Sheet Drying Methods

Equally important as the actual forming of the sheet is the process used for removing excess water from the sheet and the drying of the newly formed paper. No matter what drying method is used, always dry the paper slowly.

Paper made from high shrinkage fibers, such as linen, must be dried under pressure to keep them flat. Otherwise, distortion, cockling, and other irregularities will appear in the dried sheets.

Method 1: Drying under a press

Place a stack of sheets with alternating felts (a"post") into press. As the post is created, it is naturally curved which facilitates pressure that forces water from the center out. This technique strengthens the paper by increasing fiber bonding and accelerates drying by squeezing out large amounts of water.

Presses range from boards with heavy weights to elaborate, large screw presses or large hydraulic presses.

This process often requires that forced air be used in conjunction with sandwiched layers of damp paper, blotters, and corrugated or porous plates. These layers are kept under moderate pressure while air is forced through the entire stack, until the paper is dry. Most papermakers do not fully dry sheets of paper in a press. The need for good air circulation and other considerations make alternative methods more practical.

Method 2: Drying under a press- Exchange Method

Place a stack of sheets with alternating felts (a"post") into press. As the post is created, it is naturally curved which facilitates pressure that forces water from the center out.

Presses range from boards with heavy weights to elaborate, large screw presses or large hydraulic presses.

1st Press- Remove most of water using a press.
The press is then used to expel water from the paper sheets. This technique strengthens the paper by increasing fiber bonding and accelerates drying by squeezing out large amounts of water. Remove felts and damp sheets as soon as approximately 1/2 hour of water expulsion.

2nd Press- Separate felts and sheets. Lift sheets using opposite corners of closest long side. If this is too difficult, pick up the felt. Take care to not remove the sheet below.
Stack sheets with new dry felts and re-press with lighter pressure.

3rd Press-Restack with a dry felt at the top and bototomof the stack. No felts between paper. Press again more lightly than before. Repeat this 3rd press several times. Each time you should separate and restack the papers until the papers are dry and smooth.

Method 3: Nepalese-style

When sheets of paper are formed Nepalese-style, the sheets are formed in a floating, cloth-covered mold. In this technique, the sheets are then dried in the same mold used for sheet creation. Usually sunlight and air alone dry this type of paper, they are not pressed). Following the Nepalese tradition requires a large number of molds since each mold is in use throughout the drying process.

Method 4: Restraint Drying

Paper can be dried sheet by sheet, with one side applied to a flat surface, such as formica or plexiglass, and the other exposed to the air. This process gives the paper a two-sided quality: the side exposed to the air often softer and less compressed; the side facing the surface is dense, with a regular almost glasslike surface.

Method 5: Traditional Western