|MadSci Network: Chemistry|
Paper is made of cellulose fibers. In many ways it is similar to a cotton shirt. When you wash a cotton shirt it usually is wrinkled until you iron it. Paper is similar. Paper making machines press the cellulose pulp into sheets. As it dries, the fibers stick together. If the fibers dry in a more random arrangement, wrinkling will result. Rewetting and pressing will eliminate the wrinkles (take care not to scorch the paper). An interesting reference on the discovery of cellulose: http://www.afandpa.org/products/products.html
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