Pulp & Paper Industry Forum: Desperately seeking nano-sensors

Nov. 17, 2017
Real-time, in situ analysis of tiny particles needed to advance nanocellulose manufacturing

FiberLean Technologies was formed to bring to market micro-fibrillated cellulose (MFC), a new class of renewable and sustainable nanocellulosic engineered material with the potential to deliver improved performance and value to a wide range of consumer and industrial applications.

The raw materials are natural and abundant, and the final product is extremely strong and lightweight, according to Sean Ireland, vice president of business development at FiberLean. "It can be stronger than Kevlar in some cases and lighter than carbon fiber," Ireland said.

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But manufacturing these new nanomaterials presents a number of challenges in the realms of real-time monitoring and quality control, Ireland added. He spoke about MFC and its manufacture at the Pulp & Paper Industry Forum this week at the Automation Fair event. "FiberLean Technologies is working to expand processes and applications of the technology, but innovation will be needed on many levels.”

FiberLean is passionate about nanocellulose. "It's our livelihood, and we are good at what we do,” said Ireland. "Basically, we take minerals and pulp or cellulous of some form and put it into a highly modified, technical grinding system, and out comes the product," said Ireland. "There is no pretreatment and no added chemicals.”

"The days of making paper at a paper mill are slowly changing," commented Ireland. "Paper mills are going to become bio-refineries to a certain extent. They will be making multiple products for multiple industries. There is a large pipeline of new products on the way.”

Nano particles at mega scale

“We don't make MFC in kilograms, we make it in tons,” continued Ireland. “We produce it economically, performance is great and quality assurance is top-notch. However, we still have some issues."

For example, sensors capable of doing real-time quality measurements during the manufacture of MFC don’t yet exist. Instead, FiberLean has to infer quality parameters post-production using expensive technology such as scanning electron microscopy, atomic force microscopy and thermo-gravimetrical analysis.

"The problem is we are only looking at a small, nano-size sample from a 150,000-gallon tank of the finished material," said Ireland. "With such small samples, the control has to be perfect. The sample and what's in the tank need to be exactly the same. Any small variations can completely change the product."

"As we are grinding and producing the material, we may get the particle size perfect with proper size distribution and surface area,” said Ireland. "But, if the particle shape changes in the process, you end up with two totally different materials that perform differently. As controls engineers, we need to understand the process very well in order to control it. Small variances at this scale lead to large differences in product quality and performance."

Real-time analysis on the industrial scale is still not here yet, continued Ireland. "It doesn't exist, but it needs to happen," he said. "We are looking for that. If you have any knowledge base in that area, we want to work with you.

From a process control and chemical engineering perspective, one needs to know quantum through mesoscale physics of the manufacturing process, said Ireland. ”You’ve got to be aware of event small changes; they can’t be ignored at these small sizes."