Co-mingling of particulate material and co-axial-meltblown fibers

Abstract

The present invention relates to the manufacturing equipment for web materials comprising fibers and particulate material, to a process of operating such an equipment and to particular materials resulting therefrom. Coaxially meltblown fibres are combined with a stream of particulate or short fiber material and the resulting commingled mixture is deposited onto a collector. The meltblown fibers are formed by nozzles which are divided into two or more sub-arrays configured to produce two or more different types of fiber, having e.g. different diameters and/or polymer composition.

1 . A web forming apparatus configured to form a commingled web comprising:
 a particulate material supply system oriented to deliver a vertically downwardly moving stream of particulate material;   at least one polymer supply system providing polymer material to a first and a second multi-row CA-meltblowing system, wherein the first and second multi-row CA-meltblowing system each comprise an array of polymer releasing orifices comprising at least two cross-directionally extending rows of polymer releasing orifices;   a forming box comprising: a particulate material inlet connected to the particulate material supply system, two CA-meltblown fiber inlets each connected to one of the CA-meltblowing systems, and a commingled material outlet;   a collector configured to move along a machine direction of the apparatus;   wherein each one of the CA-meltblowing inlets of the forming box is positioned machine-directionally before (“upstream”) and after (“downstream”) the particulate material inlet;   wherein the arrays of polymer releasing orifices each comprise at least a first and a second sub-array, each first and second sub-array comprises at least one row of orifices;   wherein the orifices of at least one first and second sub-arrays release fibers of different properties than the orifices of at least one different first and second sub-array;   wherein the one or more properties are at least one of:
 a. the orifices of the first and second sub-arrays exhibiting differing orifice diameters; 
 b. the orifices of the first and second sub-arrays are connected to polymer supply systems for differing polymer types; 
 c. the orifices of the first and second sub-arrays are connected to polymer supply systems for differing polymers throughput; 
 d. the orifices of the first and second sub-arrays are connected to polymer supply systems for differing polymer supply pressure; or 
 e. the orifices of the first and second sub-arrays are connected to independent temperature control systems. 
   
     
     
         2 . An apparatus according to  claim 1 , comprising a quenching system comprising
 a first quenching device machine directionally positioned upstream of the first multi-row CA-meltblowing system;   a second quenching device machine directionally positioned between the first multi-row CA-meltblowing system and the particulate material inlet;   a third quenching device machine directionally positioned between the particulate material inlet and the second multi-row CA-meltblowing system;   a fourth quenching device machine directionally positioned downstream of the second multi-row CA-meltblowing system;   each of the first, second, third and fourth quenching devices configured to release a first, second, third, and fourth quenching fluid stream, respectively, into the forming box; and   the first, second, third and fourth quenching devices comprising quenching fluid stream control systems configured to control properties of at least one of the first, second, third and fourth quenching fluid streams independently from at least one other of the first, second, third and fourth quenching fluid streams, by control means of the quenching fluid stream control systems which are at least one of:
 connecting the quenching devices to quenching fluid of different type, preferably selected from the group consisting of air, water, and steam; quenching fluid temperature control means; 
 quenching fluid supply pressure adjustment means; 
 quenching fluid supply flow rate; 
 quenching fluid exit angle relative to CA-meltblowing head; or 
 quenching fluid exit angle relative to particulate material delivery axis. 
   
     
     
         3 . An apparatus according to  claim 1 , comprising at least one of:
 removable nozzles, more preferably chamfered, grooved die heads;   a unitary die head comprising a spinneret block and nozzles;   variable die head angles relative to a die head axis; or   Bica-nozzles connected to separate polymer supply systems.   
     
     
         4 . An apparatus according to  claim 1 , wherein the first and second sub-arrays of both CA-meltblowing systems comprise orifices exhibiting a larger diameter than orifices of the respective other sub-arrays positioned machine directionally towards the particulate material inlet. 
     
     
         5 . An apparatus according to  claim 1 , comprising at least one web forming element positioned upstream of the forming box and configured to extrude filaments and forming scrim layers on outer surfaces of the commingled web. 
     
     
         6 . An apparatus according to  claim 1 , wherein said particulate material comprises pulp fibers as short fibers. 
     
     
         7 . An apparatus according to  claim 1 , wherein said particulate material comprises superabsorbent particles as particles. 
     
     
         8 . An apparatus according to  claim 2 , wherein the quenching fluids of the first, second, third, and fourth fluid streams are at least one of air, water or steam.