Luxury Or Necessity?
producers still aren't convinced that automatic inspection is a need, not a want
By Ellen Wuagneux, Associate Editor
Published February 6, 2008
This is a fair question. After all, can product manufacturers put a price tag on the loss of a consumer due to an incorrect product count or a quality issue? The cost to sort and re-inspect or re-package products is significant and an automated quality control system minimizes or eliminates this need. It is also very costly to supply a package of defective products to the consumer.
“Considering how many diapers a baby uses or how many feminine products a woman uses, the quantities add up quickly,” commented John Roberts, vice president of 20-15 Vision Solutions. “Preventing one lost customer, who usually creates two additional lost customers, per one million products produced can easily justify the cost of an inspection system. They have become extremely reliable, easy to use, very powerful, can be fully integrated into the factory automation system and are definitely cost-effective.”
Although quality control is a hot topic, how many producers are actually putting their money where their mouth is? According to many market insiders, it remains difficult for customers to actually invest in a quality control system due to a reluctance to spend money on a “luxury” item. Although most large multinational roll goods producers have installed systems on their most important lines and continue to add additional lines each year, smaller players and private companies in developing areas still need to be educated about the value of inspection systems.
“These companies should evaluate much more than price when choosing a supplier of inspection systems,” stated Bob Chiracosta of Natick, MA-based Cognex Corporation. “Any supplier can provide a basic system for about the same low price. But the value of a system consists of much more than alarming when a defect is found. When choosing a system, producers should do their homework and make an educated decision based on their current and future needs. Systems that are scaleable and upgradeable may be what are needed. It may make sense to buy state-of-the-art technology at a low initial cost and be able to upgrade later as their needs develop.”
How Low Can You Go?
Producers’ hesitance to invest in quality control has put even more pressure on equipment suppliers to provide systems with the lowest possible price tags. “The trend in the industry has been toward more automated inspection, but at lower prices,” explained Philip Russo, president of Webview, Inc. “Competitive pressures mean that manufacturers have to keep expenses low.”
Maureen Macken, marketing manager at Isra Surface Vision, agreed. “Nonwovens manufacturers are finding they need to be even more efficient in a very competitive marketplace,” she said. “Higher quality and cost reduction are driving the growth of QC equipment in the nonwovens industry. Automated inspection systems have become a greater factor in the efficiency effort to further cut costs and expand profitability.”
One important cost savings measure underway is the inspection of products during the manufacturing process rather than as finished products. “Defects detected early in the process allow for product rejection before additional value is added, resulting in a substantial savings in scrap,” opined AccuSentry’s Wei Siong Tan, CEO. “More application areas in the initial steps of production are demanding more QC equipment than in the past because more manufacturing enterprises realize that the earlier the defect can be detected, the less waste generated.”
Ms. Macken concurred. “No manufacturer wants to process defective material from an earlier process step. The earlier in a process the problem is detected, the faster the resolution—resulting in lower scrap and increased throughput of first quality material. All internal process functions require continuous quality management.”
Outside of costs issues, customers are also asking for easier to use systems with greater flexibility and more capabilities. Many production lines now have the ability to produce a span of products from baby diapers to adult incontinence products. This range requires inspection systems to detect small defects in a baby diaper measuring 300 mm x 250 mm and to see similar defects in an adult product measuring 1100 mm x 900 mm.
“This large field of view pushes the capability of a single camera to have the resolution necessary to see the very small defects in the smaller products,” observed Mr. Roberts. “In response to these needs, we have designed our systems to include higher resolution cameras and faster processors. We have also added the ability to use up to eight cameras in a system and increased the capabilities of our algorithms to better detect single pixel defects in an absorbent disposable product.”
The Global Picture
While by far the largest markets for QC equipment are North America and Europe, followed by Central and South America, the Asian and Eastern European markets are starting to feel the pressure for product quality and are expected to become a substantial part of the overall market in the near future.
“The trend toward higher quality is continuing in developing countries as customers become more quality-centric,” explained Dr. Tan. “Once manufacturers realize the tight connection between quality/product consistency and productivity/less machine down time, they will be more willing to invest.”
