SPE Library
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.
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Conference Proceedings
Case Study: Synergy Of Industrial Design And Plastics Engineering Applied To The Design Of A Hyperspectral Imaging Camera
Innovative products are recognized by designs which have creatively applied a new technology or when a common utilitarian product is been reinvented to reenergize its market appeal. This case study will describe the development of a unique medical device based on the interdependency of industrial design and plastics engineering to yield an award-winning design that could only be attained by a comprehensive integration of these two disciplines.
Effect Of Long Chain Branching On The Rheology And Flame Properties In Polycarbonate Resins
It is known from literature [1, 2] that the rheological properties of polymer melts are influenced by the degree of long chain branching (LCB). Therefore, it is very important to understand the influence of LCB on the solid-state properties to help improve material design for unique applications. The objective of the present study is to demonstrate the use of extensional rheology as a tool to understand FR performance pertaining to dripping. Further, we also demonstrate the synergistic role of LCB in polycarbonate resins for improving FR performance.
The Effect Of Boundary Conditions, Material Parameters, And Rotational Flow On Center Layer Thickness And Stability In Tri-Layer Annular Flow
A tri-layer simulation study utilizing ANSYS Polyflow was conducted in an attempt to understand the effect of the material parameters, namely viscosity and elasticity ratios, on center layer thickness and stability under annular flow. During the study, it was determined that inflow boundary conditions also had a considerable impact on the thickness trends observed. Results of two different inflow boundaries and four material parameter conditions are presented and discussed within.
Thermoplastic Elastomers: An Overview
Thermoplastic elastomers (TPEs) can be defined as a class of special type of polymers, which exhibit hybrid behavior of thermoplastics and rubbers [1-3]. They can be processed like thermoplastics and at the same time can perform like rubber over a broad use temperature range. The thermoplastic elastomers’ sector has expanded at a compound annual growth rate of 5.4% since 2012 to reach 4.24 million tonnes in 2017. Even though TPEs are an increasingly mature market, Smithers-RAPRA research shows that this growth would continue at a rate of 5.5% across the next five years to hit 5.53 million tonnes in 2022 [4].
Advancements In Decorative Pvd Chromium Coatings For Polymer Substrates
Environmentally friendly PVD on plastics for automotive decoration are rapidly gaining acceptance. They replace galvanic processes, eliminating their toxic process and waste stream for plating on plastic (POP). VTI’s SuperChrome has already received approvals from Daimler and PSA. Part design for PVD, polymer selection, and available range of color and appearance will be discussed. OEM specifications based on testing, unique to PVD and distinct from both electroplate and painted surfaces are required.
Biopolyesters For Agriculture: Permeation And Degradation For Controlling Chemical Release
Biobased and biodegradable polymers are well suited to agricultural applications where hey can be left in the field to degrade into innocuous byproducts. These polymers are lso widely used for biomedical controlled release. However, the properties and egradation rates are not necessarily suitable for the environmental conditions and utrient demand of plants. In this work, two different biodegradable polyesters are repared and contrasted in terms of their diffusion and degradation rates.
Characterization Of Recycled Polymer Compound By Thermal Analysis
Thermal analysis techniques, such as DSC, TGA, DMA and TMA are commonly used in polymer characterization. In this paper these techniques with the help of Identify, a database search software, are used to characterize recycled polymer compounds for preselection.
Heat Treated Bamboo Fiber For Sustainable Polymer Blends
This study evaluated polymer composites produced from recycled PA6 and PP blend with bamboo fiber. Blends of bamboo fiber were used as received, as well as heat treated. It was observed that heat treatment at 160ºC/180ºC improved the tensile and impact properties of the composite compared to untreated fiber composite. The goal of the study was to produce a thermally stable, lightweight composite suitable for under-hood applications.
Injection Molding Processing Of Bio-Based & Bio-Filled Resins
Injection molding with bio-based and/or bio-filled resins is becoming more commonplace as the plastics industry responds to the environmental and sustainable desires of the economy. This paper presents some intricacies of part design and processing developments when injection molding with bio-based and bio-filled resins.
Sustainable Polyamide Compounds
Value added cost effective and sustainable polyamide 6 and 66 compounds were prepared by incorporating 10 to 30% recycle content without significantly sacrificing physical properties. This was achieved by reactive extrusion with chain extending additives to couple low molecular weight chains in recycled feed streams. Three types of chain extending additives with different functionalities were evaluated in this study. Based on the performance and cost, one of the chain extending additive was identified as the best option.
The Importance Of Chemical Stabilization In Recycled Material For Corrugated And Conduit Polyolefin Pipes
Much attention has been given to stabilization packages for polyolefin pressure pipes over the past couple decades, however corrugated and conduit pipes have generally been ignored with respect to more robust stabilization packages. Certain groups such as the Florida Department of Transportation have set rules establishing oxidative resistance in HDPE corrugated pipes, but few others have followed this example. A discussion of the simplicity and importance of pipe resin stabilization as well as examples from stabilized pipes will be covered.
Strain-Hardening Behavior In Transient Elongational Viscosity For PP Containing LDPE
Transient uniaxial elongational viscosity for binary blends composed of conventional isotactic polypropylene with linear structure (PP) and low-density polyethylene produced in an autoclave reactor (LDPE) was evaluated. The blends were prepared by melt-mixing to make PP as the continuous phase. Although LDPE exists as dispersed droplets, it was found that the LDPE addition provides the strain-hardening in transient elongational viscosity for PP. During elongational flow, LDPE droplets dispersed in the PP matrix were deformed in the flow direction because the viscosity of LDPE used is lower than that of PP. As increasing the strain, however, the deformed LDPE droplets act as rigid fibers due to its strain-hardening behavior. Consequently, the PP matrix located between the fibrous LDPE droplets is deformed greatly during elongational flow. This excess localized deformation is responsible for the strain-hardening in the transient elongational viscosity for the blends.
A Studey Of The Thermo-Oxidative Degradation Of Glass-Fiber Sizings At Composite Processing Temperatures
Although not fully understood it is well recognized
that optimal working of glass fiber sizings is necessary to
maximize the performance of glass fiber reinforced
polymer composites. However, test results indicate that
the performance of polypropylene compatible glass fiber
sizing can be significantly compromised by thermooxidative
degradation at normal composite processing
temperatures. Results obtained using TGA, DSC,
microbond adhesion measurement and composite
mechanical testing indicate that a significant reduction in
composite performance is directly related to a loss of
fiber-matrix adhesion caused by thermal degradation of
some of the principal sizing components.
Pellet Heat Transfer Model With Crystallization Kinetics Using Finite Element Method
An advanced Finite Element Method (FEM) based transient pellet heat transfer model with crystallization kinetics is developed to better understand the cooling requirements for a clean pellet cut during polyethylene manufacturing. This model considers conduction/convective heat transfer in and around a polymer pellet with enthalpy changes, considering a pellet of spheroid shape surrounded by a cooling water off constant temperature. The model further accounts for the changes in stiffness or elastic modulus obtained from rheological measurements using multi-wave oscillatory test during cooling/crystallization stages of the polymer.
A series of simulations were performed to understand the effects of several parameters such as resin architecture/formulation, crystallization kinetics, initial molten pellet temperature, water inlet temperature, water to pellet ratio (i.e., water flow rate) and pellet dimensions. It was found that for resins of similar Melt Index (MI) and density, the differences in structural characteristics can significantly affect the pelletization process and pellet cut. This model may serve as a strong tool for efficient design, operation and troubleshooting of downstream equipment (e.g. pelletizer, cutter, Pellet Conveying Water (PCW) system, stripper etc.) through understanding of the effects of molecular architecture of the resins and/or optimization of various processing and operating conditions.
Modeling Of A Foamable Mixture Flow Through A Heat Exchanger And Relation To Foam Inhomogeneities
To understand transient cell size patterns in extruded foams, computational fluid dynamics (CFD) modeling was used to map temperature, velocity, and pressure in a foamable mixture traveling through a simplified heat exchanger geometry. A comparison was made between cases of clean and partially plugged heat exchanger device. The analysis revealed that the predicted inhomogeneities of temperature, pressure, and velocity do not correlate with the observed cell size pattern. However, residence time maps showed clear similitude with the observed pattern, in particular for geometries simulating partial plugging of the individual heat exchanger channels.
Development Of Thin Film Sensors: The Influence Of Layer Variation On The Measurement Quality For Inline Melt Temperature Measurements
Temperature is an important criterion, on which many process variables depend. Therefore, temperature measurement plays a major role in various technical areas, from system monitoring to process improvement. It is often of particular interest to detect temperatures on components and tools during the production process in order to react as quickly as possible to undesired temperature changes. Otherwise, these temperature differences result in uneven melt viscosity and cause defects, component distortion and surface degradation. Also, measuring the temperature within tools via conventional sensors is often not possible due to the risk of causing defects within the product and the negative temperature influence of the tool walls. In order to determine an appropriate inline temperature of the actual melt temperature without interrupting the melt flow, this paper shows various steps of a thin-film thermocouple development. Different custom-made thin-film thermocouples are evaluated based on their long-term stability, thermal insulation capability and response time.
Viscoelastic Effect On The Warpage Prediction Accuracy And Experimental Validation In Injection Molding
Recently, many Internet of Things (IoT) have been proposed and developing to industry and markets. They drive people to design and create an automatic production environment. Before executing automatic production, how to retain good quality for injection products is one of the crucial factors. To retain good quality, it is commonly using CAE to assist from original design to revision and to fabrication. However, even using CAE, it doesn’t guarantee the quality factors obtained from CAE can be applied to real experiments.
In this study, first we have focused on what the major factors were to cause the difference between CAE simulation and real testing on the warpage quality. We further applied numerical simulation to decouple what the main driving forces are to make the difference. Results showed that in the original process setting, the warpage difference between simulation prediction and experiment is 0.34 mm. We further found out the major difference came from the injection filling response is too slow (delayed about 29%) and packing pressure is insufficient (23% lower) in real experiment comparing to simulation prediction. Moreover, after calibrate the machine response the warpage difference between simulation prediction and experiment is reduced to 0.12 mm. We also studies viscoelastic (VE) effect and found the VE has a great impact on the warpage in this case study. However, the influence of VE is great or not for other cases that should be further investigated.
Long-Term Analysis Of Surface Coatings For Their Wear Resistance In The Injection Moulding Process
The coatings of tools and moulds used in plastics processing, especially in extrusion and injection molding, are of importance in various respects. In most cases, coatings serve to reduce wear and increase the service life and maintenance intervals of the molds during production. Such anti-adhesive and corrosion-protective coatings can be used to produce high-quality products that stand out from those of other competitors.
Conventional surface coating techniques have so far led to very good coating properties, such as the reduction of wear, and guarantee anti-adhesive behaviour between the plastic melt and the metallic mold surface. However, in addition to their limited applicability for micro- or nanostructured surfaces, such processes are often a significant cost factor due to their complex application processes. Moreover, it is difficult to remove damaged inorganic coatings.
This paper presents an investigations method that enables a study of the long-term stability and wear resistance of coatings.
Investigating The Effect Of Temperature And Frequency On Dielectric Properties Of Polyvinylidene Fluoride (Pvdf) For Its Application In A Skin Temperature Sensor
Monitoring physiological parameters of crew on spaceflight missions is of upmost importance for long term microgravity expeditions. Body temperature is one particularly important parameter, as changes in thermoregulation or circadian rhythms may be connected to decreased mental and physical performance if it deviates significantly from 37° C. In this paper, the effects of temperature and frequency on the dielectric properties of 3D printed polyvinylidene fluoride (PVDF) discs were studied. The objective is to incorporate the polymer into an electromagnetic resonating sensor to measure skin temperature. The temperature dependent dielectric permittivity of the polymer interacting with the electromagnetic field of the sensor will result in a resonant frequency shift that can be correlated to report body temperature in a noninvasive, lightweight, and wirelessfashion.
Direct And Converse Piezoelectric Behavior Of Three-Dimensionally Printed Polymer Without Filler Or Poling, With Relevance To Monitoring And Actuation
The direct and converse piezoelectric effects are useful for stress/strain monitoring and actuation, respectively. We report these effects in 3D-printed (bottom-up stereolithography, 26-46 μm layer thickness) polymer without filler or poling, using a polymer (unmodified photopolymerizable resin) that is not known to be piezoelectric. This means that the piezoelectric behavior is inherent to the printed material. The inherent behavior is due to the process-induced 2D in-plane shear stress encountered by the resin during printing and the consequent 2D in-plane molecular alignment. The smaller is the layer thickness, the greater is the shear stress, the more is the molecular alignment, and the stronger is the piezoelectric effect. The out-of-plane piezoelectric coupling coefficient is up to 0.43 pC/N - higher than values previously reported for 3D-printed polyvinylidene fluoride, which is known to be piezoelectric.
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