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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
Thermal Properties Of Carbon Fiber Reinforced Polyamide 66 Composites Throughout The Direct Long-Fiber Reinforced Thermoplastic Process
Takashi Kuboki, March 2019
The direct long fiber reinforced thermoplastics (D-LFT) process is a series of processes involving two twin-screw extruders, a conveyer, and a compression molding machine. This study investigates variation on thermal properties of carbon fiber reinforced polyamide 66 (PA66) composites throughout the D-LFT process. Samples were taken from five different locations along the D-LFT process and characterized using thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results suggested that the thermal stability was decreased continuously up to the halfway point of the conveyer, but increased from the half conveyer to the compression molding. The degree of crystallinity was little changed throughout the process, but the crystallization half-time was increased after the half conveyer.
Effects Of Fiber Content On Optical, Viscoelastic, And Thermal Properties Of Cellulose Nanofiber Reinforced Poly(Methyl Methacrylate)
Takashi Kuboki, March 2019
This study investigates the effects of cellulose nanofiber (CNF) content on optical, thermal, and viscoelastic properties of CNF reinforced poly(methyl methacrylate) (PMMA). CNF/PMMA with different CNF contents were prepared through a solution casting method with acetone and compression-molded to create nanocomposite films. The films were characterized using an ultraviolet–visible-near infrared (UV-VIS-NIR) spectrophotometry, dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA). The results suggested that the viscoelastic and thermal properties of the CNF/PMMA were increased with the increase of CNF content while maintaining a high degree of transparency and increasing attenuation capability of ultraviolet light.
Injection Molding And Injection Compression Molding Of Ultra-High Molecular Weight Polyethylene: Minimized Thermal Degradation And Delamination Layer Formation
Galip Yilmaz, March 2019
Ultra-high molecular weight polyethylene (UHMWPE) in powder form was processed using injection molding (IM) with different cavity thicknesses and injection-compression molding (ICM). Tensile tests and impact tests showed that the ICM samples were superior to those of IM. Increased cavity thickness and ICM were helpful for improving the mechanical properties due to effective packing of the material. A delamination skin layer (around 300 μm thick and independent of cavity thickness) was formed on all IM sample surfaces while it was absent in the ICM samples, suggesting two different flow behaviors between IM and ICM during the packing phase.
The Effect Of Hygrothermal Exposure On The Thermal Conductivity Of Nanocellulose Based Foams
Whitney LaMarche, March 2019
Environmentally friendly insulation and packaging materials, driven by consumers and growing stringent global regulations against plastics, make biobased alternative materials a competitive market. Cellulose-based foams, consisting mainly of cellulose, are a greener replacement option over traditional petroleumbased insulation materials. One of the challenges associated with cellulose-based foams is their susceptibility to moisture, especially at elevated temperatures. Composite foams of nanocrystalline cellulose (NCC) and polyvinyl alcohol (PVA) were fabricated using a freeze casting method with a wide range of cooling rates during freezing. The physical properties of the foams, i.e., density, porosity and thermal conductivity were then evaluated before and after hygrothermal exposure at 40 °C with a relative humidity range from 96 to 77%. The results showed that the foams prepared with the highest rate of freezing exhibited the lowest relative density (0.019 g/cm3) and the lowest thermal conductivity (20 mW/mK). In general, the foams’ thermal conductivity increased after hygrothermal exposure. However, the foams with the highest freezing rate exhibited recoverable thermal conductivity behavior after exposure to heat and moisture. The possible mechanism for the differences were also discussed.
Investigation Of The In-Flow Effect On Weld Lines In Injection Molding Of Glass Fiber Reinforced Polypropylene
Giovanni Lucchetta, March 2019
In the injection molding process, weld lines can occur when two flow fronts rejoin due to either multi-gated molds or obstacles in the mold cavity. The weakness of plastic at weld lines provides serious difficulties for the design and long term durability of injection molded parts. Various methods to reduce the strength loss of weld lines include optimization of material composition, mold design and process conditions. To this purpose, this paper experimentally explores the influence of in-flow on the strength of weld lines for a commercial polypropylene compound reinforced with glass fibers. In-flow is defined as the flow within the mold cavity, below the solidified layer, that continues after the local region of the mold cavity is filled. In particular, the comparison of the weld line strength between specimens manufactured with and without in-flow was carried out and related to the reinforcement distribution in the welding zone.
