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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To meet the continued commitment on environmental sustainability, SABICTM has developed and commercialized PCR PC/ABS blends portfolio, which provide more options for customer to choose Cycoloy product. PCR Cycoloy grades are all PC/ABS blends containing 30~35% recycled polycarbonate from post-consumer CD and/or water bottle. RCM6123 and RCM6134 are filled grades, while RCY6214, RCY6113, RCY6013 and RCY6713 are non-filled. These grades were developed for various applications with additional value on environmental sustainability. At the same time, in most applications they showed comparable properties to corresponding virgin grade.
Jun Peng, Xiaofei Sun, Yottha Srithep, Xiang-Fang Peng, Lih-Sheng Turng, May 2014
This paper presents a new process for producing vapor-foamed polycarbonate (PC) parts using water vapor as the physical blowing agent and two kinds of nucleating agents, namely, sodium chloride (NaCl) particles and active carbon (AC) powder. The effects of these two nucleating agents on the surface roughness, mechanical properties, and microstructure of solid and foamed parts were characterized. The results were compared with microcellular injection molded parts using supercritical fluid (SCF) nitrogen as the physical blowing agent without a nucleating agent. The water vapor-foamed PC parts with NaCl as the nucleating agent had a smooth surface comparable to that of solid injection molded parts. Foamed PC parts with AC had desirable specific mechanical properties as well as an advantageous average weight reduction of 16.4 wt%. AC powder, serving as nucleating agents, water carrier, and reinforcing fillers, positively improved the microcellular structure and mechanical properties of vapor-foamed PC parts. Based on infrared spectrometry (IR) and gel permeation chromatography (GPC) results, the melt compounding processing to incorporate the nucleating agent and the vapor-foaming process caused minor thermal degradation and hydrolytic degradation, respectively. Without the nucleating agent, vapor-foamed PC parts exhibited much larger and fewer bubbles within the molded parts.
Xiaofei Sun, Hrishikesh Kharbas, Lih-Sheng Turng, May 2014
A novel and cost-effective method of microcellular injection molding using gas-laden pellets has been developed. In this study, several methods, as well as their combinations to enhance the gas-laden pellets’ foamability, have been attempted including (a) enhancing homogeneous nucleation by blending N2- and CO2-laden pellets to create an N2/CO2 synergetic effect, (b) enhancing heterogeneous nucleation by incorporating talc as a nucleating agent, and (c) enhancing heterogeneous nucleation by compounding PP/HDPE immiscible blends. The results show that these methods effectively improved the cell nucleation rate and cell morphology. Moreover, it was found that these methods could also be superimposed on one another without conflict, thus leading to further improvements.
The mobile communication devices require high speed transmission of large volume data and reduction in size and weight. When signal is transtitted in high speed and frequency on PCB, signal integrity becomes a big problem. One of the most widely used methods to solve the problem is to apply materials having good adhesion and low Dk/Df characteristics. Although various materials are available for the purpose, they tend to be expensive and require special care during the fabrication process. Therefore, PCB makers have been looking for more affordable and easily handleable materials that can be implemented outstanding adhesion and low Dk/Df. To meet these demands, we have developed epoxy resins containing fluorine. This fluorine type epoxy resins are obtained by applying fluorine based materials having high adhesion and low Dk/Df properties. So after epoxidation, the introduction of fluorine into the chain of the epoxy resin resulted in improving the adhesion and dielectric properties.
Danyang Zhao, Huiqing Tian, Minjie Wang, Guobao Jin, May 2014
A polymer micro tube with multi-lumen is difficult to fabricate. In this study, an extrusion die of double-lumen micro tube was designed and fabricated. Different processing conditions affecting the ovality and the thickness uniformity were investigated. The results indicated that the contour ovality was significantly influenced by gas flow rate, screw speed, die temperature and vacuum degree of water tank. The thickness uniformity of micro tube was determined by the die design method and the manufacturing precision. The desired double-lumen tube with an outer diameter of 1.6 mm was obtained by the optimization of processing conditions.
Xuelian Chen, Wenbin Liang, Shih-yaw Lai, May 2014
Crosslinking is widely used to improve foaming properties for low melt-strength polyethylene. However, premature crosslinking will not only suppress the growth of microcells, but also severely affect the melt processibility. It is thus very difficult to obtain highly crosslinked foamed polyethylene products. This paper describe a novel foaming process through manipulating the viscoelasticity of the polymer melt in response to the decomposition of the chemical blowing agent (BA). Practical guidelines to achieve low density polyethylene foam products with high crosslinking degree are provided.
