A high-speed, wine-bottling line at Stone Hill Winery applies screw caps

In a patented system, nitrogen is injected into the bottles through the valves and nozzles that dispense the wine. The wine is only filled into the bottle after the injected nitrogen has displaced the air.

Nestled among the rolling hillsides near the Missouri River is the little town of Hermann, MO. Perched prominently on one of these hills, with a commanding view of the village, is Stone Hill Winery. Established in 1847, Stone Hill grew to be the second largest winery in the U.S. The wines were world renowned, winning gold medals in eight world fairs. By the turn of the century, the winery was shipping 1.25 million gal of wine/year.

Unfortunately, the advent of Prohibition in 1920 killed the wine industry in Missouri, and the winery's spectacular arched, underground cellars (the largest series of vaulted cellars in America) were used to grow mushrooms. In 1965, Jim and Betty Held bought the winery and began the long process of restoring its picturesque buildings and vaulted, underground cellars, which had fallen into disrepair after Prohibition. Today, Stone Hill is Missouri's oldest and most awarded winery. In 2006, Stone Hill produced 215,000 gal of wine.

Last year, Stone Hill made a momentous decision. It decided to apply screw caps to some of its wines instead of corks, and in July 2006, it installed a new $1-million-plus bottling line to accomplish this. It is currently applying screw caps to its sweet and semi-sweet wines, including Steinberg Red, which was running on the line when PD visited the plant. "Our move to screw-top closures was a way to retain the high quality of our wines," says senior winemaker David Johnson. "Screw caps are a better closure, but they have never gained popularity in the U.S. for quality wines, because the quality wines have all used cork closures, while screw caps were limited to cheap wines. The big impetus for screw caps comes from their use by New Zealand wineries on their high-quality Sauvignon Blancs. We feel we have made the right decision based on the fact that four to seven percent of all corked wines are tainted by trichloroanisole, a rather offensive-smelling compound commonly know as TCA," Johnson explains. "TCA is a complex chemical that comes from reactions within cork involving natural mold and chlorine that is used in cork manufacture or is naturally occurring. Screw caps are not a cheaper way of bottling wines, but a way to ensure that every bottle will be free of cork taint.

"When it came time to upgrade to a faster bottling line, we knew that we wanted the capability to screw-cap our wines, especially our fruit-driven whites and rosés," says Johnson. "We also bought new equipment to apply corks to the wines that are likely to be laid down and cellared for several years, such as the Norton and Port varieties. For these wines, we will continue to only buy corks from suppliers that follow very stringent cork-screening tests to minimize the problem with cork taint." The integrator for the new bottling line was Scott Laboratories, which also supplied the conveyors, the rinser/filler/capper/corker, which is manufactured by MBF S.p.A., and the caps, which are manufactured by Alplast S.p.A.. "We looked at bottling lines in a number of other plants and decided that this system from Scott would be best for our operation," says Johnson. "It has lived up to all of our expectations, and the service from Scott has been excellent. We couldn't have made a better choice."

The 6-head capper applies roll-on, tamper-evident caps to the bottles.

During PD's visit, the line was running Steinberg Red wine in 750-mL glass bottles. To start the operation, workers place 12-pack cases of bottles, which are supplied by Vitro Packaging, on a declining roller track that delivers them to an automatic case unloader. This is the only old piece of equipment on the line. Everything else is new. The cases travel up an inclined conveyor and are transported overhead to the automatic case packer, while bottles are conveyed to the monobloc rinser/filler/corker/capper, which is housed in a Class 100 enclosure. This continuous conveyor runs through the enclosure, and bottles are diverted from it at each machine and back onto it at the exit of each machine.

The system includes a 30-head rinser, a 35-head filler, a 6-head corker and a 6-head capper. Each has a starwheel infeed and an exit starwheel. A feedscrew delivers the bottles to the starwheel, which feeds them into the rotary rinser, where grippers pick them up and invert them over nozzles that spray water into the bottles. Spraying is initiated upon receipt of a signal indicating the presence of a bottle. The water drains from the bottles as they travel around the machine, and they are rotated back into an upright position as they approach the discharge. The bottles exit the machine onto the conveyor through a starwheel that is fitted with a safety device that stops the rinser in case a jam occurs. Next, they enter a screw that directs them to the starwheel feeding the 35-valve low-vacuum filler. Because it is essential that the filled bottles retain as little oxygen as possible, the filler at Stone Hill incorporates new technology developed by MBF that removes oxygen from the bottles before they are filled with wine. In this patented system, nitrogen is injected into the bottles through the valves and nozzles that dispense the wine. The wine is only filled into the bottle after the injected nitrogen has removed the air from the bottle.

