A Look Inside the Bale

Apr 17, 2019, 20:25 PM
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March/April 2019

By Michael McSween and Bill Moore

Paper-Bale-Quality_MA19The U.S. paper manufacturing sector is one of the world’s biggest consumers of recovered fiber, with more than three-quarters of domestic mills using recovered fiber in some or all of their products. The United States is also a huge contributor to the recovered fiber supply, achieving 65.8 percent recovery, nearly 51 million tons, in 2017, according to the American Forest & Paper Association (Washington, D.C.). Despite that strong domestic supply and demand, quality measurement in recovered paper has not been as effective as it could be. Times are changing, however, and new technologies are offering more detailed and reliable methods to measure and report bale quality and yield, data that can provide more growth and opportunity for today’s buyers and suppliers.

A look back

The recovered fiber sector’s lack of fundamental quality-control measures that are consistent, thorough, and reproducible has been a significant liability for fiber buyers. Up until a few years ago, quality measurement relied primarily on what’s called “ocular technology”—a visual assessment of the exterior of the bale. While experienced mill operators can tell a lot about a bale’s quality simply by looking at it, this approach has significant drawbacks: Results will vary from person to person, and you’re only seeing the exterior of the bale.

The first systematic approaches to measuring bale quality were aimed at moisture. Visual observations of a bale’s exterior can identify very high moisture content, roughly 20 percent or more, whereas 12 percent is what the preamble of ISRI’s scrap specifications for paper stock declares is the maximum acceptable moisture content. That substantial gap between the acceptable moisture limit and what the naked eye can see could be costly to a mill that ends up purchasing excessive moisture when it expects to be buying fiber.

The first commonly used moisture measurement tool was a moisture probe, a long and narrow metal rod that can penetrate a few inches into a bale at best. It’s certainly an improvement over visual examination, but the inspector must do multiple insertions to get a sense of moisture variation throughout the bale. This measurement device takes away some of the person-to-person variation of visual inspection, but it is not widely known for its accuracy.

Plate-style devices were the next advancement in bale moisture measurement. These devices are an improvement over probes in that they can read moisture levels deeper into a bale and evaluate much more of a bale’s content, and they’re still in wide use by U.S. paperboard mills.

The most advanced approach to moisture measurement available today is a microwave frame, which is prevalent in some parts of Europe and China. This technology can evaluate the moisture content in an entire bale or a whole shipment of bales while it’s on the truck—but only if the shipment is on an open-sided or soft-sided truck. The microwave technology’s inability to work with metal truck or container bodies, which are by far the most common in the United States, explains why it has not been adopted in North America despite its distinct advantage over older technologies.

Seeking more and better quality analysis

While the industry has certainly experienced progress, all the above approaches, short of those overseas, have only been aimed at moisture, with no systematic way to measure the other important compositional components of recovered fiber that could greatly impact quality and yield, such as plastic and ash content. To date, the only reliable way for mills to measure those other factors has been to break open the bales and weigh the different contaminants, which is a very laborious and expensive endeavor. It was a routine practice at U.S. newsprint mills, but few recycled newsprint mills remain in North Amer-ica. The practice has been less common at paperboard and tissue mills.

Moore & Associates believes recovered paper buyers could benefit from a better analysis of the entire composition of the bale to understand how the shipment conforms to the grade’s specification in terms of prohibitives and outthrows—not just moisture—and to calculate the total amount of usable fiber. Having access to this type of information would provide valuable quantitative data to buyers for claim management as well as serve as inputs for buyers looking to normalize the true landed cost of fiber. It can also be useful for a mill’s papermakers to determine what recipe of recovered paper to use.

If buyers can calculate purchase costs as they relate to measured fiber percentage, then they can obtain the true cost per ton of the fiber alone. Furthermore, by understanding how each supplier’s bale yield contributes to a paper mill’s overall yield, buyers can quantify yield improvements through the supply base while normalizing costs. Moore & Associates has calculated that a typical U.S. paperboard mill could save approximately $400,000 a year for each 1-percent increase in fiber it purchases rather than moisture or contaminants.

Those are not the only drivers that have the industry seeking better recovered fiber quality measurement. The strict 0.5-percent prohibitives level China instituted on imports of recovered fiber in 2018 has suppliers very cautious about the quality of scrap paper shipments to that country. At the same time, tissue mills and other producers of paper products are seeking better ways to adjust their papermaking recipes for the various fiber compositions in the high-grade recovered fiber they use.

Europe pioneers a new approach

In the past five years, the European paper industry has started to embrace equipment that uses near-infrared technology that can more accurately measure moisture, outthrows and prohibitives, ash content, fiber composition, and even the brightness of recovered fiber bales. Early on, Spanish paperboard producer SAICA (Zaragoza, Spain) pioneered NIR systems that mechanically extract bale cores and analyze them. More recently, systems installed in Europe along with a few in China have used a manual core drilling approach with insertable NIR probes. While still an emerging technology in recovered paper, other industries, such as those producing animal feed, have used NIR spectroscopy to understand sample composition for years.

