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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Conference Proceedings
High Performance EVOH Nanocomposites of Interest in Packaging Applications
Eugenia Núñez | Jose M. Lagaron, November 2011
EVOH are materials with broad application in high barrier packaging due to transparency and superior oxygen barrier. However | these materials suffer from strong plasticization in properties due to sorption of moisture | which handicaps their application under high moisture conditions such as those applied in many packaging cases. This paper[1] shows the development of novel nanocomposites based on an optimized kaolinite grade | commercially marketed as O2Block® | which exhibit enhanced UV and gas barrier and decreased water permeability and sensitivity.
THE EFFECT OF COMPOSITION AND PROCESSING PARAMETERS ON THE MORPHOLOGY AND PROPERTIES OF PC/ABS/ORGANOCLAY NANOCOMPOSITES
Marianna I. Triantou | Petroula A. Tarantili, November 2011
In this study | blends based on poly(acrylonitrile-butadiene-styrene) (ABS) and polycarbonate (PC) were prepared and studied | in an attempt to explore the performance of mixtures deriving from recycling of waste electrical and electronic equipment (WEEE). The modification of ABS and ABS/PC blends via the incorporation of reinforcing fillers | such as organic modified montmorillonite nanoparticles (OMMT) | was also explored and its effect on the structure and properties was evaluated.
Electrically conductive PC/ABS polymer nanocomposites for automotive industry
Michele Modesti | Stefano Besco | Alessandra Lorenzetti | Denis Hrelja| Tony McNally, November 2011
Multiwall carbon nanotubes are widely studied as nanostuctured electrically conductive filler for polymers with high efficiency at low percentages. In this contribution the physical and thermal properties of PC/ABS based nanocomposites obtained by melt compounding and containing different amounts of nanotubes and nanoclay were investigated. A complex selective segregation of fillers inside specific polymer phases has been observed | thus explaining the low percolation threshold obtained for electric conductivity. The goal was to obtain lightweight electrically conductive polymers in order to reduce the chemical treatments necessary for the chrome-plating of the automotive components | with enormous economical and ecological advantages.
Lab scale development and industrial scale-up of PET based nanocomposites technology for packaging applications
Stefano Besco | Alessandra Lorenzetti | Stefano Donadi | Michele Modesti, November 2011
Polyethylene-terephthalate (PET) has become the dominant material for packaging due to its optical clarity when blow moulded and relative low permeability to oxygen and carbon dioxide. In order to further improve PET’s barrier properties | if impermeable nanoparticles are incorporated into the polymer | the gas molecules are forced to wiggle around them in a random walk | hence diffusing by a tortuous path. Moreover | the molecular mobility in the polymer matrix is diminished | thus leading to a decrease in diffusivity of such small molecules. In this research two different strategies have been followed: the first | based on blending PET with an aromatic polyamide (PA) and the second based one on the use of different kinds of inorganic nanoparticles. Several nanocomposites based on pristine PET or PET/PA blends and different nanoclays (natural and organically modified layered silicates | POSS® | i.e. polyhedral oligomeric silsesquioxanes) have been prepared by melt blending optimizing formulations and process parameters. Moreover industrial trials proved that the nanocomposite materials developed could be successfully stretch-blow moulded to give bottles with decreased gas permeability than PET.In particular PET/POSS based bottles are characterised by an optical clarity comparable to the one of pristine PET based containers.
MULTIFUNCTIONAL ACTIVE NANOCOMPOSITES FOR FOOD PACKAGING APPLICATIONS
M.A. Busolo | J.M. Lagaron, November 2011
Results on the active performance of oxygen scavenging, free radical scavenging and antimicrobial clay-based nanocomposites are presented. The antioxidant nanoclay was modified to exhibit high dispersion and efficiency when incorporated into EVOH and in a multilayer system of LLDPE-EVOH-LLDPE. Oxygen scavengers based on iron were also incorporated into LDPE | HDPE and PET, which exhibited some color but little impact in optical properties. Finally | incorporation of silver based clays into PLA matrixes allowed to obtain antimicrobial composites | showing high antimicrobial activity. The presented active systems are alternatives to preserve and extend the shelf-life of packaged products.
ELECTROSPUN NANOFIBROUS MATS BASED ON POLY (LACTIC ACID) AND POLY (ε-CAPROLACTONE) CONTAINING TETRACYCLINE HYDROCHLORIDE AS AN ACTIVE WOUND DRESSING
Payam Zahedi | Zeinab Karami | Iraj Rezaeian, November 2011
Electrospun nanofibrous mats made from poly (lactic acid) and poly (ε-caprolactone) containing tetracycline hydrochloride antibiotic as an active wound dressings were prepared and their properties investigated. Samples of poly (lactic acid) and poly (ε-caprolactone) solutions in chloroform/dimethylformamide (9/1) with 9, 12 and 15 (w/v)% containing 500 μg/ml drug were prepared. These nanofibrous samples were then investigated by pre-designed tests such as scanning electron microscopy | water-uptake capacity | UV-vis spectroscopy and antibacterial drug evaluations. The results showed that 15 (w/v)% poly (ε-caprolactone) samples with 500 μg/ml concentration tetracycline hydrochloride had a higher release rate efficiency compared with the other nanofibrous samples.
POLYSILOXANE/LAYERED SILICATE HYBRIDS: MODELLING OF MECHANICAL PERFORMANCE IN RELATION WITH NANOCOMPOSITE STRUCTURE
Sozon P. Vasilakos | Petroula A. Tarantili, November 2011
Nanocomposite blends | based on condensation type polysiloxane rubber | reinforced with organically modified montmorillonite (OMMT) nanoparticles | were prepared via the sonication process. Two grades of commercial montmorillonite | namely Cloisite 30B and Cloisite 20A | with different types of organic modification were studied. A significant improvement of mechanical properties of the pure polysiloxane was observed by the incorporation of the examined types of clay reinforcements. Comparison between the experimental and theoretical values of elastic modulus was performed by the use of micromechanical simulation models | such as the Halpin-Tsai model | that interrelates Young’s modulus with clay structure in the nanocomposite.
TRENDS AND ADVANCES IN MULTILAYER STRUCTURES
Peter Cox, November 2011
Over the years that polymers have been in practical use there has always been an application where the properties of different layers within the final product have been used to produce superior properties over that for any single layer polymer. Despite the advances in polymers this principle has continued to grow in all areas of use. The paper will review the progress in the areas of packaging | construction | automotive and biopolymers from both the polymer properties and manufacturing methods. The role of nanoparticles will be reviewed along with other methods of reducing permeation through polymers. Production methods reviewed will be mainly those associated with extrusion processes including injection moulding | cast extrusion | sheet extrusion | profile extrusion and blown film extrusion.
Investigation of the Chemical Resistance and the Material Aging Conditions of Polyethylene for Pipe Applications
Anita Redhead | Andreas Frank | Gerald Pinter, November 2011
The chemical resistance of polyethylene (PE) for pipe applications was investigated with special regard to physical and chemical material aging. Therefore, tensile tests were conducted on films which were exposed to two different aggressive media for different predefined periods of time and at two different temperatures as well as on films which were not exposed to the media. The impact of the media on the Young´s modulus E, the stress at yield σy, the strain at yield εy and the strain at failure εf were studied. Potentially physical or chemical material aging was investigated by the degree of crystallization, the Oxidation Induction Time (OIT) and via Infrared (IR)-spectroscopy.
IMPRESS | an innovative pilot injection-compression moulding platform for the production of micro-nanostructures on plastic parts
M.Moguedeta | E.Bamburyb | N.Blondiauxc | C.Coustald | S.Dessorsa | H.Eigenbrode | P.Fugierf | E.Gerritsenf | A.Giroudg | Z.Guttenbergh | JL.Halperi | A.Heinrichj | S.Kallerk | F. Lacanl | E.Pletscherm | R.Puginc | N.Ribeiron | M.Rochowicze | G.Salauno | S.Scholzl, November 2011
IMPRESS targets the development of a technological injection moulding platform for serial production of plastic components incorporating micro or nano scale functional features. The platform is based on most advanced facilities divided in three modules: - tool manufacturing | involving different technologies of micro- nano direct manufacturing | from top-down to bottom-up such as self-assembling, - injection moulding | including equipments fitted with innovative hardware technologies to improve replication quality and capability, - intelligence | dedicated to advanced process control and online metrology integration. Beside this large panel of facilities | three case studies will be presented for biology | medical and energy applications. We present the main results obtained during the first year of the project.
