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PET water bottles flow through filling

AquaPenn rinses, fills and caps PET bottles on a bloc system twice as fast as a former line, producing 1/2-L and 20-oz bottles of spring water. Improved bottle handling slashes downtime, resulting in a nearly 20% increase in efficiency.
To keep pace with phenomenal sales gains in bottled water AquaPenn Spring Water Co. built a 108-sq' headquarters/bottling plant in Milesburg PA. Opened in May '95 the plant houses five bottling lines. At the heart of the most advanced line is a bloc system used for the company's two highest-volume retail offerings 20-oz and 1/2-L bottles of polyethylene terephthalate. AquaPenn is the first bottled water producer to use the bloc system from Krones (Franklin WI). It includes cleaning filling and capping equipment mounted to a common base. The bloc operates at speeds to 600/min for the 1/2-L size 480/min for the 20-oz version considerably quicker than the 320/min and 280/min rates achieved on a line at AquaPenn's former plant in State College PA. "The machinery on that line was limited in terms of its bottle handling" explains company president chairman and founder Ed Lauth. "Lightweight PET bottles are
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difficult to handle prior to filling. We had bottles falling off the conveyor and jamming equipment. This caused downtime and reduced our line efficiencies." Another limiting factor he says was that the older line was used to fill five bottle sizes. "Changeovers limited efficiency so now we run only our two highest-volume bottles on the Krones line. It can also fill a 12-ounce size that we produce in small volumes on another line." Meanwhile the former line has been upgraded. At the new plant that line is now dedicated to 1- and 1.5-gal PET bottles that don't require the speeds achieved by the Krones bloc system. Measuring efficiency "Milesburg is the most modern bottled water plant in North America" boasts Lauth. "And with the addition of the Krones bloc system we've reduced empty bottle handling problems increased our filling speeds and are in position to attain the highest standards of quality control in rinsing filling and capping." These improvements result in an increase in overall efficiency which AquaPenn measures as a percentage of machine capability over a period of operating time. "The sheer amount of equipment on the line prevents us from reaching numbers close to 100-percent efficiency because if any one machine is down even one percent of the time we lose line efficiency. With the Krones bloc system we've improved our efficiency by 15 to 20 percent. Our efficiency is up to about 70 percent now but our goal is to improve that to between 80 and 90 percent. We hope to reach that this summer by adding a faster case packer. "And though we use the same amount of labor as before we're able to produce much more than we used to so our labor-per-case figures have produced quite a savings" he notes. So what's the payback for the machinery? "Our number one concern is providing the highest standards in quality control and packaging in the industry period" he explains. "There is no gray area when it comes to this it's either an 'A' or 'F' grade. While the Krones bloc system is more expensive than others I believe the quality control features and production efficiencies far surpass those of others in the field." Milesburg is scheduled to ship a total of 100 million PET bottles this year Lauth says. The plant also produces 1- and 2.5-gal high-density polyethylene containers for retail sale and 5-gal polycarbonate bottles for commercial customers on other dedicated filling lines. On-site molding to come AquaPenn runs the bloc line six days per week keeping two shifts busy nearly 24 hours/day. The five sizes of PET bottles are injection/ stretch blow-molded by Johnson Controls (Manchester MI). Bottle gram weights are 24 for the 12-oz and 1/2-L bottles 27 for the 20-oz size 37 for the 1-L version and 42 for the 1.5 L. While the 20-oz bottle is custom molded for AquaPenn the other four sizes are stock bottles. AquaPenn is working with Johnson Controls in an effort to lightweight bottles. Lauth says "We plan to stretch/blow-mold bottles on-site by late fall of '96. With our volumes there would be economic advantages for us to do this. It's also our intention to blow-mold HDPE on-site. At that time it will be more economical for us to look at lightweighting when PET bottles are produced on-site." Why? Plant manager Louis Rizzo explains. "Bottles have to have a certain amount of strength to withstand transit from the molder to our plant. If pallets bump one another during transit they could