scholarly journals Dynamics Analysis of the Melt Conveying Process in a Novel Extruder

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Zan Huang

This study investigates dynamics of the melt conveying process in a novel extruder in which a polymer experiences a primarily elongational deformation field. The working principle of the novel extruder is completely different from that of conventional screw extruders. At the last stage of polymer processing in the proposed novel extruder, melt is conveyed through feeding and discharging processes. Here we present a mathematical model to analyze dynamics in the melt conveying process. Melt extrusion is primarily influenced by the position of vane chamber and the structural parameters of the novel extruder such as eccentricity.

2012 ◽  
Vol 472-475 ◽  
pp. 1941-1944 ◽  
Author(s):  
Jin Ping Qu ◽  
Xiao Qiang Zhao ◽  
Jian Bo Li

This paper deals with the study of power consumption in the discharging process of polymer particulate solids in a vane plasticization extruder. The structure and operating principle of the innovational vane extruder are completely different with conventional screw extruders. The process of conveying materials in vane extruder is based on volume transportation. Solids conveying zone is the first section of polymer processing in extruder. Large amounts of energy are consumed in the zone. The solids conveying process is composed of feeding, compacting and discharging process in the vane extruder. The discharging process is very unique and worthy of further study because of the particularity of the vane extruder. A mathematical model has been developed to analyze the power consumption in the process. The model shows the structural parameters have significant influence on the power consumption. In addition, the model is verified by experimental results.


2017 ◽  
Vol 12 (6) ◽  
Author(s):  
Auni Aslah Mat Daud

A Galton board is an instrument invented in 1873 by Francis Galton (1822–1911). It is a box with a glass front and many horizontal nails or pins embedded in the back and a funnel. Galton and many modern statisticians claimed that a lead ball descending to the bottom of the Galton board would display random walk. In this study, a new mathematical model of Galton board is developed, to further improve three very recently proposed models. The novel contribution of this paper is the introduction of the velocity-dependent coefficient of restitution. The developed model is then analyzed using symbolic dynamics. The results of the symbolic dynamics analysis prove that the developed Galton board model does not behave the way Galton envisaged.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2054
Author(s):  
Xiaochun Yin ◽  
Youhua Yin ◽  
Di Cheng ◽  
Yanhong Feng ◽  
Guizhen Zhang ◽  
...  

In this work, a novel melt extrusion method under synergy of extensional deformation and in-situ bubble stretching (ISBS) and corresponding apparatus were reported. The structure and working principle were introduced in detail. Polymer composites composed of high density polyethylene (HDPE)/ultrahigh molecular weight polyethylene (UHMWPE)/carbon fiber (CF) were prepared by using this new method. Effects of CF and Azodicarbonamide (AC) contents on composites’ morphology, rheological, thermal, and mechanical properties were experimentally investigated. SEM results showed that the CFs dispersed evenly in the matrix when the AC content was relatively high. DSC results showed that co-crystallization of HDPE and UHMWPE occurred in the composites, and the Xc of the composites decreased with the addition of AC or under high CF loadings. TGA results showed that the thermostability of the composites increased markedly with increasing CF loading. Mechanical properties showed that tensile strength increased by 30% with 9 wt % CF and 0.6 wt % AC added. The results aforementioned indicate that the novel melt extrusion method is a green and effective way to prepare HDPE/UHMWPE/CF composites.


2014 ◽  
Vol 989-994 ◽  
pp. 2802-2806
Author(s):  
Min Wang ◽  
Cai Dong Wang ◽  
Hui Zheng ◽  
Guo Feng Fan

According to the requirements for wheel hub assembly line, the structure and hydraulic system of carrying manipulator with six degrees of freedom (DOF) is designed. The working principle of the hydraulic system is analyzed. To minimize the output force of the hydraulic cylinder, a mathematical model of hydraulic cylinder output force and structural parameters is established. And then the manipulator structure is optimized based on Matlab software. The key components of the hydraulic system are selected. This research provides reference for design of similar hydraulic system of industrial robot.


Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 608
Author(s):  
Danielle Burton ◽  
Suzanne Lenhart ◽  
Christina J. Edholm ◽  
Benjamin Levy ◽  
Michael L. Washington ◽  
...  

The 2014–2016 West African outbreak of Ebola Virus Disease (EVD) was the largest and most deadly to date. Contact tracing, following up those who may have been infected through contact with an infected individual to prevent secondary spread, plays a vital role in controlling such outbreaks. Our aim in this work was to mechanistically represent the contact tracing process to illustrate potential areas of improvement in managing contact tracing efforts. We also explored the role contact tracing played in eventually ending the outbreak. We present a system of ordinary differential equations to model contact tracing in Sierra Leonne during the outbreak. Using data on cumulative cases and deaths, we estimate most of the parameters in our model. We include the novel features of counting the total number of people being traced and tying this directly to the number of tracers doing this work. Our work highlights the importance of incorporating changing behavior into one’s model as needed when indicated by the data and reported trends. Our results show that a larger contact tracing program would have reduced the death toll of the outbreak. Counting the total number of people being traced and including changes in behavior in our model led to better understanding of disease management.


