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Conference Proceedings
NEW DEVELOPMENTS IN HIGH-GLOSS MOLDED-IN-COLOR ENGINEERED POLYOLEFIN ALLOYS
High-gloss molded-in-color (MIC) engineered
polyolefin materials have been rapidly gaining acceptance
in the automotive industry as an alternative to painted
plastic. This is evidenced by the recent commercialization
of INDURE® X-76 for exterior trim on the Ford F-250
platform. INDURE® X-76 offers excellent surface
durability weatherability processability and part
appearance while reducing total system costs. This paper
reviews the performance attributes and applicability of this
class of high-gloss engineered polymers focusing on new
developments that extend the property and performance
envelope.
High-gloss molded-in-color (MIC) engineeredpolyolefin materials have been rapidly gaining acceptance
in the automotive industry as an alternative to painted
plastic. This is evidenced by the recent commercialization
of INDURE
??
X-76 for exterior trim on the Ford F-250?ÿ
platform. INDURE
?? X-76 offers excellent surface
?ÿ
?ÿdurability weatherability processability and part
appearance while reducing total system costs. This paper
reviews the performance attributes and applicability of this
class of high-gloss engineered polymers focusing on new
developments that extend the property and performance
envelope.
EXTRUSION FOAMING OF HIGH-MELT-STRENGTH PP WITH SUPERCRITICAL CARBON DIOXIDE I: CELL NUCLEATION BEHAVIORS
This paper investigates the cell nucleation behaviors ofnon-crosslinked high-melt-strength (HMS) polypropylene (PP)foams blown with supercritical Carbon Dioxide (CO?ÿ2). Varying?ÿ?ÿ2. It was also observed that the effect of CO2on the cell density was more pronounced when low talc contentwas used?ÿ. Regardless of the amount of nucleating and blowing?ÿ?ÿ. It also appeared that?ÿthe die pressure did not affect the cell density significantly.agent the cell density was significantly improved by using a diewith a high pressure-drop-rate geometrythe talc and CO2 content changed the cell density. The effect ofdie pressure and pressure drop rate on cell nucleation behaviorsof HMS PP was also observed by using different die geometries.Three dies were deliberately designed to have either differentpressure drop rates while having the same die pressure or withdifferent die pressures while having same pressure drop rate.Experimental results indicated that regardless of the die theeffect of talc on the cell density was more significant at a lowconcentration of CO
RHEOLOGICAL PROPERTIES OF LONG CHAIN BRANCHED POLYETHYLENE MELTS AT HIGH SHEAR RATE
Capillary extrusion experiments involving a number
of polyethylenes with emphasis on assessing the effect of
long chain branching are performed. None of the
metallocene catalyzed linear low density polyethylenes
(mLLDPE) produced by Dow Chemicals which are
believed to have some level of long chain branching show
temperature dependence on the viscosity at the gross melt
fracture regime. Furthermore these materials do not show
spurt or stick-slip flow in contrast with most linear
polyethylenes. LDPE and blends of LDPE with linear
polyethylenes also show the absence of stick-slip flow but
temperature dependence on the viscosity. From these
observations we conclude that the stick-slip flow is very
sensitive to the existence of long chain branching and the
behavior of the stick-slip flow can be used as an indicator
of LCB.
RHEOLOGICAL PROPERTIES OF LONG CHAIN BRANCHED POLYETHYLENE MELTS AT HIGH SHEAR
Capillary extrusion experiments involving a number of polyethylenes with emphasis on assessing the effect of long chain branching are performed. None of the metallocene catalyzed linear low density polyethylenes (mLLDPE) produced by Dow Chemicals, which are believed to have some level of long chain branching, show temperature dependence on the viscosity at the gross melt fracture regime. Furthermore, these materials do not show spurt or stick-slip flow, in contrast with most linear polyethylenes. LDPE and blends of LDPE with linear polyethylenes also show the absence of stick-slip flow, but temperature dependence on the viscosity. From these observations, we conclude that the stick-slip flow is very sensitive to the existence of long chain branching, and the behavior of the stick-slip flow can be used as an indicator of LCB.
SIMULATION OF SCREWS FOR INJECTION MOLDING
This paper deals with the simulation of the
plastification unit (extruder) for the injection molding
process. It shows the theory and how the method of
simulation of an extruder for the extrusion process is
modified to cover the effects in injection molding mainly
the facts that the screw stops rotating for a certain time
and it moves backward while rotating and melting the
polymer. To see the quality of the prediction of such a
modified program a set of experiments was performed. A
comparison of the results of these experiments with the
program prediction will be shown. The presentation will
also cover the most important variables to be checked for
achieving good melt delivery performance in the injection
molding process.
SIMULATION OF SCREWS FOR INJECTION MOLDING
This paper deals with the simulation of the plastification unit (extruder) for the injection molding process. It shows the theory and how the method of simulation of an extruder for the extrusion process is modified to cover the effects in injection molding, mainly the facts that the screw stops rotating for a certain time and it moves backward while rotating and melting the polymer. To see the quality of the prediction of such a modified program, a set of experiments was performed. A comparison of the results of these experiments with the program prediction will be shown. The presentation will also cover the most important variables to be checked for achieving good melt delivery performance in the injection molding process.
