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.
The SPE Library is just one of the great benefits of being an SPE member! Are you taking advantage of all of your SPE Benefits?
Not an SPE member? Join today!
| = Members Only |
|
Categories
|
Recycling
Various topics related to sustainability in plastics, including bio-related, environmental issues, green, recycling, renewal, re-use and sustainability.
Conformal Cooling Simulation for the Plastic Injection Molding Process
Duke Energy Convention Center
Cincinnati, Ohio April 22-24, 2013
4SPE
13 Church Hill Rd
Newtown, CT 06470 USA
P: +1 203-77
Modern injection mold manufacturing technologies allow internal cooling channels to be made to any shape that follow the precise geometry of the part in the mold. This aids in creating a uniform temperature distribution in the part by targeting hot spots on the part surface with arbitrary shaped cooling channels in the mold. Ultimately these result in better quality parts, shortened cycle times, reduced waste and cost reductions. Simulation of these processes requires a fully transient, three- dimensional (3-D), time dependent computational fluid dynamics (CFD) solution in these conformal cooling channels. This paper presents the further development of a (3-D) finite element based transient mold cooling simulation capability to include a solution for solving the 3-D flow in cooling channels. This new capability forms part of a future release of Autodesk Moldflow Simulation.
Creating Sustainable Growth by Incorporating Sustainable Development Behavior in Supplier Selection
As we work to make our companies more sustainable, it’s necessary to evaluate not only ourselves but also those we select to help us achieve an improved “triple bottom line”. Our vendors and suppliers today will need to be collaborative partners tomorrow if we want to achieve more impactful financial, societal and environmental results. To evaluate a potential sustainable collaborator, consider a teachable, measurable and repeatable process that outlines the questions and judges the responses; then look for potential suppliers that have an observable culture of sustainable development and continuous improvement. You should be able to witness their culture in action when dealing with company officials and representatives.
There are clear signs for companies with sustainable development cultures. When they are combined with a set of stewardship behaviors that drive sustainability, they make great suppliers. We have identified seven distinct stewardship behaviors that can be broken down into contributors to the Triple Bottom Line aspirations of every company focused on their on sustainable growth. For the environmental bottom line, consider “touch”; for societal goals, consider the behaviors such as “teach, treat and tout”; and for the profit driver, focus on behavior resources such as “time, talent and treasure”. These seven behaviors have attributes that can, and should be evaluated and measured as we chose our suppliers. In our presentation, we take a look at each separately to give us insight into the complete value a supplier can deliver.
Crosslinkable Polyolefin for Rotational Molding with Improved Processibility
Crosslinked plastic parts demonstrate prominent performance advantages over the non-crosslinked articles for a wide array of applications. New crosslinkable polyethylene compositions were recently developed which showed outstanding processibility and excellent thermal and mechanical properties, such as increased impact strength, high modulus, and enhanced environmental stress cracking resistance (ESCR). The advancement in balance of melt processibility and solid properties is ideally suited for the rotational molding process, opening opportunities to produce high-performance end-use products, including sporting boat, large agricultural and chemical containers, all-plastic cars, and other outdoor products.
Novel Poly (Lactic Acid) Based Emulsion
ANTEC 2013 Technical Paper - Biodegradable and biomass base polymers are gaining attention from the view of environmental concern. In this report, novel poly (lactic acid) based multibranched polymers self-emulsified in 100 % water are described.
Design of an Innovate and Recycle Float-Valve System by Using CAD/CAE/LCA Tools
Due to the growing worldwide interest in tasks such as environment preservation and recycling, a model of float-valve system for domestic water tanks has been proposed. It considers in its design, the use of an urban waste product such as PET bottles, as the floating device of the mentioned mechanism, having as main idea to contribute with environment care. If the new design is compared with known commercial models, it could be considered as innovative due the reutilization of plastics wastes. At the same time, the system functionality is preserved, and the final parts are easy to fabricate at low cost. Also, the estimation of the Life Cycle Assessment (LCA) for the system shows that the proposed design could be catalogued as environmental friendly.
