Sheet manufacturing apparatus and control method for sheet manufacturing apparatus

1. A sheet manufacturing apparatus comprising:

a processing unit that processes fibers into a web;

a roller unit that pinches and transports the web into which the fibers are processed by the processing unit; and

a control unit that controls at least any of a pressing state and a transport state in the roller unit,

wherein the control unit causes the web to pass in a nip unit by controlling at least any of a transport speed of the roller unit, a nip pressure of the roller unit, and a nip width of the roller unit depending on a position of a leading edge of the web with respect to the nip unit in which the roller unit pinches the web.

2. The sheet manufacturing apparatus according to claim 1 ,

wherein the processing unit transports the web at a speed corresponding to the transport speed at which the web is transported in the roller unit.

3. The sheet manufacturing apparatus according to claim 1 ,

wherein the processing unit includes a transfer unit that transfers the web to the roller unit based on control of the control unit, and

the control unit transfers, by the transfer unit, the web at a first speed at a time of a normal operation and transfers the web at a second speed that is a speed lower than the first speed, in a case where the leading edge of the web enters the nip unit.

4. The sheet manufacturing apparatus according to claim 3 ,

wherein the control unit transfers the web at a speed higher than the second speed by the transfer unit in a case where the leading edge of the web is away by a predetermined distance or longer from the nip unit.

5. The sheet manufacturing apparatus according to claim 1 , further comprising:

a tension roller that imparts a tensile force to the web,

wherein the control unit separates the tension roller from the web depending on the position of the leading edge of the web.

6. The sheet manufacturing apparatus according to claim 1 ,

wherein the roller unit includes a heating roller that heats the web.

7. The sheet manufacturing apparatus according to claim 6 ,

wherein the heating roller includes rollers as a pair, and at least one of the rollers has elasticity and has a nip width that changes depending on a nip pressure.

8. The sheet manufacturing apparatus according to claim 7 ,

wherein the nip pressure of the heating roller is adjustable by control of the control unit.

9. The sheet manufacturing apparatus according to claim 8 , further comprising:

a paper guide on a downstream side of the heating roller in a transport direction of the web,

wherein the control unit controls a gap distance between the paper guide and the heating roller depending on the position of the leading edge of the web.

10. The sheet manufacturing apparatus according to claim 6 ,

wherein the processing unit includes

a defibrating unit that defibrates a raw material including the fibers,

a mixing unit that mixes the fibers included in defibrated matter defibrated by the defibrating unit with resin, and

a web forming unit that forms the web by accumulating a mixture mixed by the mixing unit,

transfers the web toward the roller unit, and

sets an amount of the resin included in a part within a predetermined distance from the leading edge of the web to be smaller than the amount of the resin in other parts in the web based on control of the control unit.

11. The sheet manufacturing apparatus according to claim 10 ,

wherein the defibrating unit defibrates the raw material in an atmosphere,

the mixing unit mixes the fibers with the resin in the atmosphere,

the web forming unit includes a mesh belt and forms the web by dropping and accumulating the mixture on the mesh belt, and

the roller unit forms a sheet by pressing and heating the web.

12. A control method for controlling a sheet manufacturing apparatus,

the sheet manufacturing apparatus including

a processing unit that processes fibers into a web, and

a roller unit that pinches and transports the web into which the fibers are processed by the processing unit,

wherein a control unit causes the web to pass in a nip unit by controlling at least any of a transport speed of the roller unit, a nip pressure of the roller unit, and a nip width of the roller unit depending on a position of a leading edge of the web with respect to the nip unit in which the roller unit pinches the web.