Effect of Injection Molding Process on Electrical Conductivity and Mechanical Property of Nanoparticle Filled Polymer Composites

2012 ◽  
Vol 486 ◽  
pp. 34-38
Author(s):  
Jing Chao Zou ◽  
Ai Yun Jiang ◽  
Bao Feng Zhang ◽  
Hai Hong Wu ◽  
Ya Jun Zhou

Authors investigated the relationship among processing parameters, microstructures, electrical conductivity and mechanical property of injection molded nanoparticle filled polymer composites at present study. Standard tensile specimens were injected under different injecting pressures and packing pressures. The molded specimens were removing five layers from the surface to observe the microstructures at different positions of the moldings. The electrical properties were measured with a two-terminal standard resistor under DC condition at room temperature, and the mechanical properties of the moldings were measured by INSTRON 5580 Universal testing machine. The results showed that filled nanoparticles may form the best conductive path under the higher packing pressure matched with higher injection pressure. The mechanical properties of the molding depend on not only the concentration of the nanofiller, but processing conditions as well.

2012 ◽  
Vol 629 ◽  
pp. 55-59
Author(s):  
Ai Yun Jiang ◽  
Jing Chao Zou ◽  
Bao Feng Zhang ◽  
Hai Hong Wu

For conductive-carbon-fiber-filled polymer composites, the residual stresses developed during injection molding process may affect not only the molding’s conductive property, but its dimensional stability as well. In order to improve the conductivity of the molding fabricated with this kind of composites, we investigated, using layer removal method, the distribution of the residual stresses of injection-molded conductive-carbon-fiber-filled polypropylene in this paper. The residual stresses were obtained under the actions of different processing conditions. Our results indicate that processing pressures have more significant effects on the residual stresses at the skin areas than the core areas of the sample because of fiber orientation. The tensile stresses of the molding at the core areas drop under the action of packing pressure, but the compressive stresses at the skin areas increase. The results reveal that the action of packing pressure may decrease the anisotropy of the residual stresses in the molding.


Author(s):  
Catalin Fetecau ◽  
Ion Postolache ◽  
Felicia Stan

The research presented in this paper involves numerical and experimental efforts to investigate the relative thin-wall injection molding process in order to obtain high dimensional quality complex parts. To better understand the effects of various processing parameters (the filling time, injection pressure, the melting temperature, the mold temperature) on the injection molding of a thin-wall complex part, the molding experiments are regenerated into the computer model using the Moldflow Plastics Insight (MPI) 6.1 software. The computer visualization of the filling phase allows accurate prediction of the location of the flow front, welding lines and air traps. Furthermore, in order to optimize the injection molding process, the effects of the geometry of the runner system on the filling and packing phases are also investigated. It is shown that computational modeling could be used to help the process and mold designer to produce accurate parts.


Author(s):  
Maximiano V. Ramos ◽  
Armstrong Frederick ◽  
Ahmed M. Al-Jumaily

Polymer nanocomposites offer various functional advantages required for several biomedical applications. For example, polymer nanocomposites are biocompatible, biodegradable, and can be engineered to have mechanical properties suitable for specific applications. The key to the use of polymer nanocomposites for different applications is the correct choice of matrix polymer chemistry, filler type, and matrix-filler interaction. This paper discusses the results of a study in the processing and characterization of nono-filled polymer composites and focuses on the improvement of its properties for potential biomedical applications. The experimental procedure for the preparation of nano-filled polymer composite by ultrasonic mixing is described. Different types of nanofillers and polymer matrix are studied. Effects of processing parameters such as percent loading of fillers, mixing time on the mechanical properties of the composites are discussed. Preliminary results indicate improvement in shear and flexural properties, tensile and compressive properties, were observed in the prepared composites for some processing conditions.


2018 ◽  
Vol 38 (7) ◽  
pp. 695-701
Author(s):  
Christian Hopmann ◽  
Matthias Theunissen ◽  
Stefan Haase

Abstract Thermoset molding compounds have a wide range of beneficial properties such as easy handling, high temperature, chemical resistance, low shrinkage as well as low electrical conductivity. However, these properties come at the cost of a higher density than technical thermoplastic materials and thus the potential for lightweight applications is reduced. Due to the low viscosity of the resin within thermoset molding compounds a wide variety of filler materials can be used. The addition of low density hollow glass bubbles as a filler material in thermoset molding compounds offers the opportunity to decrease the density of the molding compound. At the same time the stiffness of the micro glass bubbles is expected to increase the stiffness of the material. In the present study, a thermoset molding compound was filled with different quantities of hollow glass bubbles and the effects of the filler content as well as the processing parameters were investigated regarding their effect on the weight and mechanical properties of the parts. Based on the results, significant weight reductions up to 5% were achieved. Furthermore, a significant impact of the process parameters on weight reductions was found. The results indicate that higher shearing reduces the weight. This can also contribute to damaging of the glass bubbles during the injection molding process. Similar results were found regarding the effect of process parameters on the mechanical properties.


Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 326 ◽  
Author(s):  
Valentina Volpe ◽  
Sofia Lanzillo ◽  
Giovanni Affinita ◽  
Beniamino Villacci ◽  
Innocenzo Macchiarolo ◽  
...  

The automotive industry needs to produce plastic products with high dimensional accuracy and reduced weight, and this need drives the research toward less conventional industrial processes. The material that was adopted in this work is a glass-fiber-reinforced polyamide 66 (PA66), a material of great interest for the automotive industry because of its excellent properties, although being limited in application because of its relatively high cost. In order to reduce the cost of the produced parts, still preserving the main properties of the material, the possibility of applying microcellular injection molding process was explored in this work. In particular, the influence of the main processing parameters on morphology and performance of PA66 + 30% glass-fiber foamed parts was investigated. An analysis of variance (ANOVA) was employed to identify the significant factors that influence the morphology of the molded parts. According to ANOVA results, in order to obtain homogeneous foamed parts with good mechanical properties, an injection temperature of 300 °C, a high gas injection pressure, and a large thickness of the parts should be adopted.


Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2187
Author(s):  
Krisztián Kun ◽  
Zoltán Weltsch

During the injection molding process, the melt travels with a flow due to friction. As the velocity of the layers next to the wall is less than that of those flowing in the middle of the channel, a fountain flow is formed at the melt front. The temperature of the polymer surface decreases from the melt temperature to the contact temperature after contacting the mold surface. Based on all this, a complex shell–core structure is formed in injection-molded products, which can be influenced by the processing parameters and the surface of the tool insert. This paper focuses on investigating the effect of the microstructures replicated from the insert to the polymer product on its mechanical properties. During the research, two microstructured surfaces were created, with different effects on the melt flow formed by the femtosecond laser. These were compared with a ground insert to analyze the effects. For examining the effect of technological variables on the mechanical properties, an experimental design was used. The structure created by the femtosecond laser on the surface of the tool influenced the mechanical properties of the polymer products. Recognizing the effect of microstructures on the melt front and, through this, the change in mechanical properties, a predefined polymer product property can be achieved.


2012 ◽  
Vol 532-533 ◽  
pp. 121-125
Author(s):  
Qian Chao Mao ◽  
Jin Nan Chen ◽  
Jian Wang

An approach of preparing single polymer composites (SPCs) by injection molding was demonstrated. Polypropylene (PP) was used as a model system to investigate this method. The thermal properties of PP granules and PP fibers were analyzed by Differential Scanning Calorimeter (DSC) to determine the processing temperatures. The flexural test of PP SPCs showed that the flexural strength was obviously improved compared to the non-reinforced PP. The results also indicated that the injection pressure, holding pressure and nozzle temperature greatly affect the flexural strength of PP SPCs. The microstructure observation showed no gaps between fibers and the matrix by using Scanning Electron Microscopy (SEM). The matrix melt was able to penetrate into fiber webs and the two materials had good interfacial compatibility.


2011 ◽  
Vol 341-342 ◽  
pp. 395-399 ◽  
Author(s):  
S. Esmail Mirvar ◽  
Ramin Mohamadi Kaleybar ◽  
Ahmad Afsari

Mechanical properties of plastic play an important role in defining the quality of injection molded products. Many studies have shown that mechanical properties of a product are influenced by the process parameters governing the injection-molding processes .This study employs Taguchi design parameters, to systematically investigate the influence of injection molding processing parameters on the tensile strength of Commercial grade Polyamide (PA-6). The result shows that the holding pressure time has main effect on the tensile strength, followed by cooling time, and holding pressure. Finally, a specimen produced according to the general form of the predictive equation of process parameters and verification test is performed on that. Test results show that the experimental value of tensile strength is very close to the estimated value.


Sign in / Sign up

Export Citation Format

Share Document