This week’s blog will begin a seven-week series entitled Considerations for Optimizing Tissue Converting Lines, which will discuss methods to increase a tissue conversion line’s overall equipment effectiveness (OEE).
A common question is: what does OEE stand for?
Overall Equipment Effectiveness identifies the percentage of planned production time that a manufacturing plant is truly productive, based on availability, performance, and quality. Surprisingly, most Converting Line OEE’s are 45% to low 50% OEE. What is world-class? That would be 80% or higher. Within this 7-week series, we’ll address why there is such a disparity between where most Converting OEEs are to World Class OEEs.
Considerations for Optimizing Tissue Converting Lines
This week 7-week series starts with a knowledge share that provides an overview of techniques used to enhance performance on Tissue Converting lines. Some of these techniques will be familiar, while others will hopefully provide useful nuggets and insights into improving performance as measured by OEE %. Another way to think about this is to discuss what the daily increase in cases per day would be. So, if a Retail Bath Tissue line produces 2,000,000 cases per year (5,710 cs/day), implementing all these recommendations could move this to 3,000,000 cases per year (8,570 cs/day.)
How do you make a Converting Line act as a process? This is referred to as Ramp Up / Down Line Control
This technology was added to a HWT Towel Line and a Single Roll Bath Tissue line. This allowed the entire line to run as a process with speed control on each piece of equipment. When one part of the process changes, all other components automatically adjust. If a wrapper is jammed, it automatically detects this, checks if the accumulator is nearing capacity and if so, sends a signal to slow the unwind/ embosser/ rewinder section down accordingly. Further, if the winder needs to stop, it automatically knows to cycle down for appropriate cut-off and maintains tension to minimize the number of logs lost. Start-up is also automatic. This successfully created the ability to automatically ramp up and down the unwind/embosser/rewinder without losing tension and logs, where typically 5 to 6 logs are lost due to the command to disengage the perf head. This provides significant long-term line efficiency improvement and lower waste.
Overview of a bath tissue converting line
A key point is that all major equipment manufacturers do a good job with their hardware. But, due to the use of off-the-shelf electronics and related software, it cannot effectively deal with typical challenges such as egg-shaped parent rolls, jams after the accumulator (i.e., log saws/wrapper/bundler/case packer/conveyors/unitizer), or the ability to treat the line as a process. Yes, a few after-market suppliers specialize in removing off-the-shelf electronics to handle these issues. Pulmac partners with these firms that provide their expertise to implement taking OEEs from ~45% to ~80%+.
Over this seven-week series, we will address the topics necessary to convert even older converting lines to these vaulted levels.
Future Topics:
- Week 2 – An Inexpensive Camera System.
- Week 3 – Replace Diverter Air Cylinders & Controls with more reliable linear servo technology.
- Week 4 – Replace Case Packer Air Cylinders with more reliable linear servo technology.
- Week 5 – Speed Cycling at the Rewinder
- Week 6 – Use of an HMI Command Center
- Week 7 – Additional Upgrades and wrap-up of the series.
Unsure how to proceed? Give us a call to discuss your needs and how Pulmac and our partner companies raise the bar on moving those stubborn 45% to 50% OEEs to 80% OEEs and higher without breaking the bank. Imagine taking that Retail bath line from 2,000,000 cases to 3,000,000 cases per year and avoid spending ~$30MM for a new converting line that might take OEEs from 45% to perhaps low 50% OEE.
