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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Ken Miyata , Yuuki Ichikawa , Keiji Katsuno , Akihiro Nishioka , Tomonori Koda , Go Murasawa, May 2010
Molecular structure development and the deformation
width and thickness behavior in T-die extruding of high
density polyethylene (HDPE) was studied. The extruding
through-put rate polymer material feeding rate and
winding roll temperature were fixed. The velocity of
winding roll was controlled and varied independently. The
effect of processing condition was analyzed from
molecular orientation distribution in machine direction
(MD) to transverse direction (TD) by measuring optical
retardation. To analyze crystalline structure development
behavior of HDPE film wide angle x-ray diffraction
(WAXD) pattern was also measured in TD of extruded
film. The diffraction intensity distribution on the equator
the meridian and azimuthal direction for (110) and (200)
were evaluated. We discussed major factor to control film
width and thickness. Relationship between molecular
structure development and the external form of extruded
film was studied.
Ken Miyata , Yuuki Ichikawa , Keiji Katsuno , Akihiro Nishioka , Tomonori Koda , Go Murasawa, May 2010
Molecular structure development and the deformation, width and thickness behavior in T-die extruding of high density polyethylene (HDPE) was studied. The extruding through-put rate, polymer material feeding rate and winding roll temperature were fixed. The velocity of winding roll was controlled and varied independently. The effect of processing condition was analyzed from molecular orientation distribution in machine direction (MD) to transverse direction (TD) by measuring optical retardation. To analyze crystalline structure development behavior of HDPE film, wide angle x-ray diffraction (WAXD) pattern was also measured in TD of extruded film. The diffraction intensity distribution on the equator, the meridian and azimuthal direction for (110) and (200) were evaluated. We discussed major factor to control film width and thickness. Relationship between molecular structure development and the external form of extruded film was studied
Yunior Hioe, Jesse Guerra, Siva Movva, Dante Guerra, L. James. Lee, Jose M. Castro, May 2010
Nanoparticles have shown the potential to improve the mechanical properties of fiber reinforced polymeric composites (FRPC). Premixing nano particulate into the resin is a common approach to add nanoparticles into FRPC. However, well dispersed nanoparticles will greatly increase the resin viscosity and filtering of the nanoparticles is difficult to avoid. To solve these problems, a new method to pre-bind the nanoparticles onto the long fibers has been developed by our group. We have previously presented results on the effect of nano particles on the preform permeability, in this paper we develop an approach to relate the overall preform permeability to the amount of nano fibers prebinded.
Naoya Mieda , Kenzo Okamoto , Masayuki Yamaguchi, May 2010
The rheological properties for the binary blends composed of a linear polyethylene and a branched polyethylene (LDPE) are studied. It is found that some blends show enhanced oscillatory shear moduli than the individual pure components, suggesting that the relaxation mechanism with long characteristic time is generated in a molten state. Further, they show higher zero-shear viscosities. The drawdown force, defined as the force needed for the extension of a polymer melt from a capillary rheometer, is also evaluated to comprehend the rheological information under the elongational flows and found to be quite sensitive to the anomalous behavior. Furthermore, it is found that the blends show marked flow instability, because they have longer relaxation time than the pure components.
Rachmat Mulyana, Thomas Daniel, Yong Min, Jose M. Castro, L. James Lee, May 2010
In injection molding, cycle time and sink mark are critical factors for process economics and product quality. This work focuses on reducing cycle time and sink part by utilizing water containing polymer/activated carbon pellets. Pellets were prepared by compounding a microparticle, activated carbon (AC) via extrusion, followed by a batch process of pressurizing a small amount of water into the pellets under controlled pressure and temperature. The amount of water, packing pressure and packing time were varied in the injection molding experiment. Preliminary results showed that the cycle time could be reduced to half and part shrinkage substantially decreased at a lower packing pressure without losing mechanical properties when the water content was low (e.g. 0.3 wt %). However, too much water (e.g. 2 wt %) tended to reduce mechanical properties even though the cycle time could be further reduced. We are in the process of tailoring the process conditions for optimized results, as well as evaluating the effect of residual water on the long-term properties of molded parts.
Sarah Chung, Tieqi Li, Ken Oliphant, Patrick Vibien, May 2010
Ticona has developed a new family of impact modified polyoxymethylene (POM) co-polymers that demonstrate a combination of improved stiffness, impact strength, and up to a 290% increase in weld line performance compared to similar commercially available impact modified POM co-polymers. The unique properties of the new products have been achieved through the modification of the polymer backbone. The new grades provide enhanced product performance, up to 30% faster cooling time, and less mold deposit for a variety of injection molding and extrusion applications.
