A sheet manufacturing apparatus includes a second web forming unit that processes fibers into a web shape, a sheet forming unit that pinches and transports a second web processed into the web shape by the second web forming unit, and a control unit that controls at least any of a pressing state and a transport state in the sheet forming unit. The control unit causes the second web to pass through a nip unit by controlling at least any of a transport speed of the sheet forming unit, a nip pressure of the sheet forming unit, and a nip width of the sheet forming unit depending on a position of a leading edge of the second web with respect to the nip unit in which the sheet forming unit pinches the second web.

A sheet manufacturing apparatus includes a second web forming unit that processes fibers into a web shape, a sheet forming unit that pinches and transports a second web processed into the web shape by the second web forming unit, and a control unit that controls at least any of a pressing state and a transport state in the sheet forming unit. The control unit causes the second web to pass through a nip unit by controlling at least any of a transport speed of the sheet forming unit, a nip pressure of the sheet forming unit, and a nip width of the sheet forming unit depending on a position of a leading edge of the second web with respect to the nip unit in which the sheet forming unit pinches the second web.

A monitoring system for monitoring the conditions of a band circulating in a paper-making machine, comprises a guide extending substantially along an axis; and a monitoring apparatus movable along the guide and comprising at least one measuring device configured to measure at least one parameter indicative of the conditions of the band; the apparatus is a self-propelled motorized apparatus, provided with a motor and at least one driving member operated by the motor and which engages at least one corresponding surface of the guide to move the apparatus along the guide.

A method for creping paper includes applying an adhesive composition to an outer surface of a creping cylinder (Yankee cylinder) to form an adhesive coating, contacting paper with the adhesive coating, removing the paper and adhesive coating from the creping cylinder, and determining a quality of the adhesive coating. Determining the quality of the adhesive coating may include measuring a degree of cross-linking of the adhesive polymer, a concentration of the adhesive polymer in the adhesive coating, a water content of the adhesive coating, an ash content of the adhesive coating, or combinations thereof. Determining the quality of the adhesive coating may also include determining a thickness of the adhesive coating by measuring light absorbed by the coating and calculating the thickness using Beer's Law. Systems and apparatuses for determining the quality of the adhesive coating and for creping paper are also disclosed.

A method for creping paper includes applying an adhesive composition to an outer surface of a creping cylinder (Yankee cylinder) to form an adhesive coating, contacting paper with the adhesive coating, removing the paper and adhesive coating from the creping cylinder, and determining a quality of the adhesive coating. Determining the quality of the adhesive coating may include measuring a degree of cross-linking of the adhesive polymer, a concentration of the adhesive polymer in the adhesive coating, a water content of the adhesive coating, an ash content of the adhesive coating, or combinations thereof. Determining the quality of the adhesive coating may also include determining a thickness of the adhesive coating by measuring light absorbed by the coating and calculating the thickness using Beer's Law. Systems and apparatuses for determining the quality of the adhesive coating and for creping paper are also disclosed.

Provided is a sheet manufacturing apparatus capable of desirably adjusting the thickness of the sheet, and forming sheets with highly uniform thickness or grammage. A sheet manufacturing apparatus configured to make a sheet from defibrated material of defibrated paper includes: a drum unit having a cylinder with a defibrated material storage space inside and multiple openings through which the defibrated material passes formed in the outside of the cylinder; an accumulator configured to accumulate the defibrated material that past the openings, forming a deposit; and a housing configured to enclose the drum unit and the accumulator, the housing having a vent through which air passes between the drum unit and the accumulator.

Provided is a sheet manufacturing apparatus capable of desirably adjusting the thickness of the sheet, and forming sheets with highly uniform thickness or grammage. A sheet manufacturing apparatus configured to make a sheet from defibrated material of defibrated paper includes: a drum unit having a cylinder with a defibrated material storage space inside and multiple openings through which the defibrated material passes formed in the outside of the cylinder; an accumulator configured to accumulate the defibrated material that past the openings, forming a deposit; and a housing configured to enclose the drum unit and the accumulator, the housing having a vent through which air passes between the drum unit and the accumulator.

A measurement apparatus of a moving paper web, includes an optical radiation source that outputs optical radiation toward a scattering element of the measurement apparatus. The scattering element scatters the optical radiation, and a transmitting surface of the scattering element directs the optical radiation in a scattered manner toward the moving paper web. A distance between said transmitting surface of the scattering element and a surface of the paper web is known, and the transmitting surface and a detector of the apparatus are on opposite sides of the paper web. The detector receives at least a part of the optical radiation, which is side-scattered from the moving paper web. The detector determines a moisture value and a dry weight of the paper web on the basis of spectral information on the received optical radiation and the known distance.

Provided is technology enabling appropriately maintaining or adjusting the thickness of accumulated fiber when accumulating and processing fiber. A sheet manufacturing apparatus 100 has a distributor 60 that distributes a mixture MX containing fiber; a second web former 70 that forms a second web W2; a mesh belt 72 that conveys the second web W2 in a conveyance direction F1; a roller unit 650 that compresses the second web W2; a measurement device 400 that measures the distribution of the thickness of the second web W2 in a second direction intersecting the conveyance direction F1 while the second web W2 is being compressed by the roller unit 650, or after the second web W2 is compressed by the roller unit 650; and a controller 110 that compares a measurement from the measurement device 400 with a set thickness distribution, and controls the thickness distribution of the second web W2.

Provided is technology enabling appropriately maintaining or adjusting the thickness of accumulated fiber when accumulating and processing fiber. A sheet manufacturing apparatus 100 has a distributor 60 that distributes a mixture MX containing fiber; a second web former 70 that forms a second web W2; a mesh belt 72 that conveys the second web W2 in a conveyance direction F1; a roller unit 650 that compresses the second web W2; a measurement device 400 that measures the distribution of the thickness of the second web W2 in a second direction intersecting the conveyance direction F1 while the second web W2 is being compressed by the roller unit 650, or after the second web W2 is compressed by the roller unit 650; and a controller 110 that compares a measurement from the measurement device 400 with a set thickness distribution, and controls the thickness distribution of the second web W2.