Robots and Automation

Processors are investing in new automation, reports one robot supplier. Wittmann Inc. has seen a significant increase in business over the past few months from processors adding automation equipment. Dave Preusse, president, Wittmann Inc., comments, “Although many companies may not be in a position to buy new molding machines, they want to invest in upgrading their current work cells and plants for an immediate impact on the bottom line.” Wittmann reports increased activity in a variety of markets, including appliances, cell phones, cutlery and housewares. Processors are now more likely to consider the benefits of planning a complete work cell as opposed to just buying a robot for pick and place applications. This ties in with a trend to add auxiliaries to the work cell and connect them to the robot.

Thriving on difficult technical challenges is not only the motto at VIF Mould and Plastics (St. Hyacinthe, QC); it’s the driving force behind their success. In 2000, VIF faced several production challenges when demand for a particular insert-molded product increased 100%, and costs had to be reduced by 25%.

Running three shifts per day, five-to-seven days a week, one operator would manually load/unload inserts into two separate injection molding machines. According to VIF’s President, Steve Vaskuthy, the manual load/unload operation was the one job in the plant that no one wanted to do. “The inserts are hot, insert damage was becoming an issue, it’s redundant work, and consistent cycle times are absolutely essential for part quality”.

One natural suggestion would be to use a multi-shot injection molding machine, but the particular conditions of this part, a hand tool, did not lend themselves to that solution.

Shot-to-shot consistency was critical for maximum throughput. If a part cools too much or too little, the second shot would result in flashing. The slightest delay, even two or three seconds, would produce defective parts.

After considering a wide range of possible solutions, VIF concluded the best approach was to use a conventional floor mounted robot. The final cell included one FANUC M-16iL robot, HandlingTool operation software, end-of-arm-tooling, programming and operator training. Jointly with VIF, FANUC Robotics designed, engineered and supported the entire system from its Montreal, Quebec location.

The M16iL robot is integrated in an overmolding cell with Nissei FN3000 and Nissei FS120 injection molding machines. As the robot extracts a molded core, the press closes and the polypropylene is then injected into the mold. During that cycle, the robot places the extracted core on a horizontal cooling rack. The robot then selects a cooled core and top loads it into a Nissei FS120 injection molding machine for the secondary elastomer over-molding process. Prior to the press closing, the robot extracts a completed part and presents it to a gate removal/part handling tool. The robot load/unload cycle time is 35 seconds per machine.

Production doubled

However, simply duplicating the process as it was done manually didn’t solve the problem of increasing production. VIF and FANUC Robotics worked together to develop an end-effector (end-of-arm-tooling) to handle a newly developed four-cavity mold insert. By doing so, VIF has doubled production, achieved material savings generated through part consistency, and realized a 33% cost savings by going from a two to four cavity mold. Full payback on the entire system is anticipated within two years.

From VIF’s standpoint there was a technology learning curve, but according to Vaskuthy, adopting the technology was easier than originally anticipated. “We’ve taken the self dependent approach by hiring and training employees to be dedicated in-house robotics technicians,” he added. “We’re so confident in our process and capabilities that we’ve guaranteed a price freeze to our end customer for three years; not many suppliers are willing to do that.”

Due to the ease of operation and their own comfort level, VIF has since purchased another robot, a FANUC M-710i for a separate application. With the quality and consistency demonstrated from their first two robot installations, VIF now aggressively pursues business opportunities both domestically and internationally with robotic automation in mind.

Fanuc Robotics Canada Ltd. 905-812-2300

AN ONTARIO MOLDER has installed several dual press robots from Ranger Automation at its plant in Lindsay, ON. Armada Group was attracted to the dual-press system because it was versatile enough to service either one or two presses.

The Dual Press Robot from Ranger Automation spans two side-by-side injection molding machines and mounts to the stationary platens of both presses. For over-molding applications, the robot can remove the parts molded in one press and directly insert them into the mold in the second press for injection of a second material or color. The robot can be outfitted to remove the final over-molded parts in addition to the insert loading functions.

The Ranger Dual-Press Robot also includes the option of running with just one of the molding machines, allowing custom molders to get maximum productivity from the robot.

Some over-molding applications require cooling between the first molding process and the over-mold step. The robot system controller includes the capability to place parts to a cooling fixture or rack, and then sequentially remove the cooled parts for insertion into the over-mold.

The Dual Press Robot even comes with a “dual arm” option, which allows each arm to work independently on each press for normal production, or to work together for insert-loading and over-molding jobs.

Hamilton Avtec 800-590-5546

RECOGNIZING THE NEED for standard, cost-effective air and vacuum circuits for most articulating (5-axis) or cartesian (3-axis) robots, SAS has developed Robotic Valve Boxes that will mount directly to the robot and offer air and vacuum circuits to the end-of-arm tooling. Equipped with a universal mounting plate which can be modified to fit your robot, the Valve Boxes use 24 VDC I/O’s from the robot.

SAS Automation Ltd. 888-SAS-EOAT

FOR PARTS REMOVAL and placement applications on molding machines up to 500 tons, AEC’s AEA Series offers the accuracy of a servo motor with the low cost of a pneumatic drive. The AEA robots have a slimmer 20 mm gripper for tight mold access and a power reach of 25 kg/cm2. With AEA’s servo motor operating the traverse beam, the outcome is accuracy within 0.1 mm. The vertical and strip strokes are pneumatic.

Dier International Plastics 905-474-9874

A SIMPLE YET POWERFUL CONTROL SYSTEM is the calling card of the next generation of Conair beam robots — designated Generation IV. The new “Visual” control, now the standard controller on all Conair Sepro robots, can control up to 8 axes simultaneously, executing up to three parallel subroutines, which means its ability to control peripheral equipment is greatly enhanced. The large, graphic touch-screen interface makes extensive use of icons, presenting only relevant information to the user, reducing clutter and confusion.

To provide this high level of user support, the Generation IV control system comes with 8M of memory. This is a significant increase from the 128K of memory, available only with an optional expansion card, on the last-generation S900II controller.

Stephen Sales Group 905-940-5577; Auxiplast Inc. 450-922-0282

A FULLY INTEGRATED CLOSED LOOP MATERIAL RECOVERY SYSTEM using a simple interface between a robot and a granulator is now available from Nucon Wittmann Inc. The interface provides feedback to the robot about the operating status of the granulator. The robot controls a granulator hopper cover, allowing runners and parts to either enter the feed hopper or be diverted. A vacuum loader can also be connected to the granulator to provide a closed loop with the injection molding machine. The interface option is available for both sprue pickers and robots.

In addition to reduced noise and unattended operation, the system allows fo
r runners and parts to be dropped at the same location in tight work cells.

Nucon Wittmann Inc. 888-466-8266

A HIGH PERFORMANCE SPRUE PICKER has been added to Ventax’s Viper lineup. The Viper AS 208 SP is a servo sprue picker designed for space-constrained high-speed injection molding applications. It can achieve intrusion times of one second or better.

The unique arm design reduces headroom by as much as 50% and provides a very slim profile in the molding area allowing mold open spacing to be minimized. The machine mounts inline and above the tie-bar. This allows the Viper to operate while avoiding obstructions above the mold such as core cylinders.

Ventax Robot Inc. 519-632-7834