Sarah Chung , Tieqi Li , Ken Oliphant , Patrick Vibien, May 2010
Plastic piping materials confer many advantages in Potable Water applications and have enjoyed a long and successful application history. Part of that success has been the considerable research that has been conducted to develop methodologies for characterizing and ensuring service performance. A key component of accelerated methodologies is ensuring that the observed mechanisms are the same as those potentially occurring in the field. In this paper field exposed plastic piping materials from aggressive applications are examined to determine the aging mechanisms observed in end-use environments.These mechanisms are compared with those observed in accelerated testing.
Kenji Okubo , Shigeo Tanaka , Hiroshi Ito, May 2010
This study aims to develop processing techniques to improve dimensional accuracy of micro-size parts produced by micro metal injection molding (?¬-MIM).Micro dumbbell specimens were molded by a micro injection molding machine, which can monitor the cavity pressure in injection molding process. The effects of particle size and distribution of metal powder on dimensional accuracy of micro dumbbell specimens at both grip parts were investigated. As the results, it is confirmed that the powder properties and sintering conditions to improve the dimensional accuracy of micro- MIM parts.
Howon Yoon , Kenzo Okamoto , Masayuki Yamaguchi, May 2010
Carbon nanotubes (CNT) are a great candidate to obtain a conductive path in a polymer matrix with a small amount, because it has large aspect ratio. The purpose of this study is to localize CNT at polymer surface by annealing procedure employing laminated sheets composed of an immiscible polymer pair, in which one component contains CNT and the other does not. It was found that CNT transfer occurs by Brownian motion from the composite with CNT to the surface of the pure polymer. As a result, the pure polymer obtained after the separation from the laminated sheets exhibits electrical conductivity owing to the conductive path of the CNT localized at the surface.
The high growth in the medical market along with the increased demand for high standards in injection molding in the last five years have lead to the emergence of a new class of valve gate hot runner that provides better molding process consistency along with unmatched part quality. This new valve gate hot runner uses a plate to couple valve stems to allow them to be driven by a hydraulic or electrical actuator. The coupling enables synchronicity of stem movement and the drive provides consistent high force. This paper presents this new hot runner technology that found a niche in stringent applications such as small part molding and the medical market.
Haimei Li , Yiyan Peng , Lih-Sheng Turng , Xin Wang, May 2010
Residual stresses in injection molded parts may have
negative effects on optical and mechanical properties. It is
usually two types residual stresses in the injection molded
parts - flow-induced and thermally-induced stresses. In
this paper thermal residual stresses are investigated by
comparing tensile properties of the injection molded PC
parts before and after annealing. A dielectrostrictive
sensor is developed to conduct the flow-induced stress
analysis during filling stage. The physical meaning of
obtained dielectrostriction signals is given based on the
experimental and numerical results. First the pressure
measured by the transducers was compared with the
numerical simulated results. These two values agree well
which indicates that the numerical prediction should also
be reliable for shear stress analysis. Then the shear stress
calculated based on the measured dielectrostriction signal
was compared with its corresponding numerical result.
And it has been found that the difference between these
two values within 5% at the various processing condition.
Haimei Li , Yiyan Peng , Lih-Sheng Turng , Xin Wang, May 2010
Residual stresses in injection molded parts may have negative effects on optical and mechanical properties. It is usually two types residual stresses in the injection molded parts - flow-induced and thermally-induced stresses. In this paper, thermal residual stresses are investigated by comparing tensile properties of the injection molded PC parts before and after annealing. A dielectrostrictive sensor is developed to conduct the flow-induced stress analysis during filling stage. The physical meaning of obtained dielectrostriction signals is given based on the experimental and numerical results. First the pressure measured by the transducers was compared with the numerical simulated results. These two values agree well, which indicates that the numerical prediction should also be reliable for shear stress analysis. Then the shear stress calculated based on the measured dielectrostriction signal was compared with its corresponding numerical result.And it has been found that the difference between these two values within 5% at the various processing condition.
H. C. Chen , S. C. Chen , P.M. Hsu , H. S. Peng , Y. C. Wang, May 2010
In-mold roller (IMR) injection molding is one of the
commonly used In-Mold Decoration technology for ink
transfer. The effect of processing parameters on part‘s
warpage is very important for product quality. In this
study the PET film with thickness of 0.05mm and
0.036mm is molded and computer simulation analysis is
performed to compare the result with experiment. It was
found that high melt temperature and thick film would
result in heat stagnation between surface-frozen layer and
film interface leading to a large part’s warpage. However
a high mold temperature resulted in a low warpage. For
IMR molding the mold temperature difference between
core and cavity surface was about 6.71~12.94? and the
warpage varied from 0.15mm to 0.91mm under specified
conditions.
