December 2, 2014

Helpful Tips

Winter Blast! Paper Conditioning

Paper Conditioning – Paper Prep Protocol

Great news! The blizzard conditions did not delay delivery and the paper for that hot rush order just unloaded off the truck! You need to get the stock on the press and out today!  But wait….is that such a good idea? Like a fine wine that must “breathe” and a roast just out of the oven that should “rest” before slicing ~ paper needs time to “acclimate” to its environment, too! Paperboard is affected by temperature and humidity, and like a cracker or a piece of bread, it absorbs or loses moisture based on exposure to its surroundings. The seasonal extremes in humidity and temperature during transit and storage can cause converting problems. Paper runs best when it has a chance to acclimate to ideal pressroom conditions ~ generally speaking 45%-55% relative humidity and 68°-77°F.

Recipe for Success on the Press

  • Store paper away from heaters, cold and damp concrete walls and wind. 
  • Allow 24-48 hours for paper to acclimate to the production/pressroom environment. The timing is a factor of the weight of the paper and the temperature/ relative humidity difference!  The heavier the skid and the greater the variance between the warehouse and pressroom conditions, the longer the waiting times to acclimatize. Paper exposed to great differences in temperature and humidity extremes will develop curl, tight edges, or wavy edges-especially evident in sheets.
  • Use oldest inventory first. First in-first out!
  • Keep product in original packaging until ready for use.  Remove the outer wrapping on skids and rolls just before printing or converting. Unwrap the stock as needed and rewrap unused stock after converting, printing or storing.

Following these simple steps will help to avoid some of the converting challenges that are caused by extremes in relative humidity and temperature in mid-winter and mid-summer conditions.