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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Micro Molding Drug Delivery Devices To Micron Tolerances
Micro molding drug delivery devices to micron tolerances requires extreme fine tuning of existing injection molding technologies. Unlike conventional or macro molding, micron tolerances require unconventional tooling, molding, automation, and metrology practices to achieve Cpk of 1.33 or better. This paper identifies and analyzes these 4 key factors to molding parts to micron tolerances: 1. Tooling precision2. Micro Molding Process Control 3. Micro automated assembly4. CT scanning metrologyCase studies of micron tolerances for implants and drug delivery devices (transdermal patches, injection, and slow release devices) will be presented.
Eva Polymer As A Platform For Advanced Drug Delivery
Ethylene Vinyl Acetate Copolymer: Review of high value pharmaceutical applications The potential for use of polymers in controlled drug delivery systems has been long recognized. Since their appearance in the literature, a wide range of degradable and non-degradable polymers have been demonstrated in drug delivery. The significance and features of ethylene-vinyl acetate (EVA) copolymers in initial research and development led to commercial drug delivery systems. This review examines the breadth of EVA use in drug delivery, and will aid the researcher in locating key references and experimental results, as well as understanding the features of EVA as a highly versatile, biocompatible polymer for drug delivery devices.
Antimicrobial Bi-Layer Catheters – Extrusion And Performance
This study sought to produce effective antimicrobial catheters via bi- layer extrusion. Catheter samples were extruded with inner and outer layers of biocompatible thermoplastic polyurethanes (TPU). The inner layer of low durometer was compounded with PureEaseTM processing additive, and the outer tube with Agion® AD anti-microbial zeolite. Agion® concentration, outer layer tube thickness, and processing thermal history were considered. The antimicrobial bi-layer catheters were highly effective at inhibiting cell division and reducing the number of organisms by a 5 log reduction for CRE, and 3 log reduction for MRSA. The thickness of the outer tube did not influence the catheters antimicrobial effectiveness. It is concluded that bi-layer extrusion is a viable method for obtaining highly efficient, low-cost antimicrobial catheters.
Systems Engineering For Medical Device Development: Application To Insulin Pumps
Ensuring product integrity across every component, subsystem, and system of a medical device has never posed a greater challenge. Engineering organizations are addressing this challenge by increasing the use of modeling and simulation tools across the entire product architecture and throughout the product development cycle – from functional analysis through detailed design to system verification. This approach necessitates the use of a broad array of physics modeling and other software tools. And while each individual tool may be effective at performing deep comprehensive analysis, product groups are often operating in silos, each using their own set of tools, engineering processes, and associated expertise to understand their areas of product performance. This approach can delay the understanding of the complete system, leading to delayed timelines, redesigns, and other unwanted outcomes. Using an insulin pump as an example, this talk will review how digital prototyping and systems engineering can address the needs of interdisciplinary product development teams. This more holistic approach enables engineers from diverse backgrounds to share expertise and experience as they design an optimal product.
Degradation Products Of Medical Devices In Complex Biological Environments: Risk Assessment Strategies
There is growing interest in the identification, quantitation, and risk assessment of leachable species and degradation products of polymeric medical device components. Degradation and extractable & leachable studies usually follow a two-step program. In the first step, an exaggerated extraction is conducted using simple solvent conditions more aggressive than those anticipated to be realized in a clinical setting in order to determine the complete extraction profile and to identify the potential extraction compounds, desired or undesired. In the second step, a leaching study is conducted that attempts to simulate the clinical environment of the target application. The simulated leaching environment often comprises a more complex biological matrix than those used for extraction, which in turn complicates the chemical analysis assays used to identify and quantify the leaching materials. In this presentation, we show examples of studies that required a more detailed testing assay to identify and quantify compounds coming from implanted medical devices.
