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电磁动态注射机振动参数对PP力学性能的影响 总被引:3,自引:0,他引:3
采用电磁动态注射机注塑成型PP试样,并对其进行拉伸强度、冲击强度和DSC测试,探讨振动频率和振幅对制品力学性能的影响。结果表明:施加振动后,拉伸强度和冲击强度提高;熔点向高温漂移,有利于结晶完善程度的提高。对PP注塑料,电磁动态注塑成型时最佳的振动参数范围为f=3~9Hz,A=0 10mm~0 40mm。 相似文献
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全程动态注塑对HIPS制品力学性能影响研究 总被引:2,自引:0,他引:2
在振频0-12 Hz,振幅0-0.28 mm的范围内,使用自主发明的电磁动态注塑机研究了振动参数的变化对 HIPS制品力学性能和冲击断面形态结构的影响。结果表明:制品的力学性能对振动参数的响应不完全是一个单调趋势,而是存在一个最佳的响应范围。电磁动态注塑机引入的全程动态注塑过程能够同时提高制品的拉伸性能和冲击性能,冲击强度和拉伸强度最大提高幅度分别为20%和14.4%。而制品的冲击断面微观结构也表明,全程动态注塑过程能有效改善HIPS制品的微观结构。 相似文献
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在振动力场作用下的三螺杆动态混炼挤出机上,采用硫磺硫化体系对不同配比EPDM/PP共混物进行动态硫化实验。通过调节螺杆振动参数(频率和振幅)改变加工过程中振动力场的振动强度,探讨了振动力场对 EPDM/PP共混物力学性能的影响规律。结果表明:振动力场的引入可以使热塑性硫化体系(TPV)拉伸强度最大提高23%,100%定伸应力最大提高20%,断裂伸长率最大提高28.7%;而振动力场的施加使得TPV材料的永久变形增大,说明其弹性下降,另外对硬度影响不大。 相似文献
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Dynamic injection processing experiments have been carried out on polypropylene using the self‐made electromagnetic dynamic plastics injection molding machine, and the effects of the vibration force field on mechanical properties of molding samples are studied, namely, the influence of vibration frequency and vibration amplitude on the mechanical properties of samples are researched by using tensile testing, impact testing, differential scanning calorimeter (DSC) and scanning electronic micrograph (SEM) techniques. The results show that the tensile strength and impact strength are both enhanced and the melting point shifts toward the higher temperature, which facilitates the perfection of crystal. The best vibration parameters for processing polypropylene using electromagnetic dynamic plastics injection molding machine are that frequency is from 3 to 9 Hz and amplitude is from 0.1 to 0.4 mm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 972–976, 2006 相似文献
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A custom‐made electromagnetic dynamic injection molding machine was adopted to study the mechanical properties and morphological behavior of calcium carbonate‐filled polypropylene (PP) in a dynamic injection molding process. The influence of vibration amplitude and frequency on the mechanical properties and morphological behavior of samples was investigated using tensile tests, notched Izod impact tests, differential scanning calorimetry, and scanning electronic microscopy. The tensile stress and the impact stress for all samples investigated were found to increase in a nonlinear manner with increasing vibration amplitude and frequency. The tensile stress reached a maximum value at about 8 Hz and 0.15 mm for neat PP and PP filled with 3, 20, and 30 wt% CaCO3. For PP filled with 40 wt% CaCO3, the tensile stress reached a maximum value at about 12 Hz and 0.2 mm. The impact stress reached a maximum value at about 12 Hz. From DSC experiments it was shown that the melting temperature slightly increased, but no new polymeric crystalline peak appeared under the vibration force field. The CaCO3 particles were diffused easily and distributed evenly in the PP melt under the vibration force field, so it is very useful in improving the quality of injection products. Copyright © 2006 Society of Chemical Industry 相似文献
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The effect of melt vibration on the mechanical properties of polypropylene prepared by low-frequency vibration-assisted injection molding (VAIM) has been investigated. With the application of melt vibration technology, the mechanical properties of polypropylene are improved. The yield strength increases with the increment of the vibration frequency, and a peak stands at a special frequency for VAIM; the elongation at break decreases first and then increases with increasing vibration frequency, and a valley stands at a special frequency. The tensile properties increase sharply at an enlarged vibration pressure amplitude with sharply decreased elongation at break. The Young's modulus and impact strength also increase with the vibration frequency and pressure vibration amplitude. When it is prepared at 59.4 MPa and 0.7 Hz, the maximal yield strength is approximately 40 MPa versus 33.7 MPa for a conventional sample; an 18.7% increase in the tensile strength is produced. Self-reinforcing and self-toughening polypropylene molded parts have been found to be prepared at a high vibration frequency or at a large pressure vibration amplitude. Scanning electron micrographs have shown that, in the vibration field, the enhancement of the mechanical properties is attributable to more pronounced spherulite orientation and increased crystallinity in comparison with conventional injection moldings. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
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利用普通注射成型和电磁动态注塑机注射成型制备等规聚丙烯试样,并对其进行拉伸强度、冲击强度、差示扫描量热仪(DSC)和广角X射线衍射(WAXD)测试。对动态与稳态注射成型聚丙烯制品的力学性能进行了比较,并结合微观测试结果,深入探讨了制品微观结构与力学性能之间的关系。力学测试结果表明,动态成型制品的拉伸性能和冲击性能比稳态加工条件下都有所提高,尤其是制品冲击性能的提高幅度可以达到40%以上,实现了对制品的同时增强和增韧。DSC和WAXD测试表明,动态成型制品的结晶比稳态制品完善,并且晶粒尺寸也小于稳态制品。经过理论分析,认为结晶情况的改善是制品拉伸强度提高的原因,而晶粒细化则大幅度提高了制品的冲击强度。 相似文献