Multi-objective Optimization Strategy For The Design Of Injection Mold Cooling System
Ronan Le Goff | David Garcia, November 2011
The manufacturing of thermoplastics parts needs a cooling phase to give the shape to the part. In injection molding | cooling can represent more than 70 % of the total cycle time. This is the reason why cooling channels have to be designed with great care in order to meet quality with efficiency requirements. In this paper | we propose a methodology to optimize the geometry parameters and coolant temperatures of the channels based on the use of modeFRONTIER® software combined with the injection molding simulation software MOLDFLOW®. Multi-objective optimisation will be carried out with criterions based on quality and cycle time minimization.
THE RIGHT CHOICE - NATURAL AND ACCELERATED WEATHERING TEST METHODS COMPARED
Sean Fowler | Jeffrey Quill | James Regan, November 2011
Weathering and light exposure are important causes of damage to coatings | plastics | inks | and other organic materials. This damage includes gloss loss | fading | yellowing | cracking | peeling | embrittlement | loss of tensile strength | and delamination. For many manufacturers | it is crucial to formulate products that can withstand weathering and light exposure. Accelerated weathering and light stability testers are widely used for research and development | quality control | and material certification. However | the importance of outdoor testing cannot be overlooked. Accelerated testers provide fast and reproducible results. The most frequently used accelerated weathering testers are the fluorescent UV accelerated weathering tester (ISO 4802-3 | ASTM G154) and the xenon arc test chamber (ISO 4892-2 | ASTM G155). In recent years | low cost and easy-to-use testers have been developed. This paper compares two accelerated weathering test methods: fluorescent ultraviolet and xenon arc. The paper will describe the strengths and limitations for both techniques due to: simulation of the forces of weathering | including sunlight | temperature and moisture | mounting of test specimens | control of test parameters | and operational considerations.
MICROSCOPIC EXAMINATION OF A HOT WORKING TOOL USED FOR PLASTIC INJECTION
N. Kiriakou | J. Sideris | C. Medrea | Stasinopouloi-Uddeholm, November 2011
The failure of a mould-part used for hot-forming is investigated. The die | made from AISI H13 steel was intended for the production of plastic cups. The mould-part exhibited a | single uniform crack through thickness | after five millions working-cycles | whereas it’s predicted working life was ten millions cycles. Data were collected regarding the material selection | manufacture and operational history. The die was optically inspected. Hardness measurements were carried out and chemical analysis was performed. Detailed optical and scanning electron microscopy observations suggest the type of failure and the factors that led to it.
PRELIMINARY FAILURE EXAMINATION OF A TOOL USED IN TYRE WASTE RECYCLING - CASE STUDY
A.Maragiannis | D. Papageorgiou | C. Medrea | Stasinopouloi-Uddeholm, November 2011
Tyres consist of synthetic rubber | metals and linen. Tyre waste decomposes after hundreds of years | and its presence is detrimental for the environment. Standing water | trapped into tires may be a permanent pollution source | while tyre waste next to a forest increases the possibility of fire. European legislation imposes the recycling of tyre waste | which includes the following three steps: shredding in strips | cutting strips in small pieces | and powder production from the pieces. At the last stage magnets remove the metallic pieces | while centrifugal screens remove the linen. Metals are sold to the steel industry as scrap | linen is used in limekiln as a combustion material and the rubber flakes are used in numerous applications (e.g. road surface construction, concrete additives | mouse pads | etc.).
CORRELATION BETWEEN DIFFERENT MICRO-STRUCTURAL PARAMETERS WITH PHYSICAL/MECHANICAL PROPERTIES OF POLYETHYLENE BLOWN FILMS
Shokoh Fatahi | Abdellah Ajji | Pierre G. Lafleur, November 2011
A wide range of PE materials | including LLDPE, HDPEs and LDPE were used for preparation of the blown films. By changing processing conditions | different structures for these blown films were produced and their structural parameters investigated. Establishing fundamental /structural model between structural parameters and tensile modulus of blown films was the objective of this work. A model for the tensile modulus was proposed and correlated to some structural parameters including crystallinity | orientation factors for crystalline c-axis and amorphous phase | lamellar thickness and crystal size. The measured modulus and calculated one were compared and a reasonable agreement was found between them.