H. C. Chen , S. C. Chen , P.M. Hsu , H. S. Peng , Y. C. Wang, May 2010
In-mold roller (IMR) injection molding is one of the commonly used In-Mold Decoration technology for ink transfer. The effect of processing parameters on partƒ??s warpage is very important for product quality. In this study, the PET film with thickness of 0.05mm and 0.036mm is molded and computer simulation analysis is performed to compare the result with experiment. It was found that high melt temperature and thick film would result in heat stagnation between surface-frozen layer and film interface leading to a large partƒ??s warpage. However, a high mold temperature resulted in a low warpage. For IMR molding, the mold temperature difference between core and cavity surface was about 6.71~12.94ƒ?Ÿ and the warpage varied from 0.15mm to 0.91mm under specified conditions.
Scott E. Everett, Mauricio J. Hernandez, Rickey Dubay, May 2010
In injection molding, final product quality is influenced by the cycle average mold cavity temperature, which depends on the mold coolant flow-rate. The design of a generic average temperature controller is difficult due to the nonlinear characteristics of the in-mold part cooling process. In this investigation, the parameters of a lumped-model are obtained using artificial neural network techniques to develop a generic model-based control scheme that can be implemented in a variety of molds with minimal open loop testing.
Scott E. Everett , Mauricio J. Hernandez , Rickey Dubay, May 2010
In injection molding final product quality is
influenced by the cycle average mold cavity temperature
which depends on the mold coolant flow-rate. The design
of a generic average temperature controller is difficult due
to the nonlinear characteristics of the in-mold part cooling
process. In this investigation the parameters of a lumpedmodel
are obtained using artificial neural network
techniques to develop a generic model-based control
scheme that can be implemented in a variety of molds with
minimal open loop testing.
Yuji Fujita , Naoya Aoki , Toshihiro Yoshida , Hironari Sano , Masaya Kotaki, May 2010
Polypropylene (PP)-based sandwich injection moldings with polybutylene succinate (PBS) alloys in core were studied. Different core morphologies of PBS/PP alloys were obtained by changing content and melt flow rate (MFR) of PBS and core-PP, and injection molding conditions. It was found that the core morphologies significantly affected skin/core interfacial adhesion and mechanical properties of the sandwich injection moldings. The spreading index considering dynamic viscosity and volume fraction of PBS and core-PP was proposed to discuss the mechanism of the core morphology development. Scratch and Izod impact tests according to ASTM standards were performed to investigate the effects of skin/core adhesion on scratch and impact characteristics.The sandwich injection moldings with poor skin/core adhesion caused the skin/core delamination upon the scratch and Izod impact tests.
Impregnation of linseed epoxy resin into softwood creates an all-renewable composite. This composite is intended to be a substitute for expensive hardwoods used in applications such as decking and flooring. Initial epoxy impregnation was conducted within a custom vacuum-pressure chamber with positive results. The impregnation process begins with an initial vacuum treatment to remove the air inside the wood, followed by the use of pressure to drive the resin into the wood under certain temperature conditions. This process was improved by optimizing vacuum-pressure levels and temperature, as well as the use of a high temperature curing agent. In this way, superior impregnation depths were obtained. The final result was a composite material with better mechanical properties than both the resin and the softwood themselves. Specifically, the impregnated samples showed Youngƒ??s modulus over three times higher than those of unimpregnated wood samples, in both tension and compression. Furthermore, the hardness of the wood increased significantly; depending on impregnation depth, hardness reached and surpassed 4500 lbf, the estimated value of Lignum Vitae, the hardest wood available. Secondary testing focused on automation of the initial process in order to facilitate optimized impregnation on an industrial scale. A custom multi-chambered impregnation machine was designed to perform a continuous impregnation.
Jing Wang, Wenli Zhu, Chul B. Park, Jed Randall, May 2010
Much work has been done to model the behavior of platelet-filled hybrid barrier materials and produce high barrier polymer/nanoclay composites with low clay contents. Little has been done to test the applicability of these models over a wide range of clay contents and determine whether current systems are near ideal or could be further improved. In this work, cyclic olefin copolymers are combined with organically modified montmorillonite clay via a spray deposition technique to create transparent, highly aligned model hybrids containing up to 100% clay. The structure and properties of these sheets are then characterized via XRD, DMA and OPA.
Jing Wang , Wenli Zhu , Chul B. Park , Jed Randall, May 2010
Microcellular foams of polylactic acids (PLA) with
and without molecular branching were produced on a
tandem extrusion system using carbon dioxide as the
physical blowing agent. Cell density and expansion ratio
were found to be strong functions of the molecular
structure the blowing agent content and the processing
temperature. Very low density foams were produced with
the branched PLA at the optimal processing condition
while the linear PLA exhibited severe cell opening beyond
a reasonable expansion ratio. Very low crystallinity was
detected in the foamed samples indicating that shearing
and the presence of supercritical carbon dioxide in the
extrusion system did not induce crystal growth.
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
Available: www.4spe.org.
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.
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