SPE Library

Protein based plastics were processed using anhydride chemistries in conjunction with glycerol to obtain modified soy protein polymers that were water stable. Formulations processed with chemistries such as maleic anhydride (MA) and phthalic anhydride (PTA) produced relatively water stable soy protein based plastics. Various formulations were produced by varying the anhydride content (3-10% w/w) in the final plastic mass. The respective mixtures were extruded and injection molded to form the samples for characterization. Formulations with 10% PTA were observed to have water absorption of only 19% after 24 hrs of water submersion as compared to 250% for the control formulation.

Temperature strongly affects the mechanical properties of pipe grade polyethylene (PGPE), such as strength and toughness. It is observed in this study that the temperature also affects the mechanisms of slow crack growth (SCG). A change in the mechanism of SCG is observed at certain temperature, named Crack Growth Transition Temperature (CGTT). The CGTT of the cold drawn (oriented) PGPE appears to be significantly higher than room temperature. At the temperature above CGTT the crack propagates discontinuously, stepwise, whereas at the temperature below CGTT the crack grows continuously. The slope of crack growth rate vs. stress intensity factor (SIF) is also noticeably different for temperatures above and below CGTT. The existence of CGTT implies certain limitations for commonly used extrapolation of SCG and lifetime data from the elevate temperature of an accelerated testing to the room temperature across CGTT.

In this article, polyamide 6(PA6)/Organoclay masterbatch were prepared by melt mixing, and then acrylonitrile-butadiene-styrene(ABS)/polyamide 6(PA6)(70/30,w/w) nanocomposites were prepared by the melt mixing of PA6, ABS and organoclay. The effect of organoclay platelets on dispersion of ABS/PA6/organoclay ternary nanocomposites had been investigated by wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM). Morphology analysis revealed that organoclay platelets were selectively dispersed and exfoliated in PA6 phase, but some were located in interface of PA6 and ABS phase.

A comprehensive study was conducted using three different types of extruder drive and motor configurations for a single screw extruder under identical conditions to compare the energy efficiency. Sound emission data was also measured and compared. Two systems of a conventional design used an AC or DC motor in combination with a mechanical gear reducer and were compared to a Direct Drive system using only a torque motor. The study showed that the Direct Drive system operated at higher energy efficiency and produced lower sound emissions compared to the AC & DC conventional systems. The results show that at the base speed of the drive train, the DC system consumed 10% more energy (kW) than the AC system, and the Direct Drive system consumed between 12 and 15% less energy than the AC system, depending upon the torque required.

More and more automotive structural applications are being developed with plastics / composites. Is the industry prepared for claims from our litigious and insurance-fraud fraught society - false or not - that a vehicle or component may have performed better in a crash situation if it had not been made of plastic / composite materials?

Newly developed isocyanate-based resin systems offer a combination of high thermal stability and toughness in a resin system that is easy to process and cure. This novel chemistry can be adapted to achieve low initial viscosity long open times and snap-cure profiles at elevated temperatures. The benefits of these resins lead to applications in a number of composite manufacturing processes.

The presentation will introduce a large network and cluster forming in Germany to provide a strong initiative that increases the use of composites in the automotive industry. Also discussed will be an overview of the technologies that have been selected by industry to be further developed to meet the requirements of the automotive industry.

With an uncertain economy creativity is necessary to uncover new stable RandD growth opportunities. One possibility may be to explore opportunities with the federal government. In 2009 the U.S. government increased the research and development spend 16% resulting in an unprecedented $171B budget. More than 60% of this funding is through contracts with business universities and non-profits. Whether the initiatives are with medical devices drug delivery alternative energy smart infrastructure applications improved transportation solutions or defense applications materials development is the backbone for maintaining the U.S. technical leadership position. By leveraging some of this funding a company can help mitigate risk in developing new technology products and markets.

One of the critical challenges for the structural underbody program was finding a way to attach the composite part to the steel structure in a high-volume automotive manufacturing environment and meet the complex requirements for crash. Weld bonding a combination of adhesive bonding and spot welding was selected as the primary joining method. A novel concept of bonding doubler steel strips to the composite enabled spot welding to the steel structure ensuring the compatibility with the OEM assembly processes. The structural performance of the joint including durability was assessed via analytical and physical testing under various quasi-static and dynamic loading conditions. This paper discusses the results of the experiments designed to generate key modeling parameters for finite-element analysis of the joint and presents the correlation between experimental and analytical results.

