Paper Threading on the Glue Roll After Web Breakage: Spreading or Closing the Rolls First?
With increasing competition in the paper market, paper manufacturers face significant cost pressures and equipment downtime risks.
How to quickly and stably re-thread the paper after a web breakage, thereby reducing unplanned downtime, has become a daily challenge we must address.
一. We will discuss how to achieve rapid and stable paper threading and spreading at the Glue Roll after a web breakage in a paper machine.
1. Our goal is to minimize the impact of breakage on production by optimizing the operational sequence.
With the continuous increase in paper machine speed and paper width, rapid paper threading after a breakage becomes particularly important.
The traditional method for Glue Roll threading usually involves first threading the paper tail to the back dryer to complete the spreading, and then closing the rolls.
For paper machines using single-water jet threading, especially those producing paper below 100 g/m², the following steps are recommended:
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First, complete the paper tail threading, then close the upper and lower Glue Rolls towards the paper roll.
This allows you to check the film-forming ability of the paper roll surface.
Once the film-forming ability is stable, the sizing roller (pressure roller) can be closed.
With the improvement, the entire paper feeding and spreading process can be completed within 3 minutes.
2. Operating Method:
For large-format paper machines with a width exceeding 6600 mm and employing double water jet feeding,
the upper and lower sizing rollers can be closed simultaneously during the feeding process.
When preparing to spread the paper web to both sides, the sizing roller (pressure roller) can be closed simultaneously,
while adjusting the speed difference and tension at the same time.
This method prevents the wide paper web from shaking at the roll turner after sizing, ensuring a smooth transition of the paper web from the sizing machine exit to the post-dryer.
The entire paper laying, roll closing, and adjustment process can be completed within 1 minute.
二. Paper Cut and Refeeding: Widening or Adjusting Roll Gap?
With increasing competition in the paper manufacturing market, paper companies face enormous cost pressures and equipment downtime risks.
How to quickly and stably refeed paper after a cut, thereby reducing unplanned downtime, has become a daily challenge we must address.
1. Minimizing the Impact on Production After a Paper Break
The traditional method for refeeding surface-sized paper typically involves feeding the paper strip into the dryer to complete the widening process,
and then closing the sizing rolls. This method takes 5 to 10 minutes.
For paper machines using single-jet feed, especially those producing paper under 100g, the following sequence is recommended:
First, complete the paper strip feed, then close both the upper and lower sizing rolls.
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This allows for checking the film formation on the rolls and addressing any issues promptly.
Once the film formation is stable, the sizing rolls can be closed.
With this improvement, the entire feeding and widening process can be completed within 3 minutes.
2. The Impact of Paper Width
For double-water-jet wide-width paper machines with a width exceeding 6600mm, both the upper and lower sizing rolls can be closed simultaneously during feeding.
When preparing to widen the paper width to both sides, close the sizing rolls simultaneously and adjust the speed difference and tension.
This prevents the wide paper web from vibrating at the fan after sizing, ensuring a smooth transition from the sizing outlet to the post-dryer.
The entire widening and roll adjustment process can be completed within one minute.
三、总结
By adjusting the sizing, feeding, and widening sequence for different types of paper machines, not only can the success rate be improved,
but feeding time can also be significantly shortened, minimizing unplanned downtime and increasing the paper machine’s operating efficiency.