Making paper begins of course with tress as the raw material. Although it should be said that other materials, such as sugar cane waste, bamboo, hemp, cotton, wheat straw, and many others, can be used to make paper as well. For example, cotton/linen mixture is used by the Treasury Department to mint United States currency.
Trees still make up 95% of the raw material used in papermaking. The most common kinds used include pine, fir, maple, birch, oak and spruce. Trees, in general, are composed of cellulose fibers bonded with lignin, sugar, and other organic compounds. Depending on the species of the tree they may consist of as much as 50% of suitable cellulose.
The first step in the process is to separate the cellulose from the other materials and the lignin. This process is called pulping and there are primarily two different methods. The first method is called chemical pulping and it consists of using a chemical reaction to turn the raw materials into a pulp and separate the cellulose. This method generally produces a lower yield that mechanical pulping. Mechanical pulping usually entails grinding the wood to separate the cellulose out this method usually yields about 90% or more of the wood into usable product.
The pulp is then highly diluted and the mixture is sprayed onto a moving mesh screen in layers to make a mat. The mat is taken through a series of vacuum and mechanical processes to dehydrate and compact it. It is then sent through heated rollers to squeeze the mat into paper. The paper rolls are then cut to size and packaged to be shipped onto another secondary facility for further processing.
Just a note about being green; recycled paper is possible because paper is made of the original fibers they can all be reused to make new paper. The paper is turned into a usable pulp by putting the used paper into water and chopping it up to separate the fibers and wash out inks and containments. The slurry the goes through the same process as virgin paper.