Deterioration Mechanistic Evaluation of PET Film
In recent years, the solar photovoltaic system has been attracted rising attention as an important power source in the viewpoint of environmental problems and other global issues. However, there are some problems in terms of durability of the each part. The back-sheet consisted of PET multi-layer films plays an important role to prevent moisture from outside into the main-board of the solar photovoltaic system. It is very important to investigate the durability of the back-sheet in order to maintain the usage of this system. In this research, we tried to evaluate the mechanical properties of PET films by applying the accelerated deterioration test. The durability was discussed on the basis of the results of the tensile test, the FT-IR measurement, and the SEM observation.
Developing Polymer/Ceramic Scaffolds via Thermally Induced Phase Separation for Bone Tissue Engineering
Biodegradable polymers are used to fabricate porous scaffolds for tissue engineering. Among different scaffold fabrication techniques, thermally induced phase separation (TIPS) is valuable because of producing highly porous scaffolds with interconnected structures. The effect of adding hydroxyapatite (HA) to poly (lactic-co-glycolic acid) (PLGA) scaffolds as well as other TIPS parameters was investigated in this study. The ultimate goal is to fabricate porous scaffolds that are mechanically functional, while they provide the desired porosity and pore interconnectivity for cell migration, cell growth, and transport of oxygen and nutrients.
Eco-friendly Bio-based Adhesive Tapes made from Biomass Materials
There are some bio-based plastic films however some properties of the films should be modified to use as adhesive tape film and adhesive compound materials should be designed. We improved film properties by adjusting the sheeting process. Regarding the film, it was confirmed that poly lactic acid (PLA) film, which has good heat resistance and tear strength, was obtained by using the calendar sheeting process. On the other side, low glass transition temperature materials and crosslinking materials were selected and formulated for adhesive polymers.
Developed bio-based adhesive tape was evaluated and compared to conventional acrylic adhesive tape, and comparable properties were obtained. In addition, in the case of surface protection tape, it indicated enhanced properties.
We can introduce Eco-friendly Bio-based Adhesive Tape made from biomass materials.
Effect of D-content on CO2 solubility in PLA
The pressure-volume-temperature (PVT) behavior of Poly Latcic Acid (PLA) with dissolution of CO2 was investigated using an in-house visualization device; experiments were carried out at 453 K and 473 K, and pressure was varied from 6.894 MPa to 20.684 MPa. The results indicate that as the temperature increases, the swelling decreases, whereas an increase in pressure results in an increase in swelling. The effect of molecular weight (Mw) on swelling volume was also investigated by experimenting on different grades of PLA with varying Mw. The result is that molecular weight does not have a pronounced effect on swelling volume. The effect of talc on swelling ratio was observed by the addition of 5% talc content in PLA 3001D. A comparison was made between theoretical and experimental swelling volume ratios; the theoretical data was obtained using SS-EOS and SL-EOS.
Effect of Extensive Recycling on Flow Properties of LDPE
Low density polyethylene (LDPE) was exposed to one hundred (100) consecutive extrusion cycles to simulate the process of mechanical recycling. Collected samples were characterized by means of melt flow index measurements and small amplitude oscillatory measurements to investigate flow properties. The results suggest that thermal degradation and gelation of LDPE occur after extensive extrusion which leads to simultaneous chain scission and crosslinking of the polymer chains. However, after 40 extrusions crosslinking is more dominant than chain scission. Rheological observations were confirmed by solubility studies that showed a pronounced increase in insoluble fraction after 40 extrusion cycles. This indicates that the technological parameters should be modified when processing recycled LDPE, particularly after 40 extrusion cycles.