FLEXURAL PROPERTIES AND FAILURE MECHANISM ASSESSMENT FOR ADDITIVE MANUFACTURED LOM BARS ON DIFFERENT BUILDING ORIENTATIONS
D. Olivier | J.A. Travieso | S. Borrós | G. Reyes, November 2011
Plastic Laminated Object Manufacturing has not been assessed from the flexural properties point of view. The deflection range in parts manufactured by this technique is wider than in parts fabricated by other additive manufacturing methods like SLS or FDM. This fact has increased the interest on the final application of these parts rather than restricted to Rapid Prototyping applications. In this study it will be compared the impact of building orientation and geometric features of parts over the flexural properties. Through optical observation it will be studied the failure mechanism
SEQUENTIAL INJECTION MOLDING: DESIGN CONSIDERATIONS
Jorge Aisa | Javier Castany | Angel Fernández, November 2011
New injection processes have been developed last decades, improving the designer freedom in order to launch attractive functionalities. All these procedures should be carefully analysed before to decide their use, because it is necessary to understand their natural restrictions, cost and operation requirements and rheological implications in the tools construction. This contribution presents a wide study made in the T.I.I.P., research group from the University of Zaragoza, which gives simulation results and experimental values about sequential injection moulding, and some practical considerations for designers and toolmakers, in order to get successfully results.
KINETCIS AND CHEMICAL REACTIONS OF ACETALDEHYDE STRIPPING PROCESS IN POLY(ETHYLENE TEREPHTHALATE) RESIN
Saleh A. Jabarin | Sirisha R. Kesaboina, November 2011
The Kinetics of acetaldehyde (AA) stripping from PET pellets were determined at different temperatures, along with the determination of the residual concentrations of other less volatile compounds such as 2-methyl-1,3-dioxolane (2MD). The rate constants for the polymerization and AA diffusivity coefficients were determined at different temperatures of air stripping of PET. The air stripping of AA from PET is shown to involve chemical reactions and physical changes including polymerization, diffusion and generation of AA, 2MD, EG and water. This paper discusses the mechanisms of the chemical reactions and the formation of the by-products. The techniques used to elucidate the mechanism include gas chromatography (GC), intrinsic viscosity (IV), and density.
FEED ENHANCEMENT TECHNOLOGY FOR LOW BULK DENSITY MATERIAL INTO CO-ROTATING TWIN-SCREW COMPOUNDING EXTRUDERS
Paul G. Andersen | Frank Lechner | Maria Hoelzel | Thorsten Stirner, November 2011
Effectively feeding low bulk density material into a co-rotating twin-screw extruder has always been a challenge. However with the introduction of even finer particle size fillers (sub-micron in some cases) as well as new generations of polymer reactor resins, the issue has become even more problematic. Additionally as bulk density decreases, the materials tend to fluidize more easily. Fluidization lowers the “effective” bulk density even further and exacerbates feeding issues. Typical unit operations within the compounding process where material is more susceptible to fluidization are: transfer from storage vessel to feeders, from feeder to twin-screw extruder and within the feed zone conveying section of the twin-screw extruder. While there are methods to minimize the potential for fluidization such as dense phase conveying from storage to feeder, minimization of the feeder height above the extruder feed opening, incorporating a vent into the feed hopper, extending the length of the conveying zone in the extruder feed section, the process eventually reaches a feed volume limitation, which more often than not is well below an economically viable production rate. This paper will review a new Feed Enhancement Technology (FET) that provides significant improvement for the introduction of fine particle / low bulk density materials into the extruder.
Co-rotating Fully Intermeshing Twin-screw Compounding Extruders Technology: Advancements for Improved Performance and Productivity
Paul G. Andersen | Frank Lechner, November 2011
The co-rotating fully intermeshing twin-screw extruder is the primary production unit for compounding of polymer based materials. It also has had a long term presence in processing material in the chemical and food industry and more recently in pharmaceuticals. While this equipment celebrated its 50th anniversary several years ago and might be considered a “mature” technology, it has not experienced a decline in new developments as might be expected, but rather a significant number of advancements continue to evolve. This paper will highlight several significant developments of the past 10 to 15 years. These are the implementation of high torque (power) designs, the use of increased rpm in conjunction with high torque for improved operating flexibility and productivity, and finally a technology breakthrough for feeding difficult to handle low bulk density materials.
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