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
PHYSICAL VAPOR DEPOSITION AND UV CURABLE COATINGS
Jason T. Eich, Eileen Weber, Phil Abell, Kristy Wagner, Chris Mack, May 2012
Environmental concerns with traditional chrome plating continue to expand. Parts finishers worldwide are searching for alternative that provides the visual appearance and durability of chrome plate, but without the environmental side effects and costs associated with this decades old process. “Chrome look” processes and coatings for decorative and automotive lighting PVD applications have been used in the UV curable coating industry for over twenty years. As development of UV curable coatings for PVD has progressed, so has the understanding of the PVD process and its unique capabilities and applications. This paper will address the current chrome plating process, advantages of PVD as chrome alternative, challenges associated with the various steps and layers of PVD applications, and suggestions for successful implementation of UV/PVD systems.
WIRELESS DEVICES DECORATED USING NON-CONDUCTIVE VACUUM METALLIZATION (NCVM) TECHNIQUES: CONSIDERATIONS AND COMMON FAILURE MODES
B. Varkey, Y. Huang, D.A. Wasylyshyn, May 2012
The Non-Conductive Vacuum Metallization (NCVM) process has become a mainstream metallization technology to achieve metallic like appearances on the surfaces of plastics used in wireless electronic devices while maintaining radio frequency (RF) functionality of the internal antennas. The impact on device performance and reliability of NCVM coatings has been discussed based on the most common failure modes and industrial testing standards. This paper discusses the effects of environmental conditions as well as construction variation of NCVM systems as they relate to various customer- impacting failure modes such as discoloration/corrosion, delamination and RF interference.
EMERGING FIBER LASER TECHNOLOGY FOR MARKING PLASTICS
Scott R. Sabreen, May 2012
Ytterbium Fiber Lasers are transforming laser marking of plastics. For the proper application, superior results can be achieved versus Nd:YAG and Vanadate marking lasers. However, fiber lasers are not direct replacements without thorough evaluation, and not all lasers are created equal. The metric for beam quality is M2. The smaller the M2 value, the better the beam quality, whereas M2 = 1 is the ideal laser beam. A laser with superior beam quality can be focused to a small spot size, which leads to a high energy density which is, for many applications, desirable or even required. Such is the case for many thermoplastics including POM Acetals such as Delrin. Fiber lasers are considerably less expensive to procure with zero consumables, only electricity. Further, these lasers are a “Greener” technology than YAG or Vanadate.
PVC REPLACEMENT IN RF MEDICAL DEVICE PLASTICS WELDING
Tom Ryder, May 2012
This paper will provide an overview and options for plastics sealing/welding, and also the limitations of each heat sealing method. Further discussion will focus specifically on radio frequency (RF) welding. Next, this presentation will cover the trends toward eliminating PVC, specifically in the medical device industry. Tom will discuss various ways to eliminate both PVC and PU, using RF welding techniques. Finally, the presentation will cover medical device clean room best practices and the FDA and regulatory requirements in plastics welding of medical equipment, supplies or devices.
PREPARATION OF INTERCALATED ORGANIC/INORGANIC HYBRIDS VIA IN SITU SYNTHESIS
Lichen Xiang, Matthew F. Milner, Jarett C. Martin, Cara S. Southworth, Cody A. Gummelt, Luyi Sun, May 2012
Nanostructured organic-inorganic hybrid materials, including polymer nanocomposites, layer-by-layer assembled thin films, have been extensively investigated over the past two decades and have found wide applications owing to their excellent performance. Either regular polymer nanocomposites or layer-by-layer assembled thin films are typically prepared using pre-synthesized nanofillers/nanoplatelets. Here, we report a new approach to prepare nanostructured hybrid materials via in situ synthesis of nanoplatelets within the polymer/monomer matrix. Alpha-zirconium phosphate (ZrP) was synthesized in a solution system containing a polymer (such as polyethylene glycol, PEG) or monomer. During the synthesis of ZrP, PEG chains were embedded into the ZrP interlayer space, leading to a larger interlayer distance, which is similar to the intercalated layered compound. Proper formulation ratio proved to be critical to avoid forming pristine ZrP, and avoid interfering the growth of the layered structure of ZrP. It has also been found that longer polymer chains are desirable for minimizing the formation of pristine ZrP, but would not affect the interlayer distance. All the PEG chains are perfectly parallel to the layer planes. Besides polymers, many other molecules have also been successfully embedded into the interlayer space to form an intercalated structure during in situ synthesis.