Ultrafast Removal Of Pathogens From Wastewater Using Acid-Base Foams
Pavani Cherukupally, March 2019
Bacteria adhesive surfaces (BAS) have diverse applications, such as water treatment, biofuels, and solvents production. However, currently their large-scale usage is hindered by high materials cost. Inexpensive open-cell foams can potentially serve as substrates for low-cost BAS, enabling their wider usage. This work demonstrates a passive approach for attachment of Escherichia coli or E. coli to a polyester polyurethane open-cell foam surface using pH of the wastewater. The foam’s ionic-responsive charge property was used to bind negatively charged bacteria to its pore surface at different pH conditions. At the best pH condition, the foam adsorbed E. coli with over 99% efficiency. The pH-driven bacteria adhesion to foam surface is simple, effective, and passive, therefore has potential for industrial-scale applications.
Experimental Setup Design For Processing Functionally Graded Cellular Composites In Rapid Rotational Foam Molding
REMON POP-ILIEV, March 2019
This paper presents a new manufacturing process for producing functionally graded foam for rapid rotational foam molded composites (RRFM). A new experimental setup incorporates continuous foaming operation using a physical blowing agent (PBA) and a chemical blowing agent (CBA) to deliberately generate a foamed core with varying quality based on preferred direction or orientation. Carbon dioxide will be used as the PBA to produce ultrafine cellular foam. This novel process utilizes a static mixers to create a single phase solution before foam injection phase. In the co-extrusion operation, one extruder will be used for CBA-based fine cell low density foam production and the other for PBA-based ultra-low density polymeric foaming operation.
Embedding Intelligence Into Smart Tupperware Brings Internet Of Things Home
Sangjun Eom, March 2019
The Internet of Things (IoT) has been rapidly growing in recent years and is seen as a key enabler in a wide variety of applications such as manufacturing, transportation and healthcare. Home automation, in fact, has been a major market for both hobbyists and early adopters of IoT technology. Even a wave of smart kitchen appliances has been released such as a refrigerator with a built-in screen on its door or internet-enabled coffee maker. While green activists may applaud the appearance of tiny cameras inside our refrigerators to avoid the power loss of opening the door, displaying such images on a brilliant, 200W LCD monitor is not the “killer app” that many of us believe has the power to re-shape our every-day lives.
Copolyester Elastomers For Automotive Applications With Focus On Cvj Boots
Kirsten Markgraf, March 2019
Copolyester elastomers are high performance thermoplastic elastomers, based on a polyester hard segment and a polyether or aliphatic polyester soft segment. Copolyester elastomers are used to replace thermoset rubbers in CVJ (constant velocity joint) boot applications. These require thermal stability and resistance to greases. Copolyester elastomers are well known for these properties. When the surfaces of the boots come into contact with each other (i.e. at large turning angles) this can cause squeaking noises. Looking at the future, more and more electric or hybrid cars will be built. Until now the squeak noise was muffled by the combustion engine. Electric or hybrid cars require reduced noise emission in dry and humid environments. This paper provides an overview of copolyester elastomer applications for automotive with focus on CVJ boots and noise emission testing in different environments.
Designer Polymers: Additive Manufacturing Of Smart Materials As A Complement To Injection Molding
Richard Voyles, March 2019
This paper presents the idea of “designer polymers” – these are polymers that can be custom formulated to include sensing, computation, and actuation infused throughout the bulk of the material. Designer polymers are useful in the design and fabrication of smart products and we believe they will revolutionize the co-design of complex products. The co-design of smart products involves the simultaneous design of, for example, hardware and the software that executes during the functioning of the device. In our quest to develop designer materials, we have explored a variety of fabrication methods, including insert-molding and 3-D printing, or additive manufacturing.
Contribution Of Flow Instability To Tiger Stripes Of Polypropylene Copolymers
Tieqi Li, March 2019
Tiger stripes of polypropylene copolymers are studied by modeling the mold filling process as a non-isothermal two-phase flow using a level-set method. It has been shown that the Level Set method is capable of modeling the evolution of the flow field at and behind the melt front. An area of large velocity contrast between the skin layer of high shear rates and the center core of low shear rates has been observed behind the melt front under relevant injection molding conditions. The large velocity contrast appears to be a direct origin of the flow instability. The instability in terms of alternative occurrence and disappearance of the oscillatory strain rate is proposed to be a possible root cause of the tiger stripes. The comparison of the materials of different rheology suggests that shear thinning may be a useful property to mitigate the risk with the tiger stripes.
