Blends of Poly(Propylene Carbonate)/Hydrogenated Nitrile Butadiene Rubber: Morphology and Thermal Properties

Ahmad Zohrevand, David Lepage, Dominic Rochefort, Mickaël Dollé, Arnaud Prebé, May 2017

The morphology and thermal properties of poly(propylene carbonate) (PPC) and hydrogenated nitrile butadiene rubber (HNBR) blends obtained via a meltmixing process were studied. Morphology of the blends with different compositions was observed by scanning electron microscopy (SEM). Differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) were performed to study miscibility and thermal stability of the blends. SEM image showed that PPC/HNBR blends are phase-separated at the microscopic scale and each phase showed characteristic Tg in DSC. The addition of HNBR is demonstrated as a mean to significantly improved thermal stability of PPC phase under air atmosphere.

Carbon Nanofibers Preparation from Pan Nanofibers by Cotton Candy Method

Akihiro Tada, Jitlada Boonlertsamut, Supaphorn Thumsorn, Masayuki Okoshi, Hiroyuki Inoya, Hiroyuki Hamada, Yoshifumi Aoi, May 2017

The cotton candy method was used for preparing polyacrylonitrile (PAN) nanofibers. Molecular weight (MW) of PAN was 15x104 and 20x104 g/mol. The PAN was dissolved by N-Methyl-2-pyrrolidone (NMP). The concentration of PAN solution was varied at 3-10 wt%. The PAN solution was spun through the plunger at the speed of 100 and 1,000 rpm at air pressure of 0.2 MPa. The collecting distances were set at 20, 40, 60 and 80 cm. Morphology of the fibers was observed by scanning electron microscope. The PAN nanofibers were successfully formed at 10 wt% of PAN MW 15x104 g/mol and 5wt% of PAN MW 20x104 g/mol. The fiber diameter decreased when increasing the collecting distances. The average fiber diameter was around 400-650 nm. The glass transition temperature and the oxidative degradation increased when increased the concentration of PAN. Raman spectrometry of carbon nanofiber by PAN nanofibers from CoCaM showed high crystallinity. and stretched strongly and alignment.

Evaluation of Various Weight Reduction Strategies on Mechanical Properties and Part Performance

Matthew T. Thompson, May 2017

Multiple options exist for decreasing the weight of injection molded automotive components. Each option offers unique advantages and limitations regarding weight reduction potential and mechanical performance of the final part. Advanced Composites has evaluated the effect of several strategies, including composite density reduction, wall thickness reduction, and foaming, on the performance of injection molded test specimens and parts made using a diagnostic tool. Densities and part weights were obtained as well as tensile, flexural, and impact properties. In the case of density reduction, the removal of mineral filler alone proved insufficient to maintain mechanical performance, indicating the need for optimization of the material formulation. The characteristics of foamed and thin-wall parts were also examined and demonstrate the need for careful consideration of part and material design.

Automotive Prototype from Recycled Carbon Fiber Reinforced Recycled Polyamide Composite

Omar Faruk, Birat KC, Jimi Tjong, Mohini Sain, May 2017

Automotive industries are promoting and working to improve the sustainability of their vehicles by using materials, which includes increasing of recycled and lightweight materials. Increasing recycled materials is to improve resource efficiency by recycling consumer and industrial waste and increasing lightweight materials is to improve vehicle fuel efficiency by expanding the use of lightweight materials. An automotive prototype (oil pan) is developed from 100% recycled material (20 wt% recycled carbon fiber with 80 wt% recycled polyamide) to improve fuel efficiency by light weighting and as well as sustainability. The material properties and processing parameters are compared to current production part. A global thermal cycling durability test of prototype part has been performed where the continuous high temperature is mainly concerned. It is found that the prototype part is 15% lighter than current part and as well as lower processing time. The prototype part has successfully passed the global thermal cycling durability test.

Effects of Graphite Selection on Thermally Conductive Compounds for LED Lamp Heat Sinks

Daniele Bonacchi, May 2017

Thermally conductive compounds are viewed as potential replacements of metal based heat sinks in automotive and non-automotive LED lamp applications. Graphite is certainly the main candidate for thermally conductive applications that tolerate electrical conductivity for their high efficiency and reduced costs. In this article we demonstrate that the introduction of graphite increases substantially the thermal conductivity especially along the plastic flow (in plane) direction. We have tested several commercially available graphite grades in polyolefin model polymers and have seen that the crystallinity, the average particle size and the aspect ratio are the three main factors that promote thermal conductivity. In this comparative study we have also tested special high aspect ratio graphite that delivers high thermal conductivity at low loadings giving an advantage in terms of weight reduction.