Shaped composite structures (specifically sandwich panels) are made by the combination of cold forming of thermoplastic foam core and thermoset processing of skins. This combination is ideally suited since the thermoset processing conditions are in a range that keeps the foamed core intact while simultaneously allowing the cold forming to be achieved. This technology affords a unique avenue to create sandwich and other composite structures that have curvilinear shape and 3-dimensionality via a single processing step that uses existing processing technology. Various process embodiments are described in this paper. This work discusses shaped foam composites and methods for manufacturing such composites.

The nanoscale graphene platelet (NGP) or graphene nano-sheet is an emerging class of nano materials and can be a low-cost alternative to CNTs and carbon nano-fibers (CNFs). Graphene’s applications as a nano filler in a composite material and as a functional ingredient in an energy system (supercapacitor battery and fuel cell) are imminent. However the availability of processable graphene sheets in large quantities is essential to the success in exploiting composite and other applications for graphene. This presentation begins by a review of the current processes for producing NGPs and their composites and is followed by a discussion on the new advances in materials processes and applications related to NGPs and their nanocomposites.

With the emphasis on alternative energy vehicles the need for materials that are not only structural but possess other desirable properties such as electrical conductivity thermal conductivity and barrier properties is increasingly important. Nanocomposites are opening up “windows of opportunity” to not only increase structural properties but also the non-structural surface electrical thermal and barrier properties. Graphite (graphene) nanoplatelets are a new cost-effective nanomaterial that can be used as an additive to polymers and composites to impart multifunctionality without the need for developing new or alternative processing and manufacturing methods. Examples in thermoset and thermoplastic systems -- with and without macro reinforcing fibers -- will be used to illustrate the potential of this nanomaterial.

This presentation focuses on a new silicate mesoporous nanoparticle technology which will bring significant productivity and performance benefits to both thermoset and thermoplastic moldings by increasing mechanical properties of neat resins imparting greater flame retardance and reducing processing cycle times. The particles’ intrinsic porous structure allows polymer chains to link the particles into a 3D network improving both strength and modulus at very-low particle loadings (typically 5.0 to 7.5 wt %). The technology does not require organic surface modification to achieve dispersion in the polymer matrix nor does it require retrofitting of processing equipment or modification in processing methods.

The present study examines the effects of bounded voids of different sizes and shapes on the strength and leakage of contour welds. Bounded voids are holes that are situated on the laser beam path, but whose melt flow is constrained from leaving the faying surface. The most significant result is that divot clusters can lead to quite high porosity in the interface, but even with that porosity, both high hydraulic burst test strengths and hermetic seals can be achieved.

A new class of cationic initiators, lanthanide triflates, has been studied in the cationic curing of DGEBA/PA mixtures. The reaction mechanism of the cationic curing of DGEBA/PA mixtures has been studied. The kinetics of this process has been evaluated by the Differential Scanning Calorimentry (DSC).The crosslinking degree is predicted from time and temperature of curing via the Gel-curve.

As new state-of-the-art flexible packaging technology is installed in its target markets and with processing costs under pressure to enable these technologies to ramp-up in 2011, surface pre-treatment technologies must become a key enabler relative to higher processing speed, wider widths, and requirements on inks and coatings to transfer and adhere to substrates at these speeds and widths. This paper presents evidence of new flexible packaging print performance opportunities using a new, revolutionary atmospheric plasma treatment (APT) technology.

Sandwich composites are being aggressively pursued as structural materials by various defense and commercial industries. These include navy, air force, army, automotive and sporting industries to name a few. The present work describes the compression and release response of a glass-fiber-reinforced polyester composite (GRP) under shock loading to 20 GPa. Shock experiments in GRP were performed at Sandia National Laboratories and the US Army Research Laboratory. GRP is a heterogeneous material.

Triallyl isocyanurate is a crosslinking agent in thermosets. By itself it is too brittle for practical uses. Several attempts to improve the properties of TAIC resins were unsuccessfully. PPE macromonomers have been reported to broadly enhanced performance of thermoset materials. Methacrylate-terminated PPE macromonomer was used to successfully enhance the performance of TAIC resins. The high Tg, increased toughness, low dielectric properties, low moisture absorption, and low density suggest utility in electronics.

The propensity of titanium dioxide to adsorb/desorb stearic acid can be evaluated through the adsorption isotherms. Heats of adsorption/desorption and quantities adsorbed/desorbed for stearic acid over a defined concentration range were measured via flow microcalorimetry for a variety of titanium dioxide pigments. The adsorption data were fitted to both a Langmuir and a modified form of the Freundlich adsorption model to obtain both capacity factors and intensity of adsorption parameters.

Many universities offer online or E-learning courses. Engineering Technology courses are typically more applied or hands-on and do not lend themselves to an easy transition to E-learning. There are some techniques that can ease the transition to successfully teaching engineering technology in the online arena.