The pick-and-place case packer utilizes pneumatic gripper heads to lift the bottles and servos to move them into the cases.

In this process, the starwheel places the entering bottles onto individual bottle pedestals that rise as the machine rotates and push the bottles up against the fill valves. The fill spout enters the bottle, and nitrogen is injected. It flows down the center of the bottle and pushes the air up along the walls and out of the bottle. This requires only 1.5 to 2 sec, and as the machine rotates, the nitrogen valve closes, and the fill valve opens and admits the wine. According to Scott Laboratories, this system results in residual levels consistently near 0.1 parts per million or even less. As the bottle nears the machine discharge starwheel, the bottle pedestal descends, allowing the fill valve to close, and the bottles discharge through the starwheel, onto the conveyor. The fill level is consistently within 1 mm due to another patented design of the MBF filling valve. Instead of an O-ring on the filling-tube tip, MBF utilizes a large gasket internally to close the valve. The filler incorporates an automatic clean-in-place (CIP) system that can be programmed to start at any time, even without the presence of an operator. The next piece of equipment in the monobloc is the corker. Stone Hill was not running corked bottles during PD's visit, so the bottles bypassed this machine and were conveyed to the capper.

If the plant were running corked bottles, the bottles would go through the corker and bypass the capper. A starwheel delivers the filled bottles to the capper. Roll-on, tamper-evident (ROTE) caps are loaded into a floor hopper and are air-blown over to the overhead cap hopper. The hopper rotates to orient the long-skirted caps so that they arrive at the cap-pickup point with the open end down, and they are fed into a chute that carries them down to the capper. The capper injects nitrogen into the cap chute to remove air from the caps, and another injection system located where they enter the capper displaces air that has collected in the tops of the bottles after filling. At the pickup point at the bottom of the chute, the caps protrude slightly from the chute, and the bottles in the infeed starwheel pick them up as they pass beneath. The bottles then pass beneath a stationary plate that pushes the cap down onto their tops, after which the bottles are transferred into the capper. At this point, capping chucks descend onto the bottles and rotate to screw the caps onto the bottles until the capping heads reach the preset torque. The capping heads push down with about 275 lb of force, and the threading rollers mold the caps to the bottle finish and threads.

This is a three-step process. First, the liner is compressed onto the top of the bottle, forming the seal. Next, the threader roller spins along the side of the bottle to mold the cap onto the screw thread. This holds the seal in place. Finally, the beading roller spins a small tuck just below the threads to secure the sleeve to the bottle, when the cap is removed. At this point, the chucks open and rise off of the bottles, after which the bottles travel through the discharge starwheel onto the conveyor.

One of the advantages of a monobloc system is that all of the equipment is controlled by a common programmable logic controller and an operator panel. The MBF equipment at Stone Hill is controlled by systems from Siemens Energy & Automation, Inc.. While running different bottles may require changing some bottle-handling parts, the control system remembers operating parameters for each bottle so that the system can be set up properly at the touch of a button. It also records operating data and tracks the causes of shutdowns.

A sensor at the inlet of the labeler detects the presence of labels and triggers the label feed.

Stone Hill has a capsule spinner manufactured by Nortan S.r.l. and supplied by Scott Laboratories in the U.S. that applies and pleats aluminum and tin capsules to cork-sealed bottles. This was not running during PD's visit. The bottles then travel around a curve and enter a Master automatic, rotary pressure-sensitive labeler from P.E. USA, Inc., through a feedscrew that controls the bottles as they are presented to the self-centering bottle plates via the infeed starwheel. Bottles enter the rotary carousel and are placed on individual bottle plates that are rotated by a mechanical cam. The labeler has 10 individual bottle plates. As the bottles enter the bottle plates, the centering bells of the upper, rotary carousel descend onto the tops of the bottles and provide control and stability during the labeling process. Each bottle plate is driven by a dedicated cam, which turns the plate with the utmost precision to enable the labels to be applied wrinkle-free. The driving motor is synchronized to the labeler speed by a high-resolution encoder and has been designed to keep the carousel and the p-s station in perfect synchronization for labeling accuracy, even during changes in carousel speed.

