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
STRACTURE AND INTERFACIAL ADHESION
OF PP/PBS SANDWICH INJECTION MOLDINGS
Polypropylene (PP) based sandwich injection
moldings with biomass based polymers (PBS) in the core
were studied. In order to obtain superior surface
properties such as high chemical resistance and
anti-scratch resistnce, improvement of interfacial strength
between skin and core parts is important, which can be
controlled by the additional PP component in the PBS
core part. The selection of additional PP and injection
conditions were found to be important to improve the
interfacial strength, of which phenomena was understood
by the melt rheology at the injection condition.
Scratch tests according to ASTM method was
performed to investigate the relationship between scratch
behavior and skin/core adhesion. Poor skin/core adhesion
caused the skin/core delamination upon the scratch tests.
RESPONSIVE STARCH-BASED MATERIALS
Starch a low-cost annually renewable resource is naturally hydrophilic and its properties change with relative humidity. Starchƒ??s hygroscopic nature can be used to develop materials which change shape or volume in response to environmental changes (eg humidity). For example starch-based graft copolymers have been produced using reactive extrusion for potential superabsorbent and hydrogel applications. Besides absorbing large quantities of water some of these copolymers display large volume changes in aqueous alcohol depending on solvent quality. Other examples include starch-poly(methyl acrylate) graft copolymer films which shrink at high humidities. Various levels of shrinkage can be triggered in response to changes in relative humidity. (AAm) and varying amounts of 2-acrylamido-2-methyl- 1-propane sulfonic acid (AMPS) display various degrees of swelling in aqueous solutions and approximately discontinuous volume changes in aqueous ethanol solutions over narrow ethanol concentrations. Blown films of starch-PMA graft copolymers display controlled shrinkage in response to increases in relative humidity.
DEVELOPMENT OF ANTIMICROBIAL PLA NANOCOMPOSITES WITH SILVER
CONTAINING LAYERED NANOCLAYS FOR PACKAGING AND COATING
APPLICATIONS
This paper presents the development and characterization
of the antimicrobial activity of a novel family of
commercial food contact compliant silver-modified
nanolayered clays and of their nanobiocomposites with
polylactic acid. The antimicrobial nanolayered clays
showed an antimicrobial effectiveness of 99.99% against
Gram-negative Salmonella spp. In addition the PLA-clay
nanocomposite also showed a significant antimicrobial
activity and a synergistic water vapour permeability
reduction of 32% with respect to neat PLA. The results
indicate that these novel active nanolayered fillers can
potentially exhibit numerous applications in plastic and
bioplastic packaging and coatings where simultaneous
barrier and antimicrobial performance are desirable.
DEVELOPMENT OF ANTIMICROBIAL PLA NANOCOMPOSITES WITH SILVER
CONTAINING LAYERED NANOCLAYS FOR PACKAGING AND COATING
APPLICATIONS
This paper presents the development and characterization of the antimicrobial activity of a novel family of commercial food contact compliant silver-modified nanolayered clays and of their nanobiocomposites with polylactic acid. The antimicrobial nanolayered clays showed an antimicrobial effectiveness of 99.99% against Gram-negative Salmonella spp. In addition, the PLA-clay nanocomposite also showed a significant antimicrobial activity and a synergistic water vapour permeability reduction of 32% with respect to neat PLA. The results indicate that these novel active nanolayered fillers can potentially exhibit numerous applications in plastic and bioplastic packaging and coatings where simultaneous barrier and antimicrobial performance are desirable.
OPTIMIZATION OF A PET PREFORM DESIGN FOR BETTER BOTTLE BARRIER PROPERTIES
This paper presents an investigation on the optimization of the preform design to produce PET bottles with uniform thickness distribution and better barrier properties using a blow moulding simulation software. The barrier properties were studied by calculating the blow up ratio (BUR) of the initial and the final bottles. The bottle blown up using the new preform design had a higher value of BUR indicating that it had better barrier properties due to increased molecular orientation. Results from the simulation were also used to study the mechanical strength and the internal pressure variations on the bