System and process for making a polymeric fiberous material having increased beta content

Abstract

A system and process for making a polymeric fibrous material having increased beta content is provided herein. The system is configured for meltblowing polymer into a fibrous material having high beta crystalline content and has an extruder for melting and moving a polymer to a meltblowing die. The meltblowing die has a longitudinally extending die tip with a plurality of spinnerets substantially equidistantly spaced from each other and a longitudinal fluid material flow through passage disposed along each longitudinal side of the die tip configured to axially attenuate the melted polymer from the die tip in fibrous form. A plurality of liquid spray nozzles are configured and disposed to spray a liquid into the fibrous melted polymer attenuated from the die tip.

1 . A system configured for meltblowing polymer into a fibrous material having high beta crystalline content, the system comprising:
 an extruder configured for extruding and moving melted polymer to a meltblowing die;   a receiver configured for receiving the melted polymer from the extruder with a plurality of longitudinally extending die tips, each die tip having a spinneret;   an attenuator configured for attenuating melted polymer axially from the plurality of spinnerets;   a longitudinal fluid material flow through passages disposed along each longitudinal side of each die tip and configured for flowing hot air therethrough and contacting the melted polymer at the spinneret;   a polymer outlet configured for axially attenuating the melted polymer from each spinneret in fibrous form:   a sprayer proximate each die tip, each sprayer being configured for spraying a substantial amount of liquid at an angle between about 20° and about 85° toward the attenuation axis of the die tip it is proximate therewith and into the fibrous melted polymer, immediately upon being attenuated from the proximate die tip; and   a collector configured for collecting the fibers attenuated from each spinneret.   
     
     
         2 . The system for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 1  further comprising an insulating material disposed along an outer longitudinal side of each longitudinal fluid material flow through passage. 
     
     
         3 . The system for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 1 , wherein each sprayer is configured for spraying at least about 280 cc/min of liquid toward the attenuation axis of its proximate die tip. 
     
     
         4 . The system for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 1 , wherein each sprayer is configured for spraying the liquid at a common direction toward the attenuation axis of its proximate die tip. 
     
     
         5 . The system for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 3 , wherein each sprayer is configured for spraying the liquid at an angle of about 40° toward the attenuation axis of its proximate die tip. 
     
     
         6 . The system for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 1 , wherein each sprayer is configured for spraying the liquid in droplets having a diameter of less than 150 μm. 
     
     
         7 . The system for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 1  being configured for meltblowing polymer into the fibrous material having at least a 50% increase in tensile stress in a transverse direction and at least a 30% increase in tensile stress in a machine direction, as compared to a system void of the sprayers. 
     
     
         8 . The system for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 7  being configured for meltblowing polymer into the fibrous material having at least a 100% increase in a percent elongation to break in both a machine direction and a transverse direction, as compared to a system void of the sprayers. 
     
     
         9 . The system for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 1  further comprising a blender configured for blending a Hindered Amine Light Stabilizer with the polymer. 
     
     
         10 . The system for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 1  further comprising a blender configured for blending a Hindered Amine Light Stabilizer and an antioxidant with the polymer. 
     
     
         11 . The system for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 9  being configured for forming a web having a greater elongation to break than a system void of the blender configured for blending a Hindered Amine Light Stabilizer with the polymer. 
     
     
         12 . The system for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 10  being configured for forming a web having a greater elongation to break than a system void of the blender configured for blending a Hindered Amine Light Stabilizer and an antioxidant with the polymer. 
     
     
         13 . A system configured for meltblowing polymer into a fibrous material having high beta crystalline content, the system comprising:
 an extruder configured and disposed to melt a solid polymer and move the melted polymer to a meltblowing die;   at least one meltblowing die configured and disposed to receive the melted polymer from the extruder and comprising:
 a longitudinally extending die tip having a plurality of spinnerets substantially equidistantly spaced from each other configured to axially attenuate the melted polymer therefrom; and 
 a longitudinal fluid material flow through passage disposed along each longitudinal side of the die tip configured to axially attenuate the melted polymer from the die tip in fibrous form; 
   the system further comprising a plurality of liquid spray nozzles each configured and disposed spray liquid at an angle and at a volumetric flow rate sufficient to increase a meltblowing production rate of fibrous material; and   a collector configured and disposed to collect the meltblown fibers from each die tip.   
     
     
         14 . The system configured for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 13  further comprising an insulating material disposed along an outer longitudinal side of each longitudinal fluid material flow through passage. 
     
     
         15 . The system configured for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 13 , wherein each liquid spray nozzle is disposed to spray the liquid at a common direction toward the attenuation axis of the die tip. 
     
     
         16 . The system configured for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 15 , wherein each liquid spray nozzle has its outlet configured and disposed to spray a substantial amount of liquid at an angle between about 20° and about 85° toward the attenuation axis of the die tip. 
     
     
         17 . The system configured for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 13 , wherein each liquid spray nozzle is configured to spray a liquid therefrom in droplet form having a diameter of less than 150 μm. 
     
     
         18 . The system configured for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 13  being configured to collect fibers on the collector having beta crystalline content of at least a detectable beta content, as detected by an x-ray detection technique. 
     
     
         19 . The system configured for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 18  being configured to collect fibers on the collector having at least a 100% increase in a percent elongation to break in both a machine direction and a transverse direction as compared to a system void of the liquid spray nozzles. 
     
     
         20 . The system configured for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 18  being configured to collect fibers on the collector having at least a 50% increase in tensile stress in a transverse direction and at least a 30% increase in tensile stress in a machine direction, as compared to a system void of the liquid spray nozzles. 
     
     
         21 . The system configured for meltblowing polymer into a fibrous material having high beta crystalline content of  claim 13 , wherein the extruder is configured for blending polypropylene with at least one of Hindered Amine Light Stabilizers and antioxidants. 
     
     
         22 . A fibrous mat of meltblown polymers having beta crystalline content of at least a detectable beta content, as detected by an x-ray detection technique, and at least a 50% increase in tensile stress in a transverse direction and at least a 30% increase in tensile stress in a machine direction, as compared a fibrous mat of meltblown polymers not having a detectable beta crystalline content, as detected by an x-ray detection technique.