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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Recycling

Various topics related to sustainability in plastics, including bio-related, environmental issues, green, recycling, renewal, re-use and sustainability.

Lower-Cost, Ligther and Greener Polypropylene-Based Biocomposites for Industrial Applications

MIHAELA MIHAI, May 2015

This paper discloses the viability of the formulation, processing, and performance of advanced biocomposites and bioblends based on polypropylene (PP) designed for industrial manufacturing. The PP was compounded with three different types of cellulosic fibers, in a bioblends with polylactide (PLA) as bio-sourced polymer, and in PP/PLA/cellulosic biocomposites. These biomaterials were characterized in terms of morphology, mechanical and thermal properties. Tensile strength, tensile modulus, and the heat deflection temperature of the bioblends and the biocomposites presented at least equivalent values comparing with virgin PP and with PP current industrial grades. The extruded biocomposites, foamed in injection molding process, presented similar properties as the unfoamed and reference counterparts while being up to 25 wt.% lighter, up to 50% less expensive, and up to 50% greener.

Low-Permeation Toughened Polyoxymethylene (Pom) for Injection-Molded and Blow-Molded Tanks in Small Off-Road Engine (Sore) Applications

Sunghye Kim, Lowell Larson, Philip Wlison, George Zollos, May 2015

Polyoxymethylene (POM) polymers exhibit excellent chemical resistance against various chemical substances, such as hydrocarbons. However, due to POM?s relatively low impact strength, its use in containment of chemicals, such as chemical bottles and tanks, has been limited. The development of both injection-moldable and blow moldable low-permeable, toughened POM will be discussed. Impact-modified POM, using a coupling technology, has been molded into gasoline tanks for small off-road engine (SORE) applications. The tanks passed the impact requirement, while maintaining the fuel permeation performance below the regulation limits by US Environmental Protection Agency (EPA) and California Air Resources Board (CARB).

Making Tailor-Made High Performance Thermoplastic Polyolefin (TPO)/ Polylactide (PLA) Blends for Automotive Interior Applications by Irradiation

Carolin C. Vogt, Hans-Josef Endres, J??rgen B??hring, May 2015

In order to create high performance thermoplastic Polyolefin (TPO)/ Polylactide (PLA) blend films with high heat stability for automotive interior applications it is necessary to crosslink the PLA. In this study, films of PLA and compatibilized TPO/PLA blend films were irradiated using electron beam (EB) and triallyl isocyanurate (TAIC) as crosslinking agent. The samples were irradiated with various irradiation doses. Gel fractions of the irradiated samples and FTIR spectra showed that with increasing irradiation dose mainly the crosslinking of PLA increased whereas the TPO remains in a non crosslinked state. The heat stability of the samples was tested by tensile tests at 80øC. As an indication for higher heat stability of PLA through crosslinking, 300%-Modules were analyzed. The non-irradiated TPO/PLA blend film showed 1.3 MPa as 300%-Module and the blend film irradiated with 87 kGy 2.2 MPa. Therefore the 300%-Module increased by 85% by crosslinking PLA with 87 kGy. With these studies it is proven that through crosslinking PLA films, even in a blend with TPO, PLAs heat stability and consequently the performance of the PLA blend is increased. The increased heat stability of PLA via crosslinking is helpful in expanding the applications of PLA.

Mechanical and Thermal Properties of Coaxial Electrspun Fibers Mesh of PCL-PBAT

Syed Hussain R. Rizvi, Yoni Mercier, Thunyatorn Pukkrueapun, Nandika D?Souza, May 2015

Physical morphology, mechanical and thermal properties of potential drug delivery devices and scaffold structures were examined. PCL and PBAT were selected because of their biodegradable and biocompatible nature. Properties of electrospun single component PCL and PBAT meshes were compared with coaxial fibers of PCL as a sheath material and PBAT as core. DMA test results indicate that the stiffness of the coaxial fiber sample has increased significantly diminishing the flexibility of the mesh. DMA results also reinforced that the strength of the coaxial fibers increases many fold as compared to individual fibers spun.