With a large demand of polymer composites in all manner of industries, product development has focused on good mechanical strength and functionality with fiber composites. The key of development lies on the control of fiber orientation and distribution. This study applies Gas Counter Pressure(GCP) in injection molding to investigate the fiber orientation on different layers of thickness(core, shear and skin) and numerous part locations(far, center, and near as referred to the entrance of gate). As a result, the counter pressure is directly related to fiber orientation. Under the molding parameters of 80°C mold temperature, 230°C melted temperature, and 10cm3/s injection speed, the higher counter pressure, the greater anisotropic fiber distribution. Since GCP forced the core to skin, the most anisotropic distribution is on core layer, then the orientation and skin layer in sequence. For the fiber orientation in part, it has better anisotropic fiber distribution around the area farther from the gate, which is because the fiber orientation perpendicular to the cross section of product is affected dramatically by the pressure. In addition, a simulation tool, Moldex3D, is utilized to verify experiment results. The simulation shows high agreement with experiment on the trend of various locations. It can be proved that injection molding with GCP can increase disturbing level effectively.
Shia-Chung Chen, Yu-Hsiu Liu, Sung-Wei Huang, Ming-Chang Jeng, May 2014
In this study, various polymer materials (PP, PS), product thicknesses (0.6 mm, 1.2 mm), and flow rates (5 cm3/s, 10 cm3/s, 15 cm3/s, 20 cm3/s, 30 cm3/s) were discovered by utilizing a developed molding technology called Gas Counter Pressure (GCP). Both conventional and GCP molding were performed to compare the associated influences on part shrinkage, mechanical properties, crystallinity, and shape of Melt-Front Area (MFA). The results show not only simulatively, but also experimentally that the shrinkage is reduced under GCP condition. What’s more, the degree of elastic module is enhanced, and the average ratios of tensile strength for both 0.6-mm-thick PP and 1.2-mm-thick PP increase 0.1937% and 4.6014% respectively due to the holding effect applied under GCP condition while the average ratio of tensile strength for PS decreases 1.8994% owing to the restricted molecular orientation. Furthermore, average ratio of crystallinity decreases either 1.987% (0.6 mm) or 2.560% (1.2 mm). In addition, Scanning Electron Microscope (SEM) diagram illustrates that the profile of melt-front for GCP molding is obviously flattened.
Na Zhao, Lun Howe Mark, Changwei Zhu, Chul B. Park, Qian Li, Robert Glenn, Ryan Thompson, May 2014
This paper investigated the continuous extrusion foaming of a biodegradable polymer, polyvinyl alcohol (PVOH), using supercritical carbon dioxide (scCO2) as the blowing agent. As-received PVOH pellets were first compounded with water to decrease the melting point of PVOH. In addition, the water can help to reduce the potential for thermal degradation during the extrusion foaming process. Furthermore, water also served as a co-blowing agent together with scCO2 to achieve high expansion and high cell density biodegradable polymer foams. The effect of scCO2 content and die temperature variations on the expansion ratio and cellular morphology of the PVOH foam were examined systematically.
Seung Goo Lee, Tae Min Hong, Ji Eun Lee, Hyun Il Shin, Sung Chan Lim, May 2014
The cure kinetics and tack properties of carbon/epoxy prepreg and epoxy resin were investigated. The effects of cure temperature on the cure kinetics were investigated with dynamic DSC and isothermal DSC analysis. The cure temperature range was 180-240°C and heating rate was 2-40°C/min, respectively. Activation energies were determined for resins from dynamic DSC tests by using Ozawa and Kissinger models. Consequently, the activation energy for epoxy resin increased as a function of conversion. Tack property of carbon/epoxy prepreg was measured by using probe tack test. The influence of contact time, contact force, debonding rate and plate temperature on the carbon/epoxy prepreg tack was investigated.
Heating efficiency and cavity surface temperature distribution are two key factors for the design of heating system in rapid thermal cycling molding (RTCM) mold with electric heating. Aiming at high heating efficiency and uniform cavity surface temperature distribution, an optimization method combining particle swarm optimization (PSO) with finite element method (FEM) is proposed to design the electric-heating system in RTCM mold. To verify the effectiveness of this method, the PSO-FEM method is applied to design the electric-heating system for an automotive spoiler blow mold. The results demonstrate that the proposed optimization design method can effectively obtain the optimal design parameters and significantly facilitate the heating system design process compared with the trial and error design method. Based on the optimized design parameters, an electric-heating RTCM blow mold of the spoiler is constructed and utilized to mold the automotive spoilers. The blow molding experiments conducted using the constructed RTCM mold show that the surface quality of the molded spoilers is dramatically improved.
Ken Oliphant, Sarah Chung, Patrick Vibien, Michael Conrad, May 2014
A new methodology has been developed to assess the performance of polyethylene pipe compounds in potable water applications. The methodology is the result of several connected research programs undertaken to both develop and validate a model capable of estimating performance of PE pipe in potable water applications. The validation methodology is based on testing specimens at accelerated conditions in accordance with the approach developed in ASTM F2263 to determine the minimum Stress Class at aggressive end-use environments. The resulting projections are seen to be in good agreement with those projected from full ASTM F2263 testing and, hence, provide an alternate approach for projecting PE pipe compound performance in potable water applications. The approach is also well suited for use in developing minimum performance validation criteria.
Innovation in additives continuously enhances the offering to the plastic industry. Conversion processes of engineering thermoplastics compounds can be very demanding, especially when reinforced with fillers like glass fibers. Performance, quality, productivity and weight reduction are the automotive industry drivers for plastic applications, combining excellence and awareness. The answer to these needs is the development of specific additives or solutions which provide to the compounds, outstanding protection and process improvement ability, with a particular focus on sustainability.
