How are material handling solutions being implemented on the plant floor to meet lean/flexible goals? Innovation is at work in diverse situations, as the following examples show.
ABB Automation Technologies New Zealand was approached by a manufacturer of paper and paper-related products in Australasia to upgrade their paper towel and toilet paper rewinders. The original equipment used dedicated mechanical cams for controlling the rewinding process, adding to downtime.
Engineers from ABB and the paper manufacturer automated the machinery by making it camless and sectionalizing it for greater flexibility. The sectional regenerative drive electrical system was designed, built, programmed, and commissioned at a project cost only 40% of that offered by the original OEM. The team used standard ac drives with DTC technology, and connected Profibus communications to drives and all individual control products, including encoders. The end user plans to standardize most of its rewinders in the Asia Pacific region with the ABB-based solution.
"We have completed virtually all the rewinders on the tissue machines that this international company owns here in New Zealand, and there are prospects of some installations in Australia," notes Gayomurd Desai, senior automation engineer at ABB New Zealand. "There are hundreds of such converting lines in the U.S., alone, with mechanical cams and common shaft drive. . . . The customer''s operations manager for Australia and New Zealand has said the equipment would be ideal for these upgrades." (For more, click here.)
* * *Rick Noe matches material handling equipment to various processes at Toyota Motor Manufacturing Kentucky (TMMK). Under his direction, a task force of lift truck operators met once a week for six months on safety, ergonomic, and cost issues. The group''s ideas were designed into Toyota Material Handling''s 7-Series lift trucks, including a 20 deg swivel seat option; a lighter seat hood; a hood lift assist; dimmer switches for headlights; a horn button on arm rests; and optional adjustable pedals.
TMMK also has been implementing I.D. Systems'' wireless data communications network for fleet management, with fleet utilization analysis tools, to address the costs and safety issues associated with lift trucks, tow tractors, and other material handling equipment. "I.D. Systems allows us to plot usage of lift trucks hourly, each day," Noe explains. TMMK currently has 14 rental trucks, but the company''s plan is to reduce these to zero through better utilization. Rental cost savings will amount to $21,000 a month. (For more, click here.)
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West Valley Nuclear Services, which processes and packages obsolete nuclear process equipment and materials, asked contractors Butler Construction, Quackenbush Co, and West Metal Works to build a remote handling system that could transport unprocessed nuclear waste down a long corridor and through a series of steel shield doors. The engineers came to Joyce/Dayton with two challenges -- provide a transfer system that could move a specific load a horizontal distance of 80 ft in 20 ft increments, and customize the jack and power system to meet the design challenges of the nuclear industry.
A series of 25-ton Joyce ComDRIVE systems transport the load over a horizontal distance of about 80 ft. The special rotating screw design allows the traveling nut to pass over a central support bushing in the screw with uninterrupted travel. As the ComDRIVE powers the transfer system, nuclear waste is conveyed down an 80 ft long corridor. As the load traverses, it is transferred across thresholds onto successive ComDRIVE systems until it travels the full distance. Stainless steel doors close as it passes each threshold, sealing the nuclear waste in an inner chamber. The systems include custom designed screws, jack sleeves, traveling nuts, and augmented gear reducers. (For more, click here.)
* * *A few years ago, DaimlerChrysler asked plant management at its Twinsburg, OH stamping plant to come up with modernization plans. Conrad Hawley, production control manager at Twinsburg, realized that an automated material handling process was needed, as well as updated production equipment.
Several obstacles had to be tackled. The location of the equipment, width of the narrow aisles, and irregular woodblock floor (including in-plant railroad crossings) could not be changed. There could be no interruption to production, and system flexibility was critical so the plant could be reconfigured to support production of future products. Workers objected to the idea of automation, fearing job losses. And the modernization had to provide an acceptable ROI or payback by not only keeping pace with increased production, but by reducing costs in areas (labor and damaged material) while maintaining high safety standards and addressing ergonomic issues.
The solution included FMC Technologies self-guided vehicles, SailRail over/under racks, Orchid turntables, and Blank feed tables. A key element was to break the project into small phases, prove the concept, and expand. In the first phase a two-vehicle self-guided vehicle system was installed to haul full racks from certain press lines to the shipping department. The effect on throughput was measured using simulation software, with actual values benchmarked against historical numbers at Twinsburg and against the other DaimlerChrysler stamping plants. Analysis showed that the average throughput of the SGV-serviced stamping lines was 25% higher than the manually fed line.
In the subsequent three phases, another 29 SGVs were installed, along with over/under racking and turntables. Throughput rose 25% because of reduced press room and assembly downtime, and the "documented ROI was less than one year," says Hawley. The modernization continues. Twinsburg recently installed the first forked SGV in a DaimlerChrysler stamping plant. (For more, click here.)
* * *Len Industries, a manufacturer of precision-machined automotive components, recently approached FANUC Robotics America Inc for an automated solution to depalletize randomly placed transmission gears from a plastic bin. FANUC Robotics designed a workcell that uses a FANUC M-16iB robot coupled with a FANUC integrated vision system for robot guidance.
The vision hardware includes a Pulnix TM-200 video camera, Advanced Illumination Inc RL36120 red LED ring light, high flex camera power cable, high flex camera coaxial cable, and power supply, and a Matrox 4sightII computer. The Matrox computer includes an Orion PC104+ Frame Grabber, which captures the vision information. A generic flat panel monitor, keyboard, and mouse complete the user interface to the vision system. Other major components include a custom designed and built end-of-arm-tool (EOAT), pneumatics package, robot riser, two-part rack locators, divider sheet storage rack, interface panel, and safety fence.
In addition to unloading the gears onto an exit conveyor, the robot must transfer a plastic board that divides each gear layer. Each bin, measuring 746 (L) x 686 (W) x 721 (H) mm holds 22 layers with 88 gears to a layer. To meet throughput requirements, the vision-guided robot needed to reach an average cycle time of 4.5 seconds per part. FANUC Robotics'' engineers designed the system to transfer two parts at the same time, using an inner diameter grip end-effector with two gripper modules. After four months of operation, the vision/robot cell increased production by 5% and lowered labor costs by 30%, with a system uptime above 90%. (For more, click here.)