Key Questions
The following key questions are answered in this module:
What are the common sections of a tissue machine?
A tissue machine can include a former, press or through-air dryer, Yankee dryer, and a reel. Sometimes a calender is used to produce a uniform sheet thickness.
What is a through-air dryer?
A through-air dryer, or TAD, is a large perforated roll that is often used on tissue machines to replace the press section. Hot air is used to dry the sheet. A TAD can produce a bulky sheet because it is not pressed.
What Is a Yankee dryer?
The Yankee dryer is a large, steam-heated cylinder which is used to dry the sheet and provide a surface for creping tissue. A coating is applied to adhere the sheet to the Yankee to help drying and creping.
What is creping?
A blade is used to remove the sheet from the Yankee dryer. The sheet crashes into the blade. This collision breaks up fiber bonds, so a softer, bulkier sheet is formed.
How are parent rolls converted to tissue products?
Parent rolls are unwound. While unwinding, the sheet can be printed, embossed, or combined with additional sheets. The sheet is perforated and wound onto cardboard tubes to form a log. The logs are cut into individual rolls by log saws, then wrapped and/or bundled and put into cases.