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.
|= Members Only|
Engineering Aspects of Designing with Pultruded Carbon-Fiber Composites
Often times a composite component can be used to replace a metallic component providing a significant reduction in weight while providing little or no loss in strength or stiffness. For automotive engineers to further utilize composites in new applications it is important to understand the mechanical behavior of the material in all the critical loading directions. This paper focuses on the relevant tests necessary to characterize the mechanical properties of a pultruded carbon fiber composite material. The mechanical properties evaluated include tension compression interlaminar shear and fatigue testing in the fiber direction. Included is a discussion on key aspects of the testing in order to ensure reliable results. Also a set of design criteria is developed for the use of the material according to the measured properties.
Progress in Simulations for Short & Long Glass Fiber Thermoplastic Composites
The development and implementation of lightweight materials using fiber composites made by injection molding represents an engineering challenge due to the inability to control the fiber orientation in the required direction of mechanical demand. This paper presents progress in developing the capability of predicting fiber orientation in simple and complex flow geometries for highly concentrated short-glass-fiber suspensions and the extension of this approach to long-glass-fiber suspensions. Three important aspects included in the approach are the implementation of new theories to model fiber orientation the evaluation of model parameters from rheological experiments and the use of stable numerical methods based on discontinuous Galerkin finite-element method.
Initial Finite Element Analysis of Bond-Line Read-Through in Composite Automotive Body Panels Subject to Elevated Temperature Cure
The Automotive Composites Consortium (ACC) is conducting a multiyear project to develop a better understanding of the root causes of the visual surface deformation effect known as bond-line read-through (BLRT). BLRT is associated with bonded automotive Class A exterior panels and produces out-of-plane deformations on the order of 0.010- 0.050 mm. The ACC is studying the relationship between material and process factors and BLRT severity. The majority of the investigations have focused on SMC composite panels bonded with urethane and epoxy adhesives under elevated-temperature cure conditions and subsequently primed and topcoat painted. An investigation was conducted to see if analytical tools could predict the BLRT effect observed in the physical experiments. The present work describes the initial effort to model the BLRT effect using a finite-element analysis (FEA)-based approach. As part of this effort detailed threedimensional FEA solid models were developed for two idealized panel configurations: (a) an outer panel with an adhesive bead and drops and (b) a bonded outer/inner panel assembly. Results were predicted for the case of an idealized elevated-temperature adhesive cure condition using a steady-state thermo-elastic analysis. The predicted surface curvature results indicated a good qualitative agreement to available measurement data with the analysis over-predicting the BLRT severity.
Progressive Ply Failure Analysis for Composite Structures
Design engineers working with composite materials typically use a linear finite-element-analysis (FEA) solution and a failure-index calculation based on the current state of stress in the model. However this type of analysis can only provide accurate results up to first-ply failure because of the linear assumption. This presentation will show how nonlinear progressive-ply failure analysis can go beyond first-ply failure and simulate subsequent damage propagation through a structure. This allows engineers to make a better assessment of conditions for ultimate failure so they can optimize their designs and also provide guidance on the most appropriate physical-test program.
Analysis of Woven Glass Fiber Reinforced Thermoplastic Composites under Varying Strain Rates
Increased use of polymer matrix composites depend on having a deeper understanding of their mechanical response under varying strain rates. In this study the mechanical behavior of thermoplastic woven composites was investigated under varying strain rates between 5.0 x 10-5 s-1 and 5.0 x 102 s-1 using a screw-driven universal testing machine and an impact testing and imaging apparatus. Results yielded stress vs. strain curves over the full range of loading rates highlighting the strain-rate sensitivity exhibited by the thermoplastic composites. In addition the non-contact strain-measurement system revealed the effect of woven architecture on the mechanical behavior of thermoplastic woven composites.
THERMAL AND ELECTRICAL CONDUCTIVITY OF CARBON/LIQUID CRYSTAL POLYMER COMPOSITES FOR FUEL CELL BIPOLAR PLATES
One emerging market for thermally and electrically conductive resins is for bipolar plates for use in fuel cells. Bipolar plates require high thermal and electrical conductivity. In this study, carbon black and synthetic graphite were added to a liquid crystal polymer and the resulting composites were tested for thermal and electrical conductivity. Single filler composites containing 2.5 to 15 wt% carbon black and 10 to 75 wt% synthetic graphite were tested.
APPLICATIONS AND USES OF BYK-GARDNER HAZE-GARD PLUS
The haze-gard plus is a versatile instrument used to measure transparent characteristics for the plastics industry. From liquid raw materials to transparent films and sheet goods, the haze-gard plus is equipped with hardware to measure all. This paper will discuss the capability of the haze-gard plus and many of its diverse applications. Additionally, this paper will explore trends in data measured by the instrument, and what those data reveal about process.
NANOCOMPOSITE HIERARCHICAL STRUCTURES IN BLAST MITIGATION
Development of new, cost-effective materials with multifunctional characteristics is of critical importance to the aerospace, naval and homeland security industries especially in the areas of blast-ballistic impact mitigation and containment. Research efforts address this need by the use of nanocomposites in the design of hierarchical structures. Experimental data indicate that the vinyl ester nanocomposites of this study have enhanced cost-effectiveness, energy absorption, structural integrity and reduced smoke density characteristics
MODELLING OF MICROMOULDING
Computer modelling of micromoulding faces potential challenges relating to extreme process conditions in accurate descriptions of constitutive behaviour, and various model parameters, including heat transfer and thermal conductivity coefficients. We have some initial studies using in-house code (previously developed for fluid-assisted injection moulding). Progress in the development and application of this code will be discussed, and compared with experimental data from our laboratory, for simple geometry micromoulded components.
NUMERICAL SIMULATION OF ENHANCED MELT MODULATION APPLIED TO INJECTION MOLDING
A new approach to the control of melt modulation during injection molding processes has been investigated using numerical simulation. Based on a new development in melt flow control for cold runner base injection molding, numerical simulations were used to replicate the behavior of a melt flow with multiple control valves incorporated into a single runner system. It is demonstrated that a new control technique in which all valves can be controlled as a function of ram position allows the user to locally determine the amount of flow in each runner section more precisely.
A NEW NON-CONVENTIONAL CONCEPT FOR DESIGN OF SHEET EXTRUSION DIES
A new non-conventional die design for extrusion of plastic sheet is introduced. Instead of using a conventional sheet die design, such as the coat-hanger, or fishtail design, a completely non-conventional innovative die geometry was developed to achieve a highly uniform velocity distribution at the die exit (die balancing). While balancing the flow at the die exit, with the new die concept, the pressure drop in the die was reduced to about 29% of the original value, and the sharkskin instability was also eliminated from the extrusion process.
PROFILE EXTRUSION COOLING PROCESS OPTIMIZATION VIA SIMULATION
This paper deals with the optimization of the cooling process in profile extrusion through the use of simulation and its application on a real process. Firstly, it will be shown how the simulation is calibrated" with respect to the heat transfer conditions in the different parts of the cooling process to get realistic results. This leads to the development of a novel simulation approach for hollow profiles. It will also be shown how the improved understanding of the cooling was applied towards improving the process productivity."
POSS DISPERSANTS AND FLOW AIDS FOR HIGH TEMPERATURE THERMOPLASTICS
Polyhedral Oligomeric Silsesquioxanes (POSS) were tested as processing aids and dispersants in polyetheretherketone (PEEK). Up to a 500% increase in melt flow index was observed in neat PEEK with no noticeable change in mechanical properties. POSS silanols were used as filler dispersants and showed effects similar to stearic acid but with much greater thermal stability. Thermal analysis showed that POSS is stable up to 400 ?øC. These attributes compare favorably to commercial surfactants, which cannot survive similar processing temperatures.
MODELING THE FUTURE: MANAGING THE TOOLS THAT ENABLE INNOVATION
As the global economy evolves toward an increasingly complex future, businesses are searching for a strategy toensure long-term stability. The best strategy, in many cases, may simply be to learn how to change faster than the world changes around you ' to innovate faster than your competitors. To succeed at this, companies need to make effective choices on where to invest scarce resources. Good tools lead to good results, good decisions, and compelling products. So what defines a good tool?
THE DEVELOPMENT OF INTERNAL WATER COOLING TECHNIQUES FOR THE ROTATIONAL MOULDING PROCESS
This paper reports the findings from internal mould cooling trials using a water spray configuration applied at various internal mould air temperatures from 120?§C to 180?§C for an aluminium mould. To achieve maximum benefit in terms of cycle time reduction, internal mould water cooling was used in conjunction with a combination of external forced air and water cooling. Savings in cooling times of up to 30% were achieved compared to conventional external only forced air cooling.
NOVEL DESIGN METHODOLOGY FOR PLASTIC GEARS
This paper presents a unique methodology for designing plastic gears to enhance strength and life while allowing size and wear reduction. This new approach, trade named Direct Gear Design (DGD), optimizes the gear geometry to impart superior drive performance versus traditional gear design methods. This paper explains this alternative approach and demonstrates its effectiveness for plastic gear applications.
MICROSTRUCTURAL STUDY OF GRAPHITE FILLED POLYETHYLENE TEREPHTHALATE NANOCOMPOSITES
Nanographite (NG) produced from milling by high pressure homogenisation was compounded in a Twin Screw Extruder with Polyethylene Terephthalate (PET). The resultant PET-NG pellets, produced in a variety of compositions (0-2% w/w) were subjected to Rheology, DSC, Electrical Resistivity and Tensile Analysis. No nucleation of the PET was noted even at low concentrations - 0.1%w/w NG. Viscosity of the blends was increased with addition of NG thus allowing for greater continuity of the fibres spun at the faster haul off rate.
LEAN SIX SIGMA AND INNOVATION CAN SYNERGISTICALLY FIT WITHIN PRODUCT DEVELOPMENT
In a June, 2007 Business Week article the author outlined the issues 3M faced when integrating the disciplined Six Sigma methods and tools into their innovation-oriented culture. This paper suggests the Lean Six Sigma and innovation are linked as part of an evolutionary journey and that DMAIC and Design for Lean Six Sigma are key first steps for enabling effective, efficient and predictable delivery of innovative products first to the marketplace.
CFRP LINER QUALITY CONTROL FOR REPAIR OF PRESTRESSED CONCRETE CYLINDER PIPE (PCCP)
Presented in the paper are the most recent methods developed for the safe and reliable installation of carbon fiber liners. Discussion of mobilization concerns, material requirements and related verification testing, critical paths for installation, and inspection methods for both during and post installation are provided. The installation of carbon fiber liners has many critical steps. Development of a usable quality control standard for material selection, design, installation, and inspection is critical for a successful installation.
MELT PROCESSABLE, FIBERGLASS REINFORCED, HIGH HEAT THERMOPLASTIC POLYIMIDES
The addition of fiberglass to a new high temperature (Tg 267?øC), thermoplastic polyimide yields blends with enhanced performance (these blends fall under US export control restrictions). High stiffness and low CTE make these good candidates for metal replacement. Their facile melt processability on standard injection molding machines makes them suitable for electrical connector applications. The resins are also inherently flame retardant. Physical properties, as well as processing conditions for injection molding, are discussed and compared to unfilled materials.
We're sorry, but your current web site security status does not grant you access to the resource you are attempting to view.
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.
If you need help with citations, visit www.citationmachine.net