Download or read book Mechanical Properties of Polymeric Packaging Films After Radiation Sterilization written by Viriya Pungthong and published by . This book was released on 1990 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The use of radiation as a sterilization process is increasing. The well-developed technology of the radiation sterilization as applied to medical devices has assured the food industry that the process is reliable. Due to the food industry's possibility of widespread use, it is especially crucial that an appropriate packaging material be chosen so that its integrity is maintained after irradiation. This is because the commercial food packaging process carries products through more rigorous paths and channels than medical supplies. Many polymers used in the medical field show various degrees of degradation after radiation exposure, which can be determined either by visual or physical measurement. This paper studies the mechanical properties of polymeric films after irradiation doses of less than 10.0 Mrads and the extent to which this process causes film degradation. In this study, two mechanical properties will be measured: tensile strength and percentage elongation at break. Eight polymeric films commonly used in the food packaging industry are selected as the material samples. These materials will be irradiated with doses of 2.5, 5.0, 7.0, and 10.0 Mrads to determine cause-effect and dose related effect. Data collected for tensile strength and percentage elongation at break for each sample of one type of film before and after irradiation is analyzed and compared with data collected for other samples. Two primary purposes in undertaking this analysis are (1) to determine if the type of film significantly changes or degrades after irradiation, and (2) to study the relationship between the changes in mechanical properties of each film and the radiation doses of 0.0, 2.5, 5.0, 7.0, and 10.0 Mrads. In the analysis at 0.05 level of significance, polyethylene film (TD-transverse direction) is the only film which did not significantly change in either tensile strength or percentage elongation at break. The polyester/polyethylene film (MD-machine direction) significantly changed in percentage elongation at break although not in tensile strength. The rest of the film samples -PP, OPP, PETG, Polyester/PE(TD), polyester-MYLAR, PE(MD), PE/Nylon and PS film- exhibited significant changes in both mechanical properties after irradiation with doses of 2.5, 5.0, 7.0, and 10.0 Mrads. In the analysis of the degree of relationship between mechanical properties of each film and radiation doses of less than 10.0 Mrads [0.0 (non-irradiated), 2.5, 5.0, 7.0, andlO. O Mrads] found in this study can be catagorized into three types: the dose-dependent, the dose-independent, and the weak correlation. Among three film samples which exhibited the "dose-dependent" relationship, only oriented polypropylene(OPP) film was found to have the correlation between mechanical properties (both tensile strength and percentage elongation at break) and radiation doses; both mechanical properties decreased as the dose increased. Polypropylene (PP) was determined to exhibit the same correlation but only between tensile strength and radiation dose. For polyethylene (machine direction only), this correlation was found only for percentage elongation at break and radiation dose. The rest of the film samples were found to have no correlation between either mechanical property and radiation doses such as that indicated above. They are either "dose-independent" or exhibit a weak relationship between the two variables. For example, the polyester-MYLAR film exhibited obvious "dose-independent" characteristics since both mechanical properties increased significantly from 0.0 to 5.0 Mrads and then decreased at 7.0 Mrads. The films which obviously showed a very weak relationship between the mechanical properties and the radiation doses are two films which exhibited no change in mechanical properties after irradiation in the first study [PE(TD-tensile & percentage elongation) and polyester/PE (MD- percentage elongation)]. The films which exhibited a somewhat weak relationship between the two variables are PS (MD & TD- tensile & percentage elongation) and PE (MD-tensile). These last two films also showed a very small change in the mechanical properties after irradiation although not as small as the films irradiated in the first study."--Abstract.

Download or read book The Effect of Sterilization on Plastics and Elastomers written by Laurence W. McKeen and published by William Andrew. This book was released on 2018-02-22 with total page 470 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Effect of Sterilization Methods on Plastics and Elastomers, Fourth Edition brings together a wide range of essential data on the sterilization of plastics and elastomers, thus enabling engineers to make optimal material choices and design decisions. The data tables in this book enable engineers and scientists to select the right materials and sterilization method for a given product or application. The book is a unique and essential reference for anybody working with plastic materials that are likely to be exposed to sterilization methods, be it in medical device or packaging development, food packaging or other applications. Presents essential data and practical guidance for engineers and scientists working with plastics in applications that require sterile packaging and equipment Updated edition removes obsolete data, updates manufacturers, verifies data accuracy, and adds new plastics materials for comparison Provides essential information and guidance for FDA submissions required for new medical devices