As a solutions and services provider for traders of recovered paper, merQbiz (Los Angeles) believes the data and analytics NIR technology can provide will change the industry’s operations. A quality measurement system should provide a road map for improvement by using consistent, quantitative values that connect to the business’s key performance indicators. It must give users the ability to take action based on the information they have and to ultimately get predictive as they repeat measurements over time. The quality and composition data the system can provide, in addition to existing data on paper grade, price, and transportation expenses, can reveal hidden opportunities or reduce the likelihood of buyers making bad decisions based on incomplete information. It can also add teeth to mill buyers’ claims or downgrades—and protect suppliers who provide high-quality material against unwarranted claims or downgrades—by providing an objective standard against which they’re measuring.

NIR bale quality-measurement systems require less manpower compared with bale breaking, measure more bales, and remove the variability of visual inspection for better accuracy and reproducibility. These systems also measure deep inside the bale, not just the outer surface. This is especially true for the core drilling approach with insertable NIR probes. Users of these systems are gaining confidence as more tests of the technology are underway in North America, including tests that correlate NIR measures to existing quality checks performed by manually breaking bales. While some limitations exist—NIR systems don’t separate and measure the plastic in a recovered paper bale by resin type, for example—offsetting those limitations are the benefits of its precise fiber and nonfiber measures along with the overall portability of the equipment.

Throughout the past year, merQbiz has started to bring NIR bale-quality analysis technology to recovered paper suppliers and mills with the BaleVision business tool. BaleVision can create baseline audits of a mill’s existing supply base and provide predictive fiber yield analyses. The reporting system, which launched just over a year ago, gives supply chain managers the information they need to make informed purchasing decisions while also helping mills assess desired fiber types.

Thus far, more than a half-dozen companies in North America have used the technology to evaluate moisture content, plastic prohibitives, and overall fiber bale yield. They are comparing the results to the grade specifications and using the data to identify pass/fail criteria for arriving loads. Then they are combining the quality and yield information with bale price and transit costs to determine the true landed cost of delivered fiber. The data have shown the positive and negative contributions of each supplier and quantified if the benefit is due to cost, transportation, or quality, ultimately providing transparency on how buyers can better manage their supply costs.

How it works

To perform the BaleVision bale-quality analysis, trained inspectors arrive on site at the mill or warehouse with appropriate safety gear and all necessary equipment, including a cordless drill, auger bits, and an NIR probe measuring approximately 4 feet long and a little less than 1 inch in diameter. They randomly select up to five bales from an inbound shipment to analyze. (Bales in storage are less ideal subjects for analysis as characteristics such as moisture and brightness can change over time.)

The inspectors drill a hole approximately 1 inch in diameter and 2 feet in depth into each selected bale, either manually or by using an automated system equipped with the NIR measuring device. In the manual system that merQbiz uses, the inspectors insert the NIR probe in the bale, which measures the entire surface area of the hole. Measurement outputs include moisture, plastic, ash, and ratio of mechanical to chemical pulp. The reading takes approximately one minute per hole, and the inspectors conduct multiple measurements per hole to ensure a representative bale average. The overall inspection takes between five and 15 minutes per bale depending on customer criteria.

The inspectors can test samples from 20 to 25 trailers in a typical four-day baseline inspection period. They then review supplier information to determine the resulting measured volume. To date, merQbiz has found that the 80/20 rule applies to most mill supplier bases: 20 percent of a mill’s suppliers provide 80 percent of the value and vice versa.

The BaleVision system organizes the collected data on NIR measures, which establishes a baseline of key metrics. This allows the customer to compare those metrics to the grade specification as well as to the larger merQbiz quality database, which aggregates the results across the North American recovered paper supply base. The system stores the customer’s bale inspection data with procurement information to normalize all data relative to price and logistics costs. MerQbiz recommends that each company wait until it has at least six months of procurement data for comparative averages. This establishes baseline key performance indicators for the true landed cost of fiber. Normalized data not only help paper mills determine the real cost of the fiber they purchase, but also allow mills to stack rank all of their suppliers.

Customers set the bale inspection frequency according to the volume captured per inspection period and the data points they need to gain statistical confidence for each supplier or supplying location. Consider a paper mill with an incoming volume of 40,000 tons of recovered fiber per month. It’s likely the system could capture baseline data for 60 percent or more of its supplier locations in a six- to eight-day inspection period.

The merQbiz R&D team believes the near-infrared technology it’s using to assess the quality of recovered paper bales, along with the other features of the BaleVision system, could ultimately change the way mills and suppliers conduct business. Its accuracy and in-depth analytics give suppliers and buyers a true, comprehensive measure that allows predictive, data-driven business decisions. Market participants can now use quality algorithms to offset market fluctuations and assess important variations in bale quality due to issues such as seasonality. Being able to build a reliable supplier base and drive more informed and smarter purchasing decisions will positively impact a mill’s bottom line and reward suppliers who consistently provide high-quality products.


Michael McSween is head of research and development and quality at merQbiz, a Los Angeles–based solutions and services provider for traders of recovered paper that’s a joint venture of Voith (Heidenheim, Germany) and Boston Consulting Group Digital Ventures (Boston). Bill Moore is president of Moore & Associates, an Atlanta-based paper recycling consulting firm. For more information about BaleVision, e-mail info@merqbiz.com; for more information about Moore & Associates, visit www.marecycle.com.

New technology to measure the quality of recovered fiber bales can give mills and MRFs data for more informed business decisions.

  • 2019
  • Mar_Apr

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