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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Thin-Film Thermosiphon Solar Collector Design
A very low cost, unglazed Thermosiphon Solar Collector constructed from polyethylene film and having an internal heat exchanger has been developed. The collector operates at relatively low temperature and low material stress, decreasing thermal degradation, material creep, and weight. Prototype systems have been built and tested, and processing equipment designed.
Extrusion Foaming of Poly(Lactic Acid) (PLA) Blown with CO2
This paper presents a thorough investigation of the continuous extrusion foaming of PLA using CO2 as the blowing agent. Detailed results are given for the plasticization induced as determined from on-line rheometry as well as resulting foam characteristics.
Impact of Polymer Processing on Sorption of Organic and Moisture Vapors by a Gravimetric Approach
Sorption of benzaldehyde and moisture vapors in polypropylene resin, sheet, and containers was studied via a Rubotherm magnetic suspension microbalance. Polymer processing has an impact on polymer structure and morphology. A comparison of sorption among the three polypropylene forms demonstrated the marked impact of processing on inducing changes in the barrier properties of the polymer. The simultaneous sorption of organic compounds and moisture demonstrated the combined effect on the sorption.
Dewetting Transition in Thin Polymer Films
We use a combinatorial method of investigation to obtain a near-universal scaling curve describing a wetting-dewetting transition line for polystyrene films of fixed thickness by introducing reduced temperature and surface energy variables dependent on molecular weight.
Teaching Polymer Processing Principles to Engineering Technology Undergraduate Students Utilizing a Positive, Dimensional Approach
Utilizing a positive, dimensional approach to transport phenomena provides undergraduate plastics engineering technology students with a solid foundation upon which to build the fundamental principles of polymer processing. Students are encouraged to visualize, and sketch, on three scales: molecular, microscopic, and macroscopic. They also are encouraged to progress through three levels of learning: translation to a visual mode; solution of determinate problems; and the solution of indeterminate problems.
Characterization of Material Properties in the Depth Direction of an Oriented PET Reheat Stretch Blow Molded Container
The properties of PET vary thru the depth of a blow molded article due to variation in blow up ratio. By blowing a preform constructed by injection molding three concentric sleeves, the wall of the blow molded article can be dissected and barrier and physical properties of discreet layers can be measured and correlated with process variables.
Surface Modifications of Automotive Weather Seals
Automotive sealing systems produced with thermoplastic vulcanizates (TPVs) can be modified to improve their functional performance and aesthetic appeal using techniques such as low friction co-extrusion coating, low friction spray coating, flock tape co-extrusion, electrostatic flocking, high gloss co-extrusion coating, high gloss colored or metallic tape co-extrusion, etc.
Coolant Flow Rate Manipulation for Cavity Pressure Control
Cavity pressure control in injection molding is important to maintain product quality in injection molding process. The coolant flow rate and temperature are parameters affecting the cavity pressure profile during cooling stage. A coolant flow rate control system has been designed and implemented to provide consistent heat removal from the mold cycle-to-cycle. Good and effective cavity pressure control was obtained by controlling the coolant flow rate using a predictive controller.
Experimental Investigation of PP Film Casting
In film casting, a polymer melt is extruded through a flat die before rapid cooling on a chill roll. We study experimentally the effects of draw ratio and molecular weight on polypropylene film formation. The temperature, width and velocity profiles in the air gap are measured. Neck-in and temperature profiles are affected by both draw ratio and molecular weight. The machine direction velocity decreases from the centerline value near the film edges.
Polypropylene Clay Nanocomposites with Improved Stability of Morphology to Processing
The rate of restacking of platelets in extrusion of polypropylene clay nanocomposites can be reduced significantly by edge functionalization of the clay.
ESC Failure of Polycarbonate Components: Two Case Studies
A chemical that is typically compatible with a given plastic can act as a stress-cracking agent in certain conditions. This presentation will address key contributing factors to ESC of polycarbonate components used in the medical device and health industries. Case studies will be presented.
Two-Station Embossing Process for Rapid Fabrication of Polymer Microstructures
An embossing strategy involving a hot station and a cold station for sequentially heating and cooling the embossing tool was investigated to reduce cycle times in hot embossing polymer microstructures. Experimental studies showed that aluminum stamps with a thickness of 1.4 mm can be rapidly heated from room temperature to 200°C in 3 s using contact heating against a hot station at 250°C. Selected surface microfeatures including microchannels and microlens arrays were successfully embossed using a cycle time around 10 s.
An Innovative Approach to Involve Grade School Students in College Projects
The introduction of engineering to prospective students starts when they are in high school. They have already made some decisions about their career. This project involves 6th grade students designing a car body, then Penn State Erie students commercialize that design.
A New Class of High-Performance Compostable Plastic Bags and Can Liners
Heritage Bag Company has developed compostable bags and liners, which are produced from composites utilizing polymer and mineral materials technology of Heritage Plastics, Inc. This product line is based on proprietary blends of different biodegradable polymers which have been modified using mineral reinforcement technology to produce a readily extrudable polymer composite. This modification yields polymer processing, end-use products such as film and bags with characteristics very similar those obtained with higher-alpha olefin LLDPE resins, yet meet the requirements of ASTM D 6400-99.
Investigation of Reinforcement in Polymer Nanocomposites Using Polymer Thin Films
Reinforcement in polymer nanocomposites was explored using polymer thin film technology. Polystyrene (PS) thin film spin-coated on the graphite substrate was used to resemble the interface between PS and carbon-based nanoparticles. Glass transition temperature (Tg) of the nano-confined polymer was observed to be higher than the bulk value, indicating the strong PS-substrate (graphite) interactions. The confinement becomes more pronounced with reduced film thickness. CO2-induced Tg depression was observed for this thin film system as well.
Development of New TPV Materials with Enhanced Scratch Resistance
Thermoplastic elastomers have begun penetrating automotive sealing systems due to their ability to offer weight reduction, ease of processing, long term sealing, and recyclability versus traditional thermoset materials; however use in some visible applications has been limited by scratch resistance.We describe the general principles of the scratch mechanism and the existing laboratory techniques to assess a material’s scratch resistance. A relationship between a material’s physical properties, surface properties and its scratch resistance is discussed.
The current range of products designed to attain special effects continues to expand. Growth was driven by technological innovations and through modifications of existing pigments and additives. This paper will discuss this expanded pallet and the effects and applications for which they were intended.
Modeling of Water Debinding of Metal Injection Molded Parts
An experimental protocol for measuring mass diffusivity during water debinding of metal injection molded parts is proposed. The diffusivity found, although dependent on part geometry and debinding time, can be averaged to model the polymer extraction.
Resistance Welding of Glass-Fiber-Reinforced PP: Modeling and Experiments
This research models the temperature profiles generated during resistance implant welding of polypropylene composites. The experimental current-time conditions at which meltdown occurs and experimentally measured temperatures compare favorably with the model results.
Development of a Device to Measure Rheological Properties at High Frequency
A commercially available linear vibration welder has been modified to allow measurements of complex viscosity, storage and loss moduli of polymeric materials at frequencies relevant to those encountered in vibration welding. In order to make these measurements, a parallel plate fixture was constructed and mounted on a linear vibration welder. Piezoelectric shear force sensors and two accelerometers were used to accurately measure the forces and accelerations imposed on the polymeric materials. The device has been used to test two model viscoelastic materials.
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