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A comparative analysis of the need for various knowledge and skills in plastics as viewed by Texas high school plastic teachers and Texas plastics industries

Description: This was a comparative study in which Texas teachers of industrial plastics and the employers of Texas plastic industries were surveyed in order to evaluate the need for various knowledge and skills of the plastics industry.
Date: December 1975
Creator: Reeve, Edward Lee
Partner: UNT Libraries

Phthalates in Plastics and Possible Human Health Effects

Description: This report provides background information about human exposure to phthalates in plastics and possible health effects. It also discusses evaluation and regulation of pthalates in the U.S. and internationally, as well as related legislative proposals.
Date: July 29, 2008
Creator: Schierow, Linda-Jo & Lee, Margaret Mikyung
Partner: UNT Libraries Government Documents Department

Fracture Toughness Testing of Plastics under Various Environmental Conditions

Description: The primary objective of this study is to test the applicability to plastics of a fracture toughness testing tool developed for metals. The intent is to study pre-test conditioning of several plastic materials and the effect of the depth of the razor notch cut in the chevron notched fracture toughness test specimens. The study includes the careful preparation of samples followed by conditioning in various environments. Samples were subjected to laboratory air for a specific duration or to a controlled temperature-humidity condition as per the ASTM D1870. Some of the samples were subjected to vacuum conditioning under standard test specifications. Testing was conducted using the conventional three-point bend test as per ASTM D5045-95. ASTM E1304, which sets a standard for short rod and bar testing of metals and ceramics provides some basis for conducting chevron notched four-point bend tests to duplicate the toughness tool. Correlation of these results with the ASTM test samples is determined. The four-point bend test involves less specimen machining as well as time to perform the fracture toughness tests. This study of fracture toughness testing has potential for quality control as well as the fracture property determination.
Date: December 1997
Creator: Velpuri, Seshagirirao V.
Partner: UNT Libraries

Analyses of Decay Curves of Irradiated Plastics

Description: The following report covers the results of a general program that was conducted at the Oak Ridge National Laboratory to investigate the effects on plastic materials of exposure to radiation in the pile. In the investigation, several plastics were irradiated, and on removal from the pile, their rates of decay were determined by measurement of gamma activity in an ionization chamber.
Date: June 22, 1949
Creator: Saleeby, R. N.; Cheshire, J. R. & Jensen, W. P.
Partner: UNT Libraries Government Documents Department

Compression tests of six curved paper-base plastic panels with outward-acting normal pressure

Description: Report presenting results of compression tests of six paper-base plastic panels with outward-acting normal pressure. All panels failed by separation of the skin, either from the rib or from the stiffeners. Results regarding the introduction of air pressure and types of failures encountered are provided.
Date: September 1944
Creator: Schuette, Evan H.; Rafel, Norman & Dobrowski, Charles V.
Partner: UNT Libraries Government Documents Department

Resistance of transparent plastics to impact

Description: From Summary: "The problem of developing a windshield for aircraft which will withstand the effect of bird impacts during flight is a difficult one, as an estimate of the striking energy will indicate. If the average speed of the airplane is considered to be about 200 miles per hour and that of the bird about 70 miles per hour, the speed of the bird relative to the airplane may be as great as 400 feet per second. If a 4-pound bird is involved, a maximum impact energy of approximately 10,000 foot-pounds must be dissipated. To obtain this energy in a drop test in the Washington Monument, it would be necessary to drop a 20-pound weight down the 500-foot shaft. For both theoretical and practical reasons, it is necessary to keep the mass and speed more nearly like those to be encountered. However, to get an impact of about 10,000 foot-pounds with a 4-pound falling body, it would be necessary to drop it from a height of approximately one-half mile, neglecting air resistance. These facts will indicate some of the experimental obstacles in the way of simulating bird impacts against aircraft windshields."
Date: July 1939
Creator: Axilrod, Benjamin M. & Kline, Gordon M.
Partner: UNT Libraries Government Documents Department

Plastics, Their History and Use

Description: Since the civilization, population and living standards of the peoples of the world have increased in such gigantic proportions, especially in the last fifty years; and since the supply of natural resources cannot meet the demand, we have of necessity had to find new materials to take their place. These new materials must fulfill two purposes; namely, to take the place of the natural resources so wantonly destroyed and to meet requirements that the natural materials are not able to meet. Foremost among these new materials are the synthetic resinous materials known as plastics. Plastics are one way of getting around the fact that Nature has not thought of everything. The ability of man to imagine things that he does not see and to fashion these things from what he finds around him is responsible for what we call progress -- and for plastics.
Date: August 1946
Creator: Sealy, Emma L.
Partner: UNT Libraries