Download or read book The Effect of Radiation on Properties of Polymers written by Laurence W. McKeen and published by William Andrew. This book was released on 2020-08-20 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Effect of Radiation on Properties of Polymers examines the effects of radiation on plastics and elastomers. Polymers are required in products or parts for a range of cutting-edge applications that are exposed to radiation, in areas such as space, medicine, and radiation processing. This book focuses on the effects of radiation exposure within that environment, providing in-depth data coverage organized by category of polymer. Aspects such as radiation impact on mechanical and thermal properties, including glass transition and heat deflection temperatures, are described, demonstrating how changes in these properties affect the performance of plastic or elastomer parts. The effect of radiation on electrical properties is also included. Supporting introductory chapters explain the key concepts of radiation, including the physical, mechanical, and thermal properties of plastics and elastomers. This is a vital resource for plastics engineers, product designers, and R&D professionals, working on products or parts for radioactive environments, as well as engineers and scientists in the medical, nuclear, and radiation processing industries. The book also supports researchers and scientists in plastics engineering, polymer processing and properties, polymer and coatings chemistry, materials science, and radiation. Brings together highly valuable data on the effect of radiation on the properties of polymers and elastomers Enables the reader to compare properties and to select the best possible materials for specific applications Supported by detailed explanations and analysis, ensuring that the reader understands how to interpret and utilize the data

Download or read book Effects of ionizing radiation on polymers written by R. Buchalla and published by . This book was released on 1992 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence of Uv Radiation and Vacuum on Strength and Destruction of Polymer Films written by L. M. Polyakov and published by . This book was released on 1967 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of UV radiation on the mechanical properties of poly(ethylene terephthalate) (PETP) films was studied. The changes were noted in tensile strength and deformation, and the formation of defects, i.e., cracking. The samples used were strips of PETP film, 6 mm wide, 20 mm long and 10 microns thick. The irradiated samples were subjected to tensile strength tests on a special machine. It was found that open cracks developed on the irradiated side of the samples if the irradiation took place in air. Vacuum-irradiated samples developed cracks only on deformation during the tensile test. A weakening of molecular bonds during the irradiation was assumed. Cracking began at definite stresses and deformation which decreased with an increase in the radiation dose. The tensile strength and plasticity of the irradiated films decrease with an increase in the duration of irradiation. The air-irradiated samples display a higher loss in tensile strength than the vacuum-irradiated samples, which suffer a higher loss in plasticity. Vacuum-irradiated samples form no visible defects on the surface: their surface remains smooth even after rupture of the sample. (Author).

Download or read book Radiation Effects in Materials written by Waldemar Alfredo Monteiro and published by BoD – Books on Demand. This book was released on 2016-07-20 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of radiation effects has developed as a major field of materials science from the beginning, approximately 70 years ago. Its rapid development has been driven by two strong influences. The properties of the crystal defects and the materials containing them may then be studied. The types of radiation that can alter structural materials consist of neutrons, ions, electrons, gamma rays or other electromagnetic waves with different wavelengths. All of these forms of radiation have the capability to displace atoms/molecules from their lattice sites, which is the fundamental process that drives the changes in all materials. The effect of irradiation on materials is fixed in the initial event in which an energetic projectile strikes a target. The book is distributed in four sections: Ionic Materials; Biomaterials; Polymeric Materials and Metallic Materials.

Download or read book Film Properties of Plastics and Elastomers written by Laurence W. McKeen and published by William Andrew. This book was released on 2012-04-25 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: Now in its 3e, Film Properties of Plastics and Elastomers, has been extensively revised. This is the only data handbook available on the engineering properties of commercial polymeric films. It details many physical, mechanical, optical, electrical, and permeation properties within the context of specific test parameters, providing a ready reference for comparing materials in the same family as well as materials in different families. Data is presented on the characteristics of 47 major plastic and elastomer packaging materials. New to this edition, the resin chapters each contain textual summary information including category, general description, processing methods, applications, and other facts as appropriate, such as reliability, weatherability, and regulatory approval considerations for use in food and medical packaging. Extensive references are provided. Essential data and practical guidance for engineers and scientists working with polymer films 3e expanded by nearly 50% to include new data sections and additional explanatory chapters to help readers utilize the data and work successfully with plastic films Written for engineers working across the key market sectors for polymer film applications: semiconductor, chemicals, food, beverage and pharmaceutical packaging, energy, medical devices, etc.

Download or read book Radiation Effects on Polymers written by Roger Lee Clough and published by . This book was released on 1991 with total page 656 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here is the most extensive resource on polymer radiation effects to be available in more than a decade. This new volume reviews the fundamental chemistry and physics of polymer-radiation interaction and examines recent progress in most major areas of the field. Its 38 chapters, written by leading experts from around the world, cover: fundamentals of polymer radiation chemistry; technological applications of radiation to polymers (including radiation processing; radiation curing; sterilization; cross-linking, polymerization, grafting, X-ray resists, and others); and degradation of stabilization of irradiated polymers (including nuclear plants, scintillation detectors for particle physics, and others).

