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
FLOW INSTABILITY IN MULTI-LAYER CABLE COATING DIES
Birane Toure, Jiri Vlcek, May 2012
The paper describes the study of a flow instability defect in a coextursion, cable coating process. The problem was first analyzed using a 2D Finite Element flow simulation. It was determine that the outer layer was experience very high deformation (velocity changes) when merging with the next inner layer. The problem was solved by modifying the coextruson die to reduce the velocity differences that the material experienced in the merge region. This modification stabilized the coextrusion process and removed the instabilities so that acceptable product could be made
MICROCELLULAR INJECTION MOLDING OF POLYLACTIDE WITH TALC
Amir Ameli, Davoud Jahani, Peter Ungyeong Jung, Chul B. Park, May 2012
The effects of talc content and injection flow rate on the foaming behavior of injection-molded microcellular polylactide (PLA) were investigated. Cell morphology with a cell size of less than 20 µm and cell density of greater than 108 cells/cm3 was successfully produced. The addition of 5 wt % talc to PLA increased the cell density roughly ten times and decreased the cell size about three times. Also, higher injection flow rate resulted in finer cells with greater density.
TROUBLESHOOTING RATE LIMITATIONS FOR MELT-FED SINGLE-SCREW EXTRUDERS
Mark A. Spalding, May 2012
Compounding lines that utilize single-screw extruders as the pumping device for pelletization can be severely rate limited if the metering channel of the single-screw machine is not optimized for the process. This paper provides the troubleshooting methodology for solving this type of problem using a case study.
CASE STUDIES OF NEW APPLICATION DEVELOPMENT USING ELECTRON BEAM IRRADIATION
Daniel Yasenchak, May 2012
Developing new cost-effective polymer products is challenging in the current competitive marketplace. Electron beam irradiation is a powerful tool used to improve the properties of a wide range of materials, particularly polymers, and has been used to gain a competitive advantage in many successful commercial products. This paper reviews three case studies in the development of new polymer products using electron beam irradiation and the role of the electron beam processor.
IN SITU OBSERVATION OF THE FOAMING PROCESSES OF CELLULOSE NANOFIBER REINFORCED POLYLACTIC ACID BIOCOMPOSITES
W.D. Ding, A. Wong, T. Kuboki, C.B. Park, M. Sain, May 2012
This paper examines the effect of fiber content on the foaming behavior of cellulose nanofiber reinforced polylactic acid biocomposites. The in situ observation of batch foaming processes was conducted by using a high-speed camera. It was found that nanofiber content has a significant effect on the cell nucleation and growth in the composite foams. As the fiber content increased, the cell nucleating power increased and cell growth rate decreased.
ECONOMIC BENEFITS OF CROSSLINKABLE POLYAMIDES – A LOOK AT ELECTRON BEAM IRRADIATED MOLDED PARTS
Bill Person, May 2012
A new family of radiation-crosslinkable polyamides has been developed for the North American market. A key component in the offering is technical support for product development. Companies can crosslink the polyamide using their current equipment or that of a contract electron beam processor and replace higher cost thermoplastic resins with the radiation crosslinkable polyamide. This paper discusses the technical advantages and target applications of the radiation crosslinkable polyamide.
SYNTHESIS OF POLYHEDRAL OLIGOMERIC SILSESQUIOXANE (POSS) FUNCTIONALIZED CARBON NANOTUBES
Xiaonan Kou, Christopher M. Sahagun, Robert Y. Lochhead, Sarah E. Morgan, May 2012
Polyhedral oligomeric silsesquioxane (POSS) was covalently attached to modified carbon nanotube (CNT) surfaces to improve nanotube dispersion. Two types of POSS were attached to multiwall CNTs. TGA, ATR-FTIR and TEM characterization of the CNT-g-POSS hybrids demonstrated covalent bonding of POSS to the CNT surface. POSS- modified CNTs showed homogeneous, stable dispersion in THF.
EVALUATION OF LONG-TERM PERFORMANCE ON COMPOSITE PIPES
Youjiro Minami, Tatsuro Ueda, Masahiro Muto, Kazushi Yamada, May 2012
The creep fracture of pipes is evaluated by the applied internal pressure. However, there were some disadvantages such as long testing time, large equipment and careful treatment on the stress rupture test. In this study, the new creep testing method which is simple and accelerated testing was proposed on composite pipes such as multilayer pipes. The results of the fluctuating internal pressure test on multilayer pipes were also described.
STUDY OF THE KINETIC OF SLIP AGENT MIGRATION IN POLYETHYLENE SHEETS
Richard James Silverwood, Farhad Sadeghi, Abdellah Ajji, May 2012
Line speeds in vertical form fill seal machine can be greatly increase by using slip agents such as erucamide. The focus of this research was to develop a tool to rapidly characterise the amount of slip agent in a polyethylene film sample. Using a Fourier Transform Infrared spectrometer, a model of the kinetic of erucamide migration in polyethylene film was developed. This model can further be used to determine one’s erucamide content of a sample polyethylene film.
EVALUATION OF LONG-TERM PERFORMANCE ON PLASTIC PIPES FOR HOT WATER SUPPLY
Tatsuro Ueda, Masahiro Muto, Hideo Hirabayashi, Kazushi Yamada, Hiroyuki Nishimura, May 2012
Crosslinked polyethylene (PEX) pipes and multilayer pipes of PEX and ethylene-vinyl alcohol copolymer (EVOH) as a high oxygen barrier are used for hot water pipes. The long-term performance of them was evaluated in hot water and air. It was found that the yield stress of PEX and multilayer pipes increased with elapsed time due to crystallization. It was also found that multilayer pipes had a blister at the interface between PEX and EVOH.
EXTRUSION FOAMING BEHAVIOR OF PET
Mohamad Reza Barzegari, Nemat Hossieny, Mehdi Keshtkar, Nathali Chapleau, Chul B. Park, May 2012
The extrusion foaming behavior of polyethylene terephthalate (PET) with CO2 was evaluated. The foaming morphologies of PET/nanocomposites and PET/chain extenders were also assessed. The foamed extrudates were analyzed for expansion ratio, cell structure, and degree of crystallinity using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Finally, the effect of the die temperature on the cell structure of the PET foam samples was studied.
SCREEN PRINTING PVC FILM WITH UV INK
George A. Paleo, May 2012
This study’s purpose was to develop a process for screen printing PVC film with UV-curing ink. PVC film is made with plasticizers that migrate to the surface and reduce ink adhesion. Surface treatments and ink additives were investigated. The study showed for recently manufactured film, poor ink adhesion was a result of incomplete cure. The ink’s high pigment loading impeded penetration of UV radiation. Dilution of the pigment with clear base enabled complete cure
CREEP FAILURE OF A POLYACETAL HOSE CLAMP
Niles G. Stenmark, May 2012
A plastic ratchet-type hose clamp had failed catastrophically while in service, causing water damage. The investigation revealed that the cracking occurred within a relatively short period of time due to creep rupture. Additional testing was performed to substantiate the cause of failure. This paper will focus on the steps used to characterize the mode of failure, and how accelerated testing methods were utilized to predict the life of the part.
FOAMING BEHAVIOR OF MELT COMPOUNDED THERMOPLASTIC POLYURETHANE IN PRESENCE OF BUTANE
Nemat Hossieny, Mohammadreza Nofar, Mohamad Reza Barzegari, Chul Park, May 2012
The hard segments in thermoplastic polyurethanes (TPUs) are statistically distributed in the soft matrix phase. This distribution can be changed by processing the TPU material at various conditions such as melt processing or isothermal treatments. Furthermore, the hard segments contribute to the microcrystalline phase in TPUs. In this study, the foaming behaviour of “as received” and “processed” TPUs has been investigated using n-butane as a blowing agent.
EFFECTS OF PHYSICAL SURFACE TREATMENT ON METAL SURFACE MORPHOLOGY AND MECHANICAL PROPERTIES OF METAL INSERT INJECTION MOLDINGS
Tomokazu Sasaki, Yuqiu Yang, Toshikazu, Kazushi Yamada, May 2012
This study is to clarify the adhesion mechanism as target. Various surface treatments on the metal were carried out to investigate its effect on the adhesion property of insert moldings. It is found that the surface roughness of metal could be changed by the chemical agent with different ratio of nitric hydrofluoric acid and immersion time. Optimum surface treatment exists to obtain high adhesion property between polymer and metal.
EVALUATING FRACTURE TOUGHNESS IN DEGRADED POLYMERIC THIN FILMS
Hanxiao Ge, Susan C. Mantell, May 2012
Thin polymer films are under consideration as materials for use in roof top mounted solar thermal collectors. The fracture behavior of these materials is of particular concern for this application. When exposed to UV light, film degradation can lead to reduced fracture toughness. In this paper, a method for evaluating the fracture behavior of thin films as a function of the extent of degradation is described. Pilot study results for fracture behavior of polyethylene film are presented.
MELT FRACTURE BEHAVIOR OF PLA FOAMED USING DIFFERENT DIE ENTRY ANGLES
Lun Howe Mark, Mo Xu, Chul B. Park, May 2012
This investigation focuses on effects of die entry angles on the melt fracture behavior of foamed Polylactic Acid (PLA). PLA is foamed using a physical blowing agent along with four dies with varying entry angles. The dies used in this study have entry angles of 60, 90, 120, and 180 degrees. A camera is placed at the die exit to capture snapshots of the extrudate to examine the nature of melt fracture.
FOAM INJECTION MOLDING OF GLASS FIBER REINFORCED POLYPROPYLENE COMPOSITES
Peter U. Jung, Chul B. Park, May 2012
This paper investigates the effects of the processing conditions on the foaming behavior of glass fiber reinforced polypropylene. Composites are injection molded by using an advanced structural foam molding machine with N2 as blowing agent. Samples are prepared with different processing parameters while mold pressure, void fraction and foam morphology are characterized. The results suggest that there is an optimal combination of these processing parameters, which can provide uniform void fraction and high cell density.
THE EFFECT OF CO2 ON THE MELT FRACTURE BEHAVIOR OF FOAMED PLA
Lun Howe Mark, Mo Xu, Medhi Keshtkar, Chul B. Park, May 2012
The melt fracture behavior of foamed Polylactic acid (PLA) with the presence of blowing agent is studied in this investigation. A CCD camera is utilized to examine how foaming processing parameters such as blowing agent content, mass flow rate and temperature can affect melt fracture behavior. Images captured are used to analyze severity and nature of extrudate distortion.
FEASIBILITY OF DOUBLE CRYSTAL MELTING PEAK GENERATION IN PLA FOR EXPANDED PLA BEAD FOAMS
Mohammadreza Nofar, Chul B. Park, May 2012
As the EPP and EPE bead foams have two crystal melting peaks, in order to manufacture expanded PLA bead foam (EPLA) with the same strategy, the feasibility of double crystal melting peak creation for PLA has been investigated in this work. The influence of various annealing temperatures and time on the double crystal melting peak creation is investigated for a linear and a branched PLA with two various degrees of crystallinity in a regular differential scanning calorimeter (DSC).
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