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On Cue With Quality Control



as the nonwovens industry grows, so do quality control practices within it



Published August 17, 2005
Related Searches: roll goods Automotive filament nonwoven

The speed with which roll goods and finished products are manufactured in the nonwovens industry can leave a lot of room for mistakes. Because even the smallest mistake can be costly—affecting scores of products and causing excess scrap and production returns—manufacturers are relying more and more on quality control equipment in every stage of the manufacturing process.

The good news for nonwoven producers both in the U.S. and across the world is that recent technology has made it possible for this equipment to be more precise and all encompassing, allowing manufacturers to fix a problem before it becomes a big problem.

“Even as recently as 1996, we could really only identify the location of a defect on a spunbond line,” said John Riccardi, Cognex, Alameda, CA. “We couldn’t classify it by defect type such as broken filament or eyebrow so the equipment was only useful in a limited way. We only knew what to scrap. Now with accurate defect detection, identification, and photo-quality visualization, the right resolution images show the defects more clearly so operators can see what’s happened immediately from a variety of thresholds to detect subtle defects and the new technology has eliminated false hits that could lead to unnecessary scrapping of material.”

Cognex machinery uses both matrix array and line scan technologies to address all conceivable inspection applications of the nonwoven roll goods manufacturer, converter or end user. Mr. Riccardi said he is seeing three main drivers for growth in the quality control machinery segment. For one, enabling technologies have achieved the level required to perform the basic requirements of nonwoven inspection—high resolution imaging, classification and formation grading; for another, global, industry-wide consolidation and marketing have created a hyper-competitive economic environment stimulating the aggressive use of technology for a competitive advantage. Furthermore the steep escalation of resin and raw material prices have placed a premium on any technology capable of reducing manufacturing expenses. “Web inspection can not only eliminate shipments of defective product but, more to the point, it can eliminate the manufacture of a poor product,” Mr. Riccardi opined.

Therefore, not only does quality control present a savings opportunity by eliminating excess waste or return shipments, it can also serve as a harbinger to customer satisfaction and repeat purchasing, especially in disposable categories such as baby diapers and feminine hygiene products where customers demand perfection from their products. Additionally, in the filtration segment, where a flaw could conceivably lead to illness or even fatality, quality control has become standard for manufacturers large and small.

“Variation that was acceptable five years ago, is not acceptable now,” said Krishna Gupta, president of Porous Materials, Ithaca, NY. “Customers and consumers are demanding precision and the media that comes in contact with their materials has to be better.”

Porous Materials now offers machinery that is able to test more parts of a product at different stages in the manufacturing process. These machines no longer just gauge the quality of batches but the entire product from start to finish. “We need to be able to test materials in as realistic a situation as possible,” Dr. Gupta added. “ Manufacturers want to know what the properties of the material are before it is made. If there’s a problem discovered once it’s made, then it’s too late and there could be a lot of waste.”

Not only does quality control reduce the wasted expenses associated with scrapping product, it also saves manufacturers money in the manufacturing process by requiring fewer employees to serve as a watchdogs as the material is produced. “In the past, web inspection technology was not reliable for nonwoven inspection as these systems could not consistently identify a defect in acceptable materials,” said Brian Heil, managing partner, NANOsystems, Gainesville, GA. “As production speeds and customer expectations increase, it is no longer feasible to employ people to sit and watch the web for defects.”


Nonwovens Are Newcomers
In the beginning, nonwoven goods were subject to the same quality control testing methods as their relatives in the pulp and paper industries because the smaller size of this market made quality control manufacturers wary of developing separate testing methods. This practice changed, however, as the market for nonwovens quality control testing expanded and manufacturers began to realize that pulp and paper experience a much more uniform production process than nonwovens.

“Nonwoven products worldwide have been generally very slow to embrace quality control and appreciate the benefits, both in terms of money saved by producing a system product and in terms of marketing,” said Martin Wheeler international marketing manager for Tinius Olsen, Willow Grove, PA. “Many manufacturers of all products who have active quality control, market this as a real benefit to their customers—that is they guarantee a quality product.”

Recognizing this discrepancy, Cognex designed its “SmartView ICN” web inspection technology specifically for nonwovens. The result was a system that not only has application in the nonwovens industry but in other applications such as metal and paper as well, according to Mr. Riccardi.

“While some other industries have been more aggressive in the use of quality control and process control technology, the nonwovens industry is starting to catch up,” Mr. Riccardi said. “I think there are a number of economic reasons for this trend but specific to web inspection the reason was obvious—past failures.”

