Research On The Preparation And Properties Of Superwettability Air Filter Fabric

With the increasingly serious environmental pollution and the enhancement of awareness of people’s environmental protection,air quality has become the focus of attention all over the world.As an important part of air cleaning technology,air filters（AF）are widely used in residential buildings,commercial and industrial buildings,clean rooms,food processing and other fields,which play an increasingly important role in people’s daily life.At present,dust is easily adhered to the filter net when the AF is treated with high humidity or sticky gas.The filter resistance increases and the filtration efficiency decreases,which eventually leads to the decline of the service life of AF.Therefore,AF with low resistance,high efficiency and long life has become an important research direction in this field.The superhydrophobic surface produced by the lotus leaf effect has the advantages of hydrophobicity and self cleaning.The super hydrophobic technology is applied to the surface of the fabric of AF,which can significantly improve the moisture resistance and dustproof of the fabric,thus effectively improving the service life of AF.Therefore,the research on preparation,moisture-proof and dust-proof properties and durability of superhydrophobic air filtration fabric has been carried out.Superhydrophobic PET fabric was prepared by dipping in a resin-hydrophobic silica solution.as contrast the dustproof of market’s filter and superhydrophobic fabric,it was found that the superhydrophobic fabric has good dustproof properties.The resulting composite coating,in which strong micro-nano scale roughness structure is embedded in the fiber,can withstand 20 cycles water flushing.Moreover,treated PET fabric also shows significantly high resistance to acid/alkali.Using two step dip coating method which dipped resin and SiO₂ superhydrophobic coating prepared superhydrophobic fabric（SHF）with CA of 158°and rolling angle of 6°.The basic properties of SHF,such as resin content,stiffness,tensile strength and air permeability,are in accordance with the requirements of the air filter.In addition,SHF has great durability.its contact angle is still151°after 50 times fingers grinding;SHF can withstand 20 times water flushing,and after SHF was soaked in pH=1-11 acid/alkali solution,the contact angle is maintained at 150 degrees,it shows good corrosion resistance;Meanwhile,SHF has good thermal stability,its surface still shows superhydrophobicity after 100-300℃treatment.As for moisture proof and dustproof performance,SHF also has good performance.In contrast to the original fabric and SHF in moisture proof,when the test time of moistureproof is 200 min,water absorption rate of SHF is only 1/3 of the original fabric’s;moreover,when the dust test time is 30h,dust increment rate of the original fabric is more10%than that of SHF.The superhydrophobic effect makes the difference between SHF’s and the original fabric’s moisture resistance and dust-proof performance.This also provides data support for the possibility of the application of SHF in the filter field.Through the exploration of influencing factors such as order of raw materials,temperature and fluorocarbon surfactants,the optimum preparation process of waterborne coating is finally determined.The glass fiber fabric is used as a base and it is impregnated in the water superhydrophobic coating,the treated glass fabric shows good hydrophobic and oil repellency.Moreover,durability of hydrophobic and oil repellency glass fiber fabric was studied,treated glass fiber fabrics can withstand 100 times fingers grinding and pH 1-13 acid/alkali solution;at the same time,after 60min ultrasonic test,the treated glass fiber fabric still kept hydrophobic-oleophobic property.In contrast to absorption rate of the original glass fabric and the superhydrophobic glass fiber fabric,the rate of moisture when the time is 120min,the absorption rate of untreated glass fiber fabric is up to about 150%while the treated fabric was only 35%,it indicated that the treated glass fiber fabric has excellent moisture resistance.What’s more,it also found that treated glass fiber fabric also has outstanding the ability of dustproof.