Improved Optical Properties of Polycarbonate for Light Guide Applications

Jun-ya Hayakawa, Makoto Egawa, Keisuke Tomita, Masaki Hirono, Matthew Orlando, May 2017

The materials for vehicle light guide rod or liquid crystal display need superior optical and heat resistance properties. In conventional polycarbonate, these properties were improved by adding a general heat stabilizer. A search was made for new additives effective in any other properties. As a result, it was found that heat resistance and optical properties are improved dramatically by adding combinations with specific PAG and additives. The key properties for commercial production are molding retention time and weatherability. Results revealed that both properties were sufficient to use in vehicle light guides. Improvement of optical, heat aging properties, retention molding, and weatherability of the improved polycarbonate was examined.

Development of LDS Polycarbonate and Polyamide Materials for Soldering

Matthew Orlando, Bernard Schrauwen, Tatsuya Kikuchi, May 2017

Laser Direct Structuring (LDS) is a type of Molded Interconnect Device (MID) that uses optimized plastics which are compounded with special pigments. The LDS method is often times used for producing antenna and circuitry components. Aside from thermal stability, common requirements for plastics in these applications are good mechanical strength, dimensional stability, and stable radio frequency properties at operating ranges of high frequencies. Mitsubishi Engineering Plastics currently produces polycarbonate, polybutylene terephthalate, and aromatic polyamides for LDS. Newer polycarbonates and polyamides which are suitable for soldering are being developed at this time as well.

A Revised Approach to Rheological Behaviour and Processing Parameters of Polycarbonate Compound with Dispersion

Jamal Al-Sadi, May 2017

The objective of this work is to study the rheological characteristics of the compound of polycarbonate resins with different melt flow indexes and the affects of the processing parameters PC1 content (30wt%-pph) of MFI (25gm/10mins) and PC2 content (70 wt. %-pph) of MFI (6.5gm/10mins). By understanding the relationship between shear rate and viscosity, it becomes possible to define the viscosity model and exact color shifts. The temperature was varied at three stages (230°C, 255°C and 280°C) to study its effect on rheological characteristics, colour differences (dE*), pigment size distribution and dispersions.

Keratin Bio-Composites with Polysiloxane Thermoplastic Polyurethane

Firoozeh Pourjavaheri, Oliver A.H. Jones, Isaac Martinez Pardo, Frank Sherkat, Arun Gupta, Robert A. Shanks, May 2017

A sustainable resource in the form of chicken feather derived keratin was used to enhance the thermo-mechanical properties of polysiloxane-polyurethane bio-composites. Two methods, solvent–casting–evaporation–compression molding, and solvent–precipitation–evaporation–compression molding were used to create new bio-composites incorporating 20 %·w/w of chicken feather fibers into a polysiloxane-polyurethane matrix and the results were compared. A molecular modeling visualization indicated the possible existence of hydrogen bonding between fibers and polyurethane molecules. The thermo-mechanical properties of both the polysiloxane polymer and feather reinforced bio-composites were assessed using thermogravimetry, dynamic mechanical analysis and stress–strain measurements with hysteresis loops. The dispersion uniformity of the keratin fibers in the plastic matrix was investigated via macro photography. Addition of chicken feather fibers to the polysiloxane matrix was found to decrease the recovery strain and mass loss of the composites (at lower temperatures) but increase the elastic modulus, storage modulus, and char level (at higher temperatures). The results demonstrate that keratin derived from what is currently a waste product from the poultry industry (with significant economic and environmental disposal costs) can improve the thermo-mechanical properties of the tested bio-composites simply and cheaply, with potentially large cost savings and environmental benefits.

Fabrication of Hybrid Polymeric-Metallic Foams as Scaffolds for Bone Tissue Engineering

Anil Mahapatro, Lipi Malladi, May 2016

Thermoplastic foams have been explored for their use as scaffolds for bone tissue engineering. Challenges exist in their applicability and strategies for enhancement in mechanical properties are needed. In this paper we report the fabrication of hybrid polymeric-metallic foams where magnesium was electrodeposited on polyurethane foams with the goal to enhance the mechanical properties of polyurethane foams. The foams were characterized using visual methods and optical microscopy techniques, which clearly showed the presence of magnesium fused foams.

