SPE Library
The SPE Library contains thousands of papers, presentations, journal briefs and recorded webinars from the best minds in the Plastics Industry. Spanning almost two decades, this collection of published research and development work in polymer science and plastics technology is a wealth of knowledge and information for anyone involved in plastics.
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Conference Proceedings
Rational Integration of Magnetizable Polymers for Sensor Applications
D. Drummer, G.W. Ehrenstein, May 2001
Besides improvements in the optical and mechanical properties as well as carrier-functions for conductive metal layers, the functionality of polymers in electronic applications can be extended through addition of specific fillers. Thereby, the properties of the filled polymer can approach those of the filler, Table 1. Compounding magnetizable fillers into a polymer matrix allows for the rational manufacture of more complex permanent magnets with improved material characteristics by the injection molding process.
On-Line Morphology Control and Novel Extruded Blends Produced by Continuous Flow Chaotic Mixing
S. Inamdar, D.A. Zumbrunnen, May 2001
Present-day blending technology was developed primarily to forcibly melt and mix polymers and additives. Desired morphologies are often pursued by time consuming iteration. In this study, a new continuous flow blending process is described where morphology develops progressively and more controllably by chaotic mixing. A variety of commercially important blend morphologies, including very highly multilayered blends, are described that have been extruded. The process may serve as a basis for new blending and multilayer film technologies.
Non-Newtonian Flow and Debris Deposition in an Extrusion Filter Medium
B. Seyfzadeh, D.A. Zumbrunnen, R.A. Ross, May 2001
An engineering model was developed to predict the debris particle deposition of a non-Newtonian melt in an extrusion filter medium. The model is based on mass conservation in a three-dimensional finite volume space in conjunction with a power law modified Darcy's equation for porous media flows. Validation was performed by comparison to start-up pressure drops across filter media employed in fiber spinning. Parametric studies revealed the influence on debris deposition of various filter housing contours and power law indices.
Use of the Compact Tension Specimen to Study ESCR in Polyethylene
C.N. Marzinsky, A. Lustiger, May 2001
A technique is described that enhances the ASTM D5397 Constant Tensile Load (CTL) test by replacing the standard type L" dogbone specimen with a Compact-Tension (CT) specimen. By measuring the center-line crack opening displacement (COD) of the CT specimen while stressed under a test solution one can describe crack growth properties in terms of a stress intensity factor (K) and estimate a corresponding crack growth rate."
Cooling of Coated Cable
Lukas Placek, Jiri Vlcek, May 2001
For the task of designing cooling parts of a cable coating line, it is very helpful to use modeling of the temperature behavior of the product in cooling line. This presentation shows two models, which can be used for numerical simulations. Authors also deal with the question, if the heat flux in direction of the movement is negligible. The comparison of results of simulated cases and measurement on real coated cables is shown.
Impact Modification of Nylon 6,6-An Experimental Study
Paul Elkouss, Rajath Mudalamane, Yue Huang, Keita Broadwater, David Bigio, May 2001
The effect of operating and feeding conditions on the impact modification of Nylon 6,6 with Poly-Olefin Rubber Impact Modifier (POIM) were studied. The results indicated that the notched izod values are uniformly higher for the samples with POIM fed separately downstream than those of the preblended samples. The notched izod values also show a slight correlation to the throughput, Q. The existence of a critical interparticle distance was verified by image analysis.
Extensional Flow Properties from Entrance Pressure Measurements Using Zero Length Die Versus Bagley Correction
J. Sunder, A. Goettfert, May 2001
As melt flows from the barrel of a capillary rheometer into a die the streamlines converge, producing a strong extensional flow. The entrance pressure loss is determined with orifice die and Bagley correction. The failure of the measurement with orifice die like outlet angle and length of the die is evaluated and extensional viscosity is calculated using the theory of Cogswell. The results of extensional viscosity will be compared with Rheotens elongation data.
Dynamic Cooling Design for Injection Molding
David Hatch, David Kazmer, Bingfeng Fan, May 2001
The current system of injecting hot polymer into a comparatively cold mold results in the development of a solidified layer and reduction in part quality. As a consequence of this process limitation, molding systems continue to produce inferior components during production. This paper develops an innovative mold design and preheating process to dynamically control the temperature at the mold-polymer interface during the molding cycle. Simulation indicates that a preheat system can significantly reduce residual stress compared to conventional molding given equivalent cycle times.
Acoustic Telemetry in Injection Molding
Charles Burton Theurer, Li Zhang, Robert Gao, David O. Kazmer, May 2001
The characterization of acoustic noise present in an injection mold during operation is presented for a remote in-cavity pressure sensor. This analysis is necessary to evaluate the use of ultrasound to carry process information out of the mold cavity. Experimental results are presented consisting of amplitude and frequency analysis of acoustic noise present in an injection mold as well as first attempts at transmission and demodulation of acoustic data.
Injection Nozzle Ultrasound Measurements
E.C. Brown, A.J. Dawson, P.D. Coates, May 2001
Ultrasonic measurements are a rich source of information during polymer processing. Difficulties in applying sensors to injection moulding nozzles have been overcome, and ultrasonic velocity measurements are being used to indicate process dynamics in terms of temperature and pressure change during injection. This work describes employment of a novel nozzle in which an ultrasonic signal is propagated along a path angled to the direction of melt flow, such that flow rate effects contribute to the received signal.