Therefore, while nonwovens are relatively new to quality control testing, more and more manufacturers are beginning to view it as an important market niche particularly in the hygiene, filtration and automotive areas. Part of the reason why the nonwovens industry has embraced quality control testing in recent years is the recognition of its importance both as a time and money saving device and a tool for customer satisfaction. A good quality control system not only saves time during the manufacturing process, it can save manufacturers a lot of grief in terms of product return and waste.

“Nonwoven manufacturers are looking for new ways to increase marketshare and reduce production costs,” said Maureen Macken, marketing manager of Lasor/Systronics, Norcross, GA. “Quality control equipment, such as vision inspection systems, gives them tools to move toward those objectives. The leaders will be those companies that produce the highest quality product at the lowest cost.”

In the last three years, new inspection capabilities such as smart cameras and faster processors have been developed, allowing for 100% detection of materials at high speeds where human inspection is not practical. Additionally, advancements in computer systems and networks have increased the demand for the transportation of real time quality data and defect imaging, formation analysis and streak detection have been added to material inspection, allowing the processor to understand defect problems and increase process understanding. All of these capabilities have allowed customers to raise their standards and demand better products and lower prices, according to Ms. Macken

BST-Pro Mark, Elmhurst, IL, offers nonwoven producers web guides that control the exact position of webs as they go through a process or assembly line and video web inspection systems, which are used for in-line visual or automatic inspection of print quality. Company executives said they have seen an increased use of more sophisticated sensing devices such as CCD-cameras as well as a trend toward increased monitoring and control of web width. For the video inspection systems, a trend of increased use of active systems is evident. “Continuous quality control throughout a production process allows a correction of unacceptable quality variation before a lot of value is added to the product,” explained Frank Berendsen, vice president sales for BST-Pro Mark. “The trend is therefore to inspect for and control process and quality variation throughout the production process so that rejection at the end of the production line is avoided.”

ABB Web Inspection Systems, Helsinki, Finland, began offering its quality control systems, which include CCD camera-based and visual inspection systems, to the nonwovens industry three years ago after dealing with the paper industry for 30 years and metal and glass fiber industries for 10 years, according to Juha Moisio, general manager. “The requirements are changing for web inspection systems,” Mr. Moisio said. “Smaller defects require higher system resolution and more advanced image analysis. This is a problem because system prices are often too high for nonwoven production investment when the level of technology is too high.”


The Evolution Of QC
The popularity of quality testing is the result of a trickle down effect from the consumer to the end product manufacturer to the roll goods producer. The strong economic climate coupled with increased competition in virtually all consumer product categories has led consumers to demand more from companies such as Kimberly-Clark, Dallas, TX, and Procter & Gamble, Cincinnati, OH, who, in turn, demand higher quality from their roll goods suppliers. “The consumer drives the QC market in the beginning,” said J. J. Roberts, vice president, AccuSentry, Marietta, GA. “The consumer may be P&G purchasing a nonwoven before it becomes part of a diaper. But online quality control devices are becoming a more integral part of manufacturing to help increase machine capabilities. The final customer is becoming more demanding. The consumer expects better quality and is typically getting it. Also better quality control makes manufacturing more efficient and productivity better. In good economic times, there is a high demand for product and the best way for a supplier to increase production is to optimize machine capability.”

Other economic factors such as industry consolidation, increased competition and global expansion have also contributed to the rise of quality control practices in the nonwovens industry. Consumers are too savvy and customers too fickle for roll goods producers to offer flawed products. “Consolidations, globalization and the need to reduce costs have all contributed to the adoption of inspection technology by basic nonwovens processes,” said Ms. Macken, of Lasor/Systronics. “Vision inspection systems enable the nonwovens manufacturer to eliminate defects, reduce scrap and returns and to do a better job satisfying the customer. As customers have become more demanding, vision inspection has become essential to high speed nonwovens manufacturing. At higher manufacturing speeds and for 100% inspection, human inspection and sampling are not effective.”

As is the case with virtually every modern convenience, the technological revolution has lent a big hand to the improvement of quality control machines. What was considered a decent quality control system a decade ago, now would seem obsolete to nonwoven producers. “Machine vision inspection systems have continued to mature over the last 30 years,” AccuSentry’s Mr. Roberts said. “Recent innovations are geared toward faster processing capability, true digital cameras for better image quality and simple but more powerful software. This has helped the systems become friendlier for the user, more powerful for the quality assurance manager and more reliable for the manufacturing engineer.”

