全程振动注塑对PP力学性能影响的研究

以实际生产条件为前提,在频率0～12Hz、振幅0～0．28mm范围内研究了振动对聚丙烯(PP)力学性能和冲击断面形态结构的影响。结果表明,PP的力学性能对振动参数的响应并不完全是一个单调趋势,而是存在一个最佳的响应范围;全程振动注塑能够同时提高PP的拉伸强度和冲击强度,最大增幅分别为17％和27％。     

全程动态注塑对HIPS制品力学性能影响研究

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。     

全程振动注塑对PP力学性能影响研究

以实际生产条件为前提，在频率为0～12Hz、振幅为0～0．28mm范围内研究了振动对聚丙烯（PP）力学性能和冲击断面形态结构的影响。结果表明，PP的力学性能对振动参数的响应并不完全是一个单调趋势，而是存在一个最佳的响应范围；全程振动注塑能够同时提高PP的拉伸强度和冲击强度，最大增幅分别为17％和27％。     

全程动态注塑对HDPE制品力学性能的影响

在实际生产条件下，在振频0～12Hz、振幅0～0．28mm范围内研究了振动参数对HDPE制品的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并不是单调趋势，而是存在一个最佳的响应范围；全程动态注塑过程能提高制品的拉伸和冲击性能．其中冲击强度提高尤其明显，最大可提高33％。     

全程动态注塑对HIPS制品力学性能影响研究

在实际生产的条件下，在振频0-12Hz，振幅0—0.28mm范围内研究了振动参数的变化对HIPS制品力学性能和；中击断面形态结构的影响。揭示了制品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。全程动态注塑过程能够同时提高制品的拉伸强度和冲击强度，冲击强度和拉伸强度最大提高分别为20％和14．4％。     

全程动态注塑对PS制品力学性能影响的研究

在实际生产条件下,在振频0~12Hz、振幅0~0.30mm范围内研究了振动参数对聚苯乙烯(PS)制品的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并不是单调趋势,而是存在一个最佳的响应范围;全程动态注塑过程能提高制品的拉伸和冲击性能,其中冲击强度提高尤其明显,最大可提高28.6%。     

衣架式机头动态挤出PP的力学性能

采用衣架式机头动态挤出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：振动的引入，有利于提高制品纵横两向的拉伸强度和冲击强度，并且存在最佳振动参数范围，当振幅0．1mm时，方向的力学性能改善效果最显著；而当频率为15Hz时．方向力学性能改善效果最为明显；制品熔点向高温迁移，吸热焓与结晶度也得到提高。     

动态注射成型振动参数对试样熔接痕拉伸强度及结构形态的影响

在选定的注射成型工艺参数基础上,通过动态注射成型来研究振动参数对成型PP试样和GFPP试样熔接痕拉伸强度及结构形态的影响。结果表明:对同种材料,振动参数对熔接痕拉伸强度的影响趋势相同;对PP试样,熔接痕拉伸强度对振动频率的响应有一个最优值;对GFPP试样,其在较低频率和较大振幅下,能够得到更强的熔接痕拉伸强度;振动的引入使"横躺"在PP基体上的玻纤减少,使试样熔接痕处的拉伸强度增强。     

动态填充注塑成型PP/nano-SiO2复合材料的力学性能与形貌分析

采用动态填充注塑成型(DFIM)制备了聚丙烯/二氧化硅(PP/nano-SiO2)复合材料。结果表明:与传统的注塑成型技术相比,采用DFIM法制备的PP/nano-SiO2复合材料的拉伸强度和冲击强度比纯PP材料和常规注射制备的复合材料有了较大提高;nano-SiO2通过DPIM技术可以更好地分散在PP基质中,形成的团聚较少。DFIM法制备的PP/nano-SiO2复合材料力学性能的提高,主要归因于nano-SiO2颗粒的均匀分布,使球晶的数量急剧增加,球晶的尺寸明显减小,小晶体有助于形成材料裂纹,从而进一步提高材料的力学性能。     