The Regulation Of Micro-Super-Hydrophobic Silicone Rubber To The Behavior Of Human Lens Epithelial Cells
Purpose: Evaluate the feasibility of compression molding manufactured silicone rubber which the surface infiltrative characteristic is super hydrophobic, realize and compare the effect of super hydrophobic surface to several cellular biological characteristics of human lens epithelial cell line SRA01/04 with ordinary hydrophobic surface. Methods: The silicone rubber of super hydrophobic micro surface and ordinary hydrophobic surface were manufactured by Vacuum defoamation and compression molding, and tested the property of the surface by measuring contact angle, electron microscope scan experiment and evaluation transparency. In vitro, the effect of super hydrophobic silicone rubber on cell proliferation, cell adhesion ability and cell morphological changes by SRA01/04 cells were examined. Results: The surface contact angle of super-hydrophobic silicone was greater than that of smooth silicone (153.8 vs. 116). The super-hydrophobic surface exhibited a micron-scale palisade structureunder scanning electron microscopy. However, cell number per 50× microscopic field on super-hydrophobic surfaces was markedly reduced 24 and 72 h post-seeding compared to smooth surfaces (p<0.01). Cells were cuboidal or spherical after72 h on super-hydrophobic surfaces, and exhibitednumerous surface microvilli with fluff-base polarity, while cells on smooth surfaces exhibited morphological characteristics of EMT.Conclusions: This study applies compression molding manufactured the super hydrophobic surface silicone rubber successfully. The super hydrophobic surface inhibits cell proliferation, adhesion. It could be a novel way to prevent cells’ proliferation with mechanical mechanism.Acknowledgements:This project was supported by the grants from the National Natural Science Foundation of China (81400384).
High Performance Polymers For Medical Devices
Demand for high performance polymeric materials and composites continues to increase for the Medical Device Industry as minimally-invasive procedures gain popularity.With a vast library of available types and grades, polymers offer design flexibility for a wide range of applications, allowing for the development of customized solutions based on the critical design requirements for a product or application. A variety of considerations influence polymer selection such as performance, biocompatibility and other regulatory requirements, ease of secondary processing for finishing operations such as bonding or shaping or molding, among other specifications. Minimally-invasive, image-guided techniques require X-ray detection for intraoperative guidance and maneuvering. Since polymers are X-ray transparent, radiopaque (RO) fillers are incorporated into polymer matrices through compounding processes. Such mixing processes produce uniform mixtures consisting of polymer(s), functional additive(s), filler(s), yielding customized polymer compounds.This presentation reviews how high-performance polymers and their compounds meet increasingly challenging design requirements for use in medical devices.
"Part Process" Development And Validation For Multiple Machines
“Part Process” Development and Validation for Multiple Machines:A Medical Device OEM Consortium formed to challenge the traditional plastic part validation process to facilitate moving a mold between machines – from Validation into Production.Much has been written and said regarding the “what and how-to” as it relates to process development and moving a mold between machines for the medical device industry. The Consortium member panel executed it - the economics of adopting this approach could potentially not only save tens to hundreds of thousands of dollars for each move (depending upon the number of molds), but the speed-to-market advantages and operations flexibility would be simply invaluable.
Smart Material Selection For Quiet, Smooth-Sliding Medical Devices Including New Color Concept
Engineering polymers are increasingly recognized as replacements for metal and ceramics in medical and pharmaceutical devices such as injection pens, inhalers, lancing devices and surgical instruments. These devices contain moving parts that must function efficiently with a low coefficient of friction, low noise and no wear, starting with the first activation. Regulatory requirements must also be met and Celanese has developed the portfolio of Medical Technology grades to address this requirement.Medical device performance has to be achieved in complex design environments including movements against different types of materials that are operating across a range of temperatures and chemical environments and a range of speeds and forces in operation. Their light weight and dimensional accuracy is achieved through precision molding. This, combined with good sliding performance, distinguishes these plastics from metal. Furthermore, appearance and functional color techniques are necessary to ensure device functionality. For example, for the application of a marking on a device to assure correct calibration and dosing, appropriate Medical Technology polymers have to be applied. This paper reviews traditional polymers with and without external lubricants. It also gives an overview of tribologically modified polymers that operate effectively without the aid of external lubricants including a new concept for mass colored plastics.