Download or read book The Statistical Nature of Strength and Lifetime in Polymer Films and Fibers written by Bronya Tsoi and published by CRC Press. This book was released on 2004-03-01 with total page 525 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph is an updated and extended edition of Strength and Fracture of Polymer Films, which was published in Russian in 1999. It presents the results of long-term theoretical and experimental studies of brittle and quasi-brittle fracture of solid polymers. The principal results of a comprehensive and detailed investigation of the statistical

Download or read book Influence of Radiation on Material Properties written by F. A. Garner and published by ASTM International. This book was released on 1987 with total page 806 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975-12 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Polymers as Materials for Packaging written by Jiri Štěpek and published by Ellis Horwood. This book was released on 1987 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Study of Extractable Substances and Microbial Penetration of Polymeric Packaging Materials written by G. O. Payne and published by . This book was released on 1969 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flexible packaging laminates were developed and evaluated for use with prepackaged radiation-sterilized ham, bacon and chicken. Laminate structures comprised PET as the ply, and a heat sealable inside ply, namely film of polyolefin, polyamide or polyester. These laminates were evaluated for food compativility, low-temperature resistance, and resistance to microbial and insect penetration. The flexible laminate with the polyamide as the food-contacting film was found satisfactory for use with prepackaged meat in various test environments over a one year storage period. A flexing apparatus, developed to induce bacterial penetration through defects in flexible packages, detected leaks not visible to the naked eye. The three types of laminate tested showed no negligible weight loss and no package rupture in shipping vibration tests performed at temperature as low as -180. (Author, modified-PL).

Download or read book Study of the Effects of Gamma irradiation on Polymeric Packaging Films and Heatseals Using Tensile Testing and X ray Diffraction written by Kathryn L. Hupfer and published by . This book was released on 2005 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Medical Plastics written by Robert C Portnoy and published by William Andrew. This book was released on 1998-12-31 with total page 225 pages. Available in PDF, EPUB and Kindle. Book excerpt: The use of plastics is widespread. Less widespread, however, is a clear understanding and examination of the many forms of degradation inherent within the very environments these materials must perform. Medical PlasticsùDegradation Resistance & Failure Analysis fills that void. The introductory chapter gives an overview of the medical applications of plastics and the specific performance requirements they need to meet. The following chapters discuss various degrading environments and their effects including environmental stress cracking, effect of body liquids, effect of harsh environments, and various methods of sterilization. The book also discusses the failure of medical devices due to contamination, low temperature, the effects of UV light, migration of formulation components, mechanical stresses, and problems with design and fabrication. Case histories of failures of some common products used in medicine are also provided.

Download or read book Mechanical Properties of Ultrathin Polymer Films written by Shanhong Xu and published by LAP Lambert Academic Publishing. This book was released on 2012 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is very important to understand the mechanical properties of polymers at the nanoscale with the continuing demand of decreasing the size of circuit in the electronic industry. There has been considerable research on the confinement effect in thin films with a variety of techniques, often with conflicting results. We developed the stress-strain analysis and energy balance approach to separate the surface tension contribution to the observed rubbery stiffening. Further, the geometry effect in the nanobubble inflation technique was investigated by comparing the creep behavior of circular bubbles with that of rectangular bubbles. Next, we investigated the molecular architecture effect in the nanobubble inflation technique by comparing the creep behavior of linear PS with that of the three-arm star PS. In the last part of this thesis, the capability of the nanobubble inflation technique to investigate the yield and fracture behavior of ultrathin films was demonstrated.

Download or read book UHMWPE Biomaterials Handbook written by Steven M. Kurtz and published by Academic Press. This book was released on 2009-04-27 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: UHMWPE Biomaterials Handbook describes the science, development, properties and application of of ultra-high molecular weight polyethylene (UHMWPE) used in artificial joints. This material is currently used in 1.4 million patients around the world every year for use in the hip, knee, upper extremities, and spine. Since the publication of the 1st edition there have been major advances in the development and clinical adoption of highly crosslinked UHMWPE for hip and knee replacement. There has also been a major international effort to introduce Vitamin E stabilized UHMWPE for patients. The accumulated knowledge on these two classes of materials are a key feature of the 2nd edition, along with an additional 19 additional chapters providing coverage of the key engineering aspects (biomechanical and materials science) and clinical/biological performance of UHMWPE, providing a more complete reference for industrial and academic materials specialists, and for surgeons and clinicians who require an understanding of the biomaterials properties of UHMWPE to work successfully on patient applications. The UHMWPE Handbook is the comprehensive reference for professionals, researchers, and clinicians working with biomaterials technologies for joint replacement New to this edition: 19 new chapters keep readers up to date with this fast moving topic, including a new section on UHMWPE biomaterials; highly crosslinked UHMWPE for hip and knee replacement; Vitamin E stabilized UHMWPE for patients; clinical performance, tribology an biologic interaction of UHMWPE State-of-the-art coverage of UHMWPE technology, orthopedic applications, biomaterial characterisation and engineering aspects from recognised leaders in the field