Mechanical Property Enhancement in Recycled High-Density Polyethylene (rHDPE) via Solid-State Pulverization Methods

Katsuyuki Wakabayashi, Evan Miu, Samuel Jubb, Andrew Fox, May 2015

Low-temperature, solid-state pulverization processes are explored for transformation of postconsumer, recycled HDPE (rHDPE) into value-added applications. A process called solid-state/ melt extrusion (SSME), comprising sequential solid-state pulverization and melt extrusion in a single twin screw extruder, was found to impart significant morphological and rheological changes in rHDPE, which in turn lead to improvements in tensile ductility and toughness to the level of those found in typical neat, virgin HDPE.

Meeting Global Challenges with Micro Solutions: The Role of Plasma Surface Treatment in the Future of Plastics

Paul Mills, Andy Stecher, May 2015

The industrial landscape is ever changing. Some changes come from new discoveries and improvements; others are responses to problems and failures with existing methods. Still others are triggered by competitive market forces and demands such as lower cost. This paper examines seven global trends in plastic part manufacturing:

1. Greater use of regrind and recycled plastic resins
2. Increased interest in thin walled plastic parts
3. Continuous weight reduction in automotive
4. Growth of plastics with bright metal appearance
5. Further reduction in solvent use
6. More UV coating applications for plastics
7. Continued growth of medical plastics

Each of these represents new business opportunities as well as new implementation challenges. In particular we study the role that plastics? surface are expected to play in the success or failure of these new opportunities. We propose that plasma surface treatment provides a workplace safe, environmentally friendly, and cost effective means for meeting these new challenges.

Microstructural Design of Porous Membrane for Effective Sound Absorption Performance

Shahrzad Ghaffari Mosanenzadeh, Hani Naguib, Noureddine Atalla, May 2015

Porous materials and foams are widely used for sound absorption purposes in different sectors. To answer the needs for light weight compact noise insulation material with high sound absorption capability, the microstructure of porous membranes can be designed for optimum performance while occupying the same volume with the same weight. Such engineered structures are known as Functionally Graded Material (FGM). In the present study, novel functionally graded foam with superior sound absorption is introduced and compared to uniform foams of the same porosity. The designed graded membrane demonstrates 20% improved performance. Foams are fabricated from bio-based polymer (Polylactide (PLA)) and are environmentally friendly.

Microwave Synthesis of Poly (Glycerol Sebacate)

Gildas Coativy, Manjusri Misra, Amar Mohanty, May 2015

In the present work, poly (glycerol sebacate) elastomer was obtained by microwaving glycerol with sebacic acid during 128 minutes at 180øC. The power and the temperature were recorded through the reaction. They were unstable (oscillating) during the initial period of reaction (one hour), and become stable after. The step in which the power was unstable could correspond to the pre polymerization and the second step to the polymerization. Thermogravimetric analysis, attenuated total reflectance, and mass loss measurement during the process support this hypothesis.

Nucleation of Polypropylene during High Speed Processing

Petar Doshev, Daniela Mileva, Markus Gahleitner, Rene Androsch, May 2015

Nucleation is one important tool for tailoring mechanical and optical properties of polypropylene (PP) as well its processability in various conversion technologies. Especially the latter aspect is gaining more and more importance in the light of sustainability and energy efficiency discussions, as shorter cycle times and high line speeds are aspired. The efficiency of a nucleating system is commonly determined by the crystallization temperature (Tc) of the resin as measured by differential scanning calorimetry (DSC), typically at 10 K/min. However, Tc is strongly dependent on the cooling rate. Thus, at processing relevant conditions (cooling rate 100-6000 øC/min resp. up to 100 K/s) a suppression of the nucleation effect is frequently observed, and in certain cases the nucleating agent can become completely ineffective. In this study, the crystallization behavior of polypropylene heterophasic copolymers, containing state-of-the-art nucleating systems has been compared. Non-isothermal and isothermal crystallization experiments were performed by DSC and by fast scanning chip calorimetry (FSC) at cooling rates between 0.02 and 3.000 K/s. The data obtained suggest significant differences regarding the crystallization rate. The results are discussed in light of the molecular architecture of the polymer and the type of nucleating system.

Numerical Simulation for Screw Geometry Design and Performance Effects on Fiber Breakage Study

Chao-Tsai (CT) Huang, Huan-Chang Tseng, Meng-Chih Chen, Jiri Vlcek, May 2015

Due to the high demand of smart green, the lightweight technologies become the driving force for people in automotives and others development in recent years. Among those technologies, using short and long fiber-reinforced thermoplastics (FRT) to replace some metal components can reduce the weight of an automotive significantly. However, the microstructures of fiber inside plastic matrix are too complicated to manage and control during the injection molding from screw, to runner, to gate, and to cavity. In this study, we have integrated the screw plastification, to injection molding for fiber microstructures investigation. More specifically, paid most of our attention on fiber breakage prediction during screw plastification. Results show that fiber breakage is strongly dependent on screw design and operation. When the screw geometry changed, even the compression ratio is lower, the fiber breakage could be higher.

