Packagers Choose Machine Vision Quality Inspectionto Reduce Waste and Boost ROI

By Mark Sippel, Vision Industry Specialist and Mark Traxler, Staff Writer, Omron Electronics LLC

AbstractFood and beverage packagers can choose frommany solutions to help them achieve greaterproductivity and profits without investing incapital equipment to increase capacity. Anincreasingly popular solution is to reduce theacceptable waste threshold and boost return oninvestment (ROI) using machine vision toperform quality inspections. Recenttechnological improvements have made machinevision accessible to small- and medium-sizepackagers so they can achieve improved resultsand even pursue brand risk avoidance tomaintain consumer and retailer confidence.

IntroductionFood & beverage companies invest heavily andconsistently in solutions to optimize theirmanufacturing operations in order to avoid capitalequipment investments to increase capacity. Slim profitmargins compared to other industries, and increasingquality and variety demands from customers, retailersand regulatory agencies are typical reasons for takingthis incremental improvement approach. Eachinvestment gets scrutinized for its impact on ROI andonly the strongest and most urgent projects getfunded. Many packagers are lowering their wastethresholds in production and improving package qualityusing today’s more focused, more affordable machinevision solutions. These can deliver a boost in ROI andhelp fund more capital-intensive production upgrades.A goodwill byproduct from improved quality isimproved retailer and customer confidence.

ROI Drives Three Different WasteReduction ScenariosPackagers often believe there is no need to fixsomething that is not broken. For example, eachmanufacturer has a threshold point where theacceptable level of waste becomes a problem of waste.In every case, some sort of inspection—human or semi-automated—helps judge when waste turns into aproblem. The inspection may take place in-line forwork-in-process or at the final packing stage. Humaninspectors provide reliable detection of multiple faultsover a wide range of conditions. However, they canlimit the number of inspections completed in a shift,effectively capping productivity at a low level. In manycases, machine vision systems dramatically increasethe number of inspections; reduce human error,eyestrain or repetitive motion injuries; and allow anincrease in production speed and accuracy. Here arethe three most common waste prevention scenarios:

1. Use vision as a diagnostic tool to detect which problem(s) to repair on an expensive piece of machinery.

2. Use vision to limit waste in product, packaging and marking materials when fill level is too high or too low; when the label is crooked; or when an ink jet marking system produces blobs instead of characters.

3. Use vision to remove non-saleable productfrom the supply chain.

Even a slight downward readjustment of the wastethreshold can generate sufficient savings to justify thecost of a vision inspection system and boost bottomline profitability.

Gathering Data to Diagnose MachineProblemsPackaging problems are often symptoms that can betraced back to specific machine elements that needmaintenance or replacement. The costs to repair aportion of the machine are a fraction of replacing theentire machine, and require less downtime. Unless theproblems become chronic, most packaging machinescontinue performing for many years. Machine visionsystems can provide real-time video to monitoroperations via an HMI, or can record images stored asbitmaps that get time-stamped when uploaded to adata acquisition system. Using these video images asdiagnostics can shorten troubleshooting time andreduce losses due to spoiled product.

Reducing Waste and Giveaway

Package fill level tolerances, by law, are very narrowwhen it comes to permissible underfilling. However,business profitability demands that overfill be kept to aminimum, too. Machine vision systems can check filllevel to verify minimum product requirements and alertwhen overfill results in excessive product giveaway.

Inspecting date/lot code and label quality

Monitor bottle overfill and underfill

In another case, a marking system may be usingexcessive amounts of ink, causing blobs instead ofreadable characters. On a high-speed packaging line,the seemingly tiny amount of over-inking can add up tohundreds of dollars a week in waste.

Removing Non-Saleable Product with Imperfect Labels

Products with torn, soiled or improperly positionedlabels reflect poorly on the brand and bring intoquestion the quality of the contents. The problemmagnifies when those packages remain unsold on storeshelves. If the label problem affects several cases orpallets, retailers may return them for credit or put thebrand on probation. Such situations can negativelyinfluence retailers’ decision to promote new productsor maintain shelf placement of existing products. Usinga vision sensor placed after labeling/before cartoningprevents imperfectly labeled product from getting intothe supply chain.

Machine Vision Goes Mainstream More Affordable Vision SolutionsMachine vision hardware costs have come down in thepast 5 years and improvements in the technology havelead to easier-to-install systems. This combination hasallowed in-plant systems designers to add visioninspection to each stage in their process. In April 2003,Control Engineering magazine reported the results oftheir recent research into vision system usage andnoted these trends:

• From 2003 through early 2004, respondents expected the demand for vision systems to increase (33%), while many thought it would stay the same (62%).

• The average of users surveyed showed six vision systems were bought for a total of $59,925.

• Among the many communication platforms, respondents expected Ethernet with TCP/IP (73%) and DeviceNet (46%) to increase in usage.

“There's a new, combined market developing in the U.S.for smaller, lower-cost, compact machine visionsystems,” says Mark Sippel, a vision industry specialist.“This market is taking some sales from PC-based,frame-grabber equipment. However, it also includespeople who used to stay away from $12,000+ machinevision systems that were too complex anyway, but arenow willing to invest because many systems cost$7,000 or less, and so the return on investment ismuch quicker.”

Task-Oriented SolutionsMost machine vision products are applied to a singleline or machine, performing some specific tasks. Untilrecently, vision system manufacturers have designedtheir products to be versatile enough to handle a widerange of tasks, thereby adding a significant level ofcomplexity in programming, communication andresetting for production changeover. According toSippel, “The trend now is moving toward task-orientedmachine vision products that focus on the featuresrequired to deliver outstanding performance in just asingle area.”

