Paper Industry ? Controlling Edge Curl
Moisture, Temperature, or Both for Control?
Key Words: Warp, flatness, moisture control, temperature, curl
Edge Curl and Lay Flat Index in the paper industry is a constant challenge, especially when temperature and humidity vary in the manufacturing environment. Similarly, warp is a challenge in the corrugating industry.
Cross Direction (CD) warp is when the top and bottom liner board moistures are not matched and it is the largest contributor to board quality. If the top and bottom liner board moisture levels are unequal after bonding, the variance in shrink rate will cause warp. Machine Direction (MD) warp can be caused by moisture variations between the top and bottom liners and tension control.