Mr. Roberts described demand as excellent in Eastern Europe. “Several producers in the region are beginning to make an impact and are starting to stress their ability to maintain the best quality levels attainable. We see this region as a major growth area in the next two years.”
Cognex’s Mr. Chiracosta begged to differ, describing sales in developing regions as inconsistent. While areas such China and other parts of Asia are advancing quickly, parts of Eastern Europe and Latin America are lagging behind in adapting new technology. He added that large multinational companies lead the way in bringing this technology to these regions.
“Sometimes the move to purchase an inspection system is driven by the desire for quality, but usually it is driven by nonwovens buyers’ demanding a level of quality that is not achievable without automatic, on-line, real-time inspection.” He added that lately he has also seen roll goods lines that formerly produced geotextiles switching to higher value hygiene material. “This naturally requires automatic inspection,” he said.
Ms. Macken of Isra pointed out that while many manufacturers have moved operations to developing economies to reduce costs, the same QC issues apply regardless of production geography. “The same shortcomings of human inspection are present in developing countries; therefore, the same inspection metrics apply,” she said. “The end user customers have the same quality standards no matter where the product is produced.”
With strong QC equipment sales in all areas of nonwovens production, suppliers have been busy rolling out new innovations and upgrades to existing systems. Although there are different driving factors in each segment, suppliers report that growth in QC is ultimately driven by the desire to improve profits. Here’s a look at the latest new products from key players:
20-15—The company’s newest product introduction is the 20-15 training pants inspection system, which can be used for a variety of pull-ups. According to 20-15, pull-ups are continuing to grow in the market and the consumer has begun to demand a wider range of sizes, thus increasing the need for greater production capabilities. The higher cost to the consumer for these products has forced a higher level of quality on the producers, leading to an increased need for automatic quality control systems. The integrity of the welded areas in the product’s side panels is critical to maintain the functionality of the product. This system was designed specifically to monitor those welded areas on line during production and was combined with the company’s standard 20-15 inspection system. This combination allows the end user to monitor all of the components in a pull-up and ensures the consumer receives a first quality product every time.
20-15 plans to introduce a system at INDEX that automatically locates the components on a product, automatically sets the inspection areas around those components and then automatically sets the tolerance based on an internal statistical analysis calculation assessing the production machine’s capability (similar to artificial intelligence).
ACCUSENTRY—More advanced real-time charts, graphs and reports have recently been introduced by AccuSentry. Understanding that each customer application is unique, the company has continued to develop the Sentry 9000 series to meet these demanding needs. AccuSentry introduced more advanced real time charts and graphs to the production floor to effectively monitor production effectiveness as it occurs, thus allowing real time corrections to production issues in addition to historical data review for process improvement.
For nonwovens producers, the warning limit charts and graphs allow producers to correct machine instability before it starts to produce a bad product. This increases production and reduces scrap.
The company has also unveiled a system capable of interfacing with a rotary incremental encoder to precisely view a product through a narrow slot. The encoder tracks the distance traveled by a moving product and provides a trigger signal for each specific distance traveled that corresponds to the field of view of a camera pixel. As a result, the system is able to piece together the complete image of a product, capturing only a very small segment of the product at a time.
Additionally, AccuSentry has developed the advanced capability to detect faint edges that are crucial to inspect a subtle transition layer. It also includes a graph to provide the user with the ability to visualize the strength of an edge. The user can quickly analyze the various aspects of an edge and determine the proper edge parameters to achieve consistent edge detections.
As demand for quality and productivity continue to increase, the need for additional inspection points continues to accelerate, inspecting not just the final product but throughout the production process. AccuSentry has developed a multi camera framework to allow the seamless development and integration of tightly coupled multiple camera applications in which the operation of one camera depends on the result of the operation of another camera. A consolidated display screen enables the operator to monitor the crucial elements of the process in a one central place.
