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
TIPS FOR OPTIMIZING TWIN-SCREW EXTRUDER PERFORMANCE
Bert Elliott, May 2012
A collection of 17 techniques is presented for increasing the performance of twin-screw extruders. Processors may be aware of some of these tips, but many are not well known. All are based on solid scientific principles, and have been proven in dozens of extruder installations. Also, all techniques presented are easy to apply, so the benefits can be realized quickly.
ACCELERATED TESTING AND LIFETIME PREDICTION FOR PLASTIC PIPES
Alexander Chudnovsky, Zhenwen Zhou, Haiying Zhang, May 2012
Short-term tests are used in many branches of Science and Engineering to predict future outcomes of long-term processes. It is important to ascertain criteria of similarity between the short-term test and real life events. The criteria for predicting lifetime must reproduce the mechanisms of field failures and have a technically sound procedure for extrapolation of a relatively short test data. A quantitative modeling approach as an alternative to “empirical” extrapolation is proposed in this paper.
STUDIES OF DEGRADATION EFFECTS DURING ROTATIONAL MOLDING
Payman Sharifi, Nick Henwood, Chris Liauw, Graham Lees, May 2012
This paper describes a program to assess degradation effects on polyethylene, the most common polymer used in rotomoulding. Polyethylene was compounded with a variety of antioxidant (AO) combinations, pulverized to a powder and then rotationally moulded. The impact strength of samples cut from the rotomoulded parts was correlated with assessments of material condition made using Carbonyl Index (CI) and Yellowness Index (YI). Significant differences were observed between different AO formulations.
TROUBLESHOOTING PLASTICS INDUSTRY POWDER STORAGE & HANDLING PROBLEMS USING FLOW PROPERTIES
Brian Pittenger, May 2012
This paper describes four basic flow properties of powders and bulk solids and how these properties may be used in diagnosing flow problems in existing handling processes. Included are cohesive strength, frictional properties, permeability, and segregation tendencies. Examples of common flow problems in typical handling systems are provided as well as how a specific flow property may be the controlling factor. Using these properties, a system may be evaluated, and corrective actions developed to eliminate the flow-related problems.
VARIABLE STRENGTH STRESS BEAD ANALYSIS IN A TWIN SCREW EXTRUDER
William Pappas, Harry Brown II, Graeme Fukuda, Roba Adnew, David Bigio, May 2012
An experiment has been created that relates stress distribution history with residence time distribution. To quantify the results, stress beads that break up at a specific stress were used to measure the percent of material that sees those critical stress values throughout the extruder. Two different strength stress beads were used along with two different mixing section geometries. This paper describes results for a range of different throughputs and speeds in the extruder.
ADDITIVE MIGRATION IN POLYMER FILMS
none, May 2012
Additives are commonly blended into polymer films. Oftentimes the additives and the film resins are incompatible, which leads to blooming of the additives to the film surfaces. This research focuses on quantifying the amount of additive exuded to the surfaces over time. Examples include slip agents, anti-fogging agents, and drugs in polyolefin and biopolymer films.
INFLUENCE OF PROCESS PARAMETERS OF AN UNDERWATER PELLETIZING SYSTEM ON THE MOISTURE OF WPC (WOOD-PLASTIC-COMPOSITE) PELLETS
Nils Bohm, Xiaolan Song, Volker Schoppner, May 2012
An underwater pelletizing system was used for the production of WPC pellets. In order to avoid the costs of drying prior to injection molding, the pellets must have a low moisture content before bagging. Selected screening results of the effects of different parameters on the moisture of WPC pellets are shown in the paper. By adjusting the appropriate process parameters, producers can save energy and costs by doing without or limiting the following drying steps.
EVALUATION OF FRACTURE CHARACTERISTICS OF POLYETHYLENE BLOWN FILMS USING THE ESSENTIAL WORK OF FRACTURE (EWF) WITH VARIABLE FILM ORIENTATIONS
Ilhyun Kim, Byoung-Ho Choi, May 2012
In this paper, essential work of fracture (EWF) tests for five polyethylene blown films are conducted. The fracture toughness of those samples was evaluated based on test results. The effect of the film orientation on the fracture toughness of materials was evaluated. The work calculated from load-displacement curves obtained from double edge-notched tension (DENT) specimens was analyzed as the ligament increases
EXAMINATION OF THE PERFORMANCE OF A HIGH SPEED SINGLE SCREW EXTRUDER FOR SEVERAL DIFFERENT EXTRUSION APPLICATIONS
John P. Christiano, May 2012
This study investigates the extrusion characteristics of a High Speed Single Screw Extruder, (HSSSE), to determine suitability for use in several different extrusion applications including Sheet, Fiber and Extrusion Coating. The study demonstrated that a properly designed HSSSE can greatly improve the processing capability of a small diameter single screw extruder for a wide range of applications.
ENCAPSULATED GRAPHENE WITH POLYSTYRENE BY ULTRASONICALLY INITIATED IN-SITU EMULSION POLYMERIZATION
Lei Wang, Ping Fan, Jintao Yang, Feng Chen, Mingqiang Zhang, May 2012
Graphene was successfully encapsulated with polystyrene via ultrasonically initiated in-situ emulsion polymerization in this paper. The XPS, FTIR, TEM and SEM results confirmed the PS encapsulation of grapheme nanocomposite (PS-G) was achieved through ultrasonically initiating technology without any initiators. The graphenes exhibit good compatibility and dispersion in the PS matrix. The thermal stability of nanocomposites is improved with the incorporation of graphene.