Supercritical Carbon Dioxide Assisted Extrusion Of Graphene Nanofiller Reinforced Polymers For Biomedical Applications
Over the years, the need for multifunctional medical tubing systems have grown tremendously subsequently increasing the precision tubing design and manufacturing consideration. The requirements smaller dimension along with enhanced mechanical and flexibility characteristics have resulted in elevating the complexity in manufacturing and design considerations, hence higher cost per device. A research gap exists in scientific understanding on the use of nanofillers to match similar characteristics medical tubes. This lack of understanding and industrial transition exists due to filler agglomeration at low aspect ratio and uneven dispersion within the polymer matrix. This study investigates ability of supercritical fluid technology to exfoliate graphene filler particles in order to enhance the mechanical, homogeneity and even dispersion of particles within Pebax matrix. A one step direct scCO2-assisted extrusion to exfoliate and provide even dispersion was demonstrated. These properties were verified using thermomechanical and electrical characterisation.
Engineered Polymer Surfaces For Superior Performance In Pharmaceutical Applications
Inhance Technologies transforms polymeric surfaces to high performing solutions for pharmaceutical packaging, and medical disposables and device manufacturing, improving performance, and security. Using proprietary processes, the surface properties of plastics and elastomers are permanently activated, imparting high barrier properties, lubricity (slip) or bonding properties to facilitate longer product shelf life, preserve product quality, and increase functionality. This unique technology can additionally reduce overall product costs through material substitution and down gauging.This presentation will cover the technologies behind Inhance’s material transformations, the pharmaceutical applications currently utilizing these technologies as well as newer uses on the horizon. Inhance Technologies is a Responsible Care™ Company, ISO certified and operating in many countries around the world. Topics that will be covered during the talk include,- How barrier properties can be imparted to conventional plastics - How tenacious label adhesion and print are achievable for any plastic device- How to replace glass with high performing plastics for diagnostic, assay and medical devices- How silicone-free lubricity can be achieved on elastomer and rubber components
Laser-Based Processing Of Polymers For Medical Applications
Laser-fabricated structures, including tissue engineering scaffolds, implantable sensors, and drug delivery devices, will become important tools for medical treatment over the coming decades. Over the past decade, we have examined use of several laser technologies, including pulsed laser deposition, matrix assisted pulsed laser evaporation, pulsed laser deposition, laser induced forward transfer, and two photon polymerization, to prepare microstructured and nanostructured polymers for medical applications. For example, we have shown that a laser-based approach known as two photon polymerization may be used to process a variety of photosensitive polymers into medically-relevant structures. We have also used laser ablation approaches such as matrix assisted pulsed laser evaporation and pulsed laser deposition to create nanostructured polymer films Efforts to improve the biocompatibility of laser-processed polymers and modify laser methods for clinical translation will be considered.
HD Plastics™: Roctool Material Characterizations
Roctool offers a patented technology that can change the way people design plastic parts. The technology uses induction heating to rapidly heat the tool surface thus providing many benefits including;- eliminating common molding defects such as gate blush and flow lines- cosmetically appealing parts with fillers such as glass or talc- great reduction of molded in stress- increase in flow length for thinner wall moldingThe company has been around since the year 2000 and has installed hundreds of systems worldwide. Although the technology has been adopted mostly in consumer electronics and automotive markets it can bring benefits to nearly every industry.
Effect Of Different Mold Coatings On Flow Resistance In Thin-Wall Injection Molding Of Polystyrene Parts
Injection molding of thin-wall parts is a challenging task due to the large cavity pressure gradient required during the filling phase. Low-friction mold surface coatings can be used to improve outcomes in such scenarios through reduction of the melt flow resistance by causing wall slip at the part-mold interface. This work investigates the effects of different mold coatings (DLC, CrN and CrTiNbN) on the melt flow resistance of polystyrene in thin-wall injection molding. The design of the mold allowed high-speed visualization of the molten polymer flow, measurement of the velocity profile across the cavity thickness and characterization of the wall-slip phenomenon. The results indicate that the DLC deposited on a chrome substrate can significantly reduce the melt flow resistance of polystyrene by increasing the slip velocity.
