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 SPE Library is just one of the great benefits of being an SPE member! Are you taking advantage of all of your SPE Benefits?
Six years ago we initiated a long term study on the effect of time and temperature on the data sheet modulus values for glass fiber reinforced vinyl composites. Results after the first year showed that the measured creep modulii were higher than those predicted by time-temperature superposition of dynamic mechanical data. This paper presents five years of additional creep data and examines the effect of sample aging on the creep predictions.
It is often difficult to provide consistent surface resistivity in the effective static dissipative range (about 105 to 1010 ohms/square). Thermoplastics incorporating traditional conductive additives generally exhibit discontinuous electrical behavior in this range. Conducting polymer composites have been created through in-situ deposition of conducting polymers onto carbon black substrates. By utilizing the inherent flexibility of these conducting polymer composites, compounds have been developed with controlled surface resistivity.
One of the very first principles used to develop INSITE™ Technology, a major revolution in the polymer industry, was that of learning from history. Analyzing and avoiding repetition of mistakes to do product development worked very much to Dow's advantage as the major piece of technology advanced. Too often not enough time is allotted for contemplation of how to do better based on our collective experiences and wisdom. Particularly in developing new products, experience really makes a huge impact on the speed and success rate.
To meet the challenging processing and performance demands for thin-wall housings, plastic materials must satisfy basic requirements for flow, impact resistance, and modulus. In this paper, select mechanical and processing properties of nylon 6 materials are examined for thin-wall-molding applications and compared with those for amorphous blends.
Automotive body seals are becoming increasingly complex. As there is still little knowledge about the manufacturing process, extensive investigations are done to analyze the influence of the rheological behavior of the materials, the parameters of the extrusion process and the foaming/vulcanization on the quality properties of the foamed seals. The evaluation allows a better process understanding which in combination with improved test methods leads to an increased product quality and reduced manufacturing costs.
Synthetic pearl lustre like other high aspect ratio pigments exhibit poor solid flow behaviour. In the extruder based manufacture of thermoplastic masterbatches this limits output, by restricting the conveying capacity of the feed zone. Proprietary wax encapsulation technology now allows four fold or greater improvements in the extruder output without changing the particle shape or size distribution of the pigment prior to the compounding process. The encapsulation process also leads to low dust characteristics.
Goknur Bayram, Ulku Yilmazer, Nese Orbey, May 1999
Linear viscoelastic properties of a model suspension containing hydroxyl terminated polybutadiene (HTPB) and glass beads with filler concentration up to 30% by volume were investigated by using a Haake parallel disk rheometer. For all the suspensions, it was observed that the rheological properties such as the storage modulus, G', loss modulus, G and complex viscosity ?* increases with the filler content ?. The relaxation spectra was calculated by using G' and G". The relaxation moduli Gi(?i?) decreased with the relaxation time ?i but increased with the filler content ?."
R.O. Carter III, John L. Gerlock, Cindy A. Smith, May 1999
The top, clearcoat layer of an automotive paint job protects the under layers while maintaining a beautiful appearance for the life of a car. To determine clearcoat durability, effects of the weathering protocol, of the physical and chemical transformations and effects on the appearance must be considered. To this end, we will describe photoacoustic infrared (PAS-IR), and ultraviolet (UV) technologies and UV microspectroscopy to assay the changes in chemical composition produced in clearcoat paint systems by weathering.
Sindee L. Simon, Olivier Sindt, Gregory B. McKenna, May 1999
The cure kinetics for a commercial epoxy have been established and the influence of the degree of cure on the glass transition determined. Time-temperature and time-conversion superposition principles have been built into a model that successfully predicts the development of the viscoelastic properties of the epoxy during isothermal cure from gelation to vitrification
E. Ray Harrell, Jr., Rabeh H. Elleithy, Coleen A. McFarland, James W. Summers, May 1999
The viscoelastic nature of PVC can not be ignored during the injection molding process. Strains imposed on the compound during the injection stage display recovery dynamics that are indicative of the temperature at which the strains were imposed. A mathematical model, employing approximate" time-temperature modulus relationships provided the basis for interpreting the shrinkage data. A distribution map of the various relative temperatures attained within the part during injection was determined."
