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.
In this work, specially designed zero-length dies were used for the entrance pressure drop measurements with the aim to determine uniaxial extensional viscosity of polyolefin melts by using effective entry length correction and Cogswell/Binding models and the results were compared with the extensional rheology determined with the Sentmanat extensional rheometer. Reasonable agreement between these two techniques has been obtained.
Scratching mechanisms of injection molded PC/ABS blend were investigated. The scratching damage was microscopically observed by OM, SEM, and TEM. The scaly pattern and bank were observed in ploughing, wedge formation and cutting modes commonly. The micro cracking appeared in the bank in the case of cutting mode, and it would become internal cracks growing to the cracks and a cutting tip. The film laminated structure near the surface induced by injection moldings severely deformed and wavy pattern and elongated particles were found in the bank.
In recent industry, with the miniaturization and high-precision of machine part, the development of mold manufacturing technology for mass production is accompanied by the development of new technology such as IT and BT. In this study, the spiral type injection mold with a 200 ? thickness is made for investigating the influence of injection molding parameter and the flow length is measured through an experiment. Besides, Taguchi method is used in this experiment and the obtained data are analyzed using ANOVA method.
In this study, the effect of variety foaming agents in bio-based polymer such as chemical blowing type of AC and BIH, and physical type of microsphere, has been investigated. The basic matrix of bio-based polymer was compounding PLA with native starch and calcium carbonate in twin screw extruder prior to introducing variety foaming agents at low temperature by dynamic rheometer to avoid the degradation of foaming agents.The topology of cross-section of their foams structure by SEM revealed that physical type of microspheres attained much better density but lower porosity than the others.
In the Rapid Heat Cycle Molding (RHCM) Process, the mold temperature is rapidly changed in each cycle to improve part quality and reduce cycle time. In this paper, an integrated fully transient true 3D simulation approach is proposed by considering the interplay between filling/pack and cooling stages to study and further optimize the RHCM process.
The injection molding process is a highly complex system in which multiple variables influence the final molded part quality. This paper investigates a multivariate approach to on-line quality prediction and monitoring that can be fully and readily implemented for production purposes. This approach consists of determining and monitoring the most important process data features that are generally available and automatically correlating them to critical quality attributes.
This study investigates the performance of nanojet printing processes by molecular dynamic simulation. By compressing water molecules in the Au nozzle, the whole nanojet printing process for different operation conditions are simulated. Distributions of velocity, temperature, pressure, density, and so on, are also discussed in this study. The results form various systems show that the lower operational temperatures make nanojet processes more stable and thus reduce satellite droplets. Results that show various features can help understand these processes.
A transparent mould with two injection locations, allowing flow visualization on both conventional and two materials injection molding, was used in this research.The aim of this work is to monitor and assess the polymer melt behavior under controlled processing conditions, during the filling and holding stages of the molding cycle. Visual access in the mould is allowed by the sapphire windows, surrounding the cavity. Visualization results are combined with local pressure and temperature measurements and compared with Moldflow MPI software simulations.
With increase of injection molding CAE and adoption of 3D mesh which takes more computation time in analysis, gate location optimization in shortest time and smallest resources becomes most important issue. This paper discusses about the process of determining the gate locations using injection molding CAE, and the technologies developed for the optimization, which controls flow balance and weldline of molded parts.
In this study, the effects of process parameters of plastic pipe production to the plastic pipe's wall thickness were examined. Process and wall thickness data were collected in a regular time period and statistical calculation made according to these data. X-R control schemes drawn and process capability indices were calculated. Data points, which were out of control in a statistical manner, were determined and process parameters which causes these variations determined.
Blending Polylactide (PLA) and thermoplastic starch (TPS) generally leads to brittle materials. It was found however that if the blends are properly compatibilized through reactive extrusion and plasticized, the TPS phase can significantly increase the ductility of the material leading to materials with elongation at break in excess of 200%. This paper examines compatibilization and plasticization strategies to combine PLA and TPS into useful injection moldable materials.
We studied how the dimensions of test specimens affect EWF results. One grade of commercial HDPE was evaluated. We demonstrate that reductions of ? 20 to 30% of conventional dimensions used for DDENT geometry allow reproducible and valid results, similar to those obtained with larger specimens. Results show that it is not possible to reduce dimensions more than 30% and still comply with geometric validations related to EWF.
Poly(lactic acid) (PLA) is an excellent biodegradable polymer that is widely used. The processing conditions of PLA were established by developing a Molding Area Diagram (MAD) on a Roboshot® injection molding machine with different mold temperatures. Isothermal bulk crystallization kinetics of the PLA with 1weight% of talc as a nucleating agent was studied on DSC.
The work deals with crystallization of photodegraded polypropylene containing various amounts of ?-nucleating agent. Samples were irradiated by UV-light, melted and subsequently non-isothermally crystallized. The results showed that the crystallization temperature decreased with increasing irradiation time. The irradiation caused the splitting of crystallization exotherms into two peaks indicating two crystallization mechanisms. The presence of ?-nucleating agent in the material suppressed the peak splitting.
This paper presents the results from investigations into the differences in moulding with a novel anodised machined aluminium mould material and a conventional machined aluminium mould material. Significant differences in terms of cycletime were observed between the moulding carried out with the anodised moulding and the conventional aluminium mould surface material with no change in the shrinkage, part appearance or mechanical properties noted between either.
Color is an essential part of life for human beings. It influences our bodies, our minds and our souls. Our physiological, psychological and emotional responses to color have been studied in great detail. Over time the appeal of colors changes, leading to color trends in the market place. As new colorant and special effect technologies become available, our color choices and preferences continually evolve. Studying color perception and trends could provide the edge we, as an industry, seek in better understanding the market place.
The wetting behavior of poly(dimethylsiloxane) (PDMS) ionomers on a silica surface was investigated. Spin-cast films of Li-salts of a carboxylated PDMS (Li- CPDMS) on silica resisted dewetting even after annealing at 120°C for 144 h, while the unmodified PDMS did not even form a homogeneous film.
Improved color mixing for injection molding can be improved by different variables. Screw speed, melt temperature, backpressure, barrel temperature profiles, screw design, dispersion discs, etc. can all influence color dispersion. This study will focus on the screw design and its affect on color mixing and its affect on other process parameters.
In this work, the high stalk film blowing model derived by using variational principles has been used to investigate the effect of cooling on the HMW – HDPE bubble formation with respect to final film properties. Moreover, the effect of the molecular weight and long chain branching has been theoretically studied by the help of the newly proposed generalized Newtonian model.
This work had two aspects. In the first one, the interaction between CO2 and nylon-6,6 melt is explored by investigating by the effects of CO2 on nylon-6,6 shear viscosity and hydrogen bonding. In the second one, an attempt is made to establish feasible conditions for spinning of nylon-6,6/CO2 mixtures, to produce nylon filaments. Extrusion and spinning experiments of nylon- 6,6 / CO2 were conducted on a twin- screw extruder line and the effects of carbon dioxide on viscosity and spun filaments morphology and tensile properties were investigated.
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Brown, H. L. and Jones, D. H. 2016, May.
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ANTEC 2016 - Indianapolis, Indiana, USA May 23-25, 2016. [On-line].
Society of Plastics Engineers
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