| Traditional single materials have been difficult to meet the needs of modern society.The functionalization,structuring and lightweight of composite materials are more suitable for the needs of the market and have become the inevitable trend of material development.Thermoplastic composites have gradually replaced thermoset composites due to their high modulus,high strength,high resistance,and high resistance.At present,the flexural strength and flexural modulus of wood-plastic composite building templates on the market are low.In the course of use,there are defects such as easy-to-lose-block damage,easy deformation,and low use frequency.For these problems,this project studied the preparation technology of short glass fiber,long glass fiber,and grid cloth glass fiber reinforced ASA composite sheets.The effects of different preparation techniques and grafting agent content on the properties of the composite sheet were investigated,and the influence of glass fiber content on the properties of the sheet was ascertained.The composite sheet was used as the surface layer and the PVC foamed board was used as the core layer.Three types of glass fiber reinforced ASA/PVC composite boards were developed using on-line compounding and mold lamination techniques.The effects of different preparation processes and surface types on the properties of the composite sheet were examined.The concrete conclusion is as follows:(1)Short glass fiber reinforced ASA composite sheets and sandwich composite sheets were prepared using the on-line compounding method.The effects of temperature,host speed of the twin-screw extruder,grafting content,and short glass fiber content on the properties of the sheet were studied.Through process optimization,the short glass-reinforced ASA sheet was hot-covered on the surface of the PVC foamed sheet,through rapid cold forming,the short-glass-reinforced ASA/PVC composite sheet was prepared.The bending and impact properties of the plate were investigated,and the conclusion was corroborated by the microstructure analysis.When the content of the short glass fiber is 20%,the prepared sandwich composite plate has the best performance,and its bending and impact strength are 26.17 MPa and 5.43 kJ/m2,respectively.(2)Long glass fiber reinforced ASA composite sheets and composite sandwich panels were prepared using the on-line compounding method.First,the main engine speed,feeding speed of twin-screw extruder,and number of fiber bundles used to prepare the long glass fiber composite sheet were determined by experimentation to determine the same content as the short glass fiber.The effects of temperature of twin-screw extruder,content of grafted material and long glass fiber on the properties of sheets were investigated.Using an optimal process,using the composite sheet as the surface layer and the PVC foamed sheet as the core layer,the long glass fiber reinforced ASA/PVC sandwich composite sheet was prepared by on-line compounding technology.The influence of different surface layers on mechanical properties such as bending and impact of composite sheet was Proven.The results show that when the content of long glass fiber is 20%,the prepared composite sandwich plate has the best performance,and its bending and impact strength are 29.59 MPa and 5.61 kJ/m2,respectively.(3)Mesh fiberglass reinforced ASA composite sheet was prepared by compression molding,and the effect of hot pressing temperature,pressure and time on the properties of the composite sheet was studied.The determined optimal process is hot pressing temperature 250?,pressure 5MPa,hot pressing 15min.Using the prepared composite sheet as the surface layer,the mesh cloth glass fiber reinforced ASA/PVC sandwich composite sheet was prepared by hot pressing process.The effects of hot-pressing temperature and hot-pressing time on the bending and impact properties of composite sandwich panels were studied.The bending and impact strengths were 32.71 MPa and 36.67 kJ/m2,respectively.Compared with short glass fiber and long glass fiber reinforced ASA/PVC sandwich panels,the flexural strength and impact strength of mesh fiberglass reinforced ASA/PVC composite sandwich panel were increased by 24.99%,6.75 times and 10.54%,6.54 times respectively.(4)The flexural strength and flexural modulus of the short glass fiber,long glass fiber,and mesh fiberglass reinforced ASA/PVC sandwich composite plates all meet the standards for class ? strength wood composite panels for solid core construction templates,and can replace class ? strength solid wood composite panel construction template. |
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