PRODUCT SAFETY TAKES THE SPOTLIGHT FOR BEVERAGES

From blending to capping, beverage fillers focus on getting safe products into the hands of consumers.

BY Kate Bertrand Connolly

For beverage companies, assuring product safety is a complex, vital issue involving equipment and personnel in batch processing operations as well as on the filling line.

From ingredient storage to product blending, filling and capping, top priorities include protecting the product against disease-causing microorganisms and keeping physical contaminants, such as bits of metal and glass, out of filled packages.

At the storage stage, the beverage processor needs to control temperature and humidity in the storage area to control growth of any microorganisms present in the environment or in drums of the ingredients.

Sensors that monitor the environment are useful in gathering this kind of data. For example, the wireless SureCross Temperature and Humidity Sensor from Minneapolis-based Banner Engineering Corp. can be installed in the storage room to provide temperature and humidity measurements.

Plant personnel access the data using a laptop computer or another electronic device, and the sensor can be configured to issue an alarm when the temperature gets too high or too low. The same type of sensor can be used in the batch processing or blending room to assure proper environmental conditions during product preparation. A bonus of the wireless functionality is the elimination of conduit or cabling installation.

Another type of sensor, Banner’s T-GAGE device, helps assure that liquid preparations are held at an appropriate, safe temperature. This non-contact sensor uses infrared technology to measure the surface temperature of liquids in holding tanks.

CIP FOR BLENDING EQUIPMENT 

Sanitizing the processing tanks and equipment between production runs is essential, as well. Honest Tea, Bethesda, Md., uses either a hot flush or a formal clean in place (CIP) procedure to sanitize processing tanks and equipment between runs. The company relies on a network of eight co-packing plants to prepare and fill its organic teas, “ades,” children’s drinks and kombucha (fermented tea).

“If the plant is going from Honey Green Tea to Peach White Tea, all we require is a hot flush for 10 minutes or so, because they are going from a tea to a tea,” explains Ed Castro, vice president of operations at Honest Tea. “But if they go from a tea to an ade, or they shut down and come in the next day, they need to do a CIP.”

Honest Tea’s CIP procedure is made up of five steps performed in the following order: hot water rinse, acid wash, caustic rinse, hot water wash and ambient flush. The hot water is 195 degrees F—slightly higher than pasteurization temperatures—to arrest microorganismal activity. Honest Tea uses the same hot flushing and CIP protocols to sanitize its filling equipment between production runs.

Honest Tea addresses the issue of physical contamination after the prepared product leaves the blending tank. These contaminants include bits of paper or plastic, which can enter the blended product via an ingredient. Metal can enter the product not only via ingredients but also from a broken blending paddle or other damaged equipment.

Between the blending tank’s exit and the filler’s entrance, Honest Tea’s product travels through a series of canister and cartridge filters that screen the liquid to a level of 25 to 50 microns. In case there are any metal contaminants, the liquid also moves past a rare earth magnet en route to the filler. Other beverage processors, specifically those making pumped products such as pulpy juices or slurries, opt for a pipeline metal detector to cull out metal contaminants. 

The Phantom Pipeline Metal Detector from Toronto-based Fortress Technology Inc. allows inline inspection of pumped liquid as it travels to the filler. An automatic reject valve can be built into the system to extract contaminated product from the flow.

AT THE FILLER AND BEYOND 

Additional product-safety steps occur before beverage filling and after capping. Before empty containers reach the filler, they can be examined for flaws using inspection systems.

Vision systems from Banner Engineering have been used to inspect the inside of 12-oz. cans for dents and to measure critical dimensions on the threaded section of carbonated soft drink bottles. The can inspection was performed using Banner’s PresencePLUS P4 AREA sensor, and the bottle inspection used a PresencePLUS P4 OMNI sensor.

Empty-container inspection can be performed at the high speeds required by beverage fillers. The SpectroVision modular vision system from Industrial Dynamics/filtec, Torrance, Calif., for example, can be used for online sorting of empty bottles and can inspect lines with speeds up to 72,000 bottles or cans per hour.

The Industrial Dynamics/filtec SpectroVision system uses cameras to inspect capped bottles and verify tamper-band integrity.

In addition to checking empty bottles and cans, vision systems can be used for post-filling inspections related to product safety and/or quality. These include checking for cocked caps, missing tamper bands, intact neck rings, label alignment, fill level and also verifying label text and date/lot codes on bottles.

The vision system “takes a picture of, say, a bottle, brings the picture into a computer and compares that picture to a picture of a known good bottle. If they don’t match up or fall within some limitations, the system will reject the bottle,” explains John Henry, president of Changeover.com, a training and consulting firm based in Fajardo, Puerto Rico.

Vision technology also can be used to “look at the bottom of the cap and the flange on the bottle, measuring it within thousands of an inch to determine if the cap is screwed all the way down,” Henry adds. “Or it can look at both sides of the cap and determine that the gap is the same on both sides, indicating the cap is on square and not cross threaded.”

