Spray powder on sheetfed offset: particle size versus set-off

Powder isolates; oxygen still dries

Spray powder keeps sheets from kissing in the pile while the conventional film oxidises. It does not replace airing, stay-open discipline, or a faster-oxidising grade. Typical Furey catalog bands are 15 / 25 / 35 µm. Finer grades suit lighter coverage; coarser grades suit heavy solids and thicker board—confirm on the TDS of the lot you buy.

HuiRun quotes Druckmeister spray powder alongside low-odor quickset and Honglu conventional. We will not tell you powder grade can fix a fountain that is drowning the film.

• Log nozzle setting and powder name on the ticket.
• Clean blankets; leftover powder becomes a release layer under varnish.
• Food-pack jobs still need the converter to approve the powder for that use.
• UV jobs often need little or no powder; do not copy a conventional recipe.
• Related set-off article covers ink piling and smear.

After the coater

Aqueous varnish hates a dusty sheet. If you flood-coat in-line, use the lightest powder that still prevents kiss, then brush or vacuum before the coater if the tower allows.

Health and housekeeping

Powder in the air is an EHS topic. This article is not a safety manual. Follow the SDS and your plant rules.

RFQ

Coverage, board caliper, whether you varnish in-line, and the micrometre you run today. We will name a listed powder grade we can ship from Hefei.

What the quote covers

Particle-size bands are manufacturer labels. Your nozzle wear changes the cloud. Trial on the live form.