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.
The durability of a SRIM Urethane composite are evaluated and the results are used to develop a design guide to aid in the use of this material. Test methods for static fatigue creep and impact testing are described in detail. The Oak Ridge National Laboratory developed these methods for durability testing. The raw test data from an earlier study are summarized and generalized in the form of design equations. The scope and limitations of these design equations are discussed. This material evaluation and data summary process provides a means for designing for durability using an E-glass reinforced SRIM Urethane composite.
Contemporary vehicles utilize a mix of materials in their construction consisting of metals plastics and composites. These materials must possess suitable surface properties to achieve desired performance when these parts are adhesively bonding or painted for field service. Surface preparation methods now in place oftentimes use solvents or caustics an increasingly unacceptable approach in an era of mounting environmental regulations. New methods of surface preparation are called for that are environmentally benign and economically feasible while meeting the stringent quality standards of the automotive industry. The use of energetic ultraviolet light is emerging as a promising technology to compete with the old methods of surface preparation. This paper reports the utility of using energetic UV light to generate appropriate surface chemical composition on plastics composites and metals for subsequent painting or adhesive bonding operations. UV treatments have the potential to replace the old methods of treating assorted materials used in the automotive industry in an environmentally responsible and cost-effective manner.
It is commonly accepted that bonding polypropylene to itself or other adherends is difficult and the options available for cost-effective bonding using adhesives are very limited. The aim of the presentation will be to describe a new range of heat-activated adhesives recently developed in our research laboratories and their applications. These adhesives which are now commercially available offer numerous advantages for the rapid manufacture of composite materials in addition to promoting new or improved assembly methods in a wide range of market sectors. e.g. automobile aerospace construction textiles footwear and packaging to mention but a few. The main focus of the presentation will be to outline various ways in which the film strand or pellet forms of the new adhesives may be used to solve a variety of industrial problems. The range of materials to which polypropylene can be successfully bonded (e.g. to itself to many metals and to a range of other materials notably cellulosics) will be outlined together with their associated manufacturing methodologies such as hot compression lasers and induction heating. An indication of the mechanical bond strengths which can be achieved at various temperatures will also be outlined.
Composite plate materials for use as bipolar plates in a fuel cell stack must meet certain performance criteria namely high surface and through-plane electrical conductivity very low gas permeability and chemical resistance to both coolants and reactants. In addition to these performance criteria it is necessary from a cost viewpoint that the bipolar plates are easy to manufacture. One category of materials being used for bipolar plates are carbon composites where carbon additives are mixed with a thermoset resin for net-shape compression molding of bipolar plates. A study of the corrosion resistance (via electrochemical testing) helium permeation stack performance and electrical conductivity of a variety of composite materials designed for bipolar plate applications will be presented.
At present membrane electrode assembly performance levels and stack operating conditions of PEM fuel cells a plate area specific resistance of less than approximately 20 mohm cm2 and a plate thickness of less than 2 mm are required to meet the vehicular volumetric power density target (> 2 kW/l). It is however difficult to meet these aggressive requirements and simultaneously obtain good mechanical properties when using polymeric plate materials. Polymers become brittle and break frequently at the high conductive filler loadings (e.g. > 50 v/o graphite) required for high conductivity. This study investigates a potential approach for obtaining high plate conductivity at low conductive filler loadings thus enabling high volumes of thin and ductile plates to be manufactured at low scrap rates.
This paper presents the results of a 3D FEM analysis of some layer spreading experiments performed on flat die with a coextrusion feed-block. The complete feed-block and die assembly was simulated using a commercially available 3D FEM software package and a path-line analysis was used to determine the interface position and the degree the of layer spreading. The results obtained were in good agreement with the experimental data. The simulation also provided a better insight into the flow development within these types of systems.
Microwaves provide rapid, selective and volumetric heating in processing polymers and polymer composites. A variable frequency mode-switching method was studied to uniformly bond two polymer composites with an epoxy-based adhesive. Results were compared with thermal process. For one substrate, microwave method reduced the bonding time and enhanced the bonding strength significantly. For the other substrate, microwaves reduced the bonding time and achieved equal bonding strength as that in thermal process.
The global market for liquid mixed metal stabilizers is migrating toward heavy-metal-free products. Historically, these systems have not been performance and cost competitive. High efficiency calcium-zinc stabilizers have the potential to replace heavy-metal-based products. The intrinsic value of non-phenolic lubricating calcium intermediates and calcium-zinc stabilizers are discussed within the following report.
