Perfected tubular support for the winding of material in sheets and method for its production

Abstract

A tubular support for winding a material in sheet form includes a corrugated tubular element, wherein the corrugated tubular element is positioned inside at least one outer coating element in sheet form. The internal corrugated tubular element has outer longitudinal portions and inner longitudinal portions connected by annular radial walls which form an inner corrugated wall. The internal corrugated tubular element and the outer coating element in sheet form are connected at the outer longitudinal portions. In a different embodiment, a corrugated tubular element is positioned between two coating elements in sheet form, in outer and internal positions respectively.

1 . A tubular support ( 11 ) for the winding of material in sheets comprising a corrugated tubular element ( 12 ) characterized in that said corrugated tubular element ( 12 ) is positioned inside at least one outer coating element in sheets ( 13 ). 
     
     
         2 . The tubular support ( 11 ) according to  claim 1 , characterized in that said inner corrugated tubular element ( 12 ) has outer longitudinal portions ( 14 ) and inner longitudinal portions ( 15 ) connected by annular radial walls ( 16 ) which form an inner corrugated wall. 
     
     
         3 . The tubular support ( 11 ) according to  claim 2 , characterized in that said inner corrugated tubular element ( 12 ) and said at least one outer coating element in sheets ( 13 ) are connected in correspondence with said outer longitudinal portions ( 14 ). 
     
     
         4 . The tubular support ( 11 ) according to one or more of the previous claims, characterized in that two annular radial walls ( 16 ), when connected by an outer longitudinal portion ( 14 ), define inner annular interspaces ( 17 ), whereas two annular radial walls ( 16 ), when connected by an inner longitudinal portion ( 15 ), define outer annular interspaces ( 18 ). 
     
     
         5 . The tubular support ( 11 ) according to  claim 4 , characterized in that said interspaces ( 17 ,  18 ) have a substantially rectangular profile according to the axial section. 
     
     
         6 . The tubular support ( 11 ) according to  claim 4 , characterized in that the longitudinal dimension (X) of the interspace ( 17 ) is substantially equal to that of the interspace ( 18 ). 
     
     
         7 . The tubular support ( 11 ,  111 ) according to one or more of the previous claims, characterized in that said inner corrugated tubular element ( 12 ,  112 ) is positioned between two coating elements in sheets ( 113 ,  113 ′), inner and outer respectively. 
     
     
         8 . The tubular support ( 11 ,  111 ) according to one or more of the previous claims, characterized in that said inner corrugated tubular element ( 12 ,  112 ) substantially consists of a mixture, in a widely variable percentage, of fibre glass and polypropylene and/or polyethylene and/or polystyrene and/or polyamide and/or polyester and/or similar, wherein said polypropylene can be a block copolymer, a random copolymer, a homopolymer or a terpolymer, and it can be a virgin or regenerated material, according to the desired characteristics to be conferred to said support ( 11 ,  111 ), and wherein said polyethylene can be low-density, medium-density, high-density polyethylene, linear or metallocene, and can also be virgin or regenerated. 
     
     
         9 . The tubular support ( 11 ,  111 ) according to one or more of the previous claims, characterized in that said coating element in sheets ( 13 ,  113 ) substantially consists of polypropylene and/or polyethylene and/or polystyrene and/or polyamide and/or polyester and/or similar, wherein said polypropylene can be a block copolymer, a random copolymer, a homopolymer or a terpolymer, and it can be a virgin or regenerated material, according to the desired characteristics to be conferred to said support ( 11 ,  111 ) and wherein said polyethylene can be low-density, medium-density, high-density polyethylene, linear or metallocene, and can also be virgin or regenerated. 
     
     
         10 . A method for producing a support ( 11 ) according to one or more of  claims 1  to  6 , characterized in that it comprises, in succession:
 extrusion of a smooth pipe by means of a horizontal extrusion head; 
 thermoforming of the pipe when it is still in the molten state by means of a corrugator, which confers the desired form to the tubular element ( 12 ) with contemporaneous cooling; 
 extrusion, by means of a second extrusion head having the axis of the outlet die perpendicular with respect to the axis of a first extrusion head, of said at least one outer coating element in sheets ( 13 ) directly pouring it onto said tubular element ( 12 ) when it is still in the molten state; 
 cooling of said support ( 11 ) effected for disposing of the heat of the outer coating element in sheets ( 13 ) of the corrugated tubular element ( 12 ); and 
 pulling and cutting the continuous support ( 11 ) thus formed, to obtain a surface absolutely perpendicular to the axis of the support ( 11 ). 
 
     
     
         11 . The method for producing a support ( 111 ) according to one or more of  claims 7  to  9 , characterized in that it comprises, in succession:
 extrusion of a smooth pipe by means of a horizontal extrusion head; 
 thermoforming of the pipe when it is still in the molten state by means of a corrugator which confers the desired form to the tubular element ( 112 ) with contemporaneous cooling; 
 extrusion by means of a second extrusion head having the axis of the outlet die perpendicular with respect to the axis of a first extrusion head of said outer coating element in sheets ( 113 ) directly pouring it onto said tubular element ( 112 ) when it is still in the molten state; 
 extrusion by means of a third extrusion head having the axis of the outlet die coaxial with respect to the axis of said first head of said inner coating element in sheets ( 113 ′) in contact with said tubular element ( 112 ) when it is still in the molten state; 
 cooling of said support ( 111 ) effected for disposing of the heat of the outer and inner coating element in sheets ( 113 ,  113 ′) of the corrugated tubular element ( 112 ); and 
 pulling and cutting the continuous support ( 111 ) thus formed, to obtain a surface absolutely perpendicular to the axis of the support ( 111 ).