Problem to be solved: to provide a sheet folding device capable of effectively wrapping the side portion of the sheet in transit and attaching an adhesive to the side support plate and effectively suppressing the inconvenience caused by deposition of the deposit on the side support plate.Solution: a folding device 41 of a sheet equipped with a pair of return guides 43A and 43b, and having a conveyor conveyer 42 having an angle of conveyance 42U in the upstream part 41u in the conveying direction MD and a conveying surface 42d in the downstream part 41D with an angle, and downstream part A pair of folding guides are disposed on both sides of the conveying surface 42d, and a pair of side support plates 47a on both sides of the conveying surface 42U of the upstream partThe side support plate has an outer edge 48A, 48b inclined toward the inner side in the direction perpendicular to the conveying direction toward the downstream of the conveying direction of the conveying conveyor, and is inclined downward toward the outside of the orthogonal direction CD of the conveying direction MD, and is inclined downward .Diagram【課題】搬送中のシートの側部を良好に折り返すことができるとともに、側部支持プレートに接着剤が付着したり、側部支持プレートに堆積物が堆積することによる不都合を効果的に抑制することのできるシートの折り返し装置の提供。【解決手段】一対の折り返しガイド43a,43bを具備するシートの折り返し装置41であり、搬送方向MDの上流部41Uにおける搬送面42uと下流部41Dにおける搬送面42dとが角度を持って連結された搬送コンベア42を有し、下流部41Dの搬送面42dの両側に一対の折り返しガイドが配され、上流部41Uの搬送面42uの両側に一対の側部支持プレート47a,47bが配され、該側部支持プレートは、搬送コンベアの搬送方向の下流に向かうに連れて搬送方向に直交する方向の外方から内方に近づくように傾斜した外側縁部48a,48bを有しており、搬送方向MDの直交方向CDの外方に向かって下向きに傾斜している。【選択図】図3
