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
EMPLOYING VARIANT ELECTROSTATIC FIELD GRADIENTS TO STABILIZE AND ORIENT AN ELECTROSPUN FIBER.
Innovative electrospinning techniques were explored to facilitate the production of large electrospun silk mats for applications related to wound dressings. Limitations experienced producing experimental grade materials were attributed to the intermittent polymer spray inherent in the electrospinning process. Applying fundamental electrodynamics, electrostatic field gradients generated at alternative equipotential node points on a modified potential plate were shown to stably displace and orient the spinning fiber on specific vector beyond the material damaging spray zone. High speed photography and electrostatic field gradient simulation verified a sixteen degree angular displacement of the electrified fluid jet as the equipotential was repositioned from the center to the edge of a disk shaped potential plate. Additionally, the symmetrical displacement signature around the potential plate enabled concurrent multi-spinning with one commercial apparatus. This novel electrospinning approach provides the ability to create large experimental grade electrospun silk materials suitable for biocompatibility assessments related to wound dressings and establishes manufacturing standards by which electrospun silk materials may be commercially produced.
EFFECT OF PANEL THICKNESS ON THE IMPACT AND SELF-HEALING PROPERTIES OF IONOMERS
The effect of panel thickness on impact properties of ionomers, which exhibit self-healing properties, was investigated for the purpose of determining the critical thickness that is required to observe self-healing behavior upon impact of various ionomers and the unionized base resin. Self-healing closure of the impact damage zones occurred in a panel thickness range of 5.5 ƒ?? 6.0 mm and greater for all ionomers as well as the unionized base resin investigated regardless of phase morphology, counter-ion used for neutralization, and the percent neutralization of the ethylene-methacrylic acid copolymer (EMAA) base resin. Furthermore, with an increase in panel thickness there was an increase in impact energy absorbed, however, the slope of the curve shifts at a panel thickness of 0.9 mm and 8.5 mm. The shift in slope is attributed to a shift from brittle to ductile failure and a larger to smaller overall damage zone, respectively.
MECHANICAL PROPERTIES OF A RECYCLED POST-CONSUMER PRODUCT WITH COMPLEX
CONSTRUCTION
Many consumer products have a complex construction with multiple types of materials. This makes it difficult to recycle the products if the materials are not easily separated. A mixed recycling study was conducted for a particular multi-material product to determine the degree of material segregation required to obtain a recycled feedstock with useful properties. Toothbrushes were selected as the product for this study. These were collected from a commercial take-back program and were separated by material. Different formulations were compounded with virgin material at varying percentages and molded into ASTM test specimens for mechanical property testing.
NOVEL SINGLE SCREW FOR RPVC POWDER THAT COMPOUNDS
At Antec 2008, a new single screw compounder (SSE) was introduced with newly designed mixers along the screw. These mixing elements had spiral flutes with elongational mixing (SFEM). The Elongator, hereafter SFEM, demonstrated simple processing of RPVC powder with an increased output from the historic limit of 30 rpm to a faster speed of 180 rpm at only 174 ?øC, vented, starved or flood fed. There was no need for a vacuum hopper or crammer feeder with this simple screw design.This paper presents scale up work that was performed on a 2.5' extruder with the RPVC powder. The new SSE processed RPVC powder with an increase in screw speed to 70 rpm and output temperature of only 191 ?øC, nonvented, with screw cooling, and flood feeding.This paper also presents mixing tests performed with the smaller SSE using a newly designed SFEM (hereafter SFEM-II). Two tests were performed with the RPVC powder, one using 0.5% color concentrate and the other wood flour.
THERMAL ANALYSIS IN FAILURE ANALYSIS OF POLYMERS AND COMPOSITES
Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) are two major thermal analysis techniques which can be used for failure analysis of polymers and composites. DSC and TGA offer wealth of in-depth information related to the composition, processing, structure, and properties of the materials. Important thermodynamic and kinetic parameters that determine the performance and properties of products, such as glass transition temperature, melting and crystallization, crystallinity, degree of cure, thermo-oxidative stability, and material composition, can be obtained through carefully designed experiments using individual or combined testing of DSC and TGA.