Why Titanates And Zirconates Are Better Than Silanes
Salvatore Monte, March 2019
Added to the hopper just like a color concentrate, 2 to 3 parts of a phosphato titanate or zirconate in pellet masterbatch form per 1,000 parts of filled or unfilled compound provides a method (Function 1-Coupling) for in-situ interfacial nano-surface modification of most all inorganic and organic materials in a compound independent of the interface’s hydroxyl content and absent the need for water to effect hydrolysis for coupling as with silanes while providing metallocene-like repolymerization catalysis (Function 2-Catalysis) and (Function 3) nano-intumescence for flame retardance resulting in: the use of larger amounts of regrind and recycle; copolymerization of blends of dissimilar addition and condensation polymers such as HDPE, PP and PET; prevention of delamination of PP/HDPE blends; faster production cycles at lower temperatures producing thermoplastic parts having less heat stress differentials, better finish, and increased stressstrain strength; and control of burn rate and burn rate exponent. Compounds having subject additives age better due to the removal of water at the polymer-reinforcement interface normally left when using a silane or no additives that cause loss of adhesion during water boil tests.
Preventing Discoloration In Thermoplastic Polyurethanes
Tad Finnegan, March 2019
Thermoplastic polyurethanes (TPU) are a versatile class of elastomeric polymers with physical properties that can be tuned to meet a wide range of demanding applications. TPU is known for its elasticity, transparency, abrasion resistance, and chemical resistance. This combination makes TPU an attractive material to replace materials such as rubber or polyvinyl chloride in many applications. However, like many polyurethanes, TPU is prone to oxidation and discoloration during processing and upon weathering. In this paper, combinations of antioxidants, process stabilizers, and light stabilizers were investigated to determine the best additive combinations to reduce the tendency of TPU to discolor.
Mechanical Properties Of Extruded Polypropylene Foams
Kim McLoughlin, March 2019
Extruded polypropylene foams provide a balance of high strength to weight ratio as well as thermal and sound insulation relative to solid materials. In addition, PP foams offer sustainability advantages over thermoset foams, because PP foams are readily reextruded and recycled. Used alone or as components of multi-component structures, extruded PP foams can provide mechanical properties that are valuable in a wide variety of packaging, construction, and transportation applications. Recently, Braskem commercialized a new high melt strength polypropylene (HMS-PP,) with the tradename Amppleo.® This HMS-PP grade enables efficient processing of PP foams using extrusion processesi. Using PP foam in a specific application requires an understanding of the mechanical properties, which depend on density, cell size, and cell morphology. This report provides mechanical properties for a series of Amppleo® 1025MA foams, spanning a wide range of densities and cell morphologies.
On The Use Of Silica Nanoparticles On Sls Processed Polyamide-11
Raymond Pearson, March 2019
Selective laser sintering (SLS) produces three dimensional shapes by repeatedly sintering and resurfacing a powder bed in a layer-by-layer fashion. Our short-term goal is to better understand the processing changes of a polyamide-11 powder laser sintered printing process when silica nanoparticles are added. Ultimately, we want to evaluate whether such nanocomposites results in superior z-axis strength and an overall increase in fracture resistance. Although polyamide-12 (PA-12) is more commonly used in SLS printed parts, polyamide-11 (PA-11) has the advantage of being a bio-based polymer. Like PA-12, PA-11 is a semicrystalline polymer but has a higher melting point (201 ⁰C powder / 191 ⁰C part). Rheology and solution viscometry tests confirm a molecular weight increase during printing, through a post-polymerization process. SLS printed PA-11 tensile specimens exhibit a 1.8 GPa modulus, an ultimate tensile strength of 55 MPa, and a strain to break of 66 %. Although it is not stiffer nor stronger than PA-12, PA-11 is significantly more ductile. The goal of the present study is to determine the effect of colloidal silica nanoparticle content (0 – 4 wt%) on processing behavior and mechanical properties.
Evaluation By On-Line Ftir Of The Kinetics Of Pp/Pa6 Blend Compatibilization With Pp-G-Mah During Extrusion
Lucivan Barros, March 2019
The on-line evaluation of the effects of process conditions variation during the extrusion process on the kinetics of compatibilization of polyamide 6 (PA6) in a matrix of polypropylene (PP) compatibilized with polypropylene grafted with maleic anhydride (PP-g-MAH) in different locations along the extruder by infrared (FTIR) spectroscopy is proposed in this work. As preliminary results and as a basis for comparing the on-line results that will be shown in the presentation the evolution of dispersion of the second phase of PA6 in the PP matrix is presented here. The area ratio of the peak of carbonyl stretching in amide present in PA6 at 1640 cm-1 standardized to the IR area of the peak at 1170 cm-1 relative to PP is applied to evaluate the evolution of dispersion along the extruder and the effect of the process condition in it. The standard deviation (s.d.) of the area ratio was used to correlate to the changes in dispersion condition when the process temperature, the feed rate and the screw speed were varied.
