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.
|= Members Only|
Stability of Two-Stage Single-Screw Extruders
In two-stage extrusion, the pumping section must be sized to produce the needed delivery pressure of the extruder. A method of calculating the channel depth so that the desired pressure is achieved and that the stability of the flow is optimized has been developed. Data for an example are given.
Structure Development in Melt Spinning of Cyclopolyolefin Filaments
Melt spinning of cyclo-polyolefins is presented. The birefringences of the melt-spun filaments were determined and contrasted with spinline stress. These were found to be much lower than polycarbonate and polystyrene filaments melt spun under the same conditions. The birefringence was represented in terms of polymer chain orientation.
Structure of Nanocomposites Foams
Exfoliated and intercalated polymer/clay nanocomposites were synthesized and used to prepare nanocomposite foams, using CO2 as the foaming agent. The foam structure was observed by scanning electron microscopy (SEM), while transmission electron microscopy (TEM) was used to observe the detailed clay distribution. The effect of clay dispersion and clay concentration on the cell structure was investigated.
Studies on the Influence of the Holding Pressure on the Orientation and Shrinkage of Injection Molded Parts
The shrinkage is determinant on the final dimensions of technical parts. This feature of the injection moldings is dependent on the processing setup, namely the holding pressure and the molding temperature.In this paper results are presented on studies made on a semi-crystalline material and an amorphous material that were molded in planar and tubular moldings. The shrinkage was directly measured and related to the frozen-in orientation of the part. The orientation was indirectly quantified by the across-thickness variation of the birefringence.
A Study of Degradation of LLDPE under Accelerated Conditions
In order to use linear low density polyethylene (LLDPE) as external duct lining of oil pipes, we have evaluated the aging of this polymer. The experiment has been carried out under accelerated UV fluorescent lamps exposure, during 336 hours.We focused our investigation on changes on mechanical properties occurring over the aging process.The LLDPE studied was mixed with peroxide in order to modify its properties.
Study of PVC Stabilization Using Capillary Rheometry
Capillary rheometry allows monitoring PVC thermal and shear stress degradations separately. Based on testing of PVC compounds with a capillary rheometer, stabilizers can be efficiently optimized to reduce both degradation processes. Capillary rheometry is an important tool to improve productivity of PVC processing further at high shear rates.
Study of the Effect of Velocity-to-Pressure Transfer Method on Process Robustness in the Injection Molding Process
This study will compare the use of several different transfer modes during the filling phase of the injection molding process. These modes include screw position, hydraulic pressure, and melt pressures within the cavity and nozzle. The modes will be investigated by using cavity pressure consistency when regrind and check ring wear are introduced. There are 4 transducers located in different areas within the cavity that will measure the peak pressures.
Styrene Block Copolymer Modified Food Wrap Film
Stretch wrapping film has been used for over 30 years to protect and preserve food from moisture, dirt and abrasion. These films allow increased food shelf lives and give the package an appealing smooth and shiny appearance.Styrenic block copolymers can be blended with polypropylene and co-extruded with ethylene vinyl acetate to form multi-layer structures suitable for food wrap applications. These films offer an excellent balance of properties combined with a low density.
Synthesis and Characterization of Liquid Crystalline Polyamides
By creating a dynamic interaction between aromatic and aliphatic compounds, a novel liquid crystalline polyamide was produced. By mixing various ratios of the aromatic 4,4-dimethyl bibenzoate and the flexible aliphatic 18-carbon diacid, with a stoichiometric equivalent of a single diamine, a variety of properties were developed. The homopolymer for the m-xylylene diamine produced a liquid crystalline regime of nematic and thermotropic behavior, which was the goal. Each species of diamine used; hexamethylene diamine, m-xylylene diamine, and p-xylylene diamine produced unique and distinct novel polymers.
Taguchi Based Design of Experiments of HDPE and Granite Fines
Granite-filled HDPE had lower tensile strength, modulus and elongation than unfilled HDPE. The reduction in properties is attributed to large particles that serves as stress concentrators. The mechanical properties of HDPE are improved with the use of adhesion promoters and use of metallic granite. A Taguchi design of experiment determined that the metallic component of the granite fines had higher tensile strength, modulus, hardness, and elongation at yield than the bulk granite fines.
Temperature Sensitivity of the Linear Viscoelastic Properties of Long Chain Branched Metallocene Polyethylene
The effects of long and short chain branching on the thermorheological behaviour of polyethylene are described. Long chain branched homo -polyethylene is thermorheologically complex and is most sensitive to temperature at low frequency. A technique for determining the activation energy spectra of thermorheologically complex materials is proposed. Short and long branches in the same system synergistically increase the zero-shear rate activation energy.