Research Credits For The Plastics Industry
Abstract In this ever-changing world of tax laws, the plastic industry must keep abreast of tax incentives that will benefit their business. This presentation will explore the following topics:R&D Tax CreditOne of the most under-utilized tax savings opportunities for companies in the manufacturing sector is the U.S. Credit for Increasing Research Activities (R&D tax credit). The R&D tax credit rewards companies who invest resources in innovation, developing new designs, new techniques, and process development or improvement.The types of activities that may qualify for the R&D tax credit include, but are not limited to the following: Developing new part designs for manufacturability Experimenting with manufacturing variables to improve processes Improving manufacturing processes through automation Developing new fixturing or other tooling Testing new part or tool designs through testing, sampling or trialsThis presentation will also explore new legislation that will allow eligible small businesses (less than $50 million in sales) to offset the Alternative Minimum Tax (AMT), as well as new treasury regulations that expand upon eligible expenditures for custom plastic processors.
Determining Critical Stress For Ductile-Brittle Transition Of Polyethylene Pipe Under Creep Loading
A new test approach is proposed which uses multi-relaxation stages to determine critical stress for an unusual ductile-brittle (DB) transition of polyethylene (PE) pipe that may occur after subjecting the pipe to constant loading for a long period, often more than 50 years. This paper describes the key concept for the new test approach, and presents results for three PE pipes of which two are 1-inch PE4710 pipes and one 2-inch PE2708 pipe. The results suggest that critical stress for the unusual DB transition should be around 10 MPa for the two PE4710 pipes and 8 MPa for the PE2708 pipe. These values are consistent with their hydrostatic design bases (HDB) that needs more than 1 year to determine using the standard test method. Advantage of this new approach is not just for the short time needed to determine HDB (less than one week), but also for determining the time of occurrence for the unusual DB transition under constant loading. This part of work is on-going, and the results will be presented in the conference.
Fracture Mechanical Characterization Of Non-Virgin Pipe Materials
For accelerated characterization of slow crack growth (SCG) properties of modern polyethylene pipe grades the Cyclic Cracked Round Bar Test has been developed. While many investigations on polyethylene are available with this test, only few studies have been published yet with other relevant pipe polymers such as polypropylene or polyvinyl chloride. Moreover, the increased use of non-virgin polymers for structural applications based on reprocessed or recycled resources is becoming a topic of increasing importance. The current paper presents an investigation of the general applicability of the Cyclic Cracked Round Bar Test to the mentioned polymers with a special focus on the sensibility to non-virgin materials. On the one hand the results show that this test can be used for accelerated SCG characterization of all materials. On the other it is demonstrated that the SCG resistance of non-virgin polymers is significantly lower than for virgin pipe grades.