MORPHOLOGY DEVELOPMENT OF TERTIARY BLENDS OF OLEFIN-BASED ELASTOMERS, POLYPROPYLENE AND OIL
The discovery of Olefin Block Copolymers (OBC) brought opportunities to develop novel soft compounds for the consumer durables market. These new soft compounds are primarily blends that include a rigid polymer, a rubber, and an oil. This work was aimed at developing fundamental understanding on morphology development of OBC/PP/Oil blends at two different oil levels. The results showed that mechanical properties are dominated by the development of two phase morphologies at low and high rubber volume fractions. A dynamic mechanical analysis at low strains showed that the storage modulus behavior at high rubber volume fractions could be explained with known composite models.
EXPERIMENTAL DETERMINATION OF THE AESTHETIC, DIMENSIONAL AND CONTROL PROCESS WINDOWS USING THE TECHNIQUE OF DESIGN OF EXPERIMENTS IN INJECTION MOLDING
Traditionally, the mold qualification procedure involves sampling the mold and establishing a process to make acceptable parts. Process engineering studies such as in-mold rheology, gate seal tests and generating process windows are most commonly performed. Design of Experiments (DOE) are conducted to study the effect of the molding factors on the quality of the part and sometimes to find the process to mold a part within the quality specifications. The process engineering studies and the DOEs are conducted independent of each other. This paper combines these techniques and introduces the concepts of the Aesthetic Process Window, the Dimensional Process Window and the Control Process Window.
EFFECT OF BOTH TALC FINENESS AND TALC LOADING ON HETEROGENEOUS NUCLEATION OF BLOCK COPOLYMER POLYPROPYLENE
The heterogeneous nucleation behavior of block copolymer polypropylene modified with fine talc is discussed as a function of talc fineness and loading into a polymer matrix. Specifically, three talc samples having different particle size distributions were used to modify the resin. Non isothermal and isothermal nucleation were studied and mechanical performances were evaluated as well. Itƒ??s been demonstrated that higher nucleation efficiency can be observed for the finer talc sample at the higher concentration (evaluated in experimental work). Isothermal crystallization study showed on one side a visible reduction of crystallization half time when talc is introduced in block copolymer polypropylene and kinetic parameters from Avrami models on isothermal tests confirmed efficiency of talc as nucleating agent. Besides process advantages in nucleating block copolymer polypropylene (lower cycle time in injection molding), an evident advantage in mechanical properties was observed. The addition of talc in small amount enhanced rigidity and lowered molding shrinkage, with no significant variation in impact resistance properties.
SILICONE BASED FLAME RETARDANT FOR POLYCARBONATE
Kaneka Corporation has developed a silicone based flame retardant for Polycarbonate, Kane Ace MR-01. MR- 01 realizes non-bromine and non-phosphorus flame retardant PC compound and increases low-temperature impact strength. Kaneka's renowned graft polymerization technology makes it possible to disperse the cross-linked silicone particle into Polycarbonate matrix. MR-01 achieves V-0 in UL-94 protocol at 1.2 mm thickness (Kaneka's evaluation data) with a small amount of PTFE. MR-01 also has excellent thermal stability, which provides with superior impact strength retention after heat aging, and maintains the flame retardancy after recycling process.
LASER MARKING ADDITIVES: NEW SOLUTIONS
This paper describes new materials and applications for the plastics industry focused on lasermarking polymers. In the context of the paper we will describe the current state of-the-art, equipment and the new technology.
Laser marking is generally accepted to be the best way of permanently marking plastics. As a leader in laser marking Technology, we offers laser marking additives which improve the laser sensitivity of polymers. In addition to the standard portfolio (we will call them ƒ??Lƒ? products); we have added an outstanding NEW laser additive (we will call this product line ƒ??Mƒ? products): it is a robust, high-performance additive that enhances the dark-on-lightƒ? laser marking performance of most thermoplastics. Its versatility makes it suitable for use in all processing technologies and for a wide range of applications. The pelletized product ƒ??Mƒ? can be added directly in the processing step or incorporated in masterbatches together with other additives and colors.