EXPERIMENTAL STUDY ON RUBBER-ASSISTED EMBOSSING OF MICRO FLUIDIC CHIPS
Danyang Zhao, Tom Wyatt, Donggang Yao, Minjie Wang, Allen Yi, May 2012
A flexible micro fluidic chip is difficult to fabricate using the standard hot embossing technology. In this study, rubber-assisted embossing of a micro fluidic chip was investigated. A thin polymer film was thermoformed into microchannels by rubber as soft counter-tool. Different processing conditions, as well as material selections, affecting the thickness uniformity and replicated depth were examined. A flexible micro fluidic chip was fabricated via sealing the microchannel with a layer of transparent adhesive film. A droplet of colored water flowing into the microchannel fast and steadily was observed. Experimental results indicated that the microchip had a uniform channel and good leak tightness. The proposed method demonstrated the ability of fabricating a flexible 3-D microchannel.
DIRECT FABRICATION ON THE POLYMER SURFACES BY USING PRECISION TOOLING MACHINE AND CHARACTERIZATION OF HYDROPHOBICITY AT VARIOUS ROUGH SURFACES
Donghui Chu, Akihiro Nemoto, Hiroshi Ito, May 2012
This report described the hydrophobicity of polymer surfaces, PMMA and polycarbonate. Micro-sized pillar type structures were prepared by the precision machine which could precisely fabricate the various rough surfaces on the polymer surfaces. We considered the geometric parameters, x/d and z/x, to find the factors affect of wettability. The volume of water droplet intruded in pillar spacing affected to increase the hysteresis. Furthermore, the air-pocket formed in solid-vapor contact line was attributed to reduce the hysteresis. We also demonstrated the effect of the surface defect through the ductile polymer, polycarbonate. The polycarbonate surfaces showed higher sliding angle than PMMA, which caused the surface defect pinning with water droplet.
PRECISE INJECTION MOLDING OF BIO-ABSORBABLE HAP/PLA COMPOSITES
Kazuyasu Uchiumi, Tetsuo Takayama, Hiroshi Ito, May 2012
Hydroxyapatite (HAp)/ polylactic acid (PLA) composites with different particle size distribution were fabricated using microinjection and hot compression molding. Physical properties such as mechanical and heat properties of the composites were also investigated, as were improvement mechanisms attributable to mixing particle size distribution. Flexural strength of neat PLA molded parts at room temperature was about 80 MPa, whereas that of HAp/PLA parts was 48–49 MPa, suggesting that flexural strength decreased because of dispersed HAp particles. The reduction of flexural strength apparently depended on the HAp particle size. The flexural modulus of neat PLA parts was about 3.0 GPa at room temperature, whereas that of HAp/PLA parts was 4.0–4.8 GPa, suggesting that the flexural modulus was higher because of the dispersed HAp particles. The flexural modulus of composites with bimodal particle size distribution was greater than that of composites with a monomodal particle size distribution. The height of microneedles of composites with a bimodal particle size distribution was slightly greater because of the lubricant effect of HAp.
STUDY OF THE INJECTION MOLDING TECHNOLOGY FOR THE NON-CIRCULAR LENS
Chung-Chih Lin, Jen-Yu Shie, Hsin-Shu Peng, May 2012
Compared to symmetrical and circular lenses, non-circular lenses have more issues on controlling process parameters during injection molding process. Unbalanced filling pattern and thickness variance in lens typically result in more defects which become a critical challenge in product developments. A study of non-circular lens with an aspherical contour through computer simulation assistance and design of experiments was presented. A non-circular lens and two convex lenses were assembled into a barrel to form an optical modulus for a mini projector. The optical characteristic of mini projector was dominated directly by the accuracy of the optical modulus. In this study, a reasonable injection speed which could reduce melt viscosity in molding process was calculated by simulation software and then design of experiments was conducted to investigate the influences of the molding conditions on the part quality experimentally. This study provides a systematical way to predict in which area a defect occurs and determine the optimal molding parameters based on simulation results and statistical experiments.
PREDICTION OF THE FLASHING MOMENT BY THE STRUCTURAL ANALYSIS IN CONJUNCTION WITH THE MOLDING ANALYSIS
Jae-Hyuk Choi, Joon Sung Tae, Byung-Ohk Rhee, Hyung-pil Park, Baeg-Soon Cha, May 2012
The contact-pressure-sensor detected the mold deformation caused by cavity pressure, but failed to predict the flashing moment. In this work, we tried to predict the flashing moment by the structural analysis in conjunction with the molding analysis. The pressure from the molding analysis was input to the structural analysis. The strain at the sensor location showed a close trend of the change. The stress at the parting edge showed the possible moment of the flashing.
