Usually this involves taking a log and pressing it against a rotating surface to grind off small pieces. Typically a grinder is about 4 feet long. The groundwood pulp is then often cooked to soften it, The chemical process involved cooking chips from a log in a hot bath of boiling caustic. The chemi-mechanical process is a combination of the groundwood and chemical processes. It is generally of a higher quality, a high density, and is less absorbant.
Stock is a mixture of water and paper fiber.
It can be made of wood pulp, cloth fiber, or a mixture of any cellulose and fibrous material. Most paper is made from wood pulp. It is used in almost every paper mill. Full Hydrolic Flow Boxes are head boxes that delivers stock uniformly onto the wire on a consistant basis. Coverilo and Strat-Flo Headboxes are head box designs that enable different layers of stock to be placed on the wire at the same time.