Robots Save on Consumables, Raw Material Costs
by Winn Hardin, Contributing Editor
Robotic Industries Association Posted 07/03/2002
While labor cost reduction and quality improvements have always been drivers for robotic automation, the act of automating has enabled many manufacturers to save on the consumables used in the process, including power, components and raw materials.
Although most industries that use robotic automation can point to some form of consumable savings as a result of automation, a straw poll of major robotic suppliers points to painting and other surface preparation processes as one of the best examples of these savings. For the purpose of these discussions, consumables were defined as materials used to keep a process going, such as electricity for the robot or gas for a weld gun, while raw materials included all materials and components used to create an end-product.
Painting a pretty savings
'Robot painting offers up to 30 percent savings in paint usage,' said Carl Traynor, senior director of marketing at Motoman (West Carrolton, Ohio). Simulation software gives the robot advantage over human operators. 'CAD tools simulate the dispersion of the spray from the robot. The software adjusts to the speed and movements of the robot so that you get consistent and optimized path performance with maximum coverage and minimal paint. Once you optimize the simulation, you can download it to the robot and you're ready to go.'
The software associated with robotics helps achieve cost savings in many ways, concurs Harry Beaver, III, National Sales Manager, Staubli Unimation, Inc., who points to the 'closed loop supervision' a robotic program provides to prevent overspray and to optimize atomizing airflow, fan width and paint flow.
'This (robot programming software) reduces paint and solvent waste, minimizing booth contamination. Also, quality improvements equals less rework, resulting in higher yield,' Beaver said. 'By using a robot to paint a product, the exact same path is repeated each and every time. With human painters, factors such as fatigue, boredom, etc., may cause the operator to use excessive paint, thus wasting product; or too little paint, resulting in scrap or re-work, which equates to wasted time and money.'
Paint delivery tools are also a big part of the savings realized by automated painting applications. According to Martin Rola, director of product and application engineering for paint shop automation at FANUC Robotics (Rochester Hills, MI), bell atomizers help paint shops optimize paint usage. Bell atomizers spin at speeds of 25,000 to 60,000 rpms. The paint enters from the back of the bell and transfers to the wall of the bell and is electrostatically charged prior to being atomized at the edge of the bell cup. The charge helps the paint attract to the painted surface while the high speeds of the turbine-driven bell particulate the paint into a very fine, uniform spray. In addition to paint savings of 30-40% over electrostatic spray guns, bells can also offer a reduction in compressed air usage of more than 20 percent.
FANUC recently adapted the bell atomizer to work with water-based paints in addition to solvent-based paints. 'With environmental concerns, people are pushing for water-based paints. One of the problems with water-based materials is they are very conductive. We've developed a direct charge water-born bell for water-based paints,' Rola said.
In addition to paint, Beaver notes that even more cost savings can be attributed to more efficient use of consumables such as personnel protective gear, respirators, filters and the like. 'As paint consumption is reduced, the filters in a typical cell can last longer, which adds up to tangible yearly savings. If a robot is able to replace a three-shift operation, the cost savings alone for protective clothing, respirators, etc., can add up.'
Dispensing some quiet advice (for more savings)
Other dispensing applications, such as sound dampening materials, are also seeing bottom line improvements as a result of automation. 'Sprayable dampening materials are replacing cut pads in the floor pans of cars,' explained Ray Guzowski, senior staff engineer for dispensing systems, paint shop automation, FANUC Robotics. 'As a result, the customers are seeing a material and weight savings per car of 10 to 12 pounds with equal or better noise vibration harshness (NVH) levels.'
Dampening pads are die cut, dirty the car's exterior during installation leaving contaminating marks in the automobiles paint. Also, optimizing a pad design after the initial deployment requires changing the die stamping used to cut the pads. Changing the spray material shape and placement is a simple matter of reprogramming the robot using CAD software - no tool changes are necessary.
Assessing today's software, Beaver points out how today's technology has evolved to make it more simple and easy-to-use. 'Graphical, Windows(r)-style interfaces make it possible for 'low-tech' operators to program and adjust paths and programs,' he said. 'This allows the customer to avoid hiring high-dollar programmers to program and modify the application. After initial start-up, most operators are able to add, modify and create new programs with ease.'
According to Guzowski, it's just as easy to reprogram robots and save money for 'new, ultra-lightweight seam sealing applications. New end effectors allow a controlled ribbon to seal the seams reliably with a thinner coating, resulting in another 20 to 30 percent material savings for that application,' he said.
Beaver points out some other dispensing applications that benefit from the use of robotics, including glue, foam and adhesives. 'Cost savings are in the part quality, reduced reject rate, increase in yield, uniform part quality and speed.'
Mirror, mirror (a look at robots 'in the buff')
Other surface preparation applications, such as buffing and grinding also benefit from the precision of robot controls. Vince Panzarella of ABB manufacturing industries group works with durable good manufacturers, machine tending operations and non-automotive manufacturing, such as motorcycles. Typical applications include the grinding of sheet metal to remove weld spatter, preparing sheet metal for paint, and buffing of metal for chrome plating. 'With automated processes, you have consistency of pressure regardless of whether the operator is having a good day, a bad day, a strong day, etc. You also use the entire belt rather than one little area and subjective calls about when to change belts or abrasives are predetermined, therefore the company can plan better for consumables,' Panzerella said.
According one of Panzarella's customers, Mike Kunkle, senior engineer at Harley Davidson (York, PA), 'Using robots, we get anywhere from 2 to 4 times cost savings reduction for abrasives, and about the same in labor savings.'
Motoman's Traynor has seen similar savings with plastic sheet molding compound (SMC). 'Automobiles are moving more towards plastic parts, and there's processing [of plastics] that needs to be done prior to painting. In the past that's been a manual operation with a sander. With a robot, you can optimize the path to achieve the desired effect in software, and as the sand paper loses grit, you can increase the pressure by the robot to get a more consistent part finish and maximize belt use,' Traynor explained.
Beyond painting and surface preparation
While painting and surface preparation applications are 'poster children' applications for consumable and material in robotics, most other industries using automation are also benefiting from reducing the cost of power consumption or more efficiently using raw materials.
Adept Technology Inc., a player in the electronics and telecom automation industry, believes that compared to traditional vibrating bowls and PLCs, it's FlexFeeder line of part handlers significantly reduces surface scratches that lead to rejected parts in rocker switches and HVAC controls in automobiles. FlexFeeder is also used in the electronic and medical manufacturing industries with similar results, said Joe Campbell, vice president of marketing at Adept Technologies.
Special transformers used to power robotic cells result in power savings that are reducing utility costs and tax burdens. 'That's really hit home in California where [the state] offers power savings credits if you can demonstrate capex investment that reduces power consumption,' said Motoman's Traynor.
Welding is another area where gas and wire costs are reduced through automation. 'One could argue that because the duty cycles are higher, robots give power savings, but in welding, it really comes down to consumables and waste,' said FANUC's engineering manager for materials joining, Mike Sharpe. 'An operator may manually cut wire, clip it or do a test arc. An operator is going to waste the materials, while a robot is going to lay it down the same way, over and over.'
In so many applications, robots and their precision movements are improving the efficiency of manufacturing processes along with the bottom line. New sensors and simulation software make it easier for human programmers to understand the robot's capabilities, and enable robots to react intelligently and quickly to changing conditions or processes. The result is greater cost savings related to consumables and raw materials and more companies taking advantage of these savings in ever more applications.