Capping is both a safety and a quality issue as an improperly sealed product is vulnerable to airborne microorganisms that could cause illness or product spoilage.

To detect cocked caps on Honest Tea products filled into PET bottles, the company’s co-packers use a vision system from Peco Controls Corp., Modesto, Calif., plus a Checkmat vision system from Krones Inc., Franklin, Wis.

The Industrial Dynamics/filtec SpectroVision system uses cameras to inspect capped bottles and verify tamper-band integrity.

“The Peco cap detector uses a laser to address alignment of the cap,” says Honest Tea’s Castro. “The Krones cap and fill detector takes a picture and uses visual scanning software to determine if the cap is off alignment. The computer has an image of a perfectly aligned cap, and it measures using three axes. If it detects anything off that, based on the parameters that have been set in terms of variance, it will boot the bottle off the line.”

The Krones Checkmat system, which checks fill level as well as detecting misaligned, missing, slanted and too-high caps, uses high-resolution cameras to detect even small irregularities.

The plants that fill Honest Tea products into glass bottles do not use the vision systems but instead rely on a conventional mechanical dud detector to find and reject improperly capped bottles. Honest Tea’s glass bottles are supplied by Owens-Illinois Inc., Perrysburg, Ohio.

Because Honest Tea ades and teas are hot-filled, the filling process pasteurizes the product and sterilizes the interior of the bottles. After capping, the bottles are inverted to sterilize the seal area. The initial cap inspection or dud detection occurs after capping. But a second round of inspection, using the same equipment, occurs after the bottles are labeled to ensure that bottle seals are intact prior to cartoning.

The Industrial Dynamics/filtec SpectroVision system uses cameras to inspect capped bottles and verify tamper-band integrity.

For a combination of cap checking and tamper-band verification, the Original Juice Co. plant in Brisbane, Australia, chose the In-Sight 5100 vision system from Cognex Corp., Natick, Mass. In this application, the vision system inspects at speeds of up to 300 bottles per minute, using two cameras.

The first camera inspects the bottle cap and tamper band on one side, with an LED backlight creating a silhouette image. Further down the line, the second camera, mounted on the opposite side of the conveyor, inspects the other side of the cap and band.

The system’s software is programmed to detect cap presence or absence, deformity in cap height, cap skew and tamper-band presence and quality. If images from either camera detect a defective package, a PLC triggers a reject mechanism and the bottle is pinged into a reject bin.

In addition to capping integrity, on-package coding is a product-safety issue that lends itself to inspection by vision systems. Correct batch, date and lot codes are essential for tracking and tracing products in the event of a health-related recall.

Equipment such as the SpectroVision system can be used to verify 1-D barcodes and 2-D matrix codes for correct product information. Verification results are available in plain language and can be transmitted to a host computer. Further, optical character recognition enables online reading and verification of production codes, batch registration numbers, “best before” dates and other important product information and symbols.

X-RAY SYSTEMS 

Any discussion of product safety at the plant operation level must include a mention of x-ray technology. Geared to detecting physical contaminants in filled containers, x-ray systems are not used widely on high-speed beverage lines because of the added expense. However, the technology, which has proven itself in the food processing industry, could potentially be used for beverage inspection.

Smiths Detection, Alcoa, Tenn., has successfully deployed its Eagle QuadView x-ray system for glass-in-glass inspection of filled, capped baby food jars. The system uses a four-beam design to shoot x-rays across the conveyor, evaluating up to 1,200 jars per minute. During capping, glass shards can occasionally break off and fall into the crown of the jar because of the high operational speed. The QuadView’s beams are angled specifically to cover the jar’s crown.

Because the system provides four different views of the package, “it allows you to look in the nooks and crannies in the bottom of the jar or bottle so you can see very small pieces of glass at high speeds. We can do this for beverage-packaging speeds,” says Brad Mueller, vice president and general manager of commercial safety and security at Smiths Detection.

Another technology Smiths Detection is investigating for beverage-packaging applications is dual energy x-ray absorptiometry (DEXA). With DEXA, x-rays of two different energies are beamed through a product at the same time. By looking at the differences in absorption of the two energies, it’s possible to detect foreign objects and also evaluate the product’s composition.

But even as this inspection technology and others continue to evolve, the human element remains essential for beverage safety from blending through packaging. “We have very specific tests the co-packers must perform,” says Honest Tea’s Castro. Tests are used, for example, to verify the seal on the bottles and to make sure the products are filled at the right temperatures and coming out of the cooler at the correct temperature.

Castro adds, “We go through a full range of testing every half hour. It’s all documented. Those records are sent up to us, and we review them for every run that we do. So it’s not only your equipment. It becomes a cultural thing—that your people are really in tune with the line to create an iron-clad, airtight system for protecting the product. You can have the latest technology, but if the operator falls asleep at the wheel, you’re done.”  

Kate Bertrand Connolly has written about packaging, technology and marketing for more than 25 years.