High dielectric non-woven fabrics and their synthetic process

Abstract

The present invention relates to high dielectric non-woven fabrics and their synthetic process. Particularly, the present invention relates to a process for preparing high dielectric non-woven fabrics comprising the steps of (a) mix-spinning polyvinylidene fluoride (PVDF) and polypropylene (PP) to prepare a fiber, (b) polarizing the fiber prepared in the step (a) to improve the dielectric constant of the fiber, and (c) manufacturing non-woven fabrics from the fiber having improved dielectric constant, prepared in the step (b), and non-woven fabrics prepared according to the mentioned process. The non-woven fabrics of the present invention have very improved static electricity retention properties compared to the dielectric non-woven fabrics of the prior art. Thus, when they are applied to an electrostatic filter or sweeper, they can be made into an electrostatic filter that has a longer life time and excellent filtration efficiency for micro-particles and ionic particles, or to a sweeper that has high static electricity retention property and longer life time.

What is claimed is:  
     
         1 . A process for preparing high dielectric non-woven fabrics comprising the steps of 
 (a) mix-spinning polyvinylidene fluoride (PVDF) and polypropylene (PP) to prepare fiber;    (b) polarizing the mentioned fiber prepared in the step (a) to enhance the dielectric constant of the fiber; and    (c) manufacturing non-woven fabrics from the fiber having an improved dielectric constant prepared in the step (b).    
     
     
         2 . A process for preparing high dielectric non-woven fabrics according to  claim 1 , wherein, in the step (a), the contents of polyvinylidene fluoride is 1 to 20 wt % by weight and the contents of polypropylene is 99 to 80 wt %.  
     
     
         3 . A process for preparing high dielectric non-woven fabrics according to  claim 1 , wherein the thickness of the fiber prepared in the step (a) is 5 to 20 μm.  
     
     
         4 . A process for preparing high dielectric non-woven fabrics according to  claim 1 , wherein the density of the non-woven fabrics prepared in the step (c) is 30 to 600 g/m 2 .  
     
     
         5 . A process for preparing high dielectric non-woven fabrics according to  claim 1  further comprising the step of plasma treating, corona discharging or ion beam treating the non-woven fabrics prepared in the step (c), after step (c).  
     
     
         6 . A process for preparing high dielectric non-woven fabrics according to  claim 1 , wherein inorganic antibacterial compounds are added when mix-spinning in the step (a).  
     
     
         7 . High dielectric non-woven fabrics prepared according to any one of  claims 1  to  6 .  
     
     
         8 . An electrostatic filter made from the non-woven fabrics of  claim 7 .  
     
     
         9 . A sweeper made from the non-woven fabrics of  claim 7.