As inspection systems have been able to match the speed with which roll goods and nonwoven products are made and assembled, they are a more viable tool than ever to manufacturers.“High speed online inspection systems have had a large impact,” Mr. Roberts continued. “The development of faster processing capabilities and better cameras have at least paved the way for the introduction of inspection systems. Until recently, nonwovens production rates exceeded the capabilities of the nonwoven inspection systems. Now, they are on an equal plane of capabilities. The QC systems have also become more cost effective as they have become more reliable. Newer inspection systems have the capability to match production needs. This means users will make the necessary investment to get a QC system that will provide results instead of headaches.”

Furthermore, by making quality control systems more computer driven, manufacturers eliminate an ongoing problem in testing—human error, which can be particularly evident in the high speed lines on which nonwovens are produced. “Human inspection is not an effective method to inspect any high speed product,” Lasor/Systronics’ Ms. Macken said. “The automated inspection systems deliver 100% inspection seven days a week, 24 hours a day. The image capture, two-dimensional filtering, formation analysis and streak detection modules further enhance the basic system and make it a valuable process control tool. The result is more consistent products that are 100% inspected on an objective basis.”

NANOsystems supplies 100% web inspection systems for nonwovens manufacturing that employ smart cameras to detect holes, contamination, clumps, neps, thin spots, streaks and poor formation. In the last year, NANOsystems has introduced a nonwovens inspection system that can provide an image of each defect and classify large subtle formation type defects without compromising the ability to detect small holes, neps, hard spots and contamination, according to Mr. Heil. “Improved and consistent fabric formation results in less downtime during the converting process and provides improved product performance and aesthetics,” he said. “Quickly identifying process trends and removing contamination, clumps and holes results in higher yield and reduced returns. Nonwovens producers that can monitor and control formation and eliminate customer returns are in a position to increase marketshare.”

Developments in quality control have not only made testing materials easier, they have also made compiling information and data more user friendly. For instance, personal computer technology has made it easy to quickly conduct a mechanical test and generate a printable report that can be combined with test results from other equipment in the lab. “It is the speed of data, ease of handling and portability that has greatly improved the efficiency of quality control managers and their staff,” said Tinius Olsen’s Mr. Wheeler. These test reports and data are now portable across windows platforms and other computer programs.


Is It Worth It?
All of this new technology comes with a price but most quality control manufacturers feel the savings these systems provide to their customers justify the cost. “The new technology and the new machinery is definitely more expensive,” said Porous Materials’ Dr. Gupta. “But, at the same time the new technology is using less of an operator’s time and allowing manufacturers to learn more about their product earlier. That’s really a savings.”

The rising costs of raw materials has made it more important than ever to keep scrap low and production smooth. “To be an industry leader, the roll good producer must not only master the cost of new materials but also master the production process. Surface inspection technology provides significant economic and performance benefits to the producer,” Ms. Macken of Lasor/Systronics said. “A good quality control system will capture not only a greater portion of the value-added chain but, most importantly, result in enduring, superior profit returns. The efficient processor will have less scrap, re-work and machine downtime, resulting in a better bottom line.”

NANOsystems’ Mr. Heil agreed. “Nonwovens producers are looking for technology that can improve the manufacturing process to produce a consistent product and reduce waste,” he said. “Online systems provide real time information to control the process and identify problems before hundreds of spec yards of materials are produced.”

Therefore even though the investment can be substantial, quality control testing is just as important for small companies as large multinationals. In fact, some machinery executives believe quality control can be even more effective to smaller companies whose size makes them more agile and able to fix problems more quickly and effectively.

“Quality is size independent and as larger companies improve their products and processes through the use of quality control systems, the smaller companies will be forced to follow,” said AccuSentry’s Mr. Roberts. “The investment is not that large for the benefit received and, in an industry that requires large investments for manufacturing, the cost of quality is a very small percentage of the entire investment.”

Furthermore, a consumer is not going to forgive a smaller company for defects simply because of its size. A small company is judged by the same quality standards as a large company. “Quality control is very important to smaller companies,” Ms. Macken of Lasor/Systronics said. “Five of the major nonwoven producers serve 50% of the nonwovens industry. As the marketplace becomes more and more competitive for the remaining 50%, it is essential for the small company to stay competitive. Staying abreast of the latest technology is one way the small company can maintain a competitive position against the larger manufacturer.”

Ms. Macken added that she is noticing a trend toward quality control processes outside of the U.S., Europe and Japan as world economies continue their recovery and third world consumers become more demanding. “Consumers in developing countries are behind the developed countries in the quality control demands but they are catching up rapidly,” she said. “Although the U.S., Japan and Europe have traditionally been leaders in quality control technology, many manufacturers have moved operations to developing countries for cheap labor. The same shortcomings of human inspection are present in the developing countries; therefore, the same application of inspection is taking place in these developing areas of the world. The customers have the same quality demands no matter where the product is produced.”