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
OPTICAL COATING APPLICATIONS FOR CONSUMER AND INDUSTRIAL POLYMER DISPLAYS
North American Coating Laboratories provides
vacuum- and dip-applied thin film coatings to polymer
manufacturers and suppliers across numerous market
segments. These coatings are predominantly deposited on
polycarbonate and acrylic substrates used in a wide variety
of applications. In many cases such vacuum-applied
coatings as broadband anti-reflective treatments and
polysiloxane dip-applied treatments improve the optical
quality of polymers as well as extend the lifecycle of
polymers in the field. This presentation will focus on the
full spectrum of thin-film coatings that are currently being
applied to polymers resins and displays.
OPTICAL COATING APPLICATIONS FOR CONSUMER AND INDUSTRIAL POLYMER DISPLAYS
North American Coating Laboratories provides vacuum- and dip-applied thin film coatings to polymer manufacturers and suppliers across numerous market segments. These coatings are predominantly deposited on polycarbonate and acrylic substrates used in a wide variety of applications. In many cases, such vacuum-applied coatings as broadband anti-reflective treatments and polysiloxane dip-applied treatments improve the optical quality of polymers as well as extend the lifecycle of polymers in the field. This presentation will focus on the full spectrum of thin-film coatings that are currently being applied to polymers, resins and displays.
RISING TO THE HALOGEN CHALLENGE IN FLAME-RETARDANT ENGINEERING PLASTICS
Halogenated additives have long been used toenhance the flame-retardant properties of plastics.Recently, after many years of growing concern over theenvironmental and human impact of the disposal ofcertain halogen-containing products and theirincompatibility with recycling operations, leading globalelectronics manufacturers have begun moving to eliminateor sharply reduce the use of certain halogen-containingingredients in their products. DuPont is meeting the needsof these and other environmentally consciousmanufacturers with a growing range of engineeringpolymer grades using non-halogenated flame retardantsystems. This paper shows that they can fulfilldemanding requirements for strength, toughness, hightemperature resistance and processing efficiency.
COMPARISON OF SERVO-DRIVEN ULTRASONIC WELDER TO STANDARD
PNEUMATIC ULTRASONIC WELDER
Ultrasonic welding is one of the most widely used
processes for bonding polymers valued for its speed
flexibility and low cost. Recently there has been a call for
more controlled and consistent welding processes
especially in the medical field. Dukane has worked to
meet this demand through the development of a new iQ
series Servo-Driven Ultrasonic Welder with MeltMatch™
technology.
Careful comparison detailed here has shown that the
servo-driven welder can provide more consistent results
than the standard pneumatic welder can. The newly
developed welder also offers a number of user friendly
ergonomic features superior Graphic User Interface with
Ethernet connectivity (iQ Explorer) as well as more
accurate process control capabilities.
COMPARISON OF SERVO-DRIVEN ULTRASONIC WELDER TO STANDARD PNEUMATIC ULTRASONIC WELDER
Ultrasonic welding is one of the most widely used processes for bonding polymers, valued for its speed, flexibility, and low cost. Recently there has been a call for more controlled and consistent welding processes, especially in the medical field. Dukane has worked to meet this demand through the development of a new iQ series Servo-Driven Ultrasonic Welder with MeltMatchƒ?› technology.Careful comparison, detailed here, has shown that the servo-driven welder can provide more consistent results than the standard pneumatic welder can. The newly developed welder also offers a number of user friendly ergonomic features, superior Graphic User Interface with Ethernet connectivity (iQ Explorer) as well as more accurate process control capabilities.
FLOW INDUCED CRYSTALLIZATION OF POLYMERS IN EXTENSION
In this paper the effect of uniaxial extension on the crystallization of a linear low-density polyethylene is examined by using rheometry with differential scanning calorimetry (DSC). Uniaxial extension experiments were performed at temperatures below and above the peak melting point of the polyethylene in order to characterize its flow induced crystallization behavior at extensional rates relevant to processing. The?ÿ degree of crystallinity of the stretched samples was quantified by DSC i.e. by analyzing the thermal behavior of samples after stretching. Analysis of the tensile strain hardening behavior very near the peak melt temperature revealed that crystallization depends on temperature, strain and strain rate. In addition it was revealed that a very small window of temperatures spanning just 1-2 degrees Celsius can have a dramatic effect on polymer crystallization.
EFFECT OF ANNEALING ON FAILURE BEHAVIOR OF A TRANSPARENT
NYLON UNDER HIGH SPEED IMPACT
The effects of temperature exposure as well as annealing
TROGAMID CX-7323 (CX) on its mechanical and
ballistic impact properties were examined. CX generally
exhibits ductile failure upon ballistic impact. However
upon complete penetration the impact failure behavior
occasionally changes depending on the projectile type
and size. Notched izod impact test results revealed that
annealing CX significantly increased the notch
sensitivity. However it was concluded that the notch
sensitivity does not directly influence the ballistic impact
resistance. This is attributed to the improvement of
molecular perfection via reduction in the free volume of
the polymer molecule during the annealing process.
