Pneumatic spinning apparatus and spinning method

Abstract

The present invention concerns a spinning method and a spinning apparatus for producing a yarn ( 13 ) from fibres ( 7 ). In a spinning chamber ( 2 ) the fibres ( 7 ) are subject to a rotating air vortex ( 15 ) and in this process are twisted into a yarn ( 13 ) in an inlet opening of a spindle duct ( 11 ) of a spindle ( 12 ). The fibres to be processed ( 7 ) are guided via at least one fibre feed duct ( 20, 21 ) into the spinning chamber ( 2 ). The present invention proposes that fibres ( 17 ), which are not caught into the yarn formation process are eliminated via an exhaust air duct ( 16 ), that these eliminated fibres ( 17 ) are regenerated, and that the regenerated fibres ( 17 ) are fed back into the yarn forming process.

1 . Method of producing a yarn ( 13 ) from fibres ( 7 ) in a spinning chamber ( 2 ), which fibres ( 7 ) are subject to a rotating air vortex ( 15 ) and thus are twisted into a yarn ( 13 ) in an inlet opening of a spindle duct ( 11 ) of a spindle ( 12 ) arranged in the spinning chamber ( 2 ), the fibres ( 7 ) being guided through at least one fibre supply duct ( 20 ,  21 ) into the spinning chamber ( 2 ), characterised in that 
 a) Fibres ( 17 ) not caught in the yarn forming process are separated from an exhaust air duct ( 16 );    b) The separated fibres ( 17 ) are fed back into the yarn forming process.    
     
     
         2 . Method according to the  claim 1 , characterised in that the separated fibres ( 17 ) are regenerated, in which process they are freed of any thrash particles and, if required, are aligned.  
     
     
         3 . Method according to the  claim 1  or  2 , characterised in that the fibres ( 17 ) are separated from the exhaust air stream using a circulating endless filter tape ( 50 ).  
     
     
         4 . Method according to the  claim 3 , characterised in that using the circulating endless filter tape ( 50 ) the separated fibres ( 17 ) are moved to a suction roll ( 51 ).  
     
     
         5 . Method according to the  claim 4 , characterised in that the suction roll ( 50 ) co-operates with a fibre opening means ( 30 ).  
     
     
         6 . Method according to the  claim 5 , characterised in that the suction roll ( 50 ) serves for feeding in the eliminated fibres ( 17 ) into the second fibre supply duct ( 20 ).  
     
     
         7 . Method according to one of the preceding claims, characterised in that the fibres ( 7 ) to be processed are guided through a first fibre supply duct ( 21 ) and the separated fibres ( 17 ) are guided through a second fibre supply duct ( 20 ) into the spinning chamber ( 2 ).  
     
     
         8 . Method according to the  claim 7 , characterised in that the separated fibres ( 17 ) using the second fibre supply duct ( 20 ) are fed into the centre of the rotating air vortex ( 15 ).  
     
     
         9 . Method according to the  claim 2 , characterised in that the fibres ( 17 ) separated from the exhaust air stream are transferred, in order to be regenerated, to a fibre preparing means ( 30 ), where they are blended with fibres ( 7 ) to be processed and jointly with these are prepared for the yarn forming process.  
     
     
         10 . Method according to the  claim 9 , characterised in that the fibre preparing means ( 30 ) is a drafting system.  
     
     
         11 . Method according to the  claim 9 , characterised in that the fibre preparing means ( 30 ) is a fibre opening means, which fibre opening means comprises a feed roll ( 32 ), an opening roll ( 33 ) and a suction roll ( 34 ).  
     
     
         12 . Method according to the claims  7 , characterised in that the regenerated fibres ( 17 ) are fed in at the zone of the feed roll ( 32 ) and/or of the opening roll ( 33 ).  
     
     
         13 . Spinning apparatus ( 1 ) for implementing the method according to the  claim 1 , with a spinning chamber ( 2 ), at least one fibre supply duct ( 21 ) merging into the spinning chamber ( 2 ) serving for feeding in fibres ( 7 ) to be processed, a spindle ( 12 ) arranged in the spinning chamber ( 2 ) presenting a spindle duct ( 11 ), which spindle duct ( 11 ) serves for taking off a yarn ( 13 ) spun, and an exhaust air duct ( 16 ), characterised by means ( 50 ) serving for separating fibres ( 17 ) present in the exhaust air duct ( 16 ) and by means ( 37 ,  50 ) serving for feeding the separated fibres ( 17 ) back into the spinning process.  
     
     
         14 . Spinning apparatus according to the  claim 13 , characterised in that the means for separating the fibres ( 17 ) is a circulating endless filter tape ( 50 ).  
     
     
         15 . Spinning apparatus according to the  claim 14 , characterised in that a suction roll ( 51 ) is provided for taking over the fibres ( 17 ) from the filter tape ( 50 ).  
     
     
         16 . Spinning apparatus according to one of the claims  13  through  15 , characterised in that the means for feeding back the separated fibres is a second fibre supply duct ( 20 ) serving for feeding the separated fibres ( 17 ) into the spinning chamber ( 2 ).  
     
     
         17 . Spinning apparatus according to the  claim 16 , characterised in that the second fibre supply duct ( 20 ) is arranged in such a manner that the separated fibres are fed into the centre of a rotating air vortex ( 15 ).  
     
     
         18 . Spinning apparatus according to the  claim 16  or  17 , characterised in that the first and/or the second fibre supply duct ( 20 ,  21 ) are laid out in such a manner that unwanted twisting of the fibres ( 7 ,  17 ) is prevented.  
     
     
         19 . Spinning apparatus according to the  claim 16 , characterised in that the first and/or the second fibre supply duct ( 20 ,  21 ) present a bend or an angle.  
     
     
         20 . Spinning apparatus according to one of the claims  13  through  19 , characterised in that the at least one fibre supply duct ( 20 ,  21 ) is provided with a fibre delivery edge.  
     
     
         21 . Spinning apparatus according to one of the claims  13  through  19 , characterised in that the at least one fibre supply duct ( 20 ,  21 ) merges into an essentially conical fibre guide surface.  
     
     
         22 . Yarn ( 13 ) produced according to one of the method claims  1  through  12 , characterised in that in the centre of the yarn cross-section fibres ( 17 ) are arranged, which mainly were supplied from the second fibre supply duct ( 20 ), and which are surrounded by fibres ( 7 ), which mainly were supplied from the first fibre supply duct ( 21 ).