An Analysis of a Curriculum Guide Developed for Industrial Plastics as Listed in Bulletin 615 of the Texas Education Agency

Description: This study surveyed teachers of industrial plastics and personnel of the plastics industry to evaluate an industrial-plastics curriculum guide. The respondents felt that there was no unnecessary material in the guide, that additional information should be added to several of the plastics processes in the curriculum guide, and that most of the subject areas in the guide should be studied for no less than an hour and no more than five hours.
Date: December 1974
Creator: Smith, William Elton
Partner: UNT Libraries

Effect of fuel immersion on laminated plastics

Description: Report presenting the effects of cyclic and continuous immersion in heptane, toluene, and SR-6, a test fuel, on the weight, dimensions, and flexural properties of 19 samples of laminated plastics. No one sample exhibited smaller changes than all other samples in all properties for all fuels and for both cyclic and continuous immersion. Results regarding weight and dimensional changes and changes in flexural properties are provided.
Date: June 1951
Creator: Crouse, W. A.; Carickhoff, Margie & Fisher, Margaret A.
Partner: UNT Libraries Government Documents Department

Plastic Flow During Extrusion of Tubing

Description: Abstract: "A study of plastic flow during the extrusion of tubing was made by extruding colored Plasticine billets in a small-scale extrusion press. Decreasing the included angle of the conical die and tapering the ram end of the billet decreased the amount of coextrusion of the backer block into the tubing, lubricating the billet also decreased coextrusion."
Date: July 26, 1955
Creator: Saller, Henry A.; Keeler, John R. & Cuddy, Lee J.
Partner: UNT Libraries Government Documents Department

Mechanical Properties of Five Laminated Plastics

Description: Note presenting results of mechanical tests of several laminated plastics, including canvas laminate molded at low pressure, grade-C canvas laminate, rayon laminate, paper laminate, and glass-fabric laminate. The following tests were performed: static tension, compression, and torsion tests; long-time creep tests at different stresses on specimens loaded in tension; fatigue tests of unnotched specimens in bending; fatigue tests of notched specimens in bending; fatigue tests in bending at temperatures of -75, 77, and 160 degrees Fahrenheit; and fatigue tests in torsion.
Date: August 1948
Creator: Findley, William N. & Worley, Will J.
Partner: UNT Libraries Government Documents Department

Error analysis for fast scintillator-based ICF burn history measurements

Description: Plastic scintillator material acts as a neutron-to-light converter in instruments that make ICF burn history measurements. Light output for a detected neutron has a fast rise time (420 ps) and a relatively long decay constant (1.2 ns). For a burst of neutrons whose duration is much shorter than the decay constant, instantaneous light output is approximately proportional to the integral of the neutron interaction rate with the scintillator material. Burn history is obtained by deconvolving the exponential decay from the recorded signal.
Date: July 6, 1998
Creator: Lerche, R A & Ognibene, T J
Partner: UNT Libraries Government Documents Department

Plastic Heat Exchangers : A State-of-the-Art Review

Description: Significant increases in energy utilization efficiency can be achieved through the recovery of low-temperature rejected heat. This energy conserving possibility provides incentive for the development of heat exchangers which could be employed in applications where conventional units cannot be used. Some unique anticorrosion and nonstick characteristics of plastics make this material very attractive for heat recovery where condensation, especially sulfuric acid, and fouling occur. Some of the unique characteristics of plastics led to the commercial success of DuPont's heat exchangers utilizing polytetrafluoroethylene (trade name Teflon) tubes. Attributes which were exploited in this application were the extreme chemical inertness of the material and its flexibility, which enabled utilization in odd-shaped spaces. The wide variety of polymeric materials available ensures chemical inertness for almost any application. Lower cost, compoundability with fillers to improve thermal/mechanical properties, and versatile fabrication methods are incentives for many uses. Also, since many plastics resist corrosion, they can be employed in lower temperature applications (< 436 K), where condensation can occur and metal units have been unable to function. It is clear that if application and design can be merged to produce a cost-effective alternate to present methods of handling low-temperature rejected heat, then there is significant incentive for plastic heat exchangers, to replace traditional metallic heat exchangers or to be used in services where metals are totally unsuited.
Date: July 1979
Creator: Miller, David; Holtz, Robert E.; Koopman, R. Nelson; Marciniak, Thomas J. & MacFarlane, Donald R.
Partner: UNT Libraries Government Documents Department