The unit at Stone Hill has two labeling stations that apply front and back labels. The rolls of labels are mounted horizontally, and the label web is pulled around a series of vertical rollers to maintain web tension. At the point of application, the web is pulled back around a metal plate, and the label is stripped from the web and applied to the bottle. A sensor at the inlet of the labeler detects the presence of a bottle and triggers the label feed. The speed of the label roll is matched to the precisely timed rotation of the bottle on the cam-driven bottle plate, so the label is neither stretched nor compressed during the application. "This labeler is a dream," says Johnson. "You walk in, turn it on, and it works." Bottles leave the labeler, travel around another curve, pass an accumulation table and enter a Model 101 pick-and-place case packer from A-B-C Packaging Machine Corp.. This machine utilizes pneumatic gripper heads to gently lift the bottles and servo operation to precisely transport bottle loads from the conveyor to the case.

The bottles are divided into three lanes as they enter the packer and are conveyed to the pickup area. The flow of bottles is controlled by a flag-signal mechanism that turns the conveyor on and off. When all three lanes are filled with bottles inside the case packer on the product side, the flags are tripped, and the conveyors shut off, stopping the movement of bottles from the accumulation table. Empty, glued-bottomed shipping cases from the unloading operation enter the packer on a parallel conveyor in front of the bottle conveyor. At the beginning of each cycle, two empty cases are admitted to the loading area, and plastic grids lower down over the top of the cases to guide the bottles. Grid guide fingers ensure that the partitions are located and positioned correctly. In addition, the outward-sloping tops of the grids hold the case flaps out of the way when the bottles are loaded.

Two cases of 12 bottles each are packed simultaneously, so the machine removes 24 bottles from the pickup zone per cycle. This starts the product conveyor, releases the flags and starts the conveyor of the accumulation table. The robotic pickup assembly cycles over the bottles, descends and places pneumatic gripper heads with internal bladders onto the bottles. When the heads are in place, the bladders are inflated with air. The pickup assembly then rises and cycles over the two shipping cases.

The pickup assembly separates the bottles, so they fit exactly into the partitions. It then gently lowers the bottles into the cases with essentially no contact between the bottles and partitions and no label scuffing. The bladders then deflate, leaving the bottles in the boxes. The assembly cycles back for the next loading cycle, and the cases exit.

The filled cases then travel to an A-B-C Model 436 case top-sealer, which incorporates a ProBlue 7 hot-melt unit from Nordson Corp. that uses hot-melt adhesive from H.B. Fuller Co.. When a case enters the sealer, sensors signal a pneumatically controlled tuck arm to close the minor flaps on the shipping cases and trigger the glue jets to apply glue to the minor flaps. The major flaps are then folded down by channeled plates, which square the cases before they are sealed. Cases leaving the sealer travel past a Model 5200 ink-jet case printer from Markem Corp. and are then conveyed to an A-B-C Model 72A floor-level palletizer.

When the cases reach the palletizer, an automatic infeed timing belt controls spacing and orients the cases according to preprogrammed sequences for proper row and gap configurations. Once a row of cases is present, a mechanical pusher bar transfers the cases onto a layer table. When a full layer is assembled, the layer table rises to the level of the next layer on the pallet. It then moves over the empty pallet or the existing layer, and a sweep bar holds the layer of boxes static, while the layer table retracts, leaving the layer of cases on the pallet. It automatically centers each layer on the pallet. The palletizer has a loading area for empty pallets, and when a finished pallet exits the unit, an empty pallet is automatically moved into its place. Both the case packer and sealer incorporate PLCs and touchscreen operator panels from Rockwell Automation.

"The case-packing and handling equipment has been quite a change for Stone Hill," says enologist Tavis Harris. "Prior to this, those activities were performed by hand. This level of automation has required training and practice, but it has benefited both productivity and worker safety,"

More information is available:
A-B-C Packaging Machine Corp.,727/937-5144. www.abcpackaging.com.
Alplast S.p.A. 390141668800. www.alplast.it.
H.B. Fuller Co., 651/236-5900. www.hbfuller.com.
Markem Corp., 866/263-4644. www.markem.com.
MBF S.p.A., 390442450450. www.mbf.it.
Nordson Corp., 770/497-3700. www.nordson.com.
Nortan S.r.l., 39044247844. www.nortan.it.
P.E. USA, Inc., 513/771-7374. www.pe-us.com.
Rockwell Automation, 414/382-2000. www.rockwellautomation.com.
Scott Laboratories, 707/765-6666. www.scottlab.com.
Siemens Energy & Automation, Inc., 770/871-3943. www2.sea.siemens.com.
Vitro Packaging, 800/766-0600. www.vitro.com.