A technology has been developed to produce biaxially oriented films of blends of polybutylene terephthalate (PBT) and polyethylene terephthalate (PET) using double bubble tubular film extrusion. The mechanical instabilities and the mechanisms associated with their sources of occurrence are described. The films have been structurally characterized by wide angle X-ray diffraction and optical techniques. The structure of the film is related to processing conditions.
Fibers have been melt spun from polypropylene and its blends with ethylene propylene rubber, as well as polypropylene based thermoplastic elastomers under various conditions. The spinline stresses as well as kinematics have been measured. The fibers have been structurally characterized using wide angle x-ray diffraction and birefringence and the results interpreted.
A model for flow start-up of a Newtonian liquid in an initially empty modular co-rotating twin screw extruder is developed. The changes of length of fill in front of the die and kneading disc block elements and output flow rate with time were predicted for various modular screw configurations. Experiments were also carried out on a laboratory modular machine with windows to verify the predictions. Generally, good agreement with the flow analysis was found.
The breakage of glass fibers was measured for several different types of continuous mixers including (i) Buss Kneader (ii) modular intermeshing co-rotating twin screw extruder (iii) modular intermeshing counter-rotating twin screw extruder. Comparisons are made using different screw configurations, loadings, different feeding ports and mixing elements. Downstream feeding of glass fibers and milder screw configuration favor less breakage of glass fibers.
Mark Nulman, George Mozurkewich, Boris Khaykin, May 1999
A newly developed instrument, the Echometer measures the thickness of a barrier layer in multilayer polyethylene fuel tanks. Measurement by conventional pulse-echo ultrasound fails for thin barriers due to the large and highly frequency-dependent attenuation in polyethylene. The present instrument instead uses tone-burst excitation. Echo arrival time determines barrier depth, and frequency of minimum amplitude determines barrier thickness. Similar techniques may be applied to other layered plastic structures.
Techniques for the measurement of orientation of biaxially oriented films, sheets, and shapes using birefringence measurements based on oblique incidence of a polarized multiwavelength beam and FTIR spectroscopy in both transmission and reflection modes are presented. It is shown that sufficiently precise values can be obtained for biaxial birefringences and orientation functions, and that these techniques can be used for monitoring orientation processes as well as to control the quality of oriented articles.
A new HALS technology has been developed which provides for improved light stabilization of pigmented PC-ABS blends. Significant improvements in color stability and impact strength retention have been observed for PC-ABS systems subjected to accelerated weathering xenon arc test conditions. The new HALS technology is non-interacting with the PC-styrenic blend during melt phase extrusion compounding, as observed by capillary rheometry measurements of the stabilized polymers.
Mokhtar Aouina, Mosto Bousmina, Robert Guénette, May 1999
Non linear rheology of a mixture of two immiscible viscoelastic fluids undergoing high deformation flow was considered. Using Grmela's approach of compatibility of dynamics with thermodynamics, we derived a set of highly non-linear governing equations that take into account particles breakup, coalescence and the time evolution of the complex interface between the two mixture components. The proposed model recovers previous models such as Doi-Otha, Grmela and Ait-Kadi and Lee and Park models.
In this paper, some case studies are presented to illustrate the effect of processing/assembly conditions and part design on product failure. Fractography was intensely used in these investigations. Nevertheless, mechanical analysis was occasionally used. The first case illustrates the role of assembly conditions in product failure. The second case shows the effect of part design. The third case describes the combined contribution of processing/assembly conditions and part design in product failure.
Paul Engelmann, Eric Dawkins, Michael Monfore, May 1999
Achieving parts with maximum dimensional stability coupled with minimum cycle times, is a goal of most molders. Previous studies have shown that a majority of heat contained in the molded part is removed through the core of a mold. Application of high strength, high thermal conductivity copper alloys to core, cavity, and gate areas, has led to some revelations. These data shed new light on the effect of change in temperature vs. change in thermal conductivity.
84 countries and 60k+ stakeholders strong, SPE unites
professionals worldwide – helping them succeed and strengthening their skills through networking,
events, training, and knowledge sharing.
No matter where you work in the plastics industry value
you're a scientist, engineer,
technical personnel or a senior executive-nor what your background is, education, gender, culture or
age-we are here to serve you.
Our members needs are our passion. We work hard so that we
can ensure that
everyone has the tools necessary to meet her or his personal & professional goals.
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
Note: if there are more than three authors you may use the first author's name and et al. EG Brown, H. L. et al.