Plastics Recovered from Shredded End-Of-Life Vehicles

Brian L. Riise, Peter Mackrell, Ron Rau, Ibrahim Patel, May 2015

Our industry leading separation technology enables us to recover polyolefin and styrenic plastics from complex mixed streams such as shredded end-of-life vehicles. Plastic flakes recovered using our process are compounded and sold as pellets suitable for use in injection molding and extrusion applications. This paper looks at the challenges and benefits of recovering plastics and modifying their properties for use in various injection molding and extrusion applications in the horticultural, construction, packaging and automotive industries.

Preparation and Characterization of Cellulose Nanofiber Reinforced Poly (Butylene Succinate) Nanocomposites

Jithin Joy, Cintil Jose, Sohil Shah, Lovely Mathew, Sabu Thomas, Srikanth Pilla, May 2015

Biodegradable nanocomposites were prepared from poly(butylene succinate) (PBS) and isora nanofiber (INF), a cellulosic nanofiber extracted from Helicteres isora. The nanocomposites were processed using a brabender twin-screw compounder and an injection-molding machine. The effects of INF on the mechanical (tensile and flexural), viscoelastic and thermal properties of the nanocomposites were investigated. The tensile and flexural moduli of PBS-INF nanocomposites increased with INF content, whereas the toughness and strain-at-break decreased. The tensile and flexural strengths increased up to 1.5phr INF loading beyond which they declined owing to agglomeration of INF. The storage modulus of the nanocomposites increased with the INF content. The addition of INF did not affect the Tg significantly. The area integration under tan ë curve decreased with INF loading indicating that PBS-INF nanocomposites exhibited more elastic behaviour with increasing INF. The addition of INF did not alter the thermal stability of PBS, significantly.

Relationship between Moisture Absorption, Crystallization and Rheological Property of Recycled PET Filled Pellets with Talc and Glass Bead

Takanori Negoro, Supaphorn Thumsorn, Wiranphat Thodsaratpreeyakul, Jian Jun Liu, Hiroyuki Inoya, Hiroyuki Hamada, May 2015

Talc, glass bead and poly(ethylene glycol) (PEG) were used for developing moisture absorption and improving crystallization of recycled poly(ethylene terephthalate) (RPET). RPET and fillers were compounded in twin screw extruder with using air drying along the conveyer to yielding high crystallinity of the compounds. The effect of additional fillers and PEG on intrinsic viscosity, moisture absorption, crystallization and rheological behavior was investigated. The incorporation of fillers and PEG slightly decreased intrinsic viscosity and yielded lower moisture absorption rate than neat RPET. Crystallization kinetic parameters indicated that RPET compounds were faster crystallization, which resulting in higher crystallinity than RPET. Rheological properties of RPET compounds decreased at higher talc contents and the addition of PEG. It can be noted that RPET compounds were lower moisture contents, higher crystallinity and better rheological properties at lower shear rate, which would improve mechanical properties of talc and glass bead filled RPET compounds.

Rubber De-Vulcanisation Using a Planetary Extruder

Michael W. Batton, Thomas J. Malzahn, Michael Gerdon, Ralf Quack, May 2015

Elastomers are wide-meshed cross-linked (vulcanized) polymers and recycling is difficult. Thermoplastic materials can be molten by exposing them to thermal energy and put into different shapes or mixed with other ingredients to form new compounds. Elastomers do not have a melting point, in order to put them into different shapes or mix them with other materials, first the cross-linking has to be broken and the elastomer plasticized again, in other words ?de-vulcanized?. Since this is much more difficult than just melting, in comparison to thermoplastics, elastomers, due to this difficulty, were mainly reduced in size and added as filler in other materials or burned for energy and not recycled into the original raw materials. However, until today there existed no continuous economical process that has been established in the industry.

