A sheet tray configured to accommodate a sheet includes a first tray, a second tray directly connectable to the first tray, and a third tray directly connectable to the first tray and to the second tray in a state where the second tray is disengaged from the first tray, the third tray being made of metal. The sheet tray is configured to take a first state where the first tray is directly connected to the second tray and a second state where the third tray connects the first tray to the second tray. The sheet tray is configured to accommodate a sheet having a first size in the first state and a sheet having a second size longer than the sheet having the first size in the second state.

A roller structure is disclosed and includes at least one roller unit. The roller unit includes a base, an elastic portion, a supporting portion and a rotating wheel. The base is configured to detachably assemble the roller unit on an accommodation seat. The base includes a first lateral edge. The elastic portion is disposed on the base and connected with the first lateral edge. The elastic portion includes a bent section having an end extending and bent from the first lateral edge. The supporting portion is disposed on the elastic portion and connected to the other end of the bent section. The rotating wheel is pivotally connected to the supporting portion. When the rotating wheel is pressed by a driving wheel, the supporting portion is driven to compress the elastic portion to move the rotating wheel toward the base, and the rotating wheel is driven to rotate relative to the supporting portion.

Provided are a rubber composition capable of imparting a high tensile strength to a roller main body so as to be able to be used for equipment that allows paper to pass through at high speed, while maintaining high abrasion resistance of the roller main body and a favorable paper feeding performance of the paper feeding roller; and a paper feeding roller. There is provided a rubber composition contains: a rubber that includes a non-oil extended EPDM having an ethylene content of 55 to 72%; and more than 20 parts by mass and 30 parts by mass or less of a filler, and 2.5 parts by mass or more of a peroxide crosslinking agent per 100 parts by mass of the rubber, in which the filler contains 15 to 30 parts by mass of an amorphous silica per 100 parts by mass of the rubber.

A back roller includes a roller body and a wear-resistant layer. The roller body has an axis and a roll surface disposed around the axis. The wear-resistant layer covers the roll surface. Vickers hardness (H) of the wear-resistant layer is 800 HV?H?1400 HV. The roll surface is covered by the wear-resistant layer, and the Vickers hardness (H) of the wear-resistant layer is controlled to be between 800 HV and 1400 HV, so that the roll surface is effectively protected, and wear resistance of the roll surface is improved. In this way, the wear-resistant layer is in direct contact with a material during operation, thereby effectively reducing an abrasion loss on the roll surface and extending the service life of the roll surface.

Methods and apparatus to form tear-off paperband composites that adhesively attach a paper web to an empty web spool. In some embodiments, the paperband composite is applied in several layers to an empty web spool, each layer suitable for fixedly attaching a paper web to the empty spool. Multiple layers of paperband composite allow for use during multiple turn-up procedures with one layer of paperband composite used per turn-up procedure. In some examples, the paperband composite may be applied to a paper spool tangentially along the spool face and perpendicular to the axis of rotation of the spool. In other examples, the paperband composite may be spirally wrapped around the paper spool.

A nip roller includes a core material having a surface coated with rubber. The nip roller having a support length L.sub.1 of 5 m or longer. The rubber surface has a hardness H (deg) equal to or lower than 65 deg as measured by a JIS K6253 Type A durometer (A type). Mass W (kg) of the nip roller and second moment of area I.sub.1 (m.sup.4) and the Young's modulus E.sub.1 (Pa) of the core material satisfy E.sub.1I.sub.1/W80000.

A sheet feed roller (1) is provided, which is formed of an elastomer composition containing a thermoplastic elastomer, a spherical filler and a low friction silicone compound, and has a friction coefficient of not greater than 0.5. A production method is also provided, which includes the step of extruding the elastomer composition through a die configured as corresponding to a sectional shape of the sheet feed roller.

Methods and apparatus to form tear-off paperband composites that adhesively attach a paper web to an empty web spool. In some embodiments, the paperband composite is applied in several layers to an empty web spool, each layer suitable for fixedly attaching a paper web to the empty spool. Multiple layers of paperband composite allow for use during multiple turn-up procedures with one layer of paperband composite used per turn-up procedure. In some examples, the paperband composite may be applied to a paper spool tangentially along the spool face and perpendicular to the axis of rotation of the spool. In other examples, the paperband composite may be spirally wrapped around the paper spool.

Methods and apparatus to form tear-off paperband composites that adhesively attach a paper web to an empty web spool. In some embodiments, the paperband composite is applied in several layers to an empty web spool, each layer suitable for fixedly attaching a paper web to the empty spool. Multiple layers of paperband composite allow for use during multiple turn-up procedures with one layer of paperband composite used per turn-up procedure. In some examples, the paperband composite may be applied to a paper spool tangentially along the spool face and perpendicular to the axis of rotation of the spool. In other examples, the paperband composite may be spirally wrapped around the paper spool.

A nip roller includes a core material having a surface coated with rubber. The nip roller having a support length L.sub.1 of 5 m or longer. The rubber surface has a hardness H (deg) equal to or lower than 65 deg as measured by a JIS K6253 Type A durometer (A type). Mass W (kg) of the nip roller and second moment of area I.sub.1 (m.sup.4) and the Young's modulus E.sub.1 (Pa) of the core material satisfy E.sub.1I.sub.1/W?80000.