EFFECT OF ANNEALING ON FAILURE BEHAVIOR OF A TRANSPARENT NYLON UNDER HIGH SPEED IMPACT
The effects of temperature exposure as well as annealing TROGAMID CX-7323 (CX) on its mechanical and ballistic impact properties were examined. CX generally exhibits ductile failure upon ballistic impact. However, upon complete penetration, the impact failure behavior occasionally changes depending on the projectile type and size. Notched izod impact test results revealed that annealing CX significantly increased the notch sensitivity. However, it was concluded that the notch sensitivity does not directly influence the ballistic impact resistance. This is attributed to the improvement of molecular perfection via reduction in the free volume of the polymer molecule during the annealing process.
NUMERICAL ANALYSIS OF THE MELTING PROCESS FOR BARRIER-FLIGHTED SINGLE-SCREW EXTRUDERS USING SCREW ROTATION PHYSICS
The focus of this investigation was to develop a new model for the melting dynamics of the solid bed for barrier melting sections in single-screw extruders. This analysis is an extension of the screw rotation melting model presented earlier for conventional screws. In this paper we present a new physical concept for melting in a barrier screw for single-screw extruders that is consistent with more rapid loss of solid material in the cross-channel direction when compared to conventional screw melting discussed previously. We developed a dynamic melting model and then simulated this first-order theory. The simulation qualitatively fits the literature observations for melting in a barrier-flighted melting section of a screw.
COMPUTER SIMULATION FOR FLOW BEHAVIOR
ON MICRO- AND NANO-MOLDING
3-dimensional FEM simulation was performed to
clarify the mechanism on surface replication in
micro-injection molding and thermal nano-imprinting.
Especially the filling behavior into micro- and nanosurface
features was discussed in comparison with the
experimental results. The simulation results and the
experimental results of injection molding show
possibility of the generation of air traps in the filling
stage and it is considered that those air traps have a
strong relation with replication shape and replication
rate. The simulation results of thermal imprinting
clarified penetration behavior of polymer melt into
nano-surface feature and show that the aspect ratio of
the cavity and imprinting pressure influenced flow
behavior in thermal imprinting.
COMPUTER SIMULATION FOR FLOW BEHAVIOR ON MICRO- AND NANO-MOLDING
3-dimensional FEM simulation was performed to clarify the mechanism on surface replication in micro-injection molding and thermal nano-imprinting.Especially the filling behavior into micro- and nanosurface features was discussed in comparison with the experimental results. The simulation results and the experimental results of injection molding show possibility of the generation of air traps in the filling stage and it is considered that those air traps have a strong relation with replication shape and replication rate. The simulation results of thermal imprinting clarified penetration behavior of polymer melt into nano-surface feature and show that the aspect ratio of the cavity and imprinting pressure influenced flow behavior in thermal imprinting.
ELASTIC RECOVERY BEHAVIOR OF THREE LAYER FILM STRUCTURES
COMPRISED OF TPO AND VARIOUS ETHYLENE COPOLYMERS
Stretch hood films used to protect and unitize pallet
loads are becoming more sophisticated structures that
combine the unique properties of several advanced
polymers. The combined properties of reactor TPO resins
and ethylene copolymers will continue to expand the
envelope of application and performance possibilities for
film engineers delivering enhanced strength and pallet
security heat resistance extensibility elastic recovery
and material use reduction. This paper will discuss the
relationships between film formulation and degree of
orientation on the elastic and physical properties of a
three-layer stretch hood film structure.
ELASTIC RECOVERY BEHAVIOR OF THREE LAYER FILM STRUCTURES COMPRISED OF TPO AND VARIOUS ETHYLENE COPOLYMERS
Stretch hood films used to protect and unitize pallet loads are becoming more sophisticated structures that combine the unique properties of several advanced polymers. The combined properties of reactor TPO resins and ethylene copolymers will continue to expand the envelope of application and performance possibilities for film engineers, delivering enhanced strength and pallet security, heat resistance, extensibility, elastic recovery, and material use reduction. This paper will discuss the relationships between film formulation and degree of orientation on the elastic and physical properties of a three-layer stretch hood film structure.
IMPROVEMENT OF THE MECHANICAL PROPERTIES OF THERMOPLASTIC FOAMS THROUGH MODIFICATION OF THE FOAM STRUCTURE
Foaming an injection molded thermoplastic part can reduce its weight warpage and the associated processing costs but it also results in a loss of mechanical performance. This loss can however be mitigated through specific modifications of the foam structure while at the same time the material consumption is minimized. This paper analyzes the changes that are induced by foaming in the mechanical performance of thermoplastic materials and demonstrates the gain in mechanical strength that can be achieved by inducing modifications of the foam structure for example in the skin thickness the mean cell size and the foam density.