Creep Crack Growth in Oriented Polypropylene
J.B. Slay, Z.-Y. Xia, H.-J. Sue, May 2001
Creep (slow) crack growth resistance in oriented polypropylene (PP) is investigated using a fracture mechanics approach. The equal channel angular extrusion (ECAE) process is used to induce structural anisotropy. A constant load single edge notched bend (SENB) test is performed at an elevated temperature on isotropic (unprocessed) and anisotropic (processed) PP. This test generates stress intensity (K) vs. crack growth rate (da/dt) relationships. The da/dt = Kn relationship reveals that the creep crack growth resistance and mechanical properties of PP can be greatly improved by ECAE.
Plastics Education in the Delft University Industrial Design Engineering Curriculm
Rolf Koster, Anton Heidweiller, May 2001
Industrial Design Engineering graduates from Delft University have a background in a wide range of subjects, including plastics. They have been prepared for industrial product development practice by design exercises throughout the curriculum. In these exercises the students apply various subjects, including design of plastics components. The students' general technical and plastics background is expected to improve by curriculum adjustments currently being prepared. Product Design graduates have received additional training in designing with plastics.
Measurement of Entrance Pressure Drop of Polystyrene/Supercritical CO2 Solutions
Anle Xue, Costas Tzoganakis, May 2001
Two slit dies with sudden contraction ratios of 4:1 and 18:1 were designed to investigate the effects of pressure and supercritical carbon dioxide (scCO2) content on the entrance pressure drop and rheological properties of PS/CO2 solutions. scCO2 was found to decrease the entrance pressure drop as well as the shear and extensional viscosities of PS.
Compatibilizing EPDM and Degraded PP through Hydrosilylation Reaction
Claudio Villas-Boas, Luiz Mario Nelson de Goes, Costas Tzoganakis, May 2001
A hydride-terminated PDMS was used as a coupling agent for EPDM and degraded PP (previously generated all the way in melt phase by peroxide initiated degradation) through a hydrosilylation reaction in the melt-phase. Different concentrations of PP with different degrees of degradation were used, and different amounts of catalysts were employed. Melt viscosity, blend morphology and gel were evaluated. The reaction was found to increase viscosity and to improve blend morphology.
Simulation and Analyses of the Polymer-Pellet-Flow into the First Section of a Single Screw
H. Potente, T.C. Pohl, May 2001
The flow of plastics pellets into the first flights of the screw is frequently neglected when analyzing the solids conveying process in single-screw extruders. In order to gain better insight into the complex correlations that exist between pellet properties, barrel and screw geometry, the inflow process is simulated and investigated in experimental terms. Based on these findings a simple physico-mathematical model is worked out. The aim is to develop an optimum filling geometry in respect of feed behavior and solids conveyance.
Scratch Behavior in Molecularly Oriented Polycarbonate
Zhiyong Xia, Chen Xiang, Masaya Kotaki, Hung-Jue Sue, May 2001
In this paper the scratch behavior of molecularly oriented polycarbonate (PC) is investigated. Controlled molecular orientation is achieved through the equal channel angular extrusion (ECAE) process. Ford five-finger scratch test is used to investigate the orientation effect on the scratch resistance (in terms of scratch depth) in the ECAE-oriented PC. This study shows that controlled molecular orientation can improve the scratch resistance in polymers.
Investigation of the Volume Recovery of Glass-Forming Polymers
Hung-Jue Sue, Sindee L. Simon, May 2001
Up to now, the time dependent behavior of glass-forming polymers has been modeled with only moderate success. This could be explained by the fact that the relaxation times depend on the time-temperature- pressure history of the material rather than on the instantaneous state as is generally assumed. We have developed new volume recovery experiments to examine this assumption. The impact of our results on the current theoretical models will be discussed.
Full 3-D Prediction of Warpage of Injection Molded Parts
Y. Inoue, K. Imai, M. Takahara, Y. Murayama, T. Matsuoka, K. Shinoda, Y. Mori, May 2001
A full 3-D CAE system has been developed to predict warpage of thermoplastic injection molded parts. The system consists of pre/post processors and full 3-D solvers of mold cooling, polymer filling, packing and warpage. The validity of the warpage prediction was verified by using a box-shaped part and a L-shaped one. Although they were thin-walled parts, it was confirmed that the full 3-D simulation was necessary for the accurate prediction of their warpage.
Flow Visualization of Polymer Processing Additives Effects
K.B. Migler, C. Lavallée, M.P. Dillon, S.S. Woods, C.L. Gettinger, May 2001
Flow visualization was used to understand how polymer-processing additives (PPA) eliminate sharkskin in linear low-density polyethylene (LLDPE). A sapphire capillary die was used to image the coating of the PPA onto the die wall. Depth resolved optical microscopy was used to measure the velocity profiles. When added, the PPA migrates to and coats the die wall, induces slippage, and eliminates sharkskin. The interface between the PPA and LLDPE is characterized by long stripes in the flow direction.
Structure-Property Relationships in HMW-HDPE Blown Films
Rajendra K. Krishnaswamy, May 2001
The influence of processing conditions on the performance of HMW-HDPE blown films was investigated in relation to their molecular orientation characteristics. The presence of two distinct populations of lamellar stacks in such HMW-HDPE blown films and their influence on the physical properties was also considered. Finally, the dart impact strength of certain HMW-HDPE blown films was observed to increase with increasing draw-down ratios (decreasing film thickness); the morphological features that drive this unique structure-property relationship was explored as well.
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