Weld Lines in Injection Molded Parts: Strength, Morphology and Improvement

I. Kuehnert, Y. Spoerer, M. Zimmermann, May 2016

Weld lines are rather well known as optical and/or mechanical blemishes in plastics products that can be avoided barely by mold design or process control. Although many publications show single solutions to optimize weld line strength in injection molded parts, there is no complete comparison of thermoplastic polymer materials available. Therefore, an overview about formation, morphology and strength of weld lines for amorphous, semicrystalline and filled polymer materials is given.

How to Add Value to Capillary Rheometers

Tim Haake, May 2016

Capillary Rheology has been around for many years. As technology moves on, this has opened doors to use the capillary rheometer as a base on which to build a sophisticated R&D platform to perform a wide range of other tests, which help rheologists and their colleagues. We look at extensional rheology, elasticity, pressure- volume-temperature (PVT), thermal conductivity (TC), sharkskin analysis and the effects of counter pressure measurements. Those are but a few of available options to lab managers who try to squeeze out extra capabilities from their budgets.

Single Pellet Extrusion

D.O. Kazmer, May 2016

Analysis and results are presented to model the melting of a single pellet in an extrusion screw. The analysis considers transient heat conduction with a convention boundary condition and three sources of internal generation. The results suggest that the theoretical melting time for a pellet is on the order of seconds and more optimal extrusion screw designs are possible.

The Effect of Flow Channel Aspect Ratio on Layer Uniformity in Flat Extrusion Dies

Sam Iuliano, Andrew Svenningsen, May 2016

Common extrusion systems used to produce multilayer structures include a coextrusion feedblock - which assembles individual melt streams into a narrow multilayer “sandwich”, and a flat die - whose primary purpose is to uniformly distribute this multilayer structure to the desired final width. Given the demand for improved layer uniformity, extrusion die distribution manifold features have been developed to reduce the distortion of coextrusion interfaces. This paper will discuss the effect of die manifold aspect ratio on coextrusion uniformity.

High Gloss “Piano Black” Acetal Copolymer

Bruce M. Mulholland, Coralie M. Richard, May 2016

High gloss, piano black is an appearance that continues to grow as an accent color for automotive interior, cosmetic packaging, small appliances and other markets. The most common way to achieve a piano black look is by painting plastic parts using a two-coat or three-coat painting process which adds significant part cost and scrap. A molded-in-color solution is desirable to reduce cost without sacrificing quality. This paper discusses development of a molded-in-color solution in acetal copolymer resin and how that solution compares to other resins commercially available.

The Effect of Viscous Encapsulation on Layer Uniformity and Rheology in Multilayer Coextrusion

Hyunwoo Kim, Kurt A. Koppi, Robert Wrisley, Joseph Dooley, May 2016

Multilayer coextrusion is a process in which two or more polymers are extruded and joined together in a feedblock or die to form a single structure with multiple layers. This paper will discuss the effect of viscous encapsulation especially in a flow channel with a noncircular cross-section on layer re-arrangement and rheology of a coextruded structure.

Viscosity Measurement of Multilayer Structures via Parallel Plate Rheology

Kurt A. Koppi, Christopher M. Thurber, Hyunwoo Kim, Joseph Dooley, May 2016

Parallel plate rheometry has been used to characterize the viscosity of multilayer polymer structures. It has been demonstrated that this technique is not a good substitute for performing such measurements using a coextrusion slit die rheometer. For the purpose of designing dies for producing multilayer structures, one needs good viscosity data that correctly represent the behavior of the intended structure under flow and for this reason, a coextrusion slit die rheometer is recommended.

Study on Nano Polyacrylonitrile Fiber by Cotton Candy Method

Ryo Takematsu, Masayuki Okoshi, Hiroyuki Inoya, Hiroyuki Hamada, Akihiro Tada, Yoshifumi Aoi, May 2016

New Approaches for the Integration of Process Disturbances in Injection Molding Simulation

Christian Hopmann, Benjamin Grümer, May 2016

During the product development of injection molded parts, simulation software is used to predict process parameters and part quality during the production process. The integration of process disturbances into the injection molding simulation software leads the way to a prediction of the quality variation. Thus, the optimization regarding a robust process parameter set already during early stages of the product development process is possible.

Application of TRIZ Tools to Develop a New Plastic Chemical Dispenser

Iván D. López, Juan C. Ortiz, Alberto Naranjo, May 2016

The application of several TRIZ (Theory of Inventive Problem Solving) tools to support the development of plastic products is presented. The considered tools are the Function Analysis, the Inventive principle application, the solution of Physical Contradictions and Trimming. A plastic chemical dispenser is used as study case. The design starts from a plastic fish feeder that is commercially available. After applying the TRIZ tools, the design evolves to a complete new concept, overcoming the original design limitations.