AFM was used to study the morphology of ultrathin poly[styrene -b- butadiene -b-styrene] copolymer (SBS) films deposited on polystyrene brushes. The grafting density and molecular weight of the grafted polymer layers were varied to reveal the relationship between the parameters of the brush interface and the structure of the film. We found a strong effect of the underlying brushes on the formation of the SBS films.
Large diameter high density polyethylene (HDPE) pipe, typically with diameters greater than 300 mm (12 inches) often have very different failure modes than smaller diameter pipe of the same materials. Heavier wall thicknesses, sometimes greater than 50 mm (two inches), are more susceptible to oxidation during manufacture. The aqueous media transported in such pipes may also oxidize the pipe wall. Such pipes are also often more susceptible to excessive deformation by soil settlement. In this paper, failures in three different large diameter HDPE systems will be investigated.
Multi-fiber model composites are being used in studies into the nucleation of failure in composites. Results have revealed that the nucleation of critical flaws in unidirectional fibrous composites may rely on the time-dependent redistribution of stress by the viscoelastic matrix. Although their role in flaw nucleation is not clearly understood, shear deformation bands have been detected between fiber breaks. Furthermore, interfacial phenomena have been detected in the matrix by Optical Coherence Tomography.
The flow of plastics pellets between the first flights of a single screw can lead to conveying problems. As a result, the throughput varies or not enough material reaches the following screw sections. In order to gain a better insight in the correlations that exist between pellet properties, barrel and screw geometry, a physico-analytical model is worked out. On the basis of this model, the pellet flow behavior can be analyzed relatively accurately.
Tiger striping in injection molded bars made of thermoplastic olefin (TPO) blends has been examined by a detailed analysis of the disperse phase morphology. This is evaluated in flow mark regions and out of flow mark regions on the part surface and near the wall, and also just behind the flow front but away from the wall. The results point to a way to control the rheology of the components for avoiding or delaying the onset of flow lines.
In this paper, polystyrene and polylactide were blended at a composition of 50/50 to form a co-continuous morphology. The influence of annealing on the final morphologies of the blend is investigated using SEM and Mercury Intrusion Porosimetry. It is demonstrated that a series of co-continuous networks with pore sizes ranging from 1 to 80 microns and higher have been achieved by varying the annealing conditions. A mechanism of coalescence is discussed in order to account for the said morphologies.
Ultrasonic stand-alone and film-type high temperature sensors and system have been used to measure in-line the barrel and screw wear during low-density polyethylene extrusion. These sensors are nonintrusive and non-destructive. For the screw wear measurement the system is equipped with fast data acquisition. Measurement accuracy of better than 50 ?m can be achieved.
This paper provides an overview of the application of extrusion simulation towards process analysis and screw design. The paper discusses some of what is possible today with computer aided screw design; what can be obtained from simulation results, what the limitations are, and shows a couple of examples of how to apply simulation towards design.
The determination of the crystalline lamellar thickness in semicrystalline polymers is a tricky issue. In this paper, three methods have been employed to analyze the lamellar thickness in semicrystalline polymers. The three methods are small-angle X-ray scattering correlation function method, Fast Fourier Transformation and transmission electron microscopy. Based on this study, the larger value of the two correlation length values should be assigned as the lamellar thickness.
Material recycling requirement gradually opens the automotive body sealing market to thermoplastic elastomers (TPE), which is primarily dominated by EPDM thermosetting elastomers. Due to special material behaviors of elastomers, careful attentions should be taken when analyzing the body seal performance using material testing data, especially for TPE materials. This paper will address some of the issues by analyzing body seal products using TPE materials. The general guidelines for body seal analysis and result evaluation will also be discussed.
This paper presents a new algorithm for the automatic setting of the rotational speed, back pressure and barrel temperature profiles in a reciprocating screw injection molding machine. The algorithm is based on a computer simulation of polymer plastication. It achieves maximal throughput and good quality of melting and mixing within the limits provided by the injection molding machine.
A process initialisation and setup system for the gas assisted injection moulding process is developed. The initialisation routine uses settings taken from the machine operator or machine controller to formulate the starting point for the process settings. A setup routine is required that automatically changes process settings on the machine controller to provide an acceptable product. Process variables are monitored along with feedback from the operator on the condition of the product. The process initialization routine is outlined here.
Any article that is cited in another manuscript or other work is required to use the correct reference style. Below is an example of the reference style for SPE articles:
Brown, H. L. and Jones, D. H. 2016, May.
"Insert title of paper here in quotes,"
ANTEC 2016 - Indianapolis, Indiana, USA May 23-25, 2016. [On-line].
Society of Plastics Engineers
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