It is well known that solid bed breakup in plasticating single-screw extruders can lead to defects in the downstream product, reduced rates, and process instabilities. After a review of the mechanism of solid bed melting an enhanced discussion will be presented regarding a new concept for solid bed break up. The literature generally attributes this breakup to pressure gradients emanating from the beginning of the metering section of the screw. In a previous paper  a new mechanism was proposed that was developed as a result of the physics of the melting mechanism and fluid flows associated with screw rotation physics. During the discussion after the presentation of this new mechanism at ANTEC 2013, questions were raised as to the assumptions made regarding the shape change of the solid bed during melting which the authors proposed was a result of the flow that occurs as a result of the new mechanism. In this paper more data will be presented that will help define this new concept.
Rogério L. Pagano, Verônica M. Calado, Frederico W. Tavares, Evaristo C. Biscaia, May 2014
In this work, an algebraic-differential equations (EAD) system is applied to estimate parameters using both isothermal and non-isothermal data. Temperature dependence of the specific heat is considered inside the EAD as an algebraic restriction. The estimation procedure is based on the use of a mass and energy balance in DSC furnace. The approach found all kinetic parameters by using deterministic and heuristic algorithms. The results show that the use of an energy balance is a good methodology to estimate cure kinetic parameters of both isothermal and non-isothermal experiments.
Poly(lactic acid) (PLA) is one of the most promising biodegradable aliphatic polyesters derived from renewable resources and has received significant attention over the last decade. The blending of PLA with poly(butylene adipate-co-terephthalate) (PBAT) and poly(butylene succinate) (PBS) is employed to overcome its inherent drawbacks. All prepared fully biodegradable blends show a thermodynamically stable complete wetting behavior which was in good agreement with the thermodynamic analysis. The results for the ternary blends demonstrate a viable route towards the achievement of biodegradable polymers systems with a highly balanced property set.
Adriana Pavia-Sanders, Jeniree A. Flores, Jonathan E. Sanders, Jeffrey E. Raymond, Karen L. Wooley, May 2014
Well-defined, magnetic shell crosslinked knedel-like nanoparticles (MSCKs) with hydrodynamic diameters ca. 70 nm were constructed through the co-assembly of amphiphilic block copolymers of PAA20-b-PS280 and oleic acid-stabilized magnetic iron oxide nanoparticles. These hybrid nanomaterials were designed as sequestering agents for hydrocarbons present in crude oil. Their combination of amphiphilic organic domains, for aqueous solution dispersibility and capture of hydrophobic guest molecules, with inorganic core particles for magnetic responsivity, make these nanomaterials uniquely qualified for oil spill remediation. The employment of these MSCKs in contaminated water resulted in the successful removal of the hydrophobic pollutants at a ratio of 10 mg of oil per 1 mg of MSCK. Using a magnet, the loaded nanoparticles were isolated and through “rinsing” in an ethanol sonicating bath, they were regenerated for reuse with no loss of their loading capacity.
Joel Carr, Marcelo Farah, Ana Paula de Azeredo, May 2014
Traditionally, polypropylene (PP) has not performed well in polymer processing dominated by extensional flow due to a lack of melt strength. High melt strength (HMS) can be achieved in PP through the introduction of long chain branching (LCB). These branches introduce a large amount of chain entanglements, enabling PP to perform well in extensional flow processing. The characterization of long chain branched PP is not trivial and requires some expertise and advanced analytical analysis. This work will briefly review a variety of rheological techniques, both shear and extensional, that can be used to detect varying levels of LCB in PP.
Yushan Hu, Jeff Bonekamp, Eddy Garcia-Meitin, Gary Marchand, Kim Walton, Rajen Patel, May 2014
Dow has developed a new family of polypropylene (PP) based olefin block copolymers (OBCs), based on proprietary chain shuttling catalyst technology. This novel family of block copolymers offers break-through system performance when used as a component in multilayer structures for combining polyethylene (PE), and PP. These multilayer systems offer customers unique combinations of properties such as exceptional adhesion and temperature resistance. They also enable PE to participate in some traditionally PP applications in packaging.
Andrew Shinko, Sadhan C. Jana, Mary Ann Meador, May 2014
The structure-property relationships of polyurea aerogels made using two aromatic diamines and a triamine crosslinker are compared. Diamines were chosen based on previous work reported on polyimide aerogels. Polyurea segments were created by reacting one diamine species with 4,4’-diphenylmethane diisocyanate (MDI) in anhydrous N-methyl-2-pyrrolidone (NMP). These isocyanate-capped segments were crosslinked with 1,3,5 triaminophenoxylbenzene (TAB). Gels were dried under supercritical condition after exchanging the solvent with liquid carbon dioxide. The aerogel articles were obtained with density between 0.20 and 0.23 g/cm3, average pore sizes between 11-15 nm, porosity between 81-86%, and surface area between 111 and 394 m2/g, and onset of thermal decomposition at 250 °C.
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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
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.