DYNAMIC BEHAVIOR AND EXPERIMENTAL VALIDATION OF CELL NUCLEATION AND GROWING MECHANISM IN MICROCELLULAR INJECTION MOLDING PROCESS
Tai-Yi Shun, Yuan-Jung Chang, Chao-Tsai Huang, David Hsu, Rong-Yu Chang, May 2012
We present the recent development of three-dimensional prediction of dynamic behavior of cell nucleation and growing mechanism, and the effect of nucleation-growing competition in microcellular injection molding process. Simulations of microcellular foaming process of injection molding are carried out for polyolefins with supercritical fluids (SCFs) carbon dioxide and nitrogen. In addition, we validate simulation results with experimental results to prove the capability of 3D prediction of microcellular foaming process and further compare simulations of microcellular injection molding and conventional molding to provide insights and economic guidance into design and manufacturing of injection molding products.
TEMPERATURE INVESTIGATION IN REAL HOT RUNNER SYSTEM USING A TRUE 3D NUMERICAL METHOD
Tzu-Chau Chen, Yan-Chen Chiu, Wei-Da Wang, Chao-Tsai Huang, Cheng-Li Hsu, Chen-Yang Lin, Lung-Wen Kao, May 2012
Hot runner technology has been the solutions to the molding problems on many plastic injection products, such as automobile bumper, LCD/TV cover, bottle cap and so on. However, the mechanism behind the hot runner system is too complicated to be fully understood. In addition, there exist some critical issues in the current hot runner technology, such as temperture control issues, flow imbalance, and material degradation. As a result, the simulation technolgy is highly needed for hot runner designers and makers to examine their designs before the real manufacturing. Through simulation analyses, designers and manufafctuers are able to catch the potential issues on their hot runner systems and revise their designs. Hot runner simulation technology helps with the investigations into the behavior in hot runner system. In this paper, a true 3D numerical method is proposed and applied to investigate the temperature behavior in a real hot runner system for PC material. The experiment is conducted and the simulating result is compared with that from the experiment for the validation purpose.
THE SKIN/CORE MATERIAL DISTRIBUTION OF A CO-INJECTION MOLDING PROCESS: THE EFFECT OF PROCESSING CONDITIONS AND MATERIAL SELECTION
Shih-Po Sun, Chih-Yu Hsu, Chao-Tsai Huang, Kuo-Chou Huang, Shi-Chang Tseng, May 2012
With the growing use of co-injection molding process, an understanding of skin/core material distribution in the cavity is essential. We presented numerical simulations concerning factors including filling ratio, material viscosity, and injection rate. Both core penetration behaviors and skin ratio uniformity from the material distribution profiles were compared. In addition to material distribution predictions, numerical simulation also revealed breakthrough points and cornering-effect locations. This is helpful for the part manufacturer to enhance the benefits of the co- injection process through the computer-aided simulation.
IN-SITU COMPATIBILIZATION OF HDPE-FUMED SILICA COMPOSITES: MORPHOLOGY, RHEOLOGY AND FILM BARRIER PROPERTIES
Sangita Nandi, Sanjukta Bose, Susanta Mitra, Anup K. Ghosh, May 2012
In the present study, HDPE-fumed silica (FS) composites were prepared by melt-mixing with different filler loading and in presence of PE-g-MA compatibilizer. Dynamic rheological properties and morphological analyses of the composites supported the plausible interfacial interaction between reactive groups of PE-g-MA and surface silanol groups of FS. Oxygen and water vapor permeability of the films made from composites were increased due to presence of FS as well as due to compatibilization.
ANALYSIS OF THE PROPERTIES AS CONTENT OF END-GROUP FOR POLYCARBONATE (PC) IN MELT POLYMERIZATION PROCESS
Su Ran Lee, Sanghyun Park, Byung Hoon Lim, Kwan Hwi Park, Byoung Ok Jang, May 2012
There are two processes to polymerize polycarbonate in the petrochemical industry: One is interfacial polymerization(interfacial PC) and the other is melt polymerization(melt PC). Recently, the latter is mostly used in that it is eco-friendly process. The most difference of product produced by two systems is the content of specific end-group. It is detected to a little bit value in interfacial polymerization, while it generally has more content in melt polymerization. It is supposed that the more content of the end-group is, the bigger change of the property induce as surrounding environment. In order to analyze an effect of the end-group, polycarbonate substituted to other end-group was made from melt PC using a suitable end-capping agent. And then, several properties were examined like melt index, viscosity and color. As the result, the end-capped PC showed less change of the properties than general melt PC, and it is similar to interfacial PC. It was verified that the properties of melt PC is adversely affected by the specific end-group.
