Study On Production Technology Of Continuous/Long Glass Fiber Reinforced Thermoplastic Polymer Composites

Continuous/long glass fiber reinforced thermoplastic polymer composites which have high strength, high modulus and good dimensional stability, has been widely used in recent years. The study of production and processing technology which relate to LFR composite has gained rapid development. Two melt impregnation dies which have roll type and tooth type structure have been designed and manufactured to prepare continuous/long glass fiber reinforced thermoplastic polymer composites by melt impregnation process. Polypropylene and Polyamide6(PA6) were selected as matrix, two melt impregnation dies were selected as basic apparatuses, double screw extrusion mechanism was selected as main equipment, long glass fiber reinforced polypropylene and Polyamide6(PA6) were prepared. Through the analysis of the mechanical properties and sectional microstructure of the composites, the effect of organic peroxides, melt flow rate, glass fiber content, coupling agent type, compatibility agent content and die structure on impregnation and mechanical properties of the composites were discussed. Firstly, through the study of the melt impregnation process, a theoretical model of melt impregnation was established, as a guide, Adhering to the concept of optimizing the impregnation process and expanding the application of the device, two melt impregnation device, connecting device and pre-dispersed device were designed and manufactured. Two devices are different, take advantage of the impregnation of roll type and tooth type structure, the effective combination of different modules which made the die structure simple, easy to combine, easy to debug, with good impregnation, stable production and strong continuity. LGF-PP/PA6with excellent performan-ce were prepared by the designed melt impregnation device and achieved the design goal.Secondly, factors on mechanical properties of PP-LGF composites were studied. With DCP content increased the melt viscosity of polymer decreased that got an easier impregnation, but the mechanical properties of PP-LGF declined. When the DCP content was0.1%,50%glass fiber of PP-LGF with151MPa tensile strength, get good mechanical properties. With the increase of glass content, the mechanical properties of PP-LGF the mechanical properties of PP-LGF increased, but increased amplitude decreases, when the glass content of50%, the obtained PP-LGF composites had better mechanical properties and easier processing. The add of coupling agent that improved the interfacial bonding of glass fiber and polymer matrix.SEM found a better binding interface of PP-LGF which is treated by silane coupling agent KH550.Roll type and tooth type structure both obtained good production and the same impregnation which could be seen by SEM.Finally, factors on mechanical properties of PA6-LGF composites were studied. With Glass fiber content increased the mechanical properties of PA6-LGF improved. When glass fiber content was35%-40%, the obtained PA6-LGF with more than190Mpa tensile strength had good mechanical properties and easy impregnation. The add of compatibilizer which increased the binding between polymer and glass fibers, with the increase of PP-g-MAH content, the tensile strength of PA6-LGF composite first increases and then decreases,2%-5%content of the compatibilizing agent obtained better tensile properties, melt impregnation die with tooth type structure reflects its own advantages in the preparation of high viscosity PA6-LGF composites, SEM revealed better impregnation than roll type structure. It provided a reference for the production and promotion.