Pore Structure And Mechanical Properties Of Light-weight Fiber Reinforced Thermoplastic Composites

Light-weight fiber reinforced thermoplastic-ccomposites(LWRT)is one kind of new composites with porous structure.The structure not only make LWRT to be used for sound absorption and noise reduction,but also make it to have the advantages such as short molding period,easy to processing,large design freedom,light-weight and so on,which is superior than glass mat reinforced thermoplastics(GMT).LWRT promotes the development of composite and widens the applications.In this thesis,bubbling test is used to measure pore size and distribution and volume calculation is used to measure porosity.The influence of premix structure parameters on pore structure was studied and the change of pore structure from online LWRT to reconstruction LWRT was researched.The mechanical properties of LWRT with several variables,such as GF content,GF length,needling density and reconstrucution,have been measured and researched under the target of the optimum mechanical properties.The parameters of LWRT preparation have been optimized.This thesis provides one solution to design LWRT for different requirements.The results revealed that the GF content and GF length of LWRT with optimum comprehensive mechanical properties was 50wt%and 100 mm,respectively.In the mixed fiber felt impregnation,optimum needling density is 15st/cm2,while in the film impregnation,the needling process could be omitted.LWRT have more well-distributed pore structure and lower porosity after reconstruction,so that general mechanical properties are improved.