Sheet stacking apparatus and image forming apparatus

A sheet stacking apparatus comprising:

• a storage configured to store a sheet;
• a holder configured to movably hold the storage;
• a second sealing surface provided on the storage and disposed opposite to a first sealing surface provided on the holder;
• and
• a sealing member provided on either the first sealing surface or the second sealing surface, and where the sealing member is attracted to the other of the first sealing surface or the second sealing surface by a magnetic force.

An image forming apparatus comprising:

• a sheet stacking apparatus in which a sheet is to be stacked;
• and
• an image forming portion configured to form an image on the sheet conveyed from the sheet stacking apparatus,
• wherein the sheet stacking apparatus includes:
• a storage configured to store the sheet,
• a conveyance unit configured to convey the sheet stored in the storage in a conveyance direction,
• a sealing member, and
• a holder configured to movably hold the storage in a sheet width direction orthogonal to the conveyance direction,
• wherein the storage includes:
• a first unit containing a pair of regulating members configured to regulate both edges of the sheet stored in the storage in the sheet width direction, and
• a second unit including a second positioning member configured to engage with a first positioning member provided in the holder so as to position the storage with respect to the holder in the sheet width direction, and a second sealing surface disposed opposite to a first sealing surface provided on the holder,
• wherein the sealing member is disposed between the first sealing surface and the second sealing surface, and
• wherein a relative position between the first unit and the second unit is changeable.