deform some bottles. Preforms are stronger than bottles because they have the same amount of plastic as the bottle but in a smaller area. By shipping preforms we won't need to worry as much about bottle strength. Therefore lightweighting is more possible." Transfer starwheels Lauth points out that the bloc system also enhances opportunities for lightweighting. "The system carefully handles each bottle throughout rinsing filling and capping stages on the bloc" he says. Rather than convey bottles from equipment spaced far apart the bloc design uses transfer wheels to move bottles between rinsing filling and capping equipment. At each machine bottles are handled by either clamping jaws or a combination of base plate and centering bell. "The bloc permits faster speeds and eliminates the tipping and falling problems we once had" Lauth says. "The handling capability gives us the opportunity to experiment with reduced gram weights. And with the production volumes we have the potential material savings from lightweighting could be substantial." Empty bottles are automatically depalletized then air conveyed by the neck to Krones' Variojet rotary rinser at the beginning of the bloc. The rinser filler and capper that the bloc comprises are all located within a cleanroom environment. Bottles move from a feedscrew to infeed starwheel within the rinser that uses both air and water to clean the bottle prior to filling. "Air can't clean everything out like water rinsing" notes Lauth "but if you use just water you could trap corrugated fibers or dust in the bottle. By using both we believe we have the highest rinsing standards." The cleaning process begins as a presence sensor detects the bottle as it moves into the rotary rinser. The sensor signals the bloc's PLC to activate the rinsing valves. Clamping jaws grasp the bottle and invert it over a cam-driven nozzle that enters the bottle. First the nozzle blasts air into the bottle then ozonated water is sprayed to rinse the bottle. The water empties into a drain pan and the nozzle is purged so that it can deliver the next air blast. The machine's rotational speed and electronically controlled valves operate independently to ensure that each bottle receives the proper amount of air and water. Electronic fill valves The jaws upright rinsed bottles to a discharge starwheel that transfers them directly to the filler's infeed starwheel. This star-to-star transfer system is the key handling advantage the bloc system provides compared with AquaPenn's previous bottling line. The infeed starwheel moves bottles to the base of Krones' Sensometic VP-G electropneumatic filler. Each bottle is delivered onto a lift cylinder that raises the bottle to one of 60 electronically triggered filling valves on the rotary gravity filler. This minimizes top load on the container neck helping to prevent the possibility of bottle deformation while also reducing the necessary amount of bottle strength says Rizzo. "It gives us another avenue to pursue lightweighting as well as the potential to change bottle shape since sidewall strength isn't as much of a factor in filling." Each filling valve uses what Krones refers to as a "conductance probe." This probe is part of the valve. Filling is accomplished in two stages. During the initial stage of the fill most of the water is delivered into the bottle. The second phase fills more slowly and the valve shuts off when water reaches the probe. This assures proper fill height for each bottle. A computer controls all valve functions. This eliminates the need for actuating cams levers or push button valves reducing maintenance requirements. And since fill-height adjustments can be made automatically via the computer control size changeovers require only replacement parts for the infeed screw starwheels and center guides. Bottles exit the filler via a discharge star directly to the infeed starwheel of a Fowler/Zalkin 15-head capping turret. The machine is manufactured by France-based Zalkin then modified by Fowler Products (Athens GA). The turret applies a preassembled two-piece sport cap dispensing closure and overcap by torquing the assembly onto the threads of the bottle neck. "This capper is manufactured to be a part of the bloc so its pitch matches that of the filler" notes Rizzo. "That helps stabilize bottles during the process. The starwheel transfer from the filler discharge to the capper infeed maintains the bottle captively throughout capping. This is an advantage over our previous capper where bottles conveyed from the filler to the capper and were prone to tipping which caused downtime." Creative Packaging (Buffalo Grove IL) provides AquaPenn with the 28-mm two-piece sport cap. The black-colored