IMPROVEMENT OF THE MECHANICAL PROPERTIES OF THERMOPLASTIC FOAMS THROUGH MODIFICATION OF THE FOAM STRUCTURE
Foaming an injection molded thermoplastic part can reduce its weight, warpage and the associated processing costs, but it also results in a loss of mechanical performance. This loss can, however, be mitigated through specific modifications of the foam structure, while at the same time the material consumption is minimized. This paper analyzes the changes that are induced by foaming in the mechanical performance of thermoplastic materials and demonstrates the gain in mechanical strength that can be achieved by inducing modifications of the foam structure, for example in the skin thickness, the mean cell size and the foam density.
APPLICATIONS OF HIGH-FREQUENCY INDUCTION HEATING TO HIGH-QUALITY INJECTION MOLDING
High-frequency induction heating is an efficient way to rapidly heat mold surface by utilizing a high-frequency skin effect. Because the procedure allows for the rapid heating and cooling of mold surfaces, it has been recently applied to the injection molding in various purposes. The present work introduces various industrial applications of high-frequency induction heating to high-quality injection molding including: (i) moldability improvement in thin-wall injection molding, (ii) improvement of replication ratio of micro-features, and (iii) remove of weldlines for a mobile phone cover which contains multiple holes.
UNIQUE CRYSTALLINE NATURE OF A HIGH IMPACT STRENGTH POLYPROPYLENE ALLOY
Isotactic polypropylene (PP) has been reactivelyblended with an ethylene-octene copolymer (EOC) in atwin screw extruder. Free radical polymerization ofstyrene and a multifunctional acrylate during meltextrusion has resulted in an enhancement of mechanicalproperties and discovery of unique features in bothamorphous and crystalline phases. DSC indicates thatsmall lamellar crystals are present in the reacted blends which melt and recrystallize in a much different mannercompared to ungrafted PP. XRD reinforces DSC resultsin that the size and perfection of the alpha crystallinephase are reduced by grafting. SEM shows a uniquecross-hatch structure as indicated by XRD. Polarizedlight microscopy gives evidence that grafting andbranching within the reacted blend causes a gelation-likerecrystallization.
DURABILITY OF NATURAL FIBER SHEET MOLDING COMPOUND (ECO-SMC)
Recent earth environmental concern requires easy
recycle material system and the use of biodegradable
polymer and natural fiber is noticed in composite materials.
To apply the natural fiber for the structural parts the use as
reinforcement of Sheet Molding Compound (SMC) is
desirable because it is expected that SMC can be used in
various fields in terms of high productivity and
dimensional stability. Considering that fiber reinforced
composite is used for structural part the use of long-span
must be possible. Therefore the evaluation of the
durability such as degradation is very important subject.
In this study SMC (Sheet Molding Compound) that
reinforcement was jute cloth were prepared. The jute cloth
reinforced SMC was immersed in hot water to promote the
degradation. And after immersion an increase ratio of
water and bending properties were compared with that of
jute cloth reinforced SMC without immersion. As a result
the fracture mechanism changed from the combination
of crack propagation in matrix area and delamination
in the interface around the fiber bundle to only crack
propagation in matrix area by water immersion.
Durability of Natural Fiber Sheet Molding Compound (Eco-SMC)
Recent earth environmental concern requires easy recycle material system, and the use of biodegradable polymer and natural fiber is noticed in composite materials. To apply the natural fiber for the structural parts, the use as reinforcement of Sheet Molding Compound (SMC) is desirable because it is expected that SMC can be used in various fields in terms of high productivity and dimensional stability. Considering that fiber reinforced composite is used for structural part, the use of long-span must be possible. Therefore, the evaluation of the durability such as degradation is very important subject. In this study, SMC (Sheet Molding Compound) that reinforcement was jute cloth were prepared. The jute cloth reinforced SMC was immersed in hot water to promote the degradation. And after immersion, an increase ratio of water and bending properties were compared with that of jute cloth reinforced SMC without immersion. As a result,the fracture mechanism changed from the combination of crack propagation in matrix area and delamination in the interface around the fiber bundle to only crack propagation in matrix area by water immersion.
HYDROPHOBIC-MODIFIED CELLULOSE FIBERS AND CELLULOSE MICROFIBRILAS REINFORCEMENTS FOR BIOCOMPOSITES
The hydrophobic modification of cellulose fiber (CF) and cellulose microfibril (CMF) was conducted by grafting 1'Octadecanol using TDI as a coupling agent. The optimum reaction conditions obtained for grafting were: molar ratio of cellulosic materials:1'Octadecanol:TDI 1:1:1 (molar ratios of OH groups in fibers and reactive groups in reagents), temperature of reaction 120?øC and reaction time 3 h. The grafting was confirmed by FT-IR; and TGA measurement indicated that the amounts of grafting were 16.9wt% and 13.9wt% for CF and CMF,, respectively. Moreover, the surface morphology and hydrohphobicity of the grafted fibers were investigated by SEM and static contact angle measurement.
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