Apparatus and method for realizing a web of fibrous material

Abstract

An apparatus for producing a web of fibrous material, characterised by comprising: includes a roll having incisions with a depth of 0.01-2.00 mm a width of 0.01-2.00 mm and a pitch 0.01-10.00 mm, and rotated at a peripheral velocity v 1 equal to the velocity of an upstream apparatus unit; a belt stretched between transmission rollers that advances at a velocity v 2 less than v 1 where v 1 /v 2 lies between 1.05 and 1.40; a presser roller rotating at a peripheral velocity v 2 , associated with a presser system acting to press the belt against said the metal roll with a pressure between 1 kg and 200 kg per centimeter; a system that feeds a sheet of pliable fibrous material between the belt and the roll, the belt elongating longitudinally no more than 5% dimensional stability along its entire length, and thickness between 1 cm and 10 cm, and hardness between 24° Shore and 70° Shore.

The invention claimed is: 
     
         1 . An apparatus for producing a web of fibrous material, comprising:
 a roll ( 2 ) of metal material having a lateral surface provided with incisions ( 4 ) having a circumferential component, the roll rotating at a peripheral velocity v 1  equal to a velocity of an upstream apparatus unit, said incisions ( 4 ) having   a depth of 0.01-2.00 mm,   a width of 0.01-2.00 mm, and   a pitch 0.01-10.00 mm,   at least one belt ( 8 ,  8 ′) of a compressible elastic material stretched between transmission rollers ( 10 ) and made to advance at a velocity v 2  less than the peripheral velocity v 1  of said metal roll ( 2 ), where v 1 /v 2  lies between 1.05 and 1.40;   at least one presser roller ( 12 ,  12 ′) of metal material rotating at a peripheral velocity v 2 , associated with a presser system acting to press said belt ( 8 ) against said metal roll ( 2 ) with a pressure between 1 kg and 200 kg per centimeter width of a contact band between said belt ( 8 ,  8 ′) and said metal roll ( 2 ); and   a system feeding a sheet ( 6 ) of pliable fibrous material between said belt ( 8 ,  8 ′) and said metal roll ( 2 ),   said belt ( 8 ,  8 ′) having a degree of elongability in a longitudinal direction not exceeding 5% at least on that side intended to adhere to said presser roller ( 12 ,  12 ′), dimensional stability along its entire length, thickness between 1 cm and 10 cm, and hardness between 24° Shore and 70° Shore.   
     
     
         2 . An apparatus as claimed in  claim 1 , further comprising:
 two belts ( 8 ,  8 ′) of compressible elastic material, made to advance respectively at velocities v 2  and v 3  where v 3 <v 2 , both less than the peripheral velocity v 1  of said metal roll ( 2 ), where v 1 /v 2  and v 1 /v 3  independently lie between 1.05 and 1.40, and also comprising   two presser rollers ( 12 ,  12 ′) rotating with peripheral velocities v 2  and v 3  and acting to press the respective belt ( 8 ,  8 ′) against said metal roll ( 2 ).   
     
     
         3 . An apparatus as claimed in  claim 2 , wherein said metal roll ( 2 ) is provided with a covering layer of material of different characteristics related to specific requirements of the web of fibrous material to be obtained. 
     
     
         4 . An apparatus as claimed in  claim 3 , wherein said metal roll ( 2 ) is covered with a layer of ceramic material. 
     
     
         5 . An apparatus as claimed in  claim 1 , wherein said incisions ( 4 ) extend circumferentially. 
     
     
         6 . An apparatus as claimed in  claim 1 , wherein said incisions ( 4 ) extend in spiral form. 
     
     
         7 . An apparatus as claimed in  claim 1 , wherein said incisions ( 4 ) are continuous. 
     
     
         8 . An apparatus as claimed in  claim 1 , wherein said incisions ( 4 ) are discontinuous. 
     
     
         9 . An apparatus as claimed in  claim 1 , wherein said incisions ( 4 ) have:
 a depth of 0.05-0.50 mm,   a width of 0.07-0.9 mm, and   a pitch of 0.125-1.25 mm.   
     
     
         10 . An apparatus as claimed in  claim 6 , wherein said spiral incisions ( 4 ) have an inclination not exceeding 45° to circumferential lines. 
     
     
         11 . An apparatus as claimed in  claim 1 , wherein said presser system acts to press said belt ( 8 ,  8 ′) against said metal roll ( 2 ) with a pressure between 20 kg and 40 kg. 
     
     
         12 . An apparatus as claimed in  claim 1 , wherein said belt ( 8 ,  8 ′) of elastically compressible material has a thickness between 2.5 cm and 5.0 cm. 
     
     
         13 . An apparatus as claimed in  claim 1 , wherein said belt ( 8 ,  8 ′) of elastically compressible material has a hardness between 29° Shore and 50° Shore. 
     
     
         14 . A method for producing a web of fibrous material, comprising:
 feeding a sheet ( 6 ) of pliable fibrous material between a metal roll ( 2 ) rotated at a peripheral velocity v 1 , and having a lateral surface provided with incisions ( 4 ) extending with a circumferential component and having   a depth of 0.05-0.50 mm,   a width of 0.07-0.9 mm, and   a pitch of 0.125-1.25 mm,   and at least one belt ( 8 ,  8 ′) of elastically compressible material configured to elongate in a longitudinal direction by not more than 5% at least on a side opposite that in contact with said sheet ( 6 ) of fibrous material, said belt having dimensional stability along its entire length, said belt ( 8 ,  8 ′) further having a thickness between 1 cm and 10 cm, and hardness between 24° Shore and 70° Shore;   advancing said belt ( 8 ,  8 ′) at a velocity less than a peripheral velocity of said metal roll ( 2 ), a ratio between the velocities of said belt and said metal roll being between 1.05 and 1.40; and   maintaining said belt ( 8 ,  8 ′) pressed against said roll ( 2 ) with a pressure between 1 kg and 200 kg per each centimeter of width of a band of contact between said belt ( 8 ,  8 ′) and said roll ( 2 ).   
     
     
         15 . A method as claimed in  claim 14 , wherein maintaining said belt ( 8 ,  8 ′) pressed against said roll ( 2 ) comprises maintaining said belt ( 8 ,  8 ′) pressed against said metal roll ( 2 ) with a pressure between 20 kg and 40 kg. 
     
     
         16 . A method as claimed in  claim 14 , wherein said belt ( 8 ,  8 ′) has a hardness between 29° and 50° Shore. 
     
     
         17 . A method as claimed in  claim 14 , wherein said belt ( 8 ,  8 ′) has a thickness between 2.5 cm and 5 cm.