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Article | December 31, 1997
Grace-and speed-under pressure
Amway's new pressure-netweigh filler increases speed and accuracy for viscous personal care products. Unscrambler offers gentle handling, cuts down on jams and provides 15-minute changeover.
Packaging for the Americas At the time of Packaging World's visit Line 1 was packaging Amway's Body Series skin lotion for export to several South and Central American countries as well as to Mexico. (Amway's products are distributed solely through Amway distributors worldwide.) The line starts out as boxes of containers are emptied into a stainless steel hopper. An inclined conveyor bulk-feeds bottles into the infeed chute of the Posimat's centrifugal bowl. Inside the chamber a large rotating disc slings bottles to the edge of the bowl where they are captured into 16 pockets called "selectors." Selectors cut to match each specific bottle shape orient the bottles to an upright position. Once upright bottles drop through funnels onto the vacuum discharge conveyor. To keep scuffing to an absolute minimum Amway requested that Posimat build the machine with electropolished stainless steel funnels and ultra-high-molecular-weight plastic selectors. "We've had other unscramblers whose parts were coated with a powdered paint that didn't quite achieve the level of scuff-resistance that we were looking for" says Sejat. The stainless steel funnels also reduce the number of cleanings required compared to Amway's older unscramblers. That's because static buildup which attracts dust is far less of a problem with stainless steel. For changeover to a different bottle size all 16 selectors and 16 funnels must be replaced. While that means a lot of change parts it doesn't take a lot of time according to Sejat. "An unskilled person can change the unscrambler in less than fifteen minutes without tools" he says. With all of the Posimat's bells and whistles Sejat admits the machine was "a little pricey." But he says it's worth it. "The payback was immediate. We're real happy with it." Monoblock filler/capper After bottles emerge from the Posimat's discharge conveyor they're bottom-coded and are ready to enter the Corniani monoblock filler/capper. Bottles pass through an infeed timing screw make their way around an infeed starwheel and are deposited directly onto load-cell pedestals on the filling turret. A photoeye on the infeed detects any missing bottles and signals the corresponding fill valve not to fill. During the first 10° of rotation on the turret the load cells record each bottle's tare weight. Then the nozzle opens and product is dispensed into the containers. Unlike many fillers the pedestals don't ascend and the nozzles don't descend. Instead the platforms and the filling nozzles remain in a fixed position once they're set for a given bottle size. Indeed the nozzles are a good inch above the mouths of the bottles. That's a noticeable departure from Amway's usual practice of trying to get the nozzle as close to the neck of the bottle as possible. The reason? Normally product tends to balloon outward a bit as it's dispensed before coming back together in a solid stream. To ensure this ballooning fill would drop into the bottle Amway traditionally tried to position the nozzle as close to the bottle as possible. On this filler Corniani refined the design of the fins inside the nozzle to give very clean laminar flow characteristics. This keeps ballooning to a minimum causing the stream of product to be straight and narrow by the time it reaches the container. "We've been amazed at how well we can run without spills" says Sejat. When about 98% of each container's target weight is reached the nozzle closes and the remaining 3 or 4 g of product still "in flight" falls into the container reaching 100% of the target fill. The Corniani's dedicated computer continually monitors this in-flight quantity for each nozzle using feedback from each load cell to make minute adjustments to each individual nozzle as needed. All of this control results in filling accuracies of ±1% or better. "We're quite happy with the repeatability" says Sejat. After filling bottles pass through another starwheel that hands them off to the built-in rotary capper. Although Amway could have specified anyone's capper it chose a Corniani unit to expedite the project rather than potentially slow it down by involving a capper from a third party. It has worked out just fine reports Sejat. "We're quite happy with the torque results we're seeing" he says. Fast changeover with CIP Changeover on the filler takes about two hours with one person. One hour is needed for automated clean-in-place. The hands-on part which occupies the other hour is about 90% tool-less. "What's unique about this filler" says Sejat "is that the nozzles are actually part of the base of the tank. There are no separate hoses or tubes to remove. When we CIP the filler we don't take anything off. The only parts we change are for bottle handling." On Amway's other fillers it regularly takes two people eight hours to change and clean according to Sejat. After capping product is automatically case-packed and sealed. Sejat admits that there were some concerns about the potential for delay due to working with an overseas machine builder but the line was commissioned on schedule and the filler has been running successfully for nearly a year. Indeed it's almost too smooth: "Now my biggest concern is keeping my maintenance and technical people up to date on the filler" concludes Sejat. "We've had so few problems with it most of them have forgotten it's even here."
At Amway's recently completed $17 million Personal Care Manufacturing Facility a new pressure-netweigh filler is packaging shampoos and lotions at 140 bottles/min one of the fastest personal care lines in the company's history. Located at Amway Corp.'s huge manufacturing campus and world headquarters in Ada MI this plant the newest of six manufacturing facilities on the complex houses three current packaging lines all installed within a one-year time period. One of the packaging lines features the Italian-made Corniani filler/capper monoblock supplied by ACMA/GD (Richmond VA). The line has been running since early '97. It packs a variety of products in seven bottle shapes and two bottle sizes-400 mL (13.5 oz) and 250 mL (8.4 oz)-all at the same 140/min speed.engineer who was involved in building the all-new packaging line. By using pressure Amway doesn't have to slow down the filler to accommodate variations in product viscosity brought about by even slight fluctuations in temperature. Traditionally this is an issue when filling temperature-sensitive personal care products says Sejat. "It's an amazing improvement in packaging viscous products" says Sejat. "If product is left in the tank over the weekend we can just start right up regardless of temperature." Nevertheless the company continues to warm-fill usually between 80°F and 90°F which helps thin out the product. Only a modest amount of pressure is actually used-up to 3 psi-enough to attain the higher speeds. The other important aspect of the new filler is the built-in netweigh function: There are 24 individual load cells-one under each filling nozzle-that signal the filling nozzles to cut off when the proper fill weight has been reached. "We don't have to worry about a separate checkweigher or reject system" says Sejat. Contributing to filling accuracy is the way the Corniani's dedicated computer-separate from the machine's PLC-calculates the tare weight for each bottle on the turret. Other fillers that Amway evaluated calculate an average tare weight and use that one number to determine the net weight for all bottle positions. "We weren't comfortable with that" says Sejat. "Some pedestals could have some water or product on them that would throw off those weights." The Posimat (Miami FL) unscrambler is another key piece of equipment on the line because it greatly cuts down on jams. Sejat explains: "Generally the number one place you experience jams with a sorter is at the discharge. That's where you're trying to get bottles to balance on your conveyors and that's where they can fall over." The Posimat virtually eliminates the problem by relying on a vacuum discharge conveyor that keeps the lightweight plastic bottles from tipping. The fiber belt of the conveyor is perforated so that a continuous vacuum pulls at the bottoms of the empty containers. "It's been a huge benefit over the other sorters we've had at Amway" says Sejat.
Pressure-filling enhances operation "With the viscosities we fill we felt pressure filling was critical to enhancing our operation" says Amway's Joe Sejat the plant's mechanical
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