COGNEX—The company’s latest innovation is its new web quality monitoring software package for SmartView web inspection systems. For many years, SmartView systems have been used to find and locate defects in nonwoven webs. This new tool allows roll goods producers to monitor the overall quality of the web on-line in real time. The quality of the web appearance and formation analysis are measured with immediate feedback via user display or physical alerts.
There are several unique and innovative features to this advancement. The quality measurement is performed during production and the results are reported immediately. Operators can be alerted in real time when the product appearance is out of spec. This allows corrections to be made before large amounts of material are produced or sent to added value downstream processes. No additional hardware is required. SmartView WQM uses the same cameras and lighting that is already installed for defect inspection. The measurement is completely objective and user definable.
Most off-line measurement tools use fixed algorithms to define quality and web formation. WQM groups the on-line product sample images into groups with like appearance. The QA engineer then assigns quality values based on his/her visual assessment. The system reports these values when it “sees” similar looking material. In this way the QA engineer has control of the quality monitoring and reporting.
ISRA VISION—Isra Vision has developed the Quickteach Classifier for the Smash System to accurately classify defects of interest while ignoring acceptable product variations. This enables producers to focus on customer-specific defects of interest for root cause determination and to grade and convert rolls to optimize yield. At the converting level, specific defect types can be stopped on automatically for removal. This saves time and ensures consistent quality.
Isra inspection technology is designed to go beyond defect detection and enable users to improve their process and product. Minor cross web deviations and fiber distribution differences can be trended, and the process can be monitored and controlled within tighter limits. This results in more consistent quality with reduced startup and product change-over time.
WEBVIEW—Webview has introduced its Web-i line of affordable Smart surface inspection cameras to specifically meet the needs of nonwovens manufacturers/converters and others who need a reliable, cost-efficient, yet sophisticated surface inspection system. The Web-i is a compact, rugged inspection system that is available with 1k, 2k and 4k linescan CCD sensors. The system can detect and classify bright and dark defects and also features special rate-of-change processing. The camera comes complete with software for setup, operation, imaging, archiving and roll map production.
What’s On The Radar?
When asked what technologies lay on the horizon, manufacturers expect QC/inspection data to be increasingly used to maximize yield and react to problems before large quantities of material are produced and passed on to value-added processes.
“Lower cost systems will do simple web evaluations for specific properties throughout the production process,” offered Mr. Chiracosta. “And, the data generated will continue to be available to all who need it in a form that is easily understood and useful.”
Webview’s Mr. Russo predicted that the industry will see inspection systems capable of gauging formation-type defects at a low cost. “Systems are evolving to be more like the human brain and will eventually be placed into the process loop, instead of just detecting defects and alerting an operator.”
In Dr. Tan’s opinion, the technologies needed to address today’s production equipment are: a better and faster vision analysis process, a virtual camera for large products with a limited viewing window, multiple camera capabilities, better network bandwidth for enterprise-wide monitoring and user-friendly and easy-to-use graphs, charts and other user interface elements.
One new technology entering the market is a higher resolution camera that has the speed to keep up with increased production capabilities and the need to detect smaller defects. “This requires greater processing speeds and that technology is also becoming available at a marketable cost,” Mr. Roberts observed. “Another technology is the engineering component of a system and adding the ability to integrate the inspection system into more process control functions. This is currently taking place at a very few customers but should grow dramatically over the next one to two years.”
In terms of the most significant hurdle producers face as they move forward, Mr. Russo of Webview pointed to the creation of inspection equipment featuring reliability, sophistication and reduced costs. “Providing these three elements has proven to be quite a challenge,” he said.
For Mr. Roberts, a key challenge faced by suppliers is justifying the cost of the inspection system. He pointed out that there is a significant amount of engineering time required to fit the system into the range of production machines, provide endless flexibility and see all of the defects the customer wants to see. “The hardware (as in all technology) has increased in speed and capability while costs drop,” he said. “But, the engineering and support content is not decreasing. In fact, the customers are placing greater demands on the inspection companies to supply systems that automatically do everything. Yet, they don’t want to invest in the internal support structure necessary to maintain that technology, forcing more of the support needs on the supplier.”