Effect of simulated service conditions on plastics

Description: Report presenting an investigation of the effects of simulated surface conditions, which involved exposure to various combinations of moisture, heat, and ultraviolet light, on the weight, dimensional stability, and flexural properties of reinforced plastics.
Date: July 1947
Creator: Crouse, W. A.; Caudill, D. C. & Reinhart, F. W.
Partner: UNT Libraries Government Documents Department

Effect of Simulated Service Conditions on Plastics During Accelerated and 2-Year Weathering Tests

Description: "The effects of outdoor weathering for 2 years and of an accelerated weathering test on the weight, dimensional stability, and flexural properties of selected reinforced plastics were investigated. The results of all tests, both in this report and the previous report (NACA TN No. 1240), indicate that none of the laboratory aging tests correlated with outdoor weathering with respect to all properties and all materials" (p. 1).
Date: May 1948
Creator: Crouse, W. A.; Caudill, D. C. & Reinhart, F. W.
Partner: UNT Libraries Government Documents Department

A Study of the Development and Use of Plastics in Industry with Proposals for the Adaptation of Plastics as a Phase of Industrial Arts

Description: The purpose of this study is twofold. First, it is to present evidence of the ever-increasing development and use of plastics by industry. A second purpose after presentation of evidence, is to propose that industrial arts must adapt work with plastics as a phase of its program in order to meet present-day needs of the growing generation.
Date: 1951
Creator: James, A. S., Jr.
Partner: UNT Libraries

A Comprehensive Theory of Yielding and Failure for Isotropic Materials

Description: A theory of yielding and failure for homogeneous and isotropic materials is given. The theory is calibrated by two independent, measurable properties and from those it predicts possible failure for any given state of stress. It also differentiates between ductile yielding and brittle failure. The explicit ductile-brittle criterion depends not only upon the material specification through the two properties, but also and equally importantly depends upon the type of imposed stress state. The Mises criterion is a special (limiting) case of the present theory. A close examination of this case shows that the Mises material idealization does not necessarily imply ductile behavior under all conditions, only under most conditions. When the first invariant of the yield/failure stress state is sufficiently large relative to the distortional part, brittle failure will be expected to occur. For general material types, it is shown that it is possible to have a state of spreading plastic flow, but as the elastic-plastic boundary advances, the conditions for yielding on it can change over to conditions for brittle failure because of the evolving stress state. The general theory is of a three dimensional form and it applies to full density materials for which the yield/failure strength in uniaxial tension is less than or at most equal to the magnitude of that in uniaxial compression.
Date: August 10, 2006
Creator: Christensen, R M
Partner: UNT Libraries Government Documents Department

A Study of the Different Types of Plastics to Ascertain Their Suitability as a Material in the Construction of Projects in Industrial Arts Programs

Description: This study will not attempt to analyze the various types of plastics presented with respect to the chemical ingredients and chemical processes necessary for their manufacture, but it will deal primarily with the selection and use of the various types of plastics as materials suitable for use in the construction of projects in an industrial arts program.
Date: August 1954
Creator: Fredrickson, Wade O.
Partner: UNT Libraries

Expanded plastics used as sculptural patterns for burn out in ceramic shell molds

Description: The purpose of this investigation was to develop a method of burning out expanded plastic patterns invested in ceramic shell molds. Technological information suggested that the procedure was not feasible because plastic expansion or gas combustion invariably spoiled the mold. However, burning out expanded plastic patterns would provide a practical method of using such materials in the sculptor's studio; combined with ceramic shells, the patterns would promote accurately detailed castings with ease and convenience.
Date: August 1976
Creator: Penland, Lilburn C.
Partner: UNT Libraries

An Experimental Investigation of a Prescription for Identifying Plastic Strain

Description: A series of experiments is described in which a novel prescription for the identification of plastic strain is tested to determine its validity in the context of the strain-space formulation of rate-independent plasticity. Biaxial experiments were performed on several thin-walled aluminum 1100-O cylindrical specimens.
Date: February 29, 2000
Creator: Brown, A.A.; Casey, J. & Nikkel, D.J.
Partner: UNT Libraries Government Documents Department