The Effect of Oil and Black on the Injection Molding of EPDM Compounds. I.

1969 ◽  
Vol 42 (5) ◽  
pp. 1321-1335
Author(s):  
William G. DePierri ◽  
J. R. Hopper
Keyword(s):  
Pressure Drop ◽  
Injection Molding ◽  
Flow Behavior ◽  
Injection Pressure ◽  
Flow Properties ◽  
Pressure Drops ◽  
Factors Affecting ◽  
Shear Rates ◽  
Divergent Flow ◽  
High Shear Rates

Abstract Factors affecting the flow properties of EPDM compounds have been studied and the findings of the study applied to the injection molding of these compounds. The level of oil and of black were found to change the flow properties of EPDM compounds. Higher levels of oil decreased the compound viscosity while higher levels of black increased the compound viscosity. The viscosity of the oil influenced compound viscosities. Compounds made with the more viscous (at 210° F) oil had slightly higher viscosities. However, changing from an aromatic to a naphthenic oil of similar viscosity had little effect on the compound viscosity. Compounds made from two different polymers of similar Mooney viscosity were found to have widely divergent flow behavior at high shear rates. Injection molding of EPDM compounds was studied with a molding assembly which had a capillary rheometer as barrel and plunger. Injection pressure data from the molding experiments was found to parallel closely the rheological data. An analysis of the pressure drops in passing through different parts of the mold assembly was made. The total calculated pressure drop agreed closely with the measured pressure drop. The viscous generation of heat was found to be proportional to pressure drop, and an equation is presented which relates the temperature increase to the pressure drop.

scholarly journals Effects of Nozzle Die Angle on Extruding Polymethylmethacrylate in Open-Source 3D Printing

2018 ◽  
Vol 15 (2) ◽  
pp. 663-665 ◽  
Author(s):  
Nor Aiman Sukindar ◽  
Mohd Khairol Anuar Mohd Ariffin ◽  
B.T. Hang Tuah Baharudin ◽  
Che Nor Aiza Jaafar ◽  
Mohd Idris Shah Ismail
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Pressure Drop ◽  
3D Printing ◽  
Open Source ◽  
Flow Behavior ◽  
Three Dimensional ◽  
3D Printer ◽  
Element Analysis ◽  
Factors Affecting

Open-source 3D printer has been widely used for fabricating three dimensional products. However, this technology has some drawbacks that need to be improved such as accuracy of the finished parts. One of the factors affecting the final product is the ability of the machine to extrude the material consistently, which is related to the flow behavior of the material inside the liquefier. This paper observes the pressure drop along the liquefier by manipulating the nozzle die angle from 80° to 170° using finite element analysis (FEA) for polymethylmethacrylate (PMMA) material. When the pressure drop along the liquefier is varied, the printed product also varies, thus providing less accuracy in the finished parts. Based on the FEA, it was found that 130° was the optimum die angle (convergent angle) for extruding PMMA material using open-source 3D printing.

Non-Newtonian Flow Behavior in Microchannels for Emulsion Formation

2006 ◽  
Author(s):  
Ravi Arora ◽  
Eric Daymo ◽  
Anna Lee Tonkovich ◽  
Laura Silva ◽  
Rick Stevenson ◽  
...  
Keyword(s):  
Shear Stress ◽  
Pressure Drop ◽  
Wall Shear Stress ◽  
Power Law ◽  
Flow Behavior ◽  
Scale Up ◽  
High Wall Shear Stress ◽  
Shear Rates ◽  
Wall Shear ◽  
Low Shear

Emulsion formation within microchannels enables smaller mean droplet sizes for new commercial applications such as personal care, medical, and food products among others. When operated at a high flow rate per channel, the resulting emulsion mixture creates a high wall shear stress along the walls of the narrow microchannel. This high fluid-wall shear stress of continuous phase material past a dispersed phase, introduced through a permeable wall, enables the formation of small emulsion droplets — one drop at a time. A challenge to the scale-up of this technology has been to understand the behavior of non-Newtonian fluids under high wall shear stress. A further complication has been the change in fluid properties with composition along the length of the microchannel as the emulsion is formed. Many of the predictive models for non-Newtonian emulsion fluids were derived at low shear rates and have shown excellent agreement between predictions and experiments. The power law relationship for non-Newtonian emulsions obtained at low shear rates breaks down under the high shear environment created by high throughputs in small microchannels. The small dimensions create higher velocity gradients at the wall, resulting in larger apparent viscosity. Extrapolation of the power law obtained in low shear environment may lead to under-predictions of pressure drop in microchannels. This work describes the results of a shear-thinning fluid that generates larger pressure drop in a high-wall shear stress microchannel environment than predicted from traditional correlations.

Rheology of Plastisols of Poly(Vinyl Chloride)

1979 ◽  
Vol 52 (3) ◽  
pp. 676-691 ◽  
Author(s):  
E. A. Collins ◽  
D. J. Hoffmann ◽  
P. L. Soni
Keyword(s):  
Flow Behavior ◽  
Basic Mechanism ◽  
Particle Sizes ◽  
Solvent Interaction ◽  
Factors Affecting ◽  
Shear Rates ◽  
Wide Range ◽  
Size Of Particles ◽  
Increasing Temperature ◽  
Future Work

Abstract The viscosity of PVC plastisols is seen to be affected by numerous variables. Increase in concentration of the resin causes the viscosity to rise, with the increase being more abrupt at the higher concentrations. Deviation from Newtonian behavior also increases with concentration. Decrease in the size of particles results in an increase in viscosity, the effect being more pronounced at low shear rates. Broadening the distribution of particle sizes results in a decrease in viscosity. Porous particles yield plastisols with higher viscosity as compared to nonporous compact particles. The type of plasticizer also affects the viscosity. A plasticizer which is a better solvent for PVC (low value of polymer-solvent interaction parameter, χ) results in a higher viscosity due to an increase in the amount of dissolved polymer. Additives such as alcohols and soaps affect the viscosity in an, as yet, unknown way. Fillers, heat stabilizers, and pigments also increase the viscosity. With increasing temperature, the viscosity first decreases, passes through a minimum and then increases until gelation. With further rise in temperature the viscosity again decreases and then levels out before degradation occurs. In future work, particular emphasis needs to be given to the understanding of the basic mechanism involved in the effect of additives on the flow behavior. Systematic experiments with a range of well-defined particle sizes and over a wide range of shear rates are also needed. A better understanding of the factors affecting the behavior of plastisols will go a long way in changing the art of plastisol formulation to a science.

