to describe the features of the container of the invention , we shall firstly describe the method for the production thereof . two pieces of plastic strip 2 , e . g . pet or pvc , with a thickness of 125 microns , are affixed ( for example glued using vinyl glue ) to a sheet of cardboard 1 ( or other material suitable to form the container ) ( fig1 ). subsequently , with the use of an automatic machine of well - known type , a punching and creasing operation is performed on the cardboard 1 , through which the blank , represented in a plan view and in enlarged scale in fig3 , is separated from the remaining part of the cardboard . it can already be noted that this blank is provided with crease or fold lines ( from 3 to 6 ) which separate from one another five different and consecutive portions of cardboard designed to form — in the finished container — a bottom wall 7 , a front wall 8 , a rear wall 9 , a top wall 10 and a front wall which is divided into two parts 11 and 11 a by a predetermined and facilitated tearing line or knurling 12 : a shaped cut is produced in the part 11 a , which delimits therein an appendix 13 integral with the part 11 and suitable to be inserted ( as will be explained hereunder ) in a shaped opening 14 produced in the wall 8 . the fold or crease line 3 is composed of a discontinuous series of short segments of crease ( mutually connecting the walls 7 and 8 ) separated from one another by a series of saw tooth cuts 15 produced through punching in the wall 8 . similarly , a series of short rectilinear cuts 16 , separated from one another by a group of tooth cuts 17 forming part of a series of saw tooth cuts 17 , are produced in the part 11 a of the front wall . from the figures it can also be noted that tabs ( not numbered for simplicity ) project from the ends of all the aforesaid walls , these tabs being designed to close the two ends of the container that is obtained at the end of all the assembly operations described hereunder . the structure of the piece of cardboard blank described above is already known and is similar to the one illustrated in the prior art patents ep0369346b and u . s . pat . no . 4 , 967 , 911 mentioned in the introduction of the present description . an advantageous feature of the present invention consists in the presence of strips of plastic material 2 glued onto one ( or if necessary onto both of the opposite surfaces of the sheet of cardboard 1 ) and , simultaneously , in the fact that the saw tooth cuts 15 and 17 ( and also the series of short cuts 16 ) are obtained by simultaneous punching both on the sheet of cardboard 1 and on the pieces of strip 2 affixed thereto : it has been found that , in this manner , the teeth 15 , 17 ( which have the function of causing tearing of the thin foil of web material unwound from its roll enclosed in the container ) have a much greater resistance to deformation thereof than they would have if they were not covered , on one or both the faces thereof , by the protective layer of the plastic strip . it is evident that the plastic strip 2 is provided in those areas of the cardboard provided with the toothings having the function of causing tearing of the thin foil material which the container is designed to contain . we shall now return to consider fig2 which shows the cardboard on which , after affixing of the pieces of strip 2 , the punching and creasing operations have been performed , already described and at the end of which the blank shown in fig3 is separated from the cardboard . it is important to note that , as a result of the fact that the short rectilinear cuts 16 and the saw tooth cuts 17 produced ( during the punching operation of the cardboard ) in the part 11 a of the front wall form a single continuous longitudinal cut , when the blank of fig3 detaches from the punched cardboard a portion of the strip 2 remains attached to the cardboard frame 1 ( which is discarded ), separating from the other portion of strip which remains affixed to the part 11 a of the front wall of the container : the cuts 16 and the teeth 17 thus form a continuous series delimiting the free edge of the part 11 a designed to form part of the front wall of the container . to form the container starting from the blank of fig3 , this blank is turned over , so that it is as shown in fig4 . at this point the cardboard is folded about the fold line 4 ( fig5 ), placing the wall 7 over the wall 9 and the wall 8 over the wall 10 , then applying a layer of glue 20 along the free longitudinal edge of the portion of wall 11 a ( fig5 ); the cardboard is then folded over itself along the fold line 6 , placing the portion of wall 11 over the wall 10 and affixing ( through the layer of glue 20 ) the portion of wall 11 a to the wall 8 ( fig6 ). as can be noted in fig6 , the teeth 17 of the part 11 a of the front wall of the cardboard are placed over the fold lines 3 of the wall 8 , the cusps or tips of these teeth 17 projecting slightly beyond the respective fold lines 3 , while the teeth 15 are placed over the cuts 16 , also projecting slightly over and beyond these cuts . at this point the operations for industrial production of the container are terminated and , by exerting a force for mutual approach ( in the direction shown schematically by the arrows a - a in fig6 ), the container assumes a square shape which delimits a trapezoidal cavity defined by a bottom wall 7 , by a front wall 8 , by a rear wall 9 and by a top wall 10 from which an end wall 11 , 11 a extends , placed over the front wall 8 and divided into the two portions 11 , 11 a by the transverse and tearable knurling 12 . a roll 30 of thin foil material 31 ( fig1 ), a portion of which can be unwound and torn from the roll 30 , can be inserted in the assembled container described above ( through the ends of the container , still open ). as in the closed container containing the roll 30 the portion of wall 11 , 11 a is glued to the outer surface of the wall 8 , to open this container it is necessary and sufficient to break the wall 11 , 11 a along the tearing line 12 : in this manner the portion of wall 11 a will remain fixed and glued to the wall 8 , while the portion of wall 11 can be lifted upward ( together with the wall 10 ), rotating about the fold line 5 : it will thus be possible to grasp the free edge of the thin foil 31 and pulling it out of the container — to unwind from the roll 30 a portion of the desired length which can then be easily torn ( and removed ) by pressing it against the teeth 15 and 17 delimiting the lower front corner of the container ( fig7 and 10 ). for greater clarity , fig8 and 9 represent , in enlarged scale , two ( partial ) sections of the container , taken according to the lines 8 - 8 and 9 - 9 of fig7 . from these fig7 , 8 and 9 , the most important feature of the container described above can easily be perceived . it is seen that a substantial part of the teeth 17 ( projecting from the portion of wall 11 a which is glued to the wall 8 , is resting on and held pressed on the this wall 8 , while only a small portion ( the cusps ) of these teeth 17 project beyond the lower surface of the wall 7 ; and that a substantial part of the teeth 15 ( projecting from the wall 7 ) is resting on and supported by the free edges of the cuts 16 , while only a small portion ( the cusps ) of these teeth projects beyond the outer surface of the part of wall 11 a . therefore , along the entire front and lower corner of the container there is provided a continuous cutting edge formed by the series of teeth 15 and 17 , which are practically non - deformable under the thrust of the foil 31 which is torn from the roll 30 . it is evident that the structure of the container for the roll of thin foil material can differ from the one represented in the accompanying drawings . this structure can be of any known shape for the object at which the present invention is aimed ; for example , the container can have the shape of any one of the containers described in the prior art patents already cited or have the toothed edge produced solely on the free edge of the wall 8 or on the free edge of the portion of wall 11 a , or yet another solution . it is advantageous that the teeth designed to cut the thin foil material extracted from the container are protected and covered , a least on one surface thereof , by a layer or strip of plastic material or the like ( e . g . a thin foil of metal , such as a foil of aluminium ) in which the toothing for tearing is produced by punching simultaneously to the toothing produced in the sheet of cardboard or the like .