Development of a Fiber Orientation Measurement Methodology for Injection Molded Thermally-Enhanced Polymers

2012 ◽  
Author(s):  
Timothy Hall ◽  
Arumugham Vaishnavi Subramoniam ◽  
Hugh A. Bruck ◽  
Satyandra K. Gupta
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Polymer Composites ◽  
Fiber Orientation ◽  
Experimental Methodology ◽  
Injection Molding Process ◽  
Molding Process ◽  
Orientation Measurement ◽  
Promising Alternative ◽  
Injection Molded

Thermally-enhanced polymer composites are a promising alternative to exotic metals in seawater heat exchanger applications due to the low cost and corrosion resistance of base polymers and heat transfer rates competitive with corrosion-resistant metals such as titanium or stainless steel. While the properties of thermally-enhanced polymer composites are well-suited for heat exchanger applications, fiber orientation has a strong influence on the structural and thermal performance of the manufactured components. In this study, a method of creating samples, sectioning and polishing them for imaging, microscope sampling for the identification of fibers, image processing to characterize fiber orientation, and finally comparison to predictions from computer-aided engineering (CAE) software is demonstrated for collecting experimental information on fiber orientation of molded parts. Understanding fiber orientation in injection-molded polymer heat exchangers is important for ensuring ideal heat transfer and structural performance and this study presents an experimental methodology for determining the influence of injection molding process parameters on fiber orientation in thermally-enhanced polymer composite geometries.

Calculation on the Residual Stresses of Injection-Molded Conductive-Carbon-Fiber-Filled Polymer Composites

2012 ◽  
Vol 629 ◽  
pp. 55-59
Author(s):  
Ai Yun Jiang ◽  
Jing Chao Zou ◽  
Bao Feng Zhang ◽  
Hai Hong Wu
Keyword(s):  
Carbon Fiber ◽  
Residual Stresses ◽  
Polymer Composites ◽  
Injection Molding Process ◽  
Molding Process ◽  
Filled Polymer ◽  
The Core ◽  
Packing Pressure ◽  
Core Areas ◽  
Injection Molded

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.

Incorporating Moldability Considerations During the Design of Polymer Heat Exchangers

2011 ◽  
Vol 133 (8) ◽  
Author(s):  
Juan Cevallos ◽  
S. K. Gupta ◽  
Avram Bar-Cohen
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Polymer Composites ◽  
Heat Exchangers ◽  
Life Cycle Cost ◽  
Heat Transfer Performance ◽  
Integrated Design ◽  
Parametric Models ◽  
Transfer Performance ◽  
Molding Process

Recently, available formulations of thermally enhanced polymer composites are attractive in heat exchanger applications due to their low cost and improved corrosion resistance compared to the conventional metal options. This paper presents a systematic approach to the design of plate-fin heat exchangers made out of thermally enhanced polymer composites. We have formulated the design problem as the life cycle cost minimization problem. The integrated design model introduced here accounts for heat transfer performance, molding cost, and assembly costs. We have adopted well-known models to develop individual parametric models that describe how heat transfer performance, molding cost, and assembly cost varies as a function of the geometric parameters of the heat exchanger. Thermally enhanced polymer composites behave differently from the conventional polymers during the molding process. The desired thin walled large structures are expected to pose challenges during the filling phase of the molding process. Hence, we have utilized experimentally validated simulations to develop a metamodel to identify difficult and impossible to mold design configurations. This metamodel has been integrated within the overall formulation to address the manufacturability considerations. This paper also presents several case studies that show how the material and labor cost strongly influence the final design.

scholarly journals The use of image analysis in evaluation of the fibers orientation in Wood-polymer composites (WPC)

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Arkadiusz Bednarz ◽  
Wiesław Frącz ◽  
Grzegorz Janowski
Keyword(s):  
Injection Molding ◽  
Polymer Composites ◽  
Fiber Orientation ◽  
Point Of View ◽  
Injection Molding Process ◽  
Molding Process ◽  
Mathematical Algorithm ◽  
Wood Polymer ◽  
Wood Polymer Composites ◽  
Fibers Orientation

Abstract In this paper a novel way of a digital analysis of fibers orientation with a five-step algorithmwas presented. In the study, a molded piece with a dumbbell shape prepared from wood-polymer composite was used. The injection molding process was examined in experimental and numerical way. Based on the developed mathematical algorithm, a significant compliance of fiber orientation in different areas of the molded piece was obtained. The main aim of thisworkwas fiber orientation analysis of wood-polymer composites. An additional goal of thiswork was the comparison of the results reached in numerical analysis with results obtained from an experiment. The results of this research were important for the scientific and also from the practical point of view. In future works the prepared algorithm could be used to reach optimal parameters of the injection molding process.