THERMAL CONDUCTIVITY OF
EPOXY FILLED WITH EXPANDED GRAPHITE PLATELETS
Expanded graphite (EG)-filled epoxy composites with thermal conductivity of 56 W/m-k were developed for applications as bipolar plates in proton exchange membrane (PEM) fuel cells. The high thermal conductivity resulted from the high intrinsic thermal conductivity of EG of 600 W/m-k. The global conductive network of graphite in the composites was achieved via solution intercalation mixing followed by compression molding and curing process. Characterization of surface chemistry of the EG by XPS showed strong potential for interfacial adhesion between graphite and epoxy matrix, which in the final composites resulted in reduced interfacial thermal boundary resistance, and thus high thermal conductivity.The composites also showed high electrical conductivity of 200-500 S/cm.
POLYMER-CLAY NANOCOMPOSITES OF POLY (BUTYLENE ADIPATE-CO-TEREPHTHALATE) AND POLY (LACTIC ACID) BLEND: EFFECTS OF INCORPORATING ORGANICALLY MODIFIED SILICATE LAYERS AND THE MIXING SEQUENCE ON THE MORPH
This paper describes new materials and applications for the plastics industry focused on lasermarking polymers. In the context of the paper we will describe the current state of-the-art, equipment and the new technology.
Laser marking is generally accepted to be the best way of permanently marking plastics. As a leader in laser marking Technology, we offers laser marking additives which improve the laser sensitivity of polymers. In addition to the standard portfolio (we will call them ƒ??Lƒ? products); we have added an outstanding NEW laser additive (we will call this product line ƒ??Mƒ? products): it is a robust, high-performance additive that enhances the dark-on-lightƒ? laser marking performance of most thermoplastics. Its versatility makes it suitable for use in all processing technologies and for a wide range of applications. The pelletized product ƒ??Mƒ? can be added directly in the processing step or incorporated in masterbatches together with other additives and colors.
EFFECT OF A BLOWING AGENT ON THE FLOW PROPERTIES IN EXTRUSION AND INJECTION MOLDING
In this paper, the effect of a dissolved blowing agent on the flow rate in extrusion and injection molding is studied using a single-screw foaming extruder with an accurate gas injection control. Although the decrease of the viscosity with the dissolution of the blowing agent has been measured and modeled, the flow properties have not been quantitatively evaluated to determine the processing window in foam extrusion and injection molding. This research measures the flow rate change systematically with varying the gas content in the polymer melt while maintaining the pressure constant by controlling the gear pump speed. The reduced viscosity increased the mass flow rate of the polymer significantly despite the decreased density with the dissolution of gas.
STANDARD FOR ENERGY RATING WITH RESIN DRYERS
AND CLASSIFICATION OF DRY AIR QUALITY
When it comes to resin drying, energy consumption is quickly becoming a key factor in the decision making process for one technology over another. However, drying energy consumption has several elements and key factors that affect the overall energy use of a dryer. It is a combination of heat-up energy and sustainable drying energy that are the elements that will, in the end, affect how much it costs to dry your resin on an annual basis.A uniform industry test standard would define the air capacity, basic load and kWh/unit of material. An industry test standard would allow users to plug in there given material, throughput and local energy rate, to calculate the true annual energy cost.
STATIC DEFLECTION MODELING OF A PIEZOELECTRIC ACTUATED CANTILEVER COMPOSITE LAP JOINT BEAM
This work studies the use of surface bonded piezoelectric
induced strain actuators and their effect on the static
deflection of a single lap joint epoxy-fiber composite
cantilever beam. Euler-Bernoulli beam theory was utilized
to derive the elastic curves for pre-load and post-load
actuation, accounting for changes in flexural rigidity of
the beam. The model accounts for physical properties of
the composite beam and piezoelectric, as well as the
piezoelectric bond location. A numerical study aimed at
evaluating the effectiveness of piezoelectric actuation
based pre-load and post-load actuation, as well as bond
region has been performed. Post-load actuation was found
to be from 2.5% - 70% more effective than pre-load
actuation, depending on the bond location. Bond Region I
was found to be most effective for both pre-load and postload
actuation.
