If you’ve read our previous blogs, this statement will come as no surprise: there isn’t a standard, universal metric for ‘correct’ felt permeability. This is because achieving optimal permeability is unique to each machine. And it’s determined by two sets of variables.
So how do you find the optimal felt permeability? Well, as is often the case with improving your machine’s performance, it’s a matter of ongoing investigation. Here’s how…
Read MoreAfter you install a new felt, it's normal for its dynamic permeability (the combination of airflow and vacuum) to fall. This means the felt is compacting. However, contamination will also make it denser.
To distinguish between these two possible causes for a denser felt, you need to take the felt caliper into account. And the only way to get an accurate point of reference—knowinwhether the felt is ‘relatively thick’ or ‘relatively thin’ today compared to previous days—is to take daily measurements.
Read MoreThe top layer of the batt, in direct contact with the sheet (should) act like a one-way valve. It allows water to pass through easily down towards the base but prevents it from flowing back.
You don’t want the top batt layer to be too dense, because then you’ll get dewatering problems at the nip entry.
Read this article to learn why a felt may become too dense and how to avoid over-density.
Read MoreThe most important job of the press felt on a paper machine is to remove the water from the sheet, without harming the sheet’s strength or surface quality.
But it’s not all plain sailing. Compared to other machine components, like press roll covers or the machine frame, press felts change behavior over their lifetime, especially in their level of permeability.
Read MoreA lot of papermakers come to our website to learn about felt permeability and how it affects the performance of their paper machine. In this blog series, we share a simple breakdown of what felt permeability is, and why it matters.
Read MoreIn the paper production process, the paper machine dryer section plays a crucial role in ensuring the final product meets the desired quality standards. Understanding the importance of this section and implementing optimization practices is essential for efficient operations and high-quality paper output.
In this blog, we'll explore the journey through the paper machine's dryer section, offering you the best practices for keeping things running smoothly.
Read MoreEvery piece of machine clothing must run at precisely controlled speeds, or you’ll run into the same issues as the aforementioned mill. But controlling those individual speeds comes from the speed control system making a calculated guess: multiplying the roll diameter and the thickness of the felt or fabric with π and the revs of the drive: v(fabric) = π * 2 * R(roll+fabric) * N.
Read MoreA graphic paper machine in the Netherlands, Europe, initially erected in the 1960’s, was running at approximately 150% of its original design speed—causing numerous vibration issues.
The fourth press was vibration prone, resulting in a felt life of only two weeks and press roll covers lasting just four to six weeks. Even the granite counter roll showed excessive wear. Under the guise of supplier reduction, they had one supplier for all of their press felts.
When you focus on innovation, you find ways to get maximum value from your paper machine clothing and in return, future proof your mill.
While PMC tests and trials may seem inconvenient at first, they are highly profitable in the long run.
There are three important principles to consider when running PMC trials, detailed below.
Read MoreIf you have to replace PMC regularly, should your next piece perform the same as the previous one, or should you aim for continuous improvement?
Surprisingly, most papermakers choose the first option.
It’s the perceived cost and risk of running PMC trials that causes our industry to play it safe. But this status quo chains papermakers to their PMC suppliers, killing innovation and the long-term survival of the mill.
Read MoreDesigning a successful press felt is an art form. One that requires a careful blend of technical expertise, data, and gut feeling from a real human—the press felt designer. A greater understanding of the complexity of press felts is key to unlocking innovation—and in turn, helping papermakers produce more paper.
When a forming fabric doesn’t want to run straight it usually causes many problems and costs. In the worst case, it actually runs into the machine frame and the fabric is completely destroyed.
Read MoreWe are blowing up the balloons and hanging the garlands, because there is something to celebrate: it is Feltest’s 20-year anniversary! For this special occasion, founder and owner Marcel Lensvelt was interviewed:
Read MoreWith 2022 drawing to a close, now’s the perfect time to put in place the processes that will optimize your 2023 paper production.
To help you do just that, we’ve launched three new products so you can run your own daily felt tests in as little as 20 minutes.
Read MorePaper machine clothing (PMC) can make or break a papermaker’s future, yet our industry’s attitude toward testing feels stuck in the past.
Both papermakers and PMC suppliers will benefit from more and better quality data - so a rising tide will lift all ships!
Read MoreIncrease your machine output through better performing press felts. Simply because there is still a lot of potential in this part of the machine. On average, getting 1 percentage point dryer out of the press section results in 4% more output. So why be satisfied with 54% dry content after the nip, when it could be 55% or 56%? This would result in 4% and 8% more output respectively.
How many more tons would you produce if your machine has 4% or 8% more output?
Read MoreIf you can create a baseline based on daily measurements in the press section, then you can ensure your content comes out of the press section 1% dryer. And 1% dryer out of the press section means 4% more output.
The only investment you have to make is your own time and effort in performing daily measurements and creating a baseline. That’s it. It is really that simple. No other CAPEX or major investment necessary.
Read MoreIf you can improve your felt performance and the sheet leaves the press section 1% dryer, it will increase your machine’s output by 4% in average. And with every percentage point dryer out of the press section, your output doubles. So, 2% dryer out of the press section means 8% more production!
Read MoreWhen press vibrations take place in the papermaking process, machine speed has to be slowed down. This has an immediate negative effect on output and ultimately production targets. Replacing the felt is often the expensive solution papermakers reach for, but it is only addressing the symptoms. How to extend the life of your next felt?
Read MoreHow better PMC can really increase your paper machine’s output? Think about it. Leaving the press section 1% dryer results in 4% more output. Instead of 54% dry content after the nip, you could have 55% or 56%.
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