A Study on the Birefringence Measurement in Injection Molded Parts Using Two Different Laser Sources and R-G-B Separation of White Light

2006 ◽  
Vol 326-328 ◽  
pp. 187-190
Author(s):  
Jong Sun Kim ◽  
Chul Jin Hwang ◽  
Kyung Hwan Yoon
Keyword(s):  
White Light ◽  
Low Cost ◽  
Main Idea ◽  
Injection Molding Process ◽  
Molding Process ◽  
Laser Method ◽  
High Productivity ◽  
Molded Parts ◽  
Injection Molded ◽  
Plastic Parts

Recently, injection molded plastic optical products are widely used in many fields, because injection molding process has advantages of low cost and high productivity. However, there remains residual birefringence and residual stresses originated from flow history and differential cooling. The present study focused on developing a technique to measure the birefringence in transparent injection-molded optical plastic parts using two methods as follows: (i) the two colored laser method, (ii) the R-G-B separation method of white light. The main idea of both methods came from the fact that more information can be obtained from the distribution of retardation caused by different wavelengths. The comparison between two methods is demonstrated for the same sample of which retardation is up to 850 nm.

Process comparison on the microstructure and mechanical properties of fiber-reinforced polyphenylene sulfide using MuCell technology

2018 ◽  
Vol 37 (15) ◽  
pp. 1020-1034 ◽  
Author(s):  
Christoph Lohr ◽  
Björn Beck ◽  
Frank Henning ◽  
Kay André Weidenmann ◽  
Peter Elsner
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Injection Molding ◽  
Fiber Orientation ◽  
Polyphenylene Sulfide ◽  
Injection Molding Process ◽  
Fiber Reinforced ◽  
Molding Process ◽  
Glass Fiber Reinforced ◽  
Foam Injection Molding

The MuCell process is a special injection molding process which utilizes supercritical gas (nitrogen) to create integral foam sandwiches. The advantages are lower weight, higher specific properties and shorter cycle times. In this study, a series of glass fiber-reinforced polyphenylene sulfide foam blanks are manufactured using the MuCell injection molding process. The different variations of the process (low-pressure also known as structural foam injection molding) and high-pressure foam injection molding (also known as “core back expansion,” “breathing mold,” “precision opening,” decompression molding) are used. The sandwich structure and mechanical properties (tensile strength, bending strength, and impact behavior) of the microcellular and glass fiber-reinforced polyphenylene sulfide foams are systematically investigated and compared to compact material. The results showed that the injection parameters (injection speed, foaming mechanism) played an important role in the relative density of microcellular polyphenylene sulfide foams and the mechanical properties. It could be shown that the specific tensile strength decreased while increasing the degree of foaming which can be explained by the increased number of cells and the resulting cell size. This leads to stress peaks which lower the mechanical properties. The Charpy impact strength shows a significant dependence on the fiber orientation. The specific bending modulus of the high-pressure foaming process, however, surpasses the values of the other two processes showing the potential of this manufacturing variation especially with regard to bending loads. Furthermore, a high dependence of the mechanical properties on the fiber orientation of the tested specimens can be found.

Development of Injection-Molded Gas Turbine Components: Investigation Into Toughening GTE PY6 Si3N4

1991 ◽  
Author(s):  
D. Sordelet ◽  
J. Neil ◽  
M. Mahoney ◽  
A. Hecker
Keyword(s):  
Gas Turbine ◽  
Process Development ◽  
General Motors ◽  
Injection Molding Process ◽  
Foreign Object ◽  
Molding Process ◽  
Foreign Object Damage ◽  
Research Activities ◽  
Injection Molded ◽  
Microstructural Control

GTE Laboratories has been supporting Allison Gas Turbine Division of General Motors under the current ATTAP program since early 1988. Injection-molding process development and component fabrication has been the emphasis of this effort, but material property enhancement studies have also been an important complement. Attempts to increase the resistance to foreign object damage have been made through parallel investigations of microstructural control and SiC whisker reinforcement. The research activities aimed at improving fracture toughness of GTE PY6 Si3N4 are discussed.