CARBON NANOTUBE MAT BIOCOMPOSITE FOR ENZYMATIC GLUCOSE/O2 BIOFUEL CELL
In this paper, mediator-, separator-less glucose/O2 biofuel cell was built on carbon nanotube (CNT) mat electrodes. Glucose oxidase (GOx) and bilirubin oxidase (BOD) were immobilized on the mat via covalent bonding. The CNT mat is a sheet of multi-walled carbon nanotubes (MWNTs) which has high electrical conductivity and aspect ratio. CNT mat is expected to be one of the ideal electrode materials for biochemical applications for its easy functionalization, electrical conductivity, large surface area, porosity, and ability to lower the overpotential in various bio-chemical species. The electron transfer rate constant obtained in this study is 1.78 s-1. The open circuit voltage and maximum power density obtained from this biofuel cell are 50 mV and 38.7 ?¬A/cm2, respectively.
EFFECT OF ORGANOCLAY STRUCTURE AND DISPERSION ON THE IMPACT AND SELF-HEALING PROPERTIES OF IONOMER-NANOCLAY COMPOSITES
The effect of organoclay structure and panel thickness on the impact properties of ionomer/organoclay composites was investigated for the purpose of determining if incorporation of surface treated clay platelets within an ionomer matrix improves the self-healing properties of ionomers upon impact for military applications. Full self-healing closure of the damage caused by projectile impact was achieved at a panel thickness of 1.6 mm for the ionomer/organoclay composites, which is approximately 3.5 times less than that required with the corresponding unfilled ionomer matrix. Furthermore, self-healing closure requires good dispersion of the clay platelets within the ionomer matrix, where most of the platelets exhibit an exfoliated morphological structure.
Novel Methods of Incorporating Nanoparticles into Fiber Preforms
Conventional fiber reinforced polymer composites offer many desirable properties such as high strength to weight ratio and high modulus to weight ratio. Nanoparticles have shown great promise for improving mechanical properties. Successful incorporation of nanoparticles has long been a great challenge for the composite industry. In this study, a novel approach is applied to incorporate nanoparticles into WindStrand' glass fiber preforms, Vinyl Ester composite panels were manufactured through vacuum assisted resin transfer molding. Mechanical properties of the composites were measured. Flexural strength and modulus were improved with incorporation of nanoparticles.
THERMAL AND RHEOLOGICAL PROPERTIES OF POLY-(3-HYDROXYBUTYRATE-CO-3-HYDROXYVALERATE) AND POLY (LACTIC ACID) BLENDS FOR FOOD PACKAGING APPLICATIONS
The objective of this study was to characterize the thermal and rheological properties of Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) blended with Poly (L-lactic acid) (PLA) resin at different concentrations and relate these findings to potential food packaging applications. The thermal analysis showed increasing concentration of PHBV resulted in lower thermal stability of PLA. Several melting transitions for the blends were observed representative of phase separated polymers. The complex viscosity showed no improvements in the PHBV when compared to the blends.
COMPARISON OF RANDOM AND BLOCK POLYPROPYLENE COPOLYMERS IN EXTRUSION FOAMING
This study aims to compare the extrusion-foaming behaviors of a random polypropylene (PP) copolymer and a block PP copolymer in terms of cell nucleation as well as foam expansion. N-butane and talc were respectively selected as a physical blowing agent and a nucleating agent for extrusion foaming. Foamed samples were obtained by conducting extrusion foaming using a single screw extruder. In addition, the amount of dissolved blowing agent and talc content were varied to observe the effect on cell morphology and expansion trend, which were then characterized with a scanning electron microscope (SEM) and a pyknometer. The die temperature as a processing parameter was also manipulated in this study. The block PP copolymer showed much higher cell nucleation than the random PP copolymer with no nucleating agent as the dispersed ethylene-propylene particles were able to function as nucleating agents in the block PP copolymer.
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