Effect of mixing time and temperature on the rheology and morphology of immiscible polymer blends prepared from polytrimethylene terephthalate [PTT] and polyamide 6,10 [PA6,10]. Kevin Lucero, Marissa
Thermoplastic immiscible polymer blends were prepared from polytrimethylene terephthalate [PTT] and polyamide 6,10 [PA6,10] by melt processing in a Brabender mixer to assess morphology developed between the immiscible domains. PTT and PA6,10 were selected as a pair of engineering polymers with complementary properties and as a blend prepared to significant extent from bio-based precursors. Overall, a 50/50 blend of these polymers has a renewable content of nearly 50%. The overall objective is to develop an engineering blend with good stiffness, strength, and dimensional stability while simultaneously being easy to process. In the present phase of the work, blend homogeneity was studied as a function of mixing time and temperature in the range of t=0-25 minutes and T=240-260 C. Results are presented in terms of torque versus time and temperature curves that are interpreted in terms of domain formation and SEM micrographs are used to define domain size and overall morphology.
Effect of Molding Conditions on the Weld Line Property of Injection Molded Jute/PP Composites
Jute fiber is of not only low density and good mechanical property but also natural and degradable property. On the other hand, recyclable Polypropylene (PP) was also good choice for environmental friendly material. Injection molding is one of the most important processes to manufacture plastic composites because it is of high quality products with low cost. However, weld lines are unavoidable when two separate melt fronts rejoin during injection molding. The presence of weld lines not only detracts from the surface quality but also significantly reduces the mechanical strength of injection- molded parts. Although it is not always easy to completely eliminate weld lines, the weld line strength could be improved through suitable adjustment of molding conditions such as melt temperature, mold temperature, hold pressure, injection speed, and so on. Therefore, in this paper the weld line property of injection molded jute/PP dumbbell shape specimen was investigated. Pultrusion technique was adopted to fabricate jute/PP long fiber pellets (LFT) and the re-compound pellets of LFT, i.e. RP was made to improve the fiber distribution. Then LFT, RP were used to mold dumbbell shape specimens with or without weld line. In particular, the influence of back pressure and holding pressure on weld line strength of injection molded jute/PP dumbbell shape specimens was discussed based on tensile test and SEM observation.
Effect of Poly(Butylene Adipate-Co-Terephthalate) Contents on Crystallization and Mechanical Properties of Polymer Blends of Poly(Lactic Acid) and Poly[(Butylene Succinate)-Co-Adipate]
The effect of poly(butylene adipate-co-terephthalate) (PBAT) contents on crystallization and mechanical properties of poly(lactic acid) (PLA) and poly(butylene succinate-co-adipate) (PBSA) blend was studied. PLA and PBSA were blended in a twin screw extruder, which incorporated PBAT as a ternary component in PLA/PBSA blend. The ratio of PLA/PBSA was set at 80/20. The contents of PBAT were varied from 0 to 50 wt%. The thermal properties and crystallization behavior of PLA/PBSA/PBAT blends were analyzed by differential scanning calorimetry. The effect of PBAT contents on non-isothermal crystallization kinetic of the composites was investigated by using Avrami equation. Tensile modulus and tensile strength of the PLA/PBSA blends decreased when increasing PBAT contents. It can be noted that the addition of 20 wt% PBAT showed the maximum impact performance of the PLA/PBSA blends.
Effect of Rice Flour Filler on Heat Seal Strength for Sustainable Designed Sealant Film
The packaging materials are spoiled in a short cycle. An environment packaging materials are demanded. The economic cost is one of problems to substitute general plastics for bio-resource sustainable plastics. In this study the potential of rice flour as compounding filler for sealant polymer was examined. Poly(butylene succinate)(PBS) / rice flour composite biodegradable film was processed directly by twin-screw extruder equipped with T-die. Heat seal property of the biodegradable film was investigated. As compounding filler material, the potential of rice flour on heat seal property was studied. At 100 ºC of heat seal temperature, the PBS / rice flour composite film showed high heat seal strength comparing with neat PBS film. By scanning electron microscopy observation, bled out rice flour grains at film surface affected heat seal property. The PBS / rice flour composite film could keep more than 80% tensile strength comparing with neat PBS. However heat seal strength for HDPE / rice flour composite film dropped. To attain high seal strength it needed longer dwell time. The compounded rice flour prevented heat seal property for HDPE. The exposed rice flour particles worked effectively for PBS / rice flour composite film.
