Plate sleeve-holder cylinder made of carbon-fibre composite material for flexographic printing and including compressed air channels
A plate sleeve-holder cylinder provided with a carbon-fibre central tube (T) comprising compressed air channels ( 6, 7, 8 ) arranged between one of the end flanges (Fb, Fm) of said plate sleeve-holder cylinder and a plurality of holes (H) formed in the outer surface of said central tube (T) made of carbon-fibre composite material. Said air channels ( 6, 7, 8 ) are partly embedded within said end flanges (Fb, Fm), partly within a thickness of a side wall (P) of said central tube (T) made of carbon-fibre composite material. Additionally, a process of manufacturing said central tube (t) is disclosed by inserting air pipes ( 6 ) into grooves ( 1 ) which are formed by mechanical milling of a surface of the supporting structure (P) of said central tube (T) obtained through a first lamination and polymerization, said grooves being coated with a surface finishing structure (S) obtained through a second lamination and polymerization.
1. A plate sleeve-holder cylinder for flexographic printing comprising:
a carbon-fibre central tube (T) and first and second flanges (Fb, Fm) respectively provided on each end of said carbon-fibre central tube (T);
compressed air channels ( 6 , 7 , 8 ) arranged between one of the first and second flanges (Fb, Fm); and
a plurality of vent holes (H) formed in the outer surface of said central tube (T) made of carbon-fibre composite material, in order to ease an insertion of sleeves onto said plate sleeve-holder cylinder;
wherein said air channels ( 6 , 7 , 8 ) are partly embedded within said first and second flanges (Fb, Fm), and partly embedded within a thickness of a side wall of said central tube (T) made of carbon-fibre composite material.
2. The plate sleeve-holder cylinder of claim 1 , wherein the portion of said air channels ( 6 , 7 , 8 ) embedded within the thickness of the side wall of said central tube (T) of carbon-fibre composite material comprises one or more air pipes ( 6 ) housed in grooves ( 1 ) formed in a supporting structure (P) of the side wall of said central tube (T).
3. The plate sleeve-holder cylinder of claim 2 , wherein a filling material ( 5 ) takes up a residual space of said grooves ( 1 ) housing an air pipe ( 6 ).
4. The plate sleeve-holder cylinder of claim 3 , wherein said filling material ( 5 ) comprises monodirectional resin-impregnated carbon fibres.
5. The plate sleeve-holder cylinder of claim 2 , wherein said one or more air pipes ( 6 ) comprises a thin layer ( 2 ) of carbon fibre, previously wrapped on a metal mandrel ( 3 ) and removed therefrom or wrapped on an embedded tubular insert ( 4 ) made of plastic or metal material.
6. The plate sleeve-holder cylinder of claim 2 , wherein said plate sleeve-holder cylinder further comprises a coating layer (S) of resin-impregnated carbon-fibre fabric which covers the entire outer surface of said plate sleeve-holder cylinder and said grooves ( 1 ) housing the air pipes ( 6 ).
7. The plate sleeve-holder cylinder of claim 2 , wherein said grooves ( 1 ) are straight and parallel to the axis of said central tube (T) made of carbon-fibre composite material.
8. The plate sleeve-holder cylinder of claim 2 , wherein said one or more air pipes ( 6 ) are connected to each other and to an external valve (V) supplying compressed air, by means of air channels ( 7 ) formed within said first flange (Fb) which forms the base end of said plate sleeve-holder cylinder.
9. The plate sleeve-holder cylinder of claim 8 , wherein an air channel ( 8 ) having a circular shape, which puts the air pipes ( 6 ) in communication with each other, is formed in said second flange (Fm) which closes the opposite end of the plate sleeve-holder cylinder, where the sleeves are inserted, said air channel ( 8 ) being provided with a plurality of radial vent holes (K) opening onto the external lateral surface of the second flange (Fm).