AN ESTIMATE OF LONG SERVICE TERM FOR GRP PRODUCTS
The long service term of GRP products such as
technological pipes ducts scrubbers etc. is determined
by the chemically resistant layer of multilayered
fiberglass which is in direct contact with the
technological environment. The diffusion of
technological medium into the structure of the GRP leads
to a change in the dielectric properties of the material.
These changes can be used to predict the long service
term of GRP products under the influence of
technological environment. The ability to predict the
residual life period of GRP products and results of the
pipe operation with the partially damage of the chemical
resistant layer under conditions of the sulfuric acid
production are considered.
AN ESTIMATE OF LONG SERVICE TERM FOR GRP PRODUCTS
The long service term of GRP products such as technological pipes, ducts, scrubbers, etc. is determined by the chemically resistant layer of multilayered fiberglass, which is in direct contact with the technological environment. The diffusion of technological medium into the structure of the GRP leads to a change in the dielectric properties of the material. These changes can be used to predict the long service term of GRP products under the influence of technological environment. The ability to predict the residual life period of GRP products and results of the pipe operation with the partially damage of the chemical resistant layer under conditions of the sulfuric acid production are considered.
BENEFITS OF AN ENERGY USAGE INDICATOR FOR INJECTION MOLDING SIMULATION
With growing concern regarding our environmental
impact greater focus has been placed on ways we can
reduce our impact by improving our decisions designs
and processes. The use of injection molding simulation
has been shown to reduce material consumption reduce
production scrap assist in recycling existing materials
create better quality products that have a prolonged life
and reduce energy consumption required during the
manufacturing process. This paper will present the
benefits of an additional measure called an Energy Usage
Indicator that can assist part designers using injection
molding simulation to easily identify the processing
requirements of a polymer material.
BENEFITS OF AN ENERGY USAGE INDICATOR FOR INJECTION MOLDING SIMULATION
With growing concern regarding our environmental impact, greater focus has been placed on ways we can reduce our impact by improving our decisions, designs and processes. The use of injection molding simulation has been shown to reduce material consumption, reduce production scrap, assist in recycling existing materials, create better quality products that have a prolonged life and reduce energy consumption required during the manufacturing process. This paper will present the benefits of an additional measure, called an Energy Usage Indicator, that can assist part designers using injection molding simulation to easily identify the processing requirements of a polymer material.
RHEOLOGY AND STRUCTURE OF FILLED PROPYLENE/ETHYLENE COPOLYMERS
We have studied a new family of propylene/ethylene(P/E) copolymers produced by The Dow ChemicalCompany which allow high filler loadings whilemaintaining good processability. Our goal was to providea fundamental understanding of the unexpectedly lowviscosity exhibited by these materials when filled withparticulates. We propose that in these copolymers interfacial slip (between the particles and the polymermelt) is enhanced by the presence of a thin layer of lowviscosity polymer around the particles. The formation ofthis layer is surface tension driven and can occur insystems such as these copolymers which are homogeneousin the bulk. Such behaviour has been observed with blockcopolymersand blends; this study is the first time it hasbeen observed in an industrial copolymer of this type.
ITERATIVE LEARNING CONTROL OF MOLD-OPEN POSITION IN INJECTION
MOLDING
Mold-open position (MOP) is an important variable in
the injection molding machine (IMM) control system. A
precise control of mold open position can improve the
process stability. This paper demonstrates that the variation
of mold-open offset which is the key problem in moldopen
positioning. Iterative learning estimator (ILE) is used
in batch direction to estimate this offset. To guarantee the
repeatability of this offset an Iterative Learning Control
(ILC) scheme is applied to control the mold-open velocity
to achieve a relatively low and stable value around the end
of mold-open. The control result shows that the combined
system of ILE and ILC can obtain precise MOP.
ITERATIVE LEARNING CONTROL OF MOLD-OPEN POSITION IN INJECTION MOLDING
Mold-open position (MOP) is an important variable in the injection molding machine (IMM) control system. A precise control of mold open position can improve the process stability. This paper demonstrates that the variation of mold-open offset, which is the key problem in moldopen positioning. Iterative learning estimator (ILE) is used in batch direction to estimate this offset. To guarantee the repeatability of this offset, an Iterative Learning Control (ILC) scheme is applied to control the mold-open velocity to achieve a relatively low and stable value around the end of mold-open. The control result shows that the combined system of ILE and ILC can obtain precise MOP.
RESEARCH OF CONVEYING CHARACTERISTICS OF POLYMER VANE
EXTRUDER
The working principles of vane extruder are entirely
different from screw extruder. Materials were conveyed
and plasticized by a group of vanes and the materials
suffered mainly normal stress during processing. The heat
history and mechanical history that the materials suffered
were greatly decreased contrast to screw extruder. In this
paper working principles of the vane extruder were
introduced in detail. Experiments were carried out on the
vane extruder to study the conveying characteristics and
the experimental results were presented. Experimental
results showed that the specific energy consumption is low
and the change of material’s properties has little effect on
throughput.