2008 ◽  
Vol 07 (01) ◽  
pp. 65-67
Author(s):  
CHANGPING ZOU ◽  
LI DU ◽  
XIANDE HUANG

A new type of six-bar swaying machine was put forward, which is an ingenious combination of plane multi-bar mechanism and high pressure oil cylinder. Preliminary analysis shows that this machine has many advantages, such as the torque produced by its unit weight, its small size, its light deadweight, etc. Thus it can be applied to situations that need swaying mechanism with low rotational speed and great torque. Firstly, the mechanism composition and working principle of the swaying machine were introduced. Secondly, parameterized modeling of the mechanism was carried out by utilizing software ADAMS. Then kinematic analysis and kinetic analysis were completed by using ADAMS. Finally, key dimensions were adjusted according to kinetic analysis. These tasks are believed to be beneficial to the development of the novel transmission.


2012 ◽  
Vol 246-247 ◽  
pp. 1220-1225
Author(s):  
You Kun Zhong

With the increasing of the number of cars, people are also getting higher and higher demands on the performance of the car, and especially pay attention to the improvement and optimization of automobile transmission system. The transmission is a key part of automobile transmission system, and transmission performance and stability depend on the synchronous machine, so in order to make the vehicle transmission system with higher efficiency, it is necessary to study the synchronous machine. On the basis of elaborating synchronous machine working principle, the use of dynamics theory to establish mathematical model of synchronous machine system, and to carry out the simulation of synchronous machine three-dimensional model in PRO/E environment, then the use of virtual prototype technology to optimize the parameters of synchronous machine, thereby improving the performance of synchronous machine.


Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 153
Author(s):  
Sang-Min Lee ◽  
Sang-Hye Lee ◽  
Jae-Seung Roh

In the present study, carbon black activated by CO2 gas was examined through XRD analysis, especially with regard to changes in its structural parameters. Based on the results, its activation process was thoroughly analyzed. The activation process was controlled by isothermally activating the carbon black inside a reaction tube through which CO2 gas flowed. With this approach, the degree of activation was varied as desired. At an early stage of the activation process, the amorphous fraction on the carbon black surface was preferentially activated, and later the less-developed crystalline carbon (LDCC) region inside the carbon black particles started to be activated. The latter process was attributable to the formation of pores inside the carbon black particles. As the activation process proceeded further, the more-developed crystalline carbon (MDCC) region started to be activated, thereby causing the pores inside the carbon black particles to grow larger. At the last stage of the activation process, La was found to be decreased to about 40 Å. This implied that the edges of the graphite crystals had been activated, thus causing the internal pores to grow and coalesce into larger pores. Activated conductive Super-P with enhanced pore properties is expected to have wide applications.


2021 ◽  
Vol 63 (2) ◽  
pp. 143-150
Author(s):  
Torben Buttler ◽  
Jens Hamje ◽  
Rolf Reiter ◽  
Volker Wesling

Abstract During polymer extrusion there are a variety of situations in which the screwthread of the extrusion screw has an unlubricated metal-to-metal contact with the barrel wall. At the same time the screw coating is subjected to the highest loads. The combination of a secondary hardening cold work steel 1.2379 and a chromium nitride coating deposited by ARC-PVD, which is frequently used in polymer processing, is characterized and investigated. The characterization is done by metallographic examination, SEM and CLSM. The tests were performed on a pin-on-disk and a pin-roll test rig. Different roughness levels were tested on the pin-on-disk test, where massive differences in wear behavior were found. A hybrid surface structure is proposed to optimize the tribosystem. On the pin-on-disk test stand, rollers made of the same material pairing were tested. The test speed was varied to highlight differences and similarities between the tribological systems. A wear minimization of 50 % was achieved and the similarities between the tribological systems were highlighted. In addition, the investigations led to the development of a new model thesis which provides a reason for the development of stippling on the screw when processing polycarbonate.


Machines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 37
Author(s):  
Heng Zhang ◽  
Yaoyao Liao ◽  
Ze Tao ◽  
Zisheng Lian ◽  
Ruihao Zhao

In the field of fully mechanized coal mining equipment, the hydraulic valve used in the hydraulic support is an on/off directional valve. There are many problems caused by the valve such as large pressure shock and discontinuous flow control. Therefore, a novel two-position three-way hydraulic proportional valve suitable for high-pressure and large-flow conditions is proposed to overcome the above problems. The novel valve utilizes a two-stage structure and the displacement follow-up principle is adopted between the pilot stage and the main stage to meet proportional control. In this paper, a simulation model of the novel proportional valve was established after a simplified analysis of the structural principle. Its reliability and the feasibility of the design were verified by the test results under different working conditions. Then, the step response characteristics of the proportional valve under different strokes were predicted and analyzed. Nonlinear characteristics were presented, and the closing time was shorter than the opening time because of the influence of nonlinear flow force. Under different ramp signals, the displacement of the main inlet spool was always approximately equal to the displacement of the pilot stage. Then, the motion relationship between the pilot stage and the main stage was studied, and the influence of the structural parameters on the stability was analyzed.


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