Tensile Properties of PE Clay Nanocomposites via Taguchi Based Design of Experiments
LDPE and HDPE clay nanocomposites prepared with melt mixing demonstrate increased stiffness and strength with increasing concentrations of clay nanocomposites and adhesion promoters. Taguchi design of experiment (DOE) methodology determined the optimum material conditions to achieve maximum strength and stiffness. The nanocomposites increased tensile modulus and tensile strength, but reduced elongation of LDPE and HDPE. Maleic anhydride and acrylic acid improved the tangent modulus and ultimate tensile strength of polyethylene/clay nanocomposites.
Terpolymer Sequences and Geometric Distribution
Chain sequence distribution calculations for terpolymers using probability model and Monte Carlo simulation methods are discussed. The SSS, AAA, SAS, SSA, ASA, AAS trial concentration are obtained. Molecular weight and ceiling temperature effects are studied using the Monte Carlo method.
Three-Dimensional Filling and Post-Filling Simulation of Metal Injection Molding
A 3D finite element code including free-surface flow is used to simulate metal injection molding (MIM) of a stainless steel compound with an aqueous gel binder. The thermal analysis couples the highly conductive MIM compound with the mold wall. Predictions are compared with pressure and melt temperature data for filling and packing a long thin plate over a wide range of operating conditions. The purpose of this work is to advance MIM technology, as has been done in the plastics industry, by interactive use of experiment and simulation.
Three-Dimensional Simulation of Thermoset Molding Applied to Semiconductor-Chip Encapsulation
In this paper, numerical methods to analyze the flow of thermoset materials during the molding process have been developed. A finite-element method is used for the three-dimensional flow analysis. The numerical analysis results have been verified by comparing with experiments. In the experiment, a semiconductor chip encapsulation process using a thermoset-molding compound has been used to observe the melt-front advancement shapes. The calculated and experimental results show good agreement.
Time-Resolved SAXS Studies on the Crystallization Behaviors of Poly(Ethylene Terephthalate) and its Copolymers
Using synchrotron radiation sources of Pohang Light Source, Pohang University of Science & Technology, Korea, small-angle X-ray scattering (SAXS) measurements have been carried out for poly(ethylene terephthalate) (PET) and poly(ethylene isophthalate-co-terephthalate) s which undergo isothermal crystallization and during subsequent re-melting. Differential scanning calorimetric (DSC) measurements were additionally conducted.
Transient Behavior of Extruders: Input Disturbances
A model of the transient response of an extruder to varying input feed rates and screw speed was developed and used to study the effect of input disturbances on the extrusion process. Simulated tests reveal that given a screw design, there is a critical frequency below which disturbances will not be damped significantly by the extruder. The relationship between screw geometry and this critical frequency is presented. The effect of specific throughput (Q/N) on damping ability of a screw geometry is also presented in this paper.
Transient Simulation of Film Blowing Process
Analysis of film blowing process using a transient, axisymmetric, non-isothermal, viscoelastic model is presented in this paper. The model developed is solved using the finite element method. Constitutive behavior of the polymer is described using a combination of modified Phan-Thien-Tanner model and anisotropic Kelvin-Voight model. A simple crystallinity model is used to describe the phase change and crystallization kinetics. Steady state solutions predicted by the model are compared with experimental results, these results along with transient results are presented in this paper.
Troubleshooting Dehumidifying Dryers
Engineering materials - such as nylon polycarbonate and the like - have a molecular attraction for moisture and are hygroscopic polymers. When exposed to a humid atmosphere these materials take up and retain water. However this process can be reversed if the pellets are exposed to an artificial environment where the air temperature and dewpoint is precisely controlled for a pre-determined length of time. A good understanding of four fundamental drying parameters along with the basic principles of operation of a dehumidifying dryer are essential to troubleshooting a drying system."
Ultrasonic Application Solutions Using the Latest Advances in Equipment Technology
Ultrasonic welding is used in many applications. The benefits of the welding process include: elimination of consumables, fast cycle times, compact machine footprint, and relatively low cost capital investment. New advances in ultrasonic products and technology make this method possible for applications not previously suitable for ultrasonics. Today’s equipment can program and profile weld and hold force as well as amplitude during the weld cycle. Also, new frequencies have been introduced which expand the capabilities of horns and energy transmission.
We're sorry, but your current web site security status does not grant you access to the resource you are attempting to view.
Any article that is cited in another manuscript or other work is required to use the correct reference style. Below is an example of the reference style for SPE articles:
Brown, H. L. and Jones, D. H. 2016, May.
"Insert title of paper here in quotes,"
ANTEC 2016 - Indianapolis, Indiana, USA May 23-25, 2016. [On-line].
Society of Plastics Engineers
Note: if there are more than three authors you may use the first author's name and et al. EG Brown, H. L. et al.
If you need help with citations, visit www.citationmachine.net