Recording media sheet processing system, image forming system including same, and insertion method used therein

A recording media sheet processing system comprising:

• a folding device, including a folding unit to fold a sheet of recording media and a squeezing unit to squeeze a folded portion of the folded sheet;
• an insertion device to insert in an envelope an enclosure including the folded sheet;
• and
• a controller operatively connected to the folding device and the insertion device and including:
• an envelope selector for selecting an envelope type from a group of selectable predetermined envelope types;
• a selector for selecting whether to fold the sheet inserted in the envelope and a folding style of the sheet from a group of selectable predetermined folding styles;
• a first storage unit to store a first folding-related equivalent quantity into which a quantity of each sheet not to be squeezed by the squeezing unit of the folding device is converted corresponding to the selected folding style;
• a second storage unit to store a maximum quantity of sheets insertable in each envelope type;
• a calculator to calculate a total converted quantity of the enclosure using the first folding-related equivalent quantity stored in the first storage unit and the folding style selected by the selector;
• a determination unit to compare the calculated total converted quantity of the enclosure with the maximum quantity of sheets insertable in the selected envelope type and to determine whether the selected envelope type accommodates the enclosure and
• a squeezing setter to set the number of times the squeezing unit squeezes the sheet and to increase the number of times the squeezing unit squeezes the sheet when the determination unit determines that insertion is not feasible,
• the controller causing the recording media sheet processing system to start processing the sheet and the insertion device to insert the enclosure in the envelope when the determination unit determines that insertion is feasible.