pull-push closure includes an injection-molded polypropylene base and PE spout. A transparent removable PP overcap is fitted onto the sport cap to serve as a dust cover. Versatile labeling Once the three-piece assembly is applied to the filled bottle the bottle discharges from the bloc system past an ink-jet printer from Videojet Systems (Wood Dale IL) that applies a two-line product manufacturing/ expiration date code just below the neck. Bottles proceed to an accumulation table before indexing to Krones' Combi labeler. For the 1/2-L and 20-oz AquaPenn brands the labeler uses Krones' Canmatic hot melt adhesive system to apply a wraparound label to each bottle. Hammer Lithograph (Rochester NY) supplies the 60# coated-one-side paper labels printed offset in four colors then cut stacked and shipped to AquaPenn. A feedscrew delivers each bottle onto a separate bottle plate. A centering bell holds the top of each bottle. While held in place the bottle rotates. A glue roller applies a stripe of hot melt adhesive onto the container. A mechanical device contacts the leading label pulling it from a magazine. As the bottle passes this device the label makes contact wrapping itself around the rotating bottle. Another mechanical device applies hot melt to the trailing edge of the label as it slightly overlaps the leading label edge. The bottles rotate past a brush station that provides a final wipedown. What makes the labeler somewhat unusual is its ability to not only apply cut-and-stack labels but also the pressure-sensitive version hence the Combi model name. As part of its contract packaging business AquaPenn uses p-s labels upon customer request. "This labeling system gives us a great deal of flexibility" Rizzo points out. "We can do changeovers in about an hour or two." The changeover includes disabling a timing belt and replacing parts such as the unwind station some pressure and bottle pads. It also requires engaging parts not in operation when paper labels are applied. "This is a real advantage for us in that we don't have to purchase and find a place for an additional machine on the line" Rizzo continues. "We don't tie up the capital and we don't have to be concerned with additional handling issues between pieces of machinery. The labeler also allowed us to add a tamper-evident bander right on the discharge starwheel." At this starwheel labeled bottles are banded by Krones' Garantomat system. Reliable Plastic Seals (Opelika AL) provides the 2-mil tubestock of polyvinyl chloride. The material is random printed flexographically in white on a clear background with brand name and the words "Sealed for Your Protection." Downstream efficiency The material unwinds over a series of tension rollers and is subsequently perforated for easy opening. Rollers guide the material over a cylindrical mandrel prior to application over the bottle neck. A rotary knife cuts the band which is placed onto the bottle. An overhead positioning belt contacts the top of the bottle effectively pushing the band down to the shoulder of the bottle. Bottles convey through a shrink tunnel to complete the banding process. Bottles are case-packed on an Ocme America (York PA) machine then palletized. "We replaced an earlier Ocme case packer that packed about 30 cases a minute with their new model that does 40 to 45 cases a minute" says Lauth. "That will increase our output and efficiency." AquaPenn also has the option of multipacking bottles into trays or fully wrapped cases. Price pleases retailers At retail the 20-oz bottle sells for 79¢ to 89¢ while the 1.5-L size retails for $1.19 to $1.29. Pure American® is AquaPenn's national brand name while Great American and AquaPenn are sold primarily within the Mid-Atlantic states region. Nearly half of AquaPenn's sales is attributable to waters that it contract packages for other companies though Lauth prefers not to name-drop. "Our products are in the mid-range price-wise" he explains. "That way convenience and retail stores can still sell individual bottles but at higher margins. In the past convenience stores for example sold water at cheap prices with margins of less than one dollar per case. With our Pure American brand they get a higher sale price. That results in higher margins. They love that. "We're planning to purchase one or two more blocs by the Spring of '97 to meet our needs" adds Lauth. And space for the new machines should be no problem either. "The Milesburg plant represents the first of three phases" he says. The second phase calls for a 125-sq' addition this Spring to accommodate on-site bottle molding. By 1998 additional warehouse space is scheduled to complete the process.

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