Study On The Composite Sound Absorption And Thermal Insulation Nonwovens With Micro/Nano Fibers

Nonwovens occupy a certain proportion in the applications of most industrial textiles,and have occupied a large proportion in the fields of health,filtration,construction and automobile.Among them,the thermal insulation nonwovens and sound absorption nonwovens have great potential in the fields of construction and automobile owing to the advantages of simple process,low cost,safety,no pollution and good effect.Therefore,with the innovation of technology,the development of new thermal insulation nonwoven and sound absorption nonwovens attracts more and more attention.However,thermal insulation nonwoven and sound absorption nonwovens with single raw material or simple structure often have some drawbacks,such as heavy shape,single performance and common effect.Therefore,this paper will develop a brand new non-woven materials with high thermal effect,good sound absorption and thinner shape by combining the Nanofiber membrane and melt blown nonwovens.The main research and analysis is as follows:(1)Firstly,the admixture melt blown nonwovens is prepared with different grammes per square metre(GSM)by using polypropylene and three-dimensional crimp polyesterthe as the raw material.Polyester is inserted into PP melt blown fiber in the melt blown process by air pressure to cotton.Based on changing the net curtain speed of melt blown equipment and conveying the speed of three-dimensional crimp polyester staple to change the GSM of the admixture melt blown nonwovens.And by testing air permeability,compression performance,warmth retention performance and sound absorption performance to research the function of the change of GSM.(2)Then the nanoscale membrane is prepared by the nano spider spinning mechanism with PAN solution as the raw material.By changing the transmission speed of the receiving device to change the surface density of the nanofiber membrane;changing the spinning voltage of the nano spider electrospinning machine to change the fiber fineness.By testing its surface density,porosity and fiber fineness to analyze the nanoscale membrane's structure.(3)Finally,the admixture melt blown nonwovens and PAN nanoscale membrane are combined with different schemes to produce a new type of composite nonwovens.A series ofperformance tests are carried out to explore the thermal effect and sound absorption effect of the composite nonwovens when the GSM of the admixture melt blown nonwovens,the density of the nanofiber film surface and the fineness of the nanofibrous fiber is different.It is shown that combining the PAN nanofiber membrane can increase 10%~40% thermal resistance of the admixture melt blown nonwovens when the thickness,weight and compression performance are almost unchanged.And with the decrease of admixture melt blown nonwovens' GSM,the effect of nanofibrous membrane on the thermal resistance is increased.The thermal resistance of the composite nonwovens increases 5%~10% with the increase of the surface density of PAN nanofibers,and the thermal resistance increases 15%~20% with the decrease of the diameter of the PAN nanofiber fiber.What's more,the thermal resistance of the nanofiber membrane contacted with the air side is about 10% higher than that on the side of the nanofiber membrane and the side of the tester.The average sound absorption coefficient of composite nonwovens increased by 20% compared with admixture melts.When the frequency of the incident wave is less than 500 Hz,the sound absorption coefficient changes indistinctly,but when the frequency is higher than 500 Hz,the sound absorption coefficient increases with the surface density of the nanofiber,and increases with the decrease of the nanofiber fiber' diameter.And the absorption coefficient of one side source of nanofiber membrane is slightly higher than that of one side of the nanofiber membrane.When the acoustic frequency is higher than 500 Hz,the sound absorption performance is positively related to the thermal performance.