RESEARCH OF CONVEYING CHARACTERISTICS OF POLYMER VANE EXTRUDER
The working principles of vane extruder are entirely different from screw extruder. Materials were conveyed and plasticized by a group of vanes and the materials suffered mainly normal stress during processing. The heat history and mechanical history that the materials suffered were greatly decreased contrast to screw extruder. In this paper working principles of the vane extruder were introduced in detail. Experiments were carried out on the vane extruder to study the conveying characteristics and the experimental results were presented. Experimental results showed that the specific energy consumption is low and the change of materialƒ??s properties has little effect on throughput.
KOAX-S-TRUDER – A NEW FLEXIBLE AND HIGH EFFICIENT PLASTICATING
CONCEPT
A way to get high and constant plasticating capacities
without using larger screw diameters or longer processing
units can be reached with a new alternative plasticating
concept. Using a separate driven coaxial feeding screw the
decrease of throughput rate especially for materials with
varying physical properties and higher screw speeds can be
reduced in a wide range. The separation of solid material
and melt within the short transition zone leads to high
plasticating capacities and lower melt temperatures by
reducing the induced shear energy caused by the rotating
screw at higher screw speeds.
KOAX-S-TRUDER A NEW FLEXIBLE AND HIGH EFFICIENT PLASTICATING CONCEPT
A way to get high and constant plasticating capacities without using larger screw diameters or longer processing units can be reached with a new alternative plasticating concept. Using a separate driven coaxial feeding screw the decrease of throughput rate especially for materials with varying physical properties and higher screw speeds can be reduced in a wide range. The separation of solid material and melt within the short transition zone leads to high plasticating capacities and lower melt temperatures by reducing the induced shear energy caused by the rotating screw at higher screw speeds.
DEVELOPMENT OF NOVEL BAYBLEND FR BLENDS WITH IMPROVED FLAMMABILITY AND HYDROLYSIS RESISTANCE
Bayer MaterialScience has commercialized a third
generation of flame retardant PC/ABS blends. The third
generation Bayblend® FR resins based on Chlorine
Bromine Antimony oxide free technology complies with
Blue Angel and White Swan requirements and has a UL94
flammability performance of V0 at 1.5 mm and 5VA rating
at 3.0 mm.
Bayblend® FR 3010 resin is a typical representative for
a non-reinforced flame resistant polycarbonate/ABS blend.
This product exhibits a good balance of flow stiffness
impact performance chemical resistance and heat distortion
properties.
Most key properties of the new Bayblend® DP
3008HR resin are similar to those of Bayblend FR 3010.
The key property of Bayblend® DP 3008HR resin is
improved hydrolytic resistance.
The new Bayblend® DP FR 3041 grade exhibits an
excellent impact performance together with outstanding
flammability ratings (V-0 at 0 75 mm and 5VA at 2.3mm)
which makes Bayblend® DP FR 3041 resin an ideal
candidate for a wide variety of thin wall applications.
Bayer MaterialScience has commercialized a thirdgeneration of flame retardant PC/ABS blends. The thirdgeneration Bayblend?ÿ?? FR resins based on Chlorine ?ÿ?ÿ?? FR 3010 resin is a typical representative for?ÿ?ÿ?? DP?ÿ?ÿ?? DP 3008HR resin is?ÿ?ÿ?? DP FR 3041 grade exhibits an?ÿ?ÿ?? DP FR 3041 resin an ideal?ÿcandidate for a wide variety of thin wall applications.excellent impact performance together with outstandingflammability ratings (V-0 at 0 75 mm and 5VA at 2.3mm)which makes Bayblendimproved hydrolytic resistance.The new Bayblend3008HR resin are similar to those of Bayblend FR 3010.The key property of Bayblenda non-reinforced flame resistant polycarbonate/ABS blend.This product exhibits a good balance of flow stiffness impact performance chemical resistance and heat distortionproperties.Most key properties of the new BayblendBromine Antimony oxide free technology complies withBlue Angel and White Swan requirements and has a UL94flammability
ADVANCED PROCESS CONTROL FOR INJECTION MOLDING BASED ON CAVITY PRESSURE
The manufacturing of complex and high-grade molded parts in the injection molding process places high demands on the process control. Unlike the conventional control of the injection molding process which is based on machine variables the presented advanced process control system performs an online control of the quality determining process variable ‘cavity pressure’. In the holding pressure phase it conducts an online optimization of the process based on the pvT-behavior of the used plastic material. By this means an optimal course of the process in the pvT-diagram is realized in each production cycle and thus the quality constancy of the produced parts can be considerably increased.
ADVANCED PROCESS CONTROL FOR INJECTION MOLDING BASED ON CAVITY PRESSURE
The manufacturing of complex and high-grade molded parts in the injection molding process places high demands on the process control. Unlike the conventional control of the injection molding process, which is based on machine variables, the presented advanced process control system performs an online control of the quality determining process variable ƒ??cavity pressureƒ??. In the holding pressure phase it conducts an online optimization of the process based on the pvT-behavior of the used plastic material. By this means, an optimal course of the process in the pvT-diagram is realized in each production cycle and thus, the quality constancy of the produced parts can be considerably increased.
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