Effects of Vibration Force Field on Extensional Stress of Polymer Melt in Contraction Die

2011 ◽  
Vol 311-313 ◽  
pp. 1114-1117
Author(s):  
Ji Chang Fan ◽  
Xiang Fang Peng
Keyword(s):  
Force Field ◽  
Vibration Frequency ◽  
Polymer Melt ◽  
Visualization Technique ◽  
Forming Process ◽  
Extensional Stress ◽  
Dynamic Extrusion ◽  
Vibration Parameters ◽  
Forming Methods

Electromagnetic dynamic plasticating extrusion, as one of main novel forming methods, has many important benefits to the forming process and the properties of its products. Here a visualization technique of flow induced birefringence was used to study the effects of the vibration parameters of screw on the extensional stress in contraction die. It is shown that , the extensional stress vibrate with the screw vibration at the same frequency; the amplitude of the extensional stress increases with the amplitude of the screw increasing; the average extensional stress at dynamic extrusion is less than that without vibration force, and it decreases with the screw vibration frequency or amplitude increasing.

Study of Rheological Behavior of Calcium Carbonate Filled Polypropylene in Dynamic Extrusion

2014 ◽  
Vol 1053 ◽  
pp. 231-234 ◽  
Author(s):  
Quan Wang ◽  
Xiao Sun ◽  
Zheng Huan Wu
Keyword(s):  
Calcium Carbonate ◽  
Vibration Frequency ◽  
Rheological Behavior ◽  
Apparent Viscosity ◽  
Polymer Melt ◽  
Measuring Apparatus ◽  
Melt Rheology ◽  
Sinusoidal Vibration ◽  
Dynamic Extrusion ◽  
Vibration Parameters

A novel rheological measuring apparatus was designed, which introduced an additional sinusoidal vibration in parallel on the extruding direction of polymer melt in this paper. Melt rheology of polypropylene filled CaCO3 particles in various amounts of filler (i.e. with 3 and 20 wt%) during capillary melt-extrusion were investigated respectively. The effects of vibration parameters on rheological behaviors were studied. Compared with the steady extrusion, the apparent viscosity of filled system decreased remarkably with the increase of vibration frequency and amplitude. The apparent viscosity reached to the minimum value as vibration frequency was about 8 Hz. When the filled percentage of CaCO3 was low, the response of apparent viscosity will be more distinct with the increasing vibration parameters.

Temperature during the vibration-assisted compression of alfalfa

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 141-150
Author(s):  
Xiaoyu Wu ◽  
Shuai Yang ◽  
Chundong Song ◽  
Kun Ding ◽  
Chuanzhong Xuan ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Vibration Frequency ◽  
Experimental Results ◽  
Maximum Temperature ◽  
Compression Time ◽  
Vibration Parameters ◽  
Reducing Energy ◽  
Compression Temperature

Compression of alfalfa into briquettes is an effective way to solve the problem of storage and transportation. In the process of compression, heat is generated and the temperature is raised in the material. In fact, the appropriate temperature can improve the quality of alfalfa briquettes and reduce the energy consumption of densification. In this study, the effect of assisted vibration on the compression temperature was tested. The results showed that when the vibration frequency was below 15 Hz, the temperature at the center and side in compressed alfalfa increased slowly with compression time. When the vibration frequency was above 20 Hz, it increased first and then decreased with the increase of time. Moreover, the maximum temperature value increased remarkably when the frequency was above 20 Hz. In the same vibration frequency and compression time, the center temperature in the compressed alfalfa was higher than the side temperature. The experimental results provide a reference for the determination of reasonable vibration parameters, and explanation of the effect of vibration on reducing energy consumption.

Modeling of Particle Migration inside Vibration Bubbles in Bubble-Stretching Dispersion Method

2013 ◽  
Vol 562-565 ◽  
pp. 1182-1189
Author(s):  
Fei Wang ◽  
Yan Ling Zhang ◽  
Liang Zhao ◽  
Xiao Ming Wang
Keyword(s):  
Initial Pressure ◽  
Polymer Melt ◽  
Theoretical Models ◽  
Particle Migration ◽  
Initial Radius ◽  
Bubble Wall ◽  
Dispersion Method ◽  
Dispersion Process ◽  
Agglomeration Of Nanoparticles ◽  
Vibration Parameters

Bubble-stretching based dispersion method can be used to prevent the agglomeration of nanoparticles during the process of preparing nanocomposites, whereas its effectiveness is restricted by the practically low migration ratio of particles onto the bubble wall. Theoretical models for bubble vibration and particle migration have been presented, followed by numerically study on effects of different parameters on migration ratio of particles on to the bubble wall. The numerical results have shown that bubble initial radius, bubble initial pressure and particle diameters impact the particle migration ratio obviously and it is found that the particle migration ratio can be improved effectively through the optimal control of the vibration parameters of the bubble happed in the dispersion process. Therefore, this article provides a theoretical basis for the efforts on increasing the particles migration ratio and thus the dispersion effectiveness of nanoparticles in polymer melt.

scholarly journals TENDENCIES IN FORMING SHEET METAL PARTS USING INCREMENTAL FORMING ADVANCED TECHNOLOGIES

2019 ◽  
Vol 25 (3) ◽  
Author(s):  
CATALINA CIOFU ◽  
BOGDAN CHIRITA ◽  
ROXANA LUPU ◽  
COSMIN GRIGORAS ◽  
CRINA RADU ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Incremental Forming ◽  
Stretch Forming ◽  
Micro Forming ◽  
Forming Process ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Advanced Technologies ◽  
Metal Materials ◽  
Forming Methods

Stretch forming of sheet metal materials is a highly required process in aerospace industry for manufacturing skin parts. Automation of some processes such as cutting, punching, forming, shearing and nesting in conventional manufacturing tends to combine these forming methods. Some researches are made on the formability of sheet metal materials obtained in incremental forming process with stretch forming and water jet incremental micro-forming with supporting dies. This paper is an attempt to review the newly researches made on optimization of manufacturing metal skin parts to achieve geometrical accuracy.