A Brief Look BackThe first examples of task-oriented vision productscame to market about five years ago with simplifiedvision sensors to handle pattern matching or simplepixel counting. These products combine a light source,camera, lens and processing into a single compactpackage that requires minimal setup. Theyrevolutionized machine vision inspection withaffordable products for common applications and witha substantially reduced engineering requirement tomake them work.

Vision sensor detects torn label

The Next Generation“Growing interest from key packaging industries—foodand beverage, pharmaceutical, and health and beautyproducts—has demonstrated the need for higher-levelvision system functionality but the same setupsimplicity. One of the first of these new task-orientedvision sensors specializes in date code verification,”said Sippel. These systems also offer the flexibility ofgreater choices in camera, lighting and lenses. The keydifference is the reduction in inspection setup to aminimum of steps. “This date code inspection sensorcan work more efficiently than a general-purposevision system with date code verification capability. Forexample, Omron’s F210 CF date code verifier bundlesfour important features for the task:

1. Built-in font libraries to eliminate character teaching

2. Advanced verification algorithms that accurately verifies date codes despite printing flaws

3. Automatic calendar update to reference date values after initial setup

4. Templates to reduce setup for frequently used code patterns like “manufactured on” date, “best before” date, and “expires on” date.

Vision Systems with OpticalCharacter VerificationPackages today carry an important load of informationrelevant to customers and regulators: date/lot/factorycodes and freshness/use-by dates. To make sure theright information is printed and the data is complete,many use machine vision systems to perform opticalcharacter verification (OCV) as well as opticalcharacter recognition (OCR).

OCV/OCR Technology Advances

Great improvements have been made in OCV/OCR inrecent years that simplify setup and enhanceinspection reliability. One major advance has been thecreation of resident font libraries enabling the vision

system to recognize characters in commonly usedfonts. Before that, users had to teach the sensor toread one character at a time in the font used, makingsetup long and tedious. Omron made inspections morereliable by adding patented QUEST algorithms thatdetect defects in the characters as well as verifyingthem. Typical marking defects include missing dots orstrokes from characters, inconsistent line width,inclination, size and blurriness. Products with thesemarking imperfections can be removed before gettinginto the retail supply chain.

More Effective Coordination“Distributed intelligence means that machine visiondevices will be able to inspect at each station of amanufacturing process, and help decide whether toreject or pull a substandard piece of work at thatstation, rather than waiting until it comes off the line,”said Sippel. “Increased networking means improveddata collection on individual inspections, as well asbetter quality monitoring and trend identification.”Popular networking options currently available in NorthAmerica include Ethernet and DeviceNet. Visionsensors with Profibus communications are popular inEurope and parts of South America.

Marketing Realities and ConsumerConfidence

“The package IS the brand.” Today most packagersacknowledge this tenet of marketing success. In fact,customers treat every aspect of the product packageas the brand. Key elements—label, freshness date,nutrition information, and tamper-evident safetyelements—contribute to the brand impression at the

Size

Inclination

BlurrinessWidth

Line widthBreaks

Compensation for these print quality conditions

shelf-front buying decision point. Any fault in thepackage diminishes the consumer’s perception of brandquality, often leaving it unsold. In times like these,consumer confidence and retailer commitment tobrands are especially fragile due to economic stressand disturbing news of terrorism, product recalls andworries over food safety, consumer brand loyalty canwaver. Packagers are now seeking ways to preserveconsumer and retailer confidence in order to growexisting business and build a favorable reception fornew products.

What’s at Risk?Food and beverage packagers historically put extensiveresources toward establishing and maintaining brandvalue. Only recently has it become fashionable to makeminimizing brand risk a priority. The authors of ARCAdvisory Group’s recently released study, Food &Beverage Industry Plant-Level Expenditures WorldwideOutlook, quantify the risk when failures in qualitycontrol create a problem. They point out that it “costsfive times as much to recall a product as it does todistribute it…. Product recall costs can be enormous,particularly if a company exports products or isseeking new markets. Other costs, such as cleaning upthe manufacturing unit or destroying certain batchesand business interruptions, often lead to major profitlosses.” Adding in-line quality inspection such asmachine vision systems can provide an early alert toproblems or head them off entirely.

In summary, packagers can make a significant impacton their bottom line with the relatively smallinvestment in today’s more economical machine visionquality inspection solutions. The waste reductionbenefits alone repay the costs quickly. The additionalbenefits in maintaining a high-quality brand perceptionwhile reducing risk of recalls or other regulatory actionelevates the addition of machine vision quality inspec-tion to an essential element for packagers’ success.

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BackgrounderOmron Electronics LLC is a leading manufacturer andprovider of industrial automation and electroniccomponent products and solutions. Offering completeautomation connectivity, extensive product groupsinclude programmable controllers, sensors, operatorinterfaces, machine vision sensors, timers, counters,servo motors and drives, software, switches and relays.Omron also provides system integration services andoffers data collection, inspection systems, motionsystems and automation systems services andproducts. Omron Electronics LLC is the Americassubsidiary of Omron Corporation, a $4.5 billion globalleading supplier of reliable, advanced electronics andcontrol system components and services.

For more information about Omron’s vision inspection solutions, visit our website at www.packaging.omron.comor phone 866-88-OMRON.

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