Effect of Stereocomplex Crystallite as a Nucleating Agent on the Isothermal Crystallization Behavior of Poly (L-Lactic Acid)
Isothermal crystallization behaviors of poly (L-lactic acid) (PLLA) blended with different contents of Poly (D-lactic acid) (PDLA) were studied by wide-angle X-ray diffraction, differential scanning calorimetry and polarized optical microscopy. PDLA molecules added to PLLA formed stereocomplex crystallites in the PLLA matrix. The stereocomplex crystallites stayed unmelted at 190 °C and embedded in the PLLA molten matrix. Isothermal crystallization measurement at 100 °C revealed that the crystal radius growth rate decreased with an increase in the isothermal crystallization temperature. The spherulite growth rate has a peculiar PDLA concentration dependence. PLLA crystallization behavior might be affected by network structure and homogeneous dispersibility of stereocomplex crystal.
Effect of Talc Filler on Recycled PET Blends Injection Moldings
Recycled PET (RPET) is known to exhibit brittle behavior in the presence of notches. Therefore, we tried to improve the toughness and other properties of RPET by incorporating E-GMA, talc filler and engineering plastics as an impact modifier and talc to increase the rigidity and heat distortion temperature of RPET. As a result, these blends with E-GMA exhibited significantly higher stiffness and strength especially with increasing E-GMA content. In addition, these blends with talc filler indicated the high heat distortion temperature due to increase the crystalinity of RPET blends. Therefore, it was found that talc played an important role in enhancing the heat resistance of RPET. Some injection molding parts, i.e. tray, chopstick, and so on, were produced from these compound materials.
Study on the Effect of Material Elasticity on Acoustic Performance and Rheological Properties of Bio-Based PLA and PHA Blend Foams
In this study, open cell foams were fabricated from blends of bio-based polymers to be used as sound absorbers. Different blends of Polylactide (PLA) with two grades of Polyhydroxyalkanoates (PHA) where foamed and characterized based on acoustic and mechanical performance. Rheological properties of pure polymers as well as their blends were studied to investigate the effect of material elasticity on the acoustic absorption of the resulting foams.
Electrical Properties of Polypropylene Composite Foams Reinforces with Long Stainless Steel Fibers
Conductive thermoplastic composite foams are a novel class of materials that can be an excellent candidate for producing cost-effective and lightweight products. In this work, electrically conductive polypropylene (PP) foams of various densities filled with varying contents of long stainless steel fibers (SSF) were successfully fabricated. The foaming of composites was achieved using a batch process and supercritical CO2 as the environmentally benign physical blowing agent. The PP-SSF foams maintained high level of electrical conductivity over a wide range of density reduction, depending on the initial loading of SSF. To better understand the conductivity behavior of solid and foamed composites, statistical percolation analysis was conducted. The analysis showed that the conductivity change with the foam density followed the percolation power law. The critical SSF concentration, calculated based on the sample’s final volume was 0.37 and 0.28 vol.% for the solid and foamed composites, respectively. In the current PP-SSF system, foaming decreased the weight up to ~70-80 % and lowered the percolation threshold by about 25%.
Sustainability and Plastic Technology
Sustainability principles are becoming associated with best practices. This paper will cover results of a 2011 survey and implications for Sustainability in the plastics industry. We will also present a few examples from the Plastics Industry that illustrate the principles of sustainability in practice.
Evaluation of Heat Transfer Conditions to the Mold Temperature Stabilization in the Injection Molding Process
In order to keep the part quality under a stable mold temperature, a number of parts should be discarded until the mold temperature reaches to a stable condition. Depending upon process and environmental conditions, the time to a stable condition varies. In this work, influencing factors to the stabilized mold temperature condition are examined. The results show that ambient temperature significantly affects the stabilization time. To predict the stabilization time with consideration of heat transfer to the molding machine, heat sink attached model in the CAE analysis was suggested. It shows a good agreement with experimental result.
|
This item is only available to members
Click here to log in
If you are not currently a member,
you can click here to fill out a member
application.
We're sorry, but your current web site security status does not grant you access to the resource you are attempting to view.
.jpg)
.jpg)
.jpg)
.jpg)