Modeling and Simulation of Vibration-Assisted Extrusion Tapping of Internal Thread with Finite Element Method (FEM)

2012 ◽  
Vol 498 ◽  
pp. 183-188 ◽  
Author(s):  
Yong Yi Li ◽  
Sheng Dun Zhao
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Material Flow ◽  
Internal Thread ◽  
The Finite Element Method ◽  
Forming Process ◽  
Effect Mechanism ◽  
Vibration Parameters ◽  
Selection Of ◽  
Element Method

This paper firstly introduces the principle and characteristic of traditional extrusion tapping of internal thread, elaborates the material flow law during tapping process. Then puts forward a novel process of vibration-assisted extrusion tapping of internal thread, explains the effect mechanism of vibration during extrusion tapping of internal thread. Finally, with the finite element method (FEM), the simplified model of extrusion tapping are built, and the simulation of thread forming process of traditional extrusion tapping of internal thread are conducted, furthermore, the characteristic and influencing law of different vibration parameters (include vibration frequency, amplitude and direction) of vibration-assisted extrusion tapping of internal thread are studied, and some practical results are obtained. The simulation results show that applying vibration to extrusion tapping of internal thread can reduce tapping torque and improve thread forming quality, the reasonable selection of vibration parameters are very crucial to this novel process.

Sheet Single Point Vibration Incremental Forming Process Simulation and Analysis of Process Parameters

2012 ◽  
Vol 430-432 ◽  
pp. 74-78 ◽  
Author(s):  
Gai Pin Cai ◽  
Cong Wen Xing ◽  
Zhi Hong Jiang ◽  
Zhong Kai Zhang
Keyword(s):  
Sheet Metal ◽  
Incremental Forming ◽  
Single Point ◽  
Product Yield ◽  
Simulation Software ◽  
Forming Force ◽  
Forming Process ◽  
Vibration Parameters ◽  
The Right ◽  
Theory Research

The deformation of vibration incremental forming process for sheet metal is in high complexity, theory research is not perfect. This subject using DEFORM simulation software, joined the vibration on the forming process of tool head and simulated the forming process base on different tool radius and vibration parameters. Simulation result indicated that vibration in greatly reduced the stress of the forming tool head. The right vibration parameters smoothed out the forming force largely, reduced sheet metal stress concentration, improved product quality and product yield. That has a higher degree of study and use value.

Ploughing-Pulling Forming for Wicking Structure of Flat Micro-Groove Heat Pipe and Machine Tool Optimization

2020 ◽  
Vol 36 (4) ◽  
pp. 423-435
Author(s):  
Xibing Li ◽  
Zhixiong Ye ◽  
Nanpeng Li ◽  
Jialun Chen ◽  
Tengyue Zou
Keyword(s):  
Machine Tool ◽  
Heat Pipe ◽  
Sharp Increase ◽  
Processing Parameters ◽  
Machining Process ◽  
Forming Process ◽  
Factors Affecting ◽  
Strength Limit ◽  
Forming Methods ◽  
Tool Optimization

ABSTRACTIn forming procedure of the micro grooves in the flat micro-groove heat pipe, the tie rod is often observed to be broken and the multi-tooth cutter is damaged due to the sharp increase of the ploughing-pulling pressure. This paper theoretically analyzes the factors affecting the capillary heat transferring limit of the micro-groove heat pipe, and simulates the machining process using finite element to acquire the best processing parameters: the squeeze angle is 120°, the drawing depth is 0.25mm, and the ploughing-pulling velocity is 100mm/s. Then these parameters are verified by real manufacturing experiments. The experimental results show that the ploughing-pulling pressure of the micro-groove forming process is close to the strength limit of the rod or multi-tooth cutter, and the process makes little swarf during work. Thus, only using the appropriate machine tool parameters, forming parameters and forming methods can make the wicking structure of flat micro-groove micro-heat pipe with the best heat transferring performance.

Finite Element Analysis and Formability Test on Incremental Forming of IS:513 CR3 Steel Sheets

2015 ◽  
Vol 766-767 ◽  
pp. 1109-1115
Author(s):  
S. Chezhian Babu ◽  
V.S. Senthil Kumar
Keyword(s):  
Metal Forming ◽  
Incremental Forming ◽  
Thickness Distribution ◽  
Forming Process ◽  
Element Analysis ◽  
Steel Sheets ◽  
Automobile Body ◽  
Metal Forming Process ◽  
High Flexibility ◽  
Forming Methods

Incremental forming is a recent sheet metal forming process that has high flexibility and repeatability. Unlike conventional forming methods this process is applicable mainly in the production of prototypes or small batches of automobile body panels, headlight reflectors, etc. In this investigation IS 513 CR3 Deep Drawing quality steel sheets of thickness 0.6 mm were incrementally formed into pyramids to study their formability characteristics. Experiments were conducted under three different spindle speeds (1000, 1500 and 2000 rpm), three tool feeds (1200, 1400 and 1600 mm.min-1) and three step depths (0.4, 0.5, and 0.6 mm). Forming time, thickness distribution and formability of the final components were studied. FEA models were created using Abaqus software and validated with experimental results.

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