Greetings from Kadant Black Clawson. We are proud to bring you our first edition of Fiber Foundations. We hope you find our content engaging and informative as we bring you news and discussion on all things stock preparation and recycling. In this quarterly publication we will keep you up to date and in the loop, tracking the industry and asking the experts.

Thank you for joining us today,

https://fiberprocessing.kadant.com/en/

I had the pleasure to meet with Kadant FrontWay Process Simulation Manager, Alexander Hedlund to discuss the concept of digital twins in the paper mill and what the future might hold for these simulation technologies within fiber processing. Alexander is a twin in real-life and he uses this as a starting point for our discussion.

When is a digital simulation a twin?

Nature or nurture.

Like human twins, real world systems and their twin counterparts in the digital world perform best with frequent and accurate communication. A key factor in the definition of a true digital twin is the back-and-forth transfer of data, the action/reaction used to maintain and optimize the performance of the real-world entity. To perform successfully, the digital twin must be provided responsibly accurate data and handle that data in an equally responsible and accurate way.

A good look in the mirror.

Raw data from the machines on the mill floor are input into digital simulations and valuable probabilities can be drawn. Performance tracked, trends identified, predictions made, and lessons learned. The real “twinning” is when simulated action from the digital side can be transferred back into the real world for successful results and better performance. 

Garbage in, garbage out.

Like the human experience, the digital twin matures with the input of more data and more feedback on its previous action/reaction performance. The beneficial digital twin can provide a safe and cost-saving environment to predict, test, and develop new methodologies, fine tune best practices, optimize performance, and manage predictive maintenance. Again, accuracy, frequency and action are the key.

What benefit can you see in the long term for digital twins?

Try before you buy.

The sustainable management of your most valuable resources finds a risk-free proving ground in the well-informed digital twin, providing predictive results and feedback on actions not yet taken, cost not yet incurred. With the correct input, a digital twin can validate recommended actions, fine tune new systems and best practices to ensure future results.

Upgrade not just upkeep.

Variations in raw materials, particularly with OCC and recycled furnish, challenge processing mills with supply loads containing a widening variety of growing debris that ultimately effect furnish quality. This variety in the fast-shifting global supply chain only compounds the formidable “wear and tear” placed upon mill equipment and the folks that maintain them.

Predictive maintenance should lead to predictive performance. Managing upkeep and avoiding costly downtime is an obvious battle a digital simulation is easily suited to help fight and win. But what about the wider goals of performance and quality? A true twin can keep the operation a step ahead through feed-forward control programming. Enabling the running of a well-balanced system and predicting results-based changes in furnish and other resources – people, power, and water.

What challenges face the evolution of these new technologies?

Security.

Given the importance of data and its accurate and responsible handling discussed earlier, security is foremost in the minds of many. As these systems become more integrated into the production environment, the risk of misuse and mischief will always be a factor. The digital twins and the systems and people that enable them must become strong gate keepers as well as informed digital partners. Responsible and successful implementation takes, hardware, software, and true human intelligence to turn the digital twin concept into results-providing reality.

FrontWay provides fiber processing industries with simulation software for process optimization. Founded in 2004 with a focus on pulp and paper industries, the company is headquartered in Norrköping, Sweden and will become part of Kadant’s Industrial Processing reporting segment. 

https://www.frontway.se

info.frontway@kadant.com



https://fiberprocessing.kadant.com/en/

It’s not big news that more and more debris is showing up in OCC and recycled furnish, challenging processing equipment and the yield it provides. What’s being done to combat the rising cost of all this debris? Are there opportunities to further optimize the system? What’s new in detrashing, aside from just the need for more of it? 

I reached out to Drew Kinsel, Upcycling Product Manager for KBC in Lebanon, Ohio. The team has done a lot of innovative work in detrashing and reject handling as of late and I was curious to hear his take.

“Getting the heavy debris, metal and wire, out of the pulping loop early is critical. Likewise, any material that doesn’t pass through the extraction plate will remain in the pulper and slow the whole show down. Taking a toll on the equipment. Efficiency and quality suffer, and valuable time and resources slip away.”

Drew put it simply. “That’s a big part of the picture and handling all this debris efficiently and responsibly is a key challenge.”

“But let’s not forget what can certainly be missing. A lot of good fiber might be leaving with the rejects.”

Debris retained in the pulper tub is typically removed by employing a detrashing system connected to a settling tank that has a direct connection to the pulper tub. As OCC bales are processed in the tub, a mixture of fiber and debris makes its way through a chute and into the settling tank. As expected, lightweight materials will float towards the top while heavier objects with a density higher than water will sink. 

The detrasher processes the lighter material which floats to the top and is then collected and concentrated. The remaining debris can then be washed in a drum screen to remove any remaining fiber before final disposal from the pulping loop. 

In the past, the typical method of removing the heavy weight debris that accumulates in the bottom of the settling tank is by using a grapple. The grapple descends into the tank and lifts the heavy material at the bottom out for final disposal. This material consists of a mix of both heavy weight debris, entrapped lightweight contaminants like plastic, and most importantly, soon-to-be lost fiber.

Clearly, we are missing something here. Lost fiber? That’s not good. But there is a better way.

Kadant has developed new technology that can take this process a step further and reduce the final reject amount from the grapple and increase overall system yield. The Wash Tower.

The Wash Tower solution introduces a small parallel tank that is used to retain and wash material from the grapple that would typically be sent directly for disposal. An extra dunking if you will, to free that entrapped light debris and fiber.

The Wash Tower strategically feeds water throughout the mix to wash the fiber from the heavy debris. An overflow back into the pulper allows for the fiber to be recovered and the light-weight material to return to the primary removal process.

After removing material from the bottom of the settling tank, the grapple trollies over and drops it in the Wash Tower. This process is repeated multiple times, allowing the heavies to concentrate in the Wash Tower while the fiber and light materials overflow back to the pulper tub, before the grapple picks up the clean heavy reject material at the bottom of the Wash Tower for final disposal. 

Quick--when were the last greenfield virgin fiber pulp mills built in the United States? There were two of them, built in 1989. One in Alabama, one in South Carolina. Thirty-five years ago!

There is certainly virgin pulp used in large quantities in the United States today. It is just that most of it comes from somewhere else.

By default, this means the growth here has been in recycled fiber. This means fiber prep has become more important than ever.

Hence we welcome "Fiber Foundations" to our portfolio of informative newsletters. And we are honored that Kadant Black Clawson has chosen Paperitalo Publications as the media channel to take this valuable information to the industry worldwide.

This will be a quarterly newsletter, packed with valuable information about properly and efficiently preparing your fiber for the paper machine, no matter the grade.

A Quebec paper mill has converted a newsprint machine to produce 132,000 short tons of recycled kraft paper per year, sourcing post-consumer fiber from eastern Canada and the Northeast U.S.

Hornifcation is a well-known phenomenon describing what happens during the drying of lignocellulosic materials, often within and between cellulosic pulp fibers.

Producing paper with recycled paper consumes about 30-70% less energy and emits less GHG than using virgin wood. However, with current recycling practices, more foreign matters are commingled with the recycled paper including hot-melt adhesives, food residues, inks, resins/sizing agents, and coating adhesives, which result in stickies issues in the paper remanufacturing process.

According to a report from the Northeast Recycling Council, the 25 announced recycled mill capacity expansions since 2017 have the potential to use more than 8 million tons of OCC and mixed paper.