Soy- and Biochar-Based Fertilizer

Jake Behrens, David Grewell, James Schrader, May 2015

Compounds of soy flour, biochar and a polymer matrix, such as PLA, have proven to be effective fertilizers comparable to commercial products. Prototype composites achieved NPK values of 2.85, 0.20, 0.49 and 3.08, 0.21, 0.48 %, respectively for PLA- and PHA-based composites. These composites only leached a fraction of nitrogen compared to a commercially available synthetic fertilizer. Low leachate values, as compared to commercial fertilizers, may be associated to the absorption and releasing of nutrients by biochar. The nitrogen within the soy is also not readily water soluble and is released over time by microbial action.

Studies on the Blending of Abs/Pla for Creation of a New Green Engineering Polymer

Ryan Vadori, Manjusri Misra, Amar Mohanty, May 2015

Studies on the development of high performing ABS/PLA polymer blends have been done. The mechanisms of individual polymers have been investigated, showing the crystallization of PLA can highly influence its toughness. This can be controlled through process engineering during the molding of the polymer. In addition, ABS has been shown to undergo a crosslinking reaction during the timeframe of melt processing. Understanding these mechanisms has been crucial in the development of high performing ABS/PLA blends that have similar properties to the original ABS. These blends and their properties are discussed.

Study of the Curing Kinetics of Biobased Epoxy Resin in the Presence of a Biobased Hardener

Ghodsieh M. Roudsari, Amar Mohanty, Manjusri Misra, May 2015

Investigation of curing kinetics of a biobased thermoset resin was the aim of this study. The curing reaction involved a combination of a petroleum based epoxy resin (diglycidyl ether of bisphenol A) and a biobased epoxy resin (epoxidized soybean oil) with a biobased curing agent (sebacic acid) and was evaluated using a differential scanning calorimeter. It was found that the addition of ESO increased the enthalpy of reaction as well as activation energy. Kissinger-Akahira-Sunose (KAS) and Starink methods have been used to analyze the results.

Study the Effect of hBN Fibre Content and Aspect Ratio on PLA Based Composite Thermal Conductivity

Shahriar Ghaffari Mosanenzadeh, Min Wen Liu, Hugo Palhares, Hani Naguib, May 2015

As electronic devices become smaller and more powerful, heat concentration and as a result heat dissipation would highly affect their efficiency. Also with rising awareness about environmental protection, using bio-based (green) materials as electronic packaging is more important than before. In this context in this research liquid crystal polymer (LCP), hexagonal boron nitride (hBN) high thermally conductive composite fibers were produced and effects of LCP-hBN fiber content and aspect ratio in composite with Poly-lactic acid (PLA) on effective thermal conductivity of the composite were studied. Based on previous studies the largest thermal barrier effect against increasing thermal conductivity of composite is filler particles percolation and phonon scattering at filler particles boundaries. In this study it is observed that the same thermal conductivity as pure fiber can be achieved in composite with lower fiber loading, as long as suitable fibers interaction exist at optimized fibers aspect ratio. This suggest that at right filler content and aspect ratio it is possible to eliminate filler percolation thermal barrier effect and transfer all of the received phonons through the composite thermal pathways rather than scattering them.

Surface Quality of Parts Manufactured Using Selective Laser Sintering

Sean A. Petzold, Jonathan Smet, Tim A. Osswald, May 2015

Surface quality remains one of the biggest problems when manufacturing products using selective laser sintering (SLS). Several experiments were performed using different SLS input variables in order to manufacture samples with different surface characteristics. The effect of virgin or recycled powder, the laser power utilized, and the roller speed were studied and related to surface defects. An Alicona metrology system, with a 4th axis for rotating and imaging tools system was utilized to analyze samples. The three main quantities investigated were average surface roughness, root mean square roughness and ratio of areas. Bearing area curves were also examined.

Synthesis and Characterization of Biopolyesters from Refined Crude Glycerol and Succinic Acid

Oscar Valerio, Manjusri Misra, Amar Mohanty, May 2015

The synthesis of biopolyesters based on refined crude glycerol and succinic acid was studied aiming to determine the influence of the molar ratio of reactants (glycerol to succinic acid) in the extent of reaction and main physic chemical properties of the products. Industrial crude glycerol refined up to 96 wt% glycerol content was employed as monomer for the synthesis along with succinic acid and the reaction was stopped before reaching the gel point in order to obtain non cross-linked products. These polyesters were characterized by gas chromatography, FTIR and thermal gravimetric analysis. It was shown that the molar ratio of reactants employed determines the amount of unreacted monomers present in the final product.