MARKET SITUATION AND POSSIBILITIES FOR INFORMATION PROCUREMENT OF BIOPOLYMERS (BIOPOLYMER DATABASE)
Maren Bengs, H.J. Endres, A. Siebert-Raths, May 2012
In the last three years the production capacities of biopolymers increased threefold. The current trend in the development of biopolymers is towards bio-based and durable materials, it veers away from biodegradable and compostable materials. As a result of this change and the significant growing market there is a bottleneck regarding the availability of information and technical data of biopolymers. The biopolymer database offers a knowledge platform about biopolymers with producer data and newly measured comparable properties. The presented comprehensive database reflects the market situation and serves as connection between manufacturers, converters and end users.
IS RTC THE LONG AWAITED PANACEA FOR INJECTION MOLDED PARTS?
Ken Crow, Raymond Foad, May 2012
In contrast to conventional injection molding, where the tool is cooled continuously, in Rapid Temperature Cycle Molding RTC™ the cavity surface is rapidly heated to around the glass transition or melting temperature of the plastic before melt injection. Benefits are summarized and quantitative results cited. These include: achieving fine surface finish and gloss, including for foamed and filled materials (Ra for foamed ABS reduces from 1500 to 30 nm and for LGF PP from 1600 to 150nm); elimination of visible weld line defects; improved transcription of surface micro- features; improved optical properties in clear moldings; reduction of injection pressure, allowing longer flow paths, lower machine tonnage, part thickness reduction with reduced cooling time, and reduced molded-in stress. Implementation of the two leading technologies for implementation of RTC™ are described: heating with steam; or use of external induction heating to rapidly raise the cavity surface temperature, both followed by water cooling. A case study for RTC™ is described, leading to series production of a metalized part for a German automotive OEM. Performance requirements dictated a thin metalized layer (0.2 -0.3?m), formed by physical vapor deposition. This being insufficient to hide weld line defects, and use of a thick primer layer (15 ?m) being unacceptable, raising the cavity surface by RTC™ induction heating was trialed and shown to be entirely successful in removing defects.
NEW DEVELOPMENTS IN FIRE RETARDANCY OF STYRENIC COPOLYMERS
Pierre Georlette, Yakov Rachmilevitch, Yaniv Hirschsohn, Sergei Levchik, May 2012
Styrenic copolymers such as HIPS and ABS are taking a very important place in the electronic industry. As they burn easily, brominated flame retardants are used to improve their flame retardancy. This paper presents developments with tris(tribromophenyl) triazine showing its contribution to environment protection by lowering carbon foot print and by its non-blooming behavior. Tris(tribromophenyl) triazine flame retardant systems enable reduction or even elimination of antimony trioxide while maintaining a good level of properties.
ADVANCED COMPUTATIONAL TECHNIQUE FOR THE OPTIMIZATION OF SPIRAL MANDREL DIES
Kenny Saul, Johannes Wortberg, Peter Köhler, Marcin Humpa Uwe Klemme,, May 2012
The extrusion-die is one of the main components in an extrusion line and influences the product quality as well as the whole process efficiency. The requirements on extrusion-dies are versatile and the design of extrusion-dies is a very complex process with the necessity for huge know-how. Therefore the whole design process of a spiral-mandrel-die (SMD) based on a parametric 3D-CAD-mastermodel has been coupled with a 3D-CFD-simulation and implemented into a fully automized process. The flexibility of the extrusion dies to reach a high product quality for different materials is one of six criteria for the automatic interpretation of the extrusion die quality.
FIBER LENGTH REDUCTION AND HOMOGENEITY OF INJECTION-MOLDED SHORT FIBER REINFORCED THERMOPLASTICS WITH SPECIAL REGARD TO THE INFLUENCE OF A STATIC MIXING NOZZLE
Elmar Moritzer, Christoper Budde, Christoper Budde, May 2012
During the injection molding of fiber reinforced materials, the molded component's mechanical properties strongly depend on the resulting distribution of the fiber lengths in the component. Owing to various influencing factors in the injection molding process, the fiber lengths are shortened in comparison to the pellet's initial fiber lengths. Within the scope of the experimental investigations, the different influencing factors, especially the influence of the mixing nozzle, were identified and analyzed.
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