Interfacial Characteristics of Insert-Injection Molding by Using Acoustic Emission

2017 ◽  
Vol 728 ◽  
pp. 258-263
Author(s):  
Badin Pinpathomrat ◽  
Suchalinee Mathurosemontri ◽  
Supaphorn Thumsorn ◽  
Hiroyuki Hamada
Keyword(s):  
Acoustic Emission ◽  
Injection Molding ◽  
Adhesive Strength ◽  
Fracture Behavior ◽  
Acoustic Emissions ◽  
Injection Molding Process ◽  
Test Machine ◽  
Molding Process ◽  
Bonding Area ◽  
Injection Molded

Aim of this study focused on insert injection molding process, which is molded the melted polymer around an inserted part placed in the molded cavity of injection molding process. The interfacial adhesive strength between the inserted and an injected polymer parts were investigated by Intron universal test machine in order to investigate the effect of material in inserted and injected part. During tensile testing the acoustic emissions (AE) measurement was applied to evaluate the fracture behavior of insert injection molding. It was found that interfacial adhesive strength of insert injection molded of all specimens increased according with increasing the bonding area of adhesive interface. The fracture mode of the insert injection molded specimens was depended on the length of bonding area of the inserted part. The fracture of mode of the insert-injection molded specimens was confirmed by acoustic emission.

Study on Improving the Life of Stereolithography Injection Mold

2012 ◽  
Vol 468-471 ◽  
pp. 1013-1016 ◽  
Author(s):  
Hua Qing Lai
Keyword(s):  
Injection Molding ◽  
Injection Molding Process ◽  
Injection Mold ◽  
Molding Process ◽  
Molded Parts ◽  
Injection Molded ◽  
Plastic Parts ◽  
Assembly Operations ◽  
Conventional Injection Molding ◽  
Shape And Size

Molding is one of the most versatile and important processes for manufacturing complex plastic parts. It is a method of fabricating plastic parts by utilizing a mold or cavity that has a shape and size similar to the part being produced. Molten polymer is injected into the cavity, resulting in the desired part upon solidification. The injection-molded parts typically have excellent dimensional tolerance and require almost no finishing and assembly operations. But new variations and emerging innovations of conventional injection molding have been continuously developed to offer special features and benefits that cannot be accomplished by the conventional injection molding process. This study aims to improving the life of stereolithography injection mold.

scholarly journals Fabrication of ATTAP Ceramic Turbine Components

1990 ◽  
Author(s):  
R. W. Ohnsorg ◽  
J. E. Funk ◽  
H. A. Lawler
Keyword(s):  
Experimental Design ◽  
Process Optimization ◽  
Current Status ◽  
Injection Molding Process ◽  
Process Variables ◽  
Molding Process ◽  
Component Process ◽  
Technology Applications ◽  
Slip Cast ◽  
Injection Molded

The development and fabrication of sintered alpha SiC injection molded axial rotors and slip cast vortexes by Carborundum for the Advanced Turbine Technology Applications Project (ATTAP) are discussed. Key injection molding process variables and their levels were identified through modeling and experimental design. Post-HIPing improved the density, strength, and uniformity of injection molded components. The fabrication and strength of slip cast components were enhanced through dispersion and powder beneficiation studies. The component process optimization approaches and current status are presented for each.

Creep Modeling for Injection-Molded Long-Fiber Thermoplastics

2008 ◽  
Author(s):  
Ba Nghiep Nguyen ◽  
Vlastimil Kunc ◽  
Satish K. Bapanapalli
Keyword(s):  
Fiber Orientation ◽  
Fiber Length ◽  
Creep Model ◽  
Elastic Fibers ◽  
Injection Molding Process ◽  
Creep Response ◽  
Equivalent Inclusion Method ◽  
Long Fiber Thermoplastics ◽  
Orientation Distributions ◽  
Injection Molded

This paper proposes a model to predict the creep response of injection-molded long-fiber thermoplastics (LFTs). The model accounts for elastic fibers embedded in a thermoplastic resin that exhibits the nonlinear viscoelastic behavior described by the Schapery’s model. It also accounts for fiber length and orientation distributions in the composite formed by the injection-molding process. Fiber length and orientation distributions were measured and used in the analysis that applies the Eshelby’s equivalent inclusion method, the Mori-Tanaka assumption (termed the Eshelby-Mori-Tanaka approach) and the fiber orientation averaging technique to compute the overall strain increment resulting from an overall constant applied stress during a given time increment. The creep model for LFTs has been implemented in the ABAQUS finite element code via user-subroutines and has been validated against the experimental creep data obtained for long-glass-fiber/polypropylene specimens. The effects of fiber orientation and length distributions on the composite creep response are determined and discussed.

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