Cushioning material and packaging box

Abstract

A cushioning material including a base and a bending portion. The base includes a first main face and a first cushioning rib protruding orthogonally to the first main face. The bending portion is bent orthogonally to the base, and includes a second main face, a second cushioning rib, and a protrusion. The second cushioning rib protrudes orthogonally to the second main face. The protrusion protrudes orthogonally to the second main face. The base has an opening and a cut portion. The opening has a rim contacting and engaging with the protrusion of the bending portion bent orthogonally to the base. The cut portion is in the rim to cause the rim to elastically deform in response to an engagement of the protrusion of the bending portion with the opening.

What is claimed is: 
     
         1 . A cushioning material comprising:
 a base including:
 a first main face; and 
 a first cushioning rib protruding orthogonally to the first main face; and 
   a bending portion bent orthogonally to the base, the bending portion including:
 a second main face; 
 a second cushioning rib protruding orthogonally to the second main face; and 
 a protrusion protruding orthogonally to the second main face, 
   wherein the base having:   an opening having a rim contacting and engaging with the protrusion of the bending portion bent orthogonally to the base; and   a cut portion in the rim to cause the rim to elastically deform in response to an engagement of the protrusion of the bending portion with the opening.   
     
     
         2 . The cushioning material according to  claim 1 ,
 wherein the first cushioning rib of the base has a recess in a first area, the recess facing the bending portion bent orthogonally to the base,   the opening is in a second area different from the first area to face the protrusion of the bending portion bent orthogonally to the base,   the second cushioning rib of the bending portion has a projection, fittable to the recess with the bending portion bent orthogonally to the base, in a third area of the bending portion, and   the protrusion is in a fourth area different from the third area of the bending portion.   
     
     
         3 . The cushioning material according to  claim 1 , further includes multiple rims including the rim,
 wherein the rim is at a position furthest from the main face of the base among the multiple rims.   
     
     
         4 . The cushioning material according to  claim 1 , further comprising a boundary that divides the base and the bending portion,
 wherein the boundary has a depression inward to a valley fold side of the boundary.   
     
     
         5 . The cushioning material according to  claim 1 , further comprising a boundary that divides the base and the bending portion,
 wherein the protrusion and the opening are formed adjacent to the boundary.   
     
     
         6 . The cushioning material according to  claim 1 ,
 wherein the protrusion has a length greater than a thickness of the rim in a protruding direction of the protrusion.   
     
     
         7 . The cushioning material according to  claim 1 ,
 wherein the protrusion has a length in a width direction and the opening has a length in the width direction, and   the length of the protrusion is shorter than the length of the opening.   
     
     
         8 . The cushioning material according to  claim 1 ,
 wherein the protrusion has a leading end extending in a protruding direction, and the leading end is an R-shaped portion or a tapered portion.   
     
     
         9 . The cushioning material according to  claim 1 ,
 wherein the cut portion is included, in the rim, in one of a center portion in a width direction, both end portions in the width direction, and multiple portions spaced from each other in the width direction.   
     
     
         10 . The cushioning material according to  claim 1 ,
 wherein the base has multiple bending portions.   
     
     
         11 . The cushioning material according to  claim 1 ,
 wherein the cushioning material includes a molded pulp.   
     
     
         12 . The cushioning material according to  claim 1 ,
 wherein the rim contacts the protrusion in a straight line in response to completion of assembling the cushioning material.   
     
     
         13 . A packaging box comprising the cushioning material according to  claim 1  to be packaged in contact with at least one packaging object. 
     
     
         14 . A cushioning material comprising:
 a base including:
 a first main face; and 
 a cushioning rib protruding from the first main face; and 
   a bending portion including:
 a second main face bent against the base in a bending direction; 
 a first protrusion fitted to the cushioning rib of the base with the second main face bent against the base; and 
 a second protrusion, 
   the base further including a restrictor to restrict a movement of the second protrusion in an opposite direction opposite to the bending direction of the second main face.   
     
     
         15 . The cushioning material according to  claim 14 ,
 wherein the second protrusion includes:   a first face facing a side face of the restrictor; and   a second face protruding to the first face to contact a leading end of the restrictor.   
     
     
         16 . The cushioning material according to  claim 14 , further comprising multiple first protrusions including the first protrusion,
 wherein the second protrusion is disposed between adjacent two of the multiple first protrusions.   
     
     
         17 . A packaging box comprising the cushioning material according to  claim 14  to be packaged in contact with at least one packaging object.