S0520301 Flow Properties of Several types of Surfactant Solutions in High Shear Rates

2014 ◽  
Vol 2014 (0) ◽  
pp. _S0520301--_S0520301-
Author(s):  
Akiomi USHIDA ◽  
Tomiichi HASEGAWA ◽  
Takatsune NARUMI ◽  
Ryuichi KAYABA
Keyword(s):  
High Shear ◽  
Flow Properties ◽  
Shear Rates ◽  
Surfactant Solutions ◽  
High Shear Rates

Characterizing Energy Consumption in Injection Molding: Model Versus Logger

2018 ◽  
Vol 140 (3) ◽  
Author(s):  
Andrea Sánchez-Valencia ◽  
Julien Loste
Keyword(s):  
Energy Consumption ◽  
Injection Molding ◽  
Specific Energy Consumption ◽  
Injection Pressure ◽  
Pressure Drops ◽  
Advantages And Disadvantages ◽  
Process Characteristics ◽  
Energy Models ◽  
Novel Approach ◽  
Statistical Systems

Recent changes in legislation along with environmental initiatives to drive sustainability and reduce carbon emissions have sprouted the development of energy models to characterize manufacturing processes. In the case of injection molding, much work has been performed in coupling sensors with control statistical systems to promptly identify process' instabilities, such as pressure drops or fluctuations in the filling point. Latest energy models for injection molding make use of injection pressure and temperature parameters that are a function of the machine, mold geometry, and process characteristics. The latest state-of-the-art way to measure energy consumption is through the use of energy loggers, which provide power data at the end of the production cycles. Although seemingly correlated, little has been published on the extrapolation of cavity signals for their use in energy calculations. In this study, the advantages and disadvantages of using cavity sensors in injection molding are explored; a novel approach to the use of cavity sensors' pressure and temperature data is proposed by exploring their input in an energy model for the estimation of specific energy consumption (SEC). The model was validated against power data obtained via an energy logger; the averaged energy reported by the model indicated a range of 60–67% accuracy.

Flow of Finite Element Analysis of Metal Powder in Medal Injection Mold Runner

2011 ◽  
Vol 189-193 ◽  
pp. 2255-2258
Author(s):  
Jie Jin ◽  
Xin Bai ◽  
Fang Yin Ning
Keyword(s):  
Injection Molding ◽  
Flow Behavior ◽  
Continuum Theory ◽  
Injection Pressure ◽  
Metal Injection Molding ◽  
Element Analysis ◽  
Circular Section ◽  
Die Filling ◽  
Control Equation ◽  
And Control

Based on the continuum theory, combined with the characteristics of metal injection molding, constructs assumptions and control equation in the die filling process of MIM.With the FLOTRAN hydro-analysis module of ANSYS software, the melt’s velocity ,temperature and pressure fields during injection molding were simulated and compared for different sizes of circular section runners,and discussed the influences between different diameter runners and injection pressure on the flow behavior of melt. The simulation provided theoretical guidance for the design and selection of mold runner in the production.

scholarly journals In-mold and Machine Sensing and Feature Extraction for Optimized IC-tray Manufacturing

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1348 ◽  
Author(s):  
Shih-Chih Nian ◽  
Yung-Chih Fang ◽  
Ming-Shyan Huang
Keyword(s):  
Injection Molding ◽  
Optimal Parameter ◽  
Flow Behavior ◽  
Injection Pressure ◽  
Effective Control ◽  
Injection Molding Process ◽  
Molding Process ◽  
Operator Experience ◽  
Injection Speed ◽  
Screw Position

Injection molding is a mature technology that has been used for decades; factors including processed raw materials, molds and machines, and the processing parameters can cause significant changes in product quality. Traditionally, researchers have attempted to improve injection molding quality by controlling screw position, injection and packing pressures, and mold and barrel temperatures. However, even when high precision control is applied, the geometry of the molded part tends to vary between different shots. Therefore, further research is needed to properly understand the factors affecting the melt in each cycle so that more effective control strategies can be implemented. In the past, injection molding was a “black box”, so when based on statistical experimental methods, computer-aided simulations or operator experience, the setting of ideal process parameters was often time consuming and limited. Using advanced sensing technology, the understanding of the injection molding process is transformed into a “grey box” that reveals the physical information about the flow behavior of the molten resin in the cavity. Using the process parameter setting data provided by the machine, this study developed a scientific method for optimal parameter adjustment, analyzing and interpreting the injection speed, injection pressure, cavity pressure, and the profile of the injection screw position. In addition, the main parameters for each phase are determined separately, including injection speed/pressure during the mold filling phase, velocity-to-pressure switching point, packing pressure and time. In this study, the IC tray was taken as an example. The experimental results show that the method can effectively reduce the warpage of the IC-tray from 0.67 mm to 0.20 mm. In addition, the parameters profiles obtained by parameter optimization can be applied for continuous mass production and process monitoring.

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