Proposed Allowable Scratch Depth For High-Density Polyethylene (Hdpe) Pipes In Safety-Related Nuclear Applications
Proposed Allowable Scratch Depth for High-Density Polyethylene (HDPE) Pipes in Safety-Related Nuclear ApplicationsAuthor(s): P. Krishnaswamy1, S. Kalyanam1, Y. Hioe1, S. Pothana1, P. Raynaud2Affiliation:1Engineering Mechanics Corporation of Columbus3518 Riverside Drive, Suite 202, Columbus, OH firstname.lastname@example.org, email@example.com, firstname.lastname@example.org, email@example.comUnited States Nuclear Regulatory CommissionRockville, Maryland Patrick.firstname.lastname@example.org The topic of flaw acceptance for HDPE pipes installed in safety-related applications of a nuclear power plant has been of interest over the last decade. From initial analysis and tests on slow crack growth (SCG) in coupon specimens to hydrostatic Notched Pipe Tests (NPT), verification studies have been conducted by several researchers. Recently, the Electric Power Research Institute (EPRI) proposed a flaw acceptance criterion for HDPE pipe based on observations from several rounds of tests on various HDPE resins. The present study proposes acceptable flaw sizes for a range of pipe diameters and thicknesses. The flaw acceptance analyses use the renowned Brown model to transfer PENT values to service life/failure time estimations, evaluate the stress-intensity factors (SIF or KI) for infinitely long axial outer diameter (OD) surface cracks (most conservative approach for flaw acceptance determination), and analyze EPRI NPT data. It is also noted that the Brown PENT model does not accurately incorporate pipe or component geometry effects, and hence needs to be modified to predict the service life of pipes. However, this model can easily be used to determine maximum allowable SIF (KI) for pipes with the same geometry but different PENT values at the same service temperature, using NPT data. The allowable flaw size (scratch depth) analysis method is presented, and the flaw acceptance criteria for various postulated pipe geometries are discussed. In addition, the allowable flaw size method is demonstrated with the example of the largest pipe diameter with the thickest wall installed to-date. In summary, a rigorous conservative approach has been developed using existing data (from EPRI), the Brown PENT model, and a fracture mechanics approach for KI, to determine the maximum allowable axial external scratch depths (flaw sizes) in HDPE parent pipe for all diameters, all wall thicknesses, and PENT ratings from 2,000 to 10,000 hours.
Effects Of Primer On Mechanical Behavior Of Cpvc Pipe
This paper compares mechanical properties for CPVC pipe with and without the exposure to primer that is commonly used for surface treatment before the pipe joining, using coupon specimens of different geometries, including round notched pipe ring (NPR) specimens with notch radii from 1 mm to 3.18 mm, flat NPR specimens and ring specimens. All specimens were subjected to the split disc tensile test at a crosshead speed of 1mm/min. The results show a strong influence of the immersion in primer on the mechanical behavior and the level of influence depends on the specimen geometry. Typically, round NPR specimens with the biggest notch radius suffers the most from the immersion in primer. Based on the results, it is believed that the primer weakens CPVC pipe material by reducing its ultimate tensile strength and decreasing the strain required to generate cracking. The study also found that such an influence is more on ductility reduction than on the strength drop, but the influences are interrelated.
Innovative Millimeter Waves Technology For Measuring Diameter, Ovality, Wall Thickness And Sagging Of Large Plastic Pipes
Technical innovation at the manufacturing of plastic pipes with diameters from 90 to 3,200 mm and large wall thicknesses lead to impressive progress in product quality and reduction of material costs. Norms precisely define the minimum and maximum permissible diameter and wall thicknesses of a specific pipe dimension and require repeatable processes. To meet these standards and growing demands in the pipe extrusion requires the use of innovative measuring and control systems already in the production process. This paper introduces a new technology based on millimeter waves. It provides a non-contact, non-destructive, online measurement of inner and outer diameter, ovality, wall thicknesses and sagging (sagging of the melt during solidification at a too high viscosity) of large plastic pipes during the extrusion process.The measurement via millimeter waves technology is based on the FMCW (Frequency Modulated Continuous Waves) runtime method. One or two constantly rotating transceivers continuously send and receive frequency modulated millimeter waves thus ensuring the complete recording of the wall thickness over 360 degrees of the entire pipe circumference. From the runtime difference the inner and outer diameter, ovality, wall thickness and sagging is defined. The measuring principle does not require any coupling media and is not influenced by temperature or the plastic material. There is no need for calibration. In the paper we will at first outline the reasons for the development of the system with regards to the demands of the market. We will introduce the new technology as well as the functional principle, technical features and advantages of the millimeter waves technology for the user compared to other available measuring methods. The technology presented leads to repeatable and optimized production processes, increased product quality and cost savings for higher efficiency during pipe extrusion.
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