POLYMER EXTRUSION CONTROL SYSTEM DESIGN
Zhenhua Jiang, Y. Yan, F. Gao, May 2012
In this paper, the overall extruder control system is constructed by two control loops, a multi-input-multi- output (MIMO) control of the barrel temperatures and a single-input-single-output (SISO) control of the melt pressure at die output. Advanced control algorithms are adopted to control these key variables. Experimental results demonstrate the fast response, near-zero overshoot and precise tracking performance of the proposed control strategies. And ultimately the effectiveness of the whole controller is well reflected by product quality.
THE INFLUENCE OF FLOW ENHANCED CRYSTALLIZATION ON SHRINKAGE PREDICTION
Franco Costa, Zhongshuang Yuan, Chittur Hadinata, May 2012
Comparison is made between a flow-induced crystallization model and measurements made on injection molded samples of a PBT material. The magnitude of shrinkage in the flow direction and the direction perpendicular to flow are found to be in good agreement, as is the degree of shrinkage anisotropy. The flow-induced components of the model are demonstrated to be crucial for the correct prediction of the shrinkage anisotropy.
RECYCLE TECHNOLOGY OF USED PLASTIC MATERIALS
Hobuyuki Imamura, Masahiro Muto, Tatsuro Ueda, Kazushi Yamada, Hiroyuki Nishimura, Hiroki Sakamoto, Shinichi Kawasaki, Takahiro Nishino, May 2012
This paper describes the recycle technology of used plastic materials such as waste HDPE films and containers, waste caps for PET bottles, and used PET bottles with caps and films. The fusion joining strength of extruded sheets of waste HDPE films and containers using a compatibilizer was firstly studied. A compounding technology of used PET bottles with caps and films using a compatibilizer was secondly studied.
A NOVEL FOAM INJECTION MOLDING PROCESS USING GAS-LADEN PELLETS
Jungjoo Lee, Lih-Sheng Turng, Eugene Dougherty, Patrick Gorton, May 2012
This paper proposes a new foam injection molding process that enables the ease of processing of the chemical blowing agent method with the foaming characteristics of a physical blowing agent, but in a cost-effective fashion. By using gas-laden (CO2 or N2) pellets in injection molding, a simple yet cost- effective dosing method can be achieved. This paper presents this new process and the properties of the injection molded foamed parts.
THE INFLUENCE OF TEST FREQUENCY AND ECCENTRIC CRACK GROWTH ON CYCLIC CRB TESTS
Andreas Frank, Redhead, Gerald Pinter, May 2012
The cyclic CRB test was standardized recently as an alternative method to characterize the SCG resistance of polyethylene pipe grades. Open questions like the influence of frequency or eccentric SCG are focused on. To study the impact of hysteretic heating, tests with thermal observation of the crack tip were conducted with different frequencies. Moreover, COD measurements were used to study the eccentricity of SCG. Both investigations confirm high reliability and reproducibility of cyclic CRB tests.
SWELLING OF PLA MELT DUE TO CO2 DISSOLUTION
Syed Mahmood, Chul Park, May 2012
The superior mechanical properties of microcellular foams such as, heat resistance, lightweight and high performance to weigh ratio, are important factors to be considered with respect to the automotive industry and foaming industries. Therefore, an understanding of the thermophysical and rheological properties of polymer/gas mixtures is critically important. This paper focuses on the pure PLA 3001D volume swelling measurement and its comparison with varying talc content. Effect of D content on swelling ratio is also discussed.
INVESTIGATION OF AIR FILTRATION EFFICIENCY FOR NANOFIBER BASED FILTERS IN ULTRAFINE PARTICLE SIZE RANGE
Martin Zatloukal, Wannes Sambaer, Dusan Kimmer, May 2012
In this work, 3D filtration modeling utilizing realistic SEM image based 3D structure model has been proposed and used for different polyurethane nanofiber based filters. For the model validation purposes, two polyurethane nanofiber layers prepared by the electrospinning process were combined to form 2 pairs of nanofiber based filters and their filtration efficiency characteristics were determined experimentally in the ultrafine particle size range (20-400 nm).
PREPARATION AND PROPERTY STUDY OF TOUGHENED AND REINFORCED NYLON WITH NON-HALOGEN FLAME-RETARDANTS
Xin Jang, Bin-yi Chen, Hao-yang Mi, Qiang Fu, Xiang-fang Peng, May 2012
The best basic composition of PA66 composites with better flame retardant properties and mechanical properties was determined by orthogonal test. POE-g-MAH was added to enhance impact strength and silane coupling agent KH-550 as surface modifier of Mg(OH)2 (MH) to modify the flame resistance of the basic composites. TGA, DSC, SEM and mechanical property testing equipments were employed to study the properties of PA66 composites. A best formula of PA66 composites was obtained.
MECHANICAL PROPERTIES OF ABS/SPARKLE ALUMINUM COMPOSITES
Jingjing Zhang, Xiaoting Xiao, Haiyan Zhu, May 2012
The Taguchi method was used to study the effect of aluminum content, coupling agent content, screw speed and barrel temperature on the mechanical properties of ABS/sparkle Al composites. Signal to noise ratios for mechanical properties were calculated to obtain the optimum set of processing parameters. It was observed that a lower sparkle Al content, higher coupling agent content, medium screw speed, and medium barrel temperature were desirable for better mechanical properties of ABS/sparkle Al composites.
AN EASY APPROACH OF MEASURING THE RESIDENCE TIME DISTRIBUTION WITH THE USE OF NIR-SPECTROSCOPY
Andreas Witschnigg, Ramesh Kumar Selvasankar, Stephan Laske, Clemens Holzer an Laske,, May 2012
The residence time distribution of polypropylene was determined directly in-line with the help of near infrared spectroscopy and with the use of an UV-absorber as tracer. Different experiment alignments such as screw speed and mass throughput and their influence on mean residence time and especially residence time distribution have been investigated.
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