Mechanical Failure In Agricultural Silo Bags
Akanksha Garg, March 2019
Silo bags are used for bulk storage of grains in farmland. There are two typical modes of their failure: while being filled with grains, or due to long-term creep deformation during storage. In the past, several numerical studies have been conducted to improve the quality of grains stored in these bags by optimizing the moisture content or CO2 levels. The failure of these bags, however, especially when excessive pressure is applied during grain filling and subsequent creep during storage, is not well understood. Explicit Dynamic Solver in Abaqus (Product of Dassault Systems Simulia Corporation, USA) was used to model polymeric silo bags storing granular material under gravitational loading and pressure. The material computational model for silo bags (film) and the granular material has been developed using material subroutines, which themselves have been calibrated through in-house tensile and creep testing for the film. Numerical analysis of agricultural silo bags has been performed to understand mechanical failure in the bags during installation and usage at different temperatures.
Mineral Fiber Filled PC+ABS Blend Designed For Large Off-Line Painted Exterior Components
Marjolein Groeneweg, March 2019
A newly developed mineral fiber-reinforced PC+ABS satisfies all OEM requirements for large, painted, exterior components. It delivers a very low CLTE value, which ensures a high dimensional stability as needed for low gap designs. The low CLTE value is combined with a low density of only 1.24 g/cm3 which facilitates lightweight components and potential cost optimization. Beside the low density, the material offers very good flow properties, which not only permit thin walls but also guarantee a high degree of design freedom, even with large, long moldings. The good flow also speeds up cycle times and contributes to a cost-efficient production process. The new substrate material has proven to provide a nice class A surface of the final component after painting. The good paint adhesion meets the most stringent OEM requirements also after climate aging. Overall, the new mineral fiber-reinforced PC+ABS formulation has proven its technical fit and is a cost-efficient alternative to metal or PC+PET materials for exterior automotive applications. These improved properties of this material will help accelerate the trend to plastic exterior panels in autonomous vehicle since they allow much better pass through of various communication and lighting signals, compared to metal body panels.
Statistical Modeling Of The Squeak Noise Occurrence Of Natural Rubber
Byunghyun Kang, March 2019
In this study, the occurrence of the squeak noise according to various material / environmental factors of natural rubber was found through friction test using custom built friction tester. Material factors such as rubber hardness, surface roughness and additive content, and environmental factors such as heat aging, temperature, surface moisture, friction speed and frictional load are considered. And the hypothesis test was conducted to determine whether there was a significant correlation between each factor and the occurrence of squeak noise. Afterwards, logistic regression analysis and neural network analysis, which considers the interactions among these factors, were performed using the statistically significant factors in the occurrence of squeak noise obtained by the hypothesis test, and a probability model of the occurrence of the squeak noise was developed. And we compared the occurrence of the squeak noise predicted by the two models with the actual occurrence of the squeak noise, and the result shows 88.15% and 87.16% of accuracy, respectively. We also verify the accuracy of two models by using receiver operating characteristic curve (ROC curve), which illustrates the diagnostic ability of a model.
Magnum Abs: The Benchmark ABS For Extrusion
Marjolein Groeneweg, March 2019
Acrylonitrile-butadiene-styrene (ABS) resins are widely used for applications such as appliances, toys, office equipment, sanitary wares, building & construction, transportation and more. Extrusion of ABS covers around 25% of the total ABS market in North America, namely through sheets, pipes, edge bands, and profiles. ABS extruded into sheets and formed into final parts, finds its way into furniture, automotive, buses, trucks, recreational and utility vehicles, sanitary applications, advertisement boards, luggage and doors. For optimum product performance and cost efficiency, the ABS resins require specific attributes. These are an excellent lot-to-lot consistency, a white and thermal stable base color, an adequate UV stability, a low amount of unmelts and a high product purity. Because sheets and edge bands are demanded in a wide range of colors, self-coloring has become a key cost driver through necessities such as color matching, UV absorbers, and optical brighteners. Limited run sizes and regrinding also lead to increased scrap and constant color adjusting. Because the surface quality of thermoformed parts is so critical, presentation of unmelts and high levels of volatile organic compounds in the resins affect aesthetics. This study discusses the attributes of ABS specifically for extrusion and thermoforming, and compares the benefits of MAGNUM™ ABS versus several emulsion ABS. It is intended to provide information to manufacturers of extrusion applications to select the most suitable ABS materials for optimum production performance and cost efficiency.


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