Sheet manufacturing apparatus and sheet production method

Abstract

A sheet manufacturing apparatus includes a defibrator that defibrates a paper piece to form a defibrated material, an accumulator that accumulates the defibrated material on a mesh belt to form an accumulating material, a forming machine that forms the transported accumulating material to produce a strip-shaped sheet, and a return mechanism that sends a residual accumulating material that is the defibrated material being accumulating to the defibrator on condition that the accumulator has stopped or is stopped during accumulation.

What is claimed is: 
     
         1 . A sheet manufacturing apparatus comprising:
 a defibrator that defibrates a fiber material to form a defibrated material;   an accumulator that accumulates the defibrated material on a transport body to form an accumulating material;   a forming machine that forms the transported accumulating material to produce a sheet; and   a return mechanism that sends a residual accumulating material that is the defibrated material being accumulating to the defibrator on condition that the accumulator has stopped or is stopped during accumulation.   
     
     
         2 . The sheet manufacturing apparatus according to  claim 1 , wherein
 the return mechanism includes a box that stores the residual accumulating material.   
     
     
         3 . The sheet manufacturing apparatus according to  claim 1 , wherein
 the return mechanism sucks air from a position of the accumulator and blows out the air at a position of the defibrator, and   the residual accumulating material is sent to the defibrator by a wind force through an inside of a tube of the return mechanism.   
     
     
         4 . The sheet manufacturing apparatus according to  claim 3 , wherein
 in the return mechanism, the tube has a circular cross section.   
     
     
         5 . The sheet manufacturing apparatus according to  claim 1 , wherein
 the transport body transports the residual accumulating material toward the return mechanism in response to accumulation of the defibrated material being stopped.   
     
     
         6 . The sheet manufacturing apparatus according to  claim 1 , wherein
 at a time of restart after a stop instruction is received during accumulation, the accumulator accumulates the defibrated material defibrated from the residual accumulating material at a time of previous stop before the accumulating material having a predetermined size.   
     
     
         7 . The sheet manufacturing apparatus according to  claim 6 , wherein
 the forming machine discards an accumulating material derived from the residual accumulating material and then forms the accumulating material having the predetermined size to produce a sheet.   
     
     
         8 . The sheet manufacturing apparatus according to  claim 1 , wherein
 when a stop instruction is given by a user, the residual accumulating material is sent to the defibrator, and then an operation is stopped.   
     
     
         9 . The sheet manufacturing apparatus according to  claim 2 , wherein
 when a stop instruction is given by a user, the residual accumulating material is not sent to the defibrator but is stored in the box, and an operation is stopped.   
     
     
         10 . The sheet manufacturing apparatus according to  claim 1 , wherein
 in the accumulator, an accumulation amount of the defibrated material immediately after start of accumulation has a large variation compared to an accumulation amount of the defibrated material after a predetermined time has elapsed from the start of accumulation.   
     
     
         11 . The sheet manufacturing apparatus according to  claim 10 , wherein
 the accumulation amount of the defibrated material immediately after the start of accumulation includes a variation of 5% or more in thickness.   
     
     
         12 . A sheet production method comprising:
 defibrating a fiber material to form a defibrated material;   accumulating the defibrated material on a transport body to form an accumulating material; and   forming the transported accumulating material to produce a sheet, wherein   a residual accumulating material that is the defibrated material being accumulating is returned to a defibrator and accumulates on the transport body in response to an instruction to stop accumulation given during accumulation.