注塑压力对粉煤灰微珠改性PP综合性能的影响

叙述了粉煤灰空心微珠改性PP注塑件在加工过程中注塑压力对体系综合性能的影响，分析了注塑压力与有关性能(冲击强度、拉伸强度、断裂伸长率、成型收缩率)之间的关系，指出了采用合适的注塑压力有助于提高体系的综合性能。     

Mechanical properties and morphological behavior of calcium carbonate‐filled polypropylene in dynamic injection molding

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     

Effect of vibration parameters of electromagnetic dynamic plastics injection molding machine on mechanical properties of polypropylene samples

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     

塑料动态注射充模过程工艺参数的优化研究

运用了Taguchi方法研究了PP动态注射成型工艺参数对制品性能的影响。研究结果表明，在注射速度、保压压力、振动频率与振幅这四个工艺参数中，在所设定的工艺范围内，对制品性能影响比较明显的是振动频率与振幅。PP试样的冲击强度随振动频率改变而改变，且在10Hz左右存在一个最佳状态，冲击强度可以增加42％。拉伸性能随着振幅的增加基本上呈上升的趋势，极限拉伸应力最大增加8％，弹性模量最大可增加18．7％。在优化的振动工艺参数下，即在1～5Hz的频率段振幅对制品的拉伸性能的影响较之明显，在7～15Hz的频率段振动频率对制品的冲击性能的影响较显著。     

Effect of Vibrating Extrusion on the Structure and Mechanical Properties of Isotactic Polypropylene

An electromagnetic dynamic plasticating extruder, invented by the authors, was used to prepare isotactic polypropylene (PP) sheets. Tensile and impact tests show that the extruded samples can simultaneously be reinforced and toughened along the flow and transverse directions in a moderate frequency and amplitude range. The microstructures of the obtained samples were characterized by differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD), and scanning electron microcopy (SEM). The results indicate that the vibration plasticating extrusion affected the morphology of the PP extrudate, it especially resulted in finer spherulites, and move tie molecules, which account for the enhancement of the tensile strength and impact toughness of PP sheets in both extrusion and transversal directions.     

The Effect of Vibration on Mechanical Properties of Blends of EPDM/PP in a Tri-screw Dynamic Mixing Extruder

The effects of vibration force field on mechanical properties of blends of EPDM/PP during process of plastics in tri-screw dynamic mixing extruders were investigated experimentally. It was found that vibration force field enhanced mechanical properties of blends of EPDM/PP, and the amplitude of enhancement varied as EPDM content varying. The yangs modulus, the impact strength and the tensile strength were improved the maximum 17, 28, and 17.3%, respectively under dynamic conditions than that under steady conditions. Mechanical properties of blends of EPDM/PP represented a tendency of a rising followed by a fall with the increase of vibration frequency and amplitude.     

振动力场下PP增强管材的制备及性能研究

采用电磁动态塑化挤出机挤出聚丙烯（PP）管材,通过爆破压力测试、拉伸性能测试、差示扫描量热（DSC）分析和X射线衍射（XRD）分析研究了振动频率和振幅对PP管材结构与力学性能的影响。力学性能测试结果表明,振动挤出PP管材的周向强度有了显著提高,实现了管材的双向自增强。与稳态挤出的PP管材相比,振动挤出PP管材的爆破压力最大提高了27．03％,轴向拉伸屈服强度最大提高了7．3％。DSC分析和XRD分析表明,振动挤出的PP管材结晶度提高,熔点升高,结晶完善,晶粒变小,有利于管材力学性能的提高。     

动态塑化过程振动参数对聚丙烯性能的影响

采用新型液压脉振式注射机成型聚丙烯(PP)试样,探讨了塑化过程中振幅和频率对PP物理力学性能和成型过程整机能耗的影响。结果表明:保持其他工艺参数不变,在塑化过程中施加振动后,PP试样的拉伸强度提高9.8%,冲击强度提高13.8%,密度提高0.3%,整机加工能耗降低6.6%。