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
A STUDY ON THE EFFECT OF NAN-O-SIL ASD ON COOLING TIME REDUCTION
A cooling time study was performed to show the benefits of the Nan-O-Sil ASD additive. Through the use of an infrared camera, the parts temperatures can be examined. The parts warpage was also measured and compared to the neat resin for each material. The materials used in this study were PP, PBT - 33% glassfilled, Nylon 6/6 ƒ?? 33% glass-filled, ABS, and HDPE. Through the use of the Nan-O-Sil silica dioxide additive, cycle time can be reduced by as much as 70% in semi-crystalline materials.
THE RAPID ROTATIONAL FOAM MOLDING PROCESSING ADVANTAGE
Over recent decades the rotational molding process has evolved into a technology that advantageously allows for creating a cellular structure, i.e., a distinct foamed layer or core within the interior of hollow moldings that can be encapsulated entirely within integrated solid skin boundary layer. However in order to survive the competition, its processing cycle time and the energy consumption must be reduced to levels not conceivable with the prior art, without compromising product quality.
STUDY OF ULTRASONIC WAVE EFFECT ON POLYPROPYLENE IN SOLUTION
The effect of ultrasonic radiation on polypropylene insolution was studied, applying different radiation doses(50 - 150 watts) for different exposure times from 10 -20 min., observing that for low energy and shortexposure time the change in molecular weight wasminor compared to greater doses and greater exposuretimes. In addition, changes in the temperature ofcrystallization and thermal properties were observedresulting from the action of the ultrasonic radiation onthe polymer .
THE BUILDING BLOCKS OF INNOVATION: DELIVERING COMPETITIVE ADVANTAGE THROUGH CREATIVE PEOPLE
The goal of innovation should be to create sustainablecompetitive advantage'not just create inventions withlittle or no market value. In order to compete, the productof service being offered must provide value to theconsumer, be differentiated from competitors' offerings,and be protected from imitation. Frequently employeesand managers involved with product development are notaware of the broader picture and the essential elementsnecessary to create innovative products.
SINGLE SCREW EXTRUSION OF BIOBASED AND BIODEGRADABLE POLY (HYDROXY BUTANOIC ACID) COPOLYMERS
The complex time and temperature dependent melt rheology of Poly (Hydroxy Butanoic Acid) or PHB copolymers is an important consideration for their extrusion. In this effort, we report the influence of temperature profile and screw design on the process stability, melt temperature, melt pressure, output rate and molecular weight retention using highly-instrumented commercial-scale extruders with smooth-bore feed sections. One important outcome of this investigation is screw design guidelines for the extrusion of PHB copolymers.
INTERACTION OF HALS AND COLORANTS: PART II
A series of colorants including yellows, reds, blues and greens have been evaluated when processed with monomeric and oligomeric HALS in PP and HDPE. Comparisons have been done in masstone and tint looking at effects on color shift and strength.
FLUOROPOLYMER PROCESS AIDS: THE EFFECT OF PROCESSING CONDITIONS
The understanding of the coating process by fluoropolymer processing aids has been of great importance to the removal of sharkskin phenomena. The current work examines the effect of fluoropolymer domain size, shear rate and viscosity ratio. Previous work demonstrated the superior performance of large-particle processing aids and the deposition in the region of the die exit, using in-sit measurements. The current work expands those findings by presenting 1) the effect of the viscosity ratio on the deposition rate on the wall, 2) the reduction of sharkskin, and 3) the reduction of the pressure drop.
ADVANCEMENTS IN STACK MOLDING TECHNOLOGY
Stack molding can be an attractive way to improve the output and efficiency of an injection molding machine. However, molding parts simultaneously at multiple parting lines can introduce new challenges to both the mold maker and the molder. Mold complexity, residence time, and cavity filling are some of the key considerations. Advancements in the melt transfer technology that bridges the machine nozzle and the hot runner melt distribution system have addressed some of these challenges. The features, configurations, and technologies employed will be examined.
SYNTHESIS, CHARACTERIZATION, AND DEGRADATION OF BIOPLASTICS FROM RENEWABLE POLYFUNCTIONAL MONOMERS
Bioplastics were produced by the copolymerization of 1,3-propanediol (PDO) with malonic acid (MA) and with itaconic acid (IA). Effects of reaction temperature and time were examined on the yields and molecular weight (MW) distributions. The resultant bioplastics were characterized using FTIR and 1H NMR and were found to contain anhydride, ester, and ether backbone functional groups. Hydrolytic degradation of the PDO-MA copolymer was also studied as a function of time, temperature, and pH.
REDESIGN OF PLASTICATING UNITS: TWO INDUSTRIAL CASES
This paper presents the redesign of two polymer processing lines involving, in the first case, a 90 mm screw design with a barrier zone and an elongational mixing unit for the manufacturing ofPP double wall sheet. A new flat die geometry was also required. The new components needed to solve homogeneity problems and grammage variations.
In the second case, a 50.8 mm- screw design with a barrier zone and a removable mixer was required for the production of thin wall containers using a 150 ton injection molding machine. A ring non-return valve was designed to assure parts reproducibility and to avoid leakages.
VOICE OF THE CUSTOMER: ITS IMPACT ON INNOVATION AND COMMERCIAL SUCCESS
This article focuses on obtaining custome rrequirements as a part of the product development process. A common mistake in product development is to begin development without obtaining the Voice of the Customer (VOC). This leads to products that are likely to be financially unsuccessful, such as the Segway'. Companies that take the time to research customer requirements can develop fiscally successful products. An example of this is the patented plastic resealable packaging developed by Kraft Foods.
POLYPHENYLENE ETHER MACROMOLECULES. VII. PERFORMANCE IN T-BUTYL STYRENE/DIVINYL BENZENE RESIN SYSTEM
The optical quality of plastic microlens arrays is very
sensitive to the presence of residual stress induced during
the molding process. In this paper, the effects of aperture
structures on the maximum value of residual stress have
been investigated. The results from numerical simulation
indicate that the geometrical configuration of the aperture
can profoundly influence the levels of residual stress in
precision injection molded microlens arrays. The five
aperture structures present similar trends to the change of
mold temperature, packing pressure, packing time and
cooling time. With regard to melt temperature and flow
rate, the trends of maximum value of residual stress
exhibit differences with different aperture structures. It is
shown that the cooling time has the least effect on the
residual stress. The aperture structure of microlens arrays
should be considered the effects on final quality of product
at the initial stage of optical design.
EFFECTS OF APERTURE STRUCTURE ON RESIDUAL STRESS OF PRECISION INJECTION MOLDED MICROLENS ARRAYS
The optical quality of plastic microlens arrays is very sensitive to the presence of residual stress induced during the molding process. In this paper, the effects of aperture structures on the maximum value of residual stress have been investigated. The results from numerical simulation indicate that the geometrical configuration of the aperture can profoundly influence the levels of residual stress in precision injection molded microlens arrays. The five aperture structures present similar trends to the change of mold temperature, packing pressure, packing time and cooling time. With regard to melt temperature and flow rate, the trends of maximum value of residual stress exhibit differences with different aperture structures. It is shown that the cooling time has the least effect on the residual stress. The aperture structure of microlens arrays should be considered the effects on final quality of product at the initial stage of optical design.
PRESSURE/FLOW PERFORMANCE OF VISCOELASTIC POLYMERIC MELTS IN CYLINDRICAL CHANNELS
One of the most widespread practical methods of polymer processing is the extrusion method that is based on pressing a polymeric melt through channels of the molding tool which have different geometrical crosssections.The basic performance of extrusion is based on the pressure/flow performance which sets functional correlation between volumetric flow rate of a polymer medium pressed through a molding tool and created pressure drop. Arguments of this correlation are the rheological parameters of polymer and the geometrical characteristics of the channel in which the polymeric melt flows. In this paper a viscoelastic model with a corrected strain energy function is implemented. The comparison of revealed theoretical expression in this paper with the experimental data for flow of polymeric melts in cylindrical channels with various cross-sections demonstrates a good convergence over a wide range of pressure.
PREPARATION OF POLYPROPYLENE-ORGANOCLAY ANOCOMPOSITES: EFFECT ON THERMAL, MORPHOLOGICAL AND VISCOELASTIC PROPERTIES
In the present work, PP-clay nanocomposites were prepared and the effect of nanoclay content on the properties of the nanocomposite was studied. polypropylene/surface modified clay nanocomposites were prepared via melt blending method in a laboratory mixing extruder (LME) using commercial polypropylene (PP) and nanoclay masterbatch in concentrations ranging from 5 to 15 wt%. The structure and thermal-mechanical features of the nanocomposites were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) as well as dynamic mechanical analyzer (DMA). For all nanoclays loadings, SEM shows homogeneous dispersion of the nanoclay in the polymer matrix. The DSC curves show a 15% increase in heat of fusion (crystallinity content) up to 5% wt nanoclay loading but then decreased at higher loadings. This is attributed to the nucleating role of the silica particles at low nanocaly content; however, at relatively high loadings, the presence of excessive number of silica particles hinders the motion of polymer chain segments and thus, retards crystal growth. The temperature sweep reveals an increase in storage modulus (G') with increasing nanoparticles content due to the restricted motion of the PP chains as a result of the interaction between the nanoclay and the matrix that depends on the interfacial area shared between the PP and the nanoclay. As the interfacial area increased, the interaction increased, and hence the chains were more restricted. Besides, the estimation of the softening temperature as well as the slope of the flat region of the curves show that the addition of the nonmaterial increases the thermal stability of the nanocomposites as compared to the neat polypropylene.
COMPARING THE RHEOLOGICAL PROPERTIES OF SELECTED POLYOLEFINS USING ROTATIONAL RHEOMETRY TO THOSE OBTAINED FROM MELT FLOW INDEX; A TRILOGY
This paper is the third in a series which was previously presented in ANTEC08(1) and ANTEC09(2). These papers showed different applications of the melt flow index, MFI, equipment. These applications included the temperature and/or shear sensitivity, extrudate (die) swell, melt density, melt strength, thermal degradation, and processability of polyolefins. In the current paper, the relation between the measured values via MFI equipment will be related to the viscoelastic properties measured by rotational rheometer. For example, the extrudate swell will be compared to the elastic properties of some polyolefins. Additionally, the processability will be analyzed via the relationships of viscosity, shear rate, and temperature. Moreover, some molecular structure parameters are indentified and then are used to interpret some of the properties measured by the MFI equipment.
HOW TO STRUCTURE FUND & FINANCE A CLEAN TECHNOLOGY VENTURE: TRENDS FOR DEVELOPING INNOVATIVE TECHNOLOGIES IN A “GREENING” MARKETPLACE
The plastics industry and related markets represents a substantial opportunity for entrepreneurial and intrapreneural activity ƒ?? particularly in the emerging Clean Technology space. Investment into clean technology is one of the fastest growing markets. However the plastics industry is currently lagging in its ability of startup technologies to tap into those funds. In order to increase access to capital the plastics industry must continue to foster innovation through its development of clean technologies companies. These companies will be built on entrepreneurial and scientific talent broad market opportunities and cutting edge technologies. There are many challenges faced by clean technology companies but with the right foresight and planning success can be achieved and new technologies commercialized.This presentation will provide insights into the clean technology marketplace and insights into successful companies within the plastics industry. In addition weƒ??ll explore what new and emerging companies will require in order to tap into investment dollars and advance their technologies.
UNDERSTANDING THE CONSEQUENCE OF DUCTILE-TO-BRITTLE TRANSITIONS IN A PLASTIC MATERIALS FAILURE
The goal of a failure analysis is to identify the mode and cause of the failure. The assignment of the failure mode is often straightforward through fractographic techniques.Comparatively the determination of the cause of the failure is often less apparent but required if proper corrective action is to be carried out. Many times the cause of the failure is related to factors that produce a ductile-to-brittle transition within the material. These factors are associated with material processing design and service issues. This paper addresses the failure modes of thermoplastic resins in regards to a ductile-to-brittle transition as the cause of the failure.
UNDERSTANDING THE CONSEQUENCE OF DUCTILE-TO-BRITTLE
TRANSITIONS IN A PLASTIC MATERIALS FAILURE
The goal of a failure analysis is to identify the mode and
cause of the failure. The assignment of the failure mode is
often straightforward through fractographic techniques.
Comparatively, the determination of the cause of the failure
is often less apparent, but required if proper corrective
action is to be carried out. Many times the cause of the
failure is related to factors that produce a ductile-to-brittle
transition within the material. These factors are associated
with material, processing, design, and service issues. This
paper addresses the failure modes of thermoplastic resins in
regards to a ductile-to-brittle transition as the cause of the
failure.
MOST CRITICAL STEPS FOR REPLACING METAL WITH HIGH PERFORMANCE ENGINEERING POLYMERS (HPEP) FOR UNDER-HOOD APPLICATIONS
In today's competitive world, speed to the global market plays a major role in overall success of a conversion program. When it comes to metal to plastic conversion, most designers still think in terms of direct part-for-part replacement which adds both cost and time to the overall development cycle. In order to expedite the conversion process, there have been significant developments in polymer science, plastic processing and simulation technologies. The new range of HPEP compounds offers the best price-performance options, whereas the latest wave of simulation technology provides a reliable method to predict part performance.
This paper talks explains the importance of understanding material properties and the re-designing for plastics to reduce product development cycle time. It also discusses the new development in simulation technology, commonly known as computer aided engineering (CAE) integration.
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