1. Technical Field
The present invention relates to a sheet manufacturing apparatus.
2. Related Art
Obtaining a sheet-shaped or film-shaped molded body by depositing a fibrous material and exerting a combining force between the deposited fibers has been performed from old times. A typical example thereof includes manufacturing a paper sheet by paper-making using water. Even in these days, paper-making method is widely used as one of the manufacturing methods of the paper sheet. In many cases, the paper sheet which is manufactured by the paper-making method has a structure in which cellulose fibers derived from wood are intertwined with each other, form hydrogen bonding, and further, are partially bonded to each other by a binder (paper strengthening agent (starch paste or water-soluble resin)).
Meanwhile, in JP-A-7-3603, a manufacturing method of a molded body made of waste paper fibers, in which a dry type waste paper defibrating machine that does not use water is used, is disclosed. In the manufacturing method, making a mixture of the binder of a synthesized resin and the waste paper fibers into a molded article by pressing and heating is described.
However, in the manufacturing method described in JP-A-7-3603, the binder is mixed before defibrating the waste paper sheet. For this reason, when the temperature increases inside the waste paper defibrating machine, a state where the binder starts melting, is not sufficiently scattered with respect the waste paper fibers, and partially coagulates, is considered. In addition, in the technology of JP-A-7-3603, it can be found that the binder is not sufficiently mixed and scattered before defibration since a solution of the binder is coated before pressing and heating the mixture. In addition, in a case where a classifying unit for deinking after defibration is provided, if the binder is mixed before defibration, a resin which is smaller than fibers and having light specific gravity is classified and removed from a system. In addition, in a case where the sheet is formed by a dry method, if the binder is liquid, coagulation of the fibers is generated, for example, it is difficult to pass through openings of a sieve. For this reason, it is difficult to uniformly perform depositing and molding by using the sieve.