Technical Guide ·
Stay-open offset ink for overnight stops: skin versus set
Stay-open grades keep the roller film from skinning on a night stop. They still need oxygen in the pile. Do not confuse roller open-time with dry-to-handle.
Two clocks
On the rollers, a stay-open conventional ink is meant to remain workable after hours of contact with air. In the pile, the same ink must still set and oxidise. Plants that treat stay-open as “never dries” get set-off. Plants that treat it as “always skins” dump drier and then cannot restart.
LC-0011 (ultra high-gloss) and LC-0022 (high-gloss) are the stay-open high-gloss pair HuiRun currently quotes from the authorized catalog, with Honglu conventional as the own-brand parallel when it fits.
- Cover fountains if the stop is longer than the TDS open-time.
- Do not spray water on rollers “to keep them open.”
- Stay-open paste is a measured aid, not a weekend tarp.
- Hot halls shorten open-time; cold halls lengthen set in the pile.
- Related high-gloss article covers stock matching.
Restart checklist
Look for a thin skin at the fountain ends. If it is there, scrape it; do not mash it into the film. Run waste until density returns. If the first 200 sheets ghost, the last job may still be in the rollers—wash, then restart.
When stay-open is the wrong buy
UV jobs, very absorbent uncoated, and plants that turn over every fountain every hour. You are paying for a property you do not use.
RFQ
Tell us typical stop length, hall temperature, and whether you need ultra high-gloss or high-gloss. We will name LC-0011, LC-0022, or Honglu conventional.
What the quote covers
Open-time hours on a TDS are laboratory films. Your air movement and fountain chemistry own the night.
Key questions
- What is the short answer?
- Stay-open grades keep the roller film from skinning on a night stop. They still need oxygen in the pile. Do not confuse roller open-time with dry-to-handle.
- Two clocks
- On the rollers, a stay-open conventional ink is meant to remain workable after hours of contact with air. In the pile, the same ink must still set and oxidise. Plants that treat stay-open as “never dries” get set-off. Plants that treat it as “always skins” dump drier and then cannot restart.
- How should the numbers in this article be used?
- The ranges here are typical shop practice. Confirm them on your press, paper lot, and lamps or dryer. Catalog numbers stay on the data sheet; the signed sheet comes from a trial.
The ranges here are typical shop practice. Confirm them on your press, paper lot, and lamps or dryer. Catalog numbers stay on the data sheet; the signed sheet comes from a trial.
Related articles
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