Knitted Spacer Fabric And Method For Producing Same

Abstract

The invention relates to a knitted spacer fabric (10) and a method for producing same. The knitted spacer fabric (10) has a first layer (11) formed by stitches (13), a second layer (12) formed by stitches (13), and connection threads (21), which connect the two layers (11, 12) arranged at a distance from one another in a height direction (H). At least one predetermined separation point (22) is formed in each layer, at which point the tensile strength is reduced. The stitches (13) are formed in each case by a thread bundle comprising a first thread (16) and a second thread (17). The threads (16, 17) have different physical and/or chemical properties, for example different melting points, different resistances to alkaline or acidic agents, etc. The second thread (17) can thus be selectively severed at the at least one predetermined separation point (22) or weakened in respect of its tensile strength, whereas the at least one first thread (16) is not severed at the predetermined separation point (22) and preferably does not experience a significant reduction of its tensile strength.

1 . A knitted spacer fabric ( 10 ) comprising:
 a first layer ( 11 ) comprising first layer stitches ( 13 ) and a second layer ( 12 ) comprising second layer stitches ( 13 ), wherein the first layer stitches ( 13 ) and the second layer stitches ( 13 ) form wales ( 14 ) in a longitudinal direction (L) and form courses ( 15 ) in a transverse direction (Q) at right angles to the longitudinal direction (L),   wherein the first layer stitches ( 13 ) and the second layer stitches ( 13 ) stitches ( 13 ) are formed by a thread bundle comprising a first thread ( 16 ) and a second thread ( 17 ), which are placed side by side without direct connection,   wherein the first layer ( 11 ) and the second layer ( 12 ) are arranged at a distance from one another and are connected to one another by connection threads ( 21 ) in a height direction (H) at right angles to the longitudinal direction (L) and the transverse direction (Q),   wherein the second thread ( 17 ) is severed and/or weakened in respect of its tensile strength in the first layer ( 11 ) and the second layer ( 12 ) along at least one predetermined separation point ( 22 ).   
     
     
         2 . The knitted spacer fabric according to  claim 1 , wherein the first thread ( 16 ) and the second thread ( 17 ) are made of different materials. 
     
     
         3 . The knitted spacer fabric according to  claim 1 , wherein the first thread's ( 16 ) material has a higher melting point than the second thread's ( 17 ) material. 
     
     
         4 . The knitted spacer fabric according to  claim 1 , wherein the first thread's ( 16 ) material has a better alkali resistance than the second thread's ( 17 ) material. 
     
     
         5 . The knitted spacer fabric according to  claim 1 , wherein the first thread's ( 16 ) material has a better acid resistance than the second thread's ( 17 ) material. 
     
     
         6 . The knitted spacer fabric according to  claim 1 , wherein one or both of the first layer ( 11 ) and the second layer ( 12 ) are formed without weft threads. 
     
     
         7 . The knitted spacer fabric according to  claim 1 , wherein the connection threads ( 21 ) do not cross a predetermined separation space ( 25 ) defined by paired predetermined separation points ( 22 ) of the at least one predetermined separation point ( 22 ) in the first layer ( 11 ) and the second layer ( 12 ). 
     
     
         8 . The knitted spacer fabric according to  claim 1 , wherein a connection thread ( 21 ) of the connection threads ( 21 ), which crosses a predetermined separation space ( 25 ) defined by paired predetermined separation points ( 22 ) of the at least one predetermined separation point ( 22 ) in the first layer ( 11 ) and the second layer ( 12 ), is made of a same material as the second thread ( 16 ). 
     
     
         9 . A method for producing a knitted spacer fabric ( 10 ) according to  claim 1 , said method comprising:
 producing the knitted spacer fabric ( 10 ) comprising the first layer ( 11 ), the second layer ( 12 ) and the connection threads ( 21 ) connecting the the first layer ( 11 ) and the second layer ( 12 ),   generating the at least one predetermined separation point ( 22 ) in the first layer ( 11 ) and/or the second layer ( 12 ) by weakening the at least one second thread ( 17 ) along the at least one predetermined separation point ( 22 ), wherein the weakening is achieved by a physical and/or chemical influence.   
     
     
         10 . The method according to  claim 9 , wherein the influence comprises introduction of energy into the at least one second thread ( 17 ) along the at least one predetermined separation point ( 22 ). 
     
     
         11 . The method according to  claim 9 , wherein the influence comprises application of a chemical agent to the at least one second thread ( 17 ) along the at least one predetermined separation point ( 22 ).