, Richard
Publication:Plastics Engineering
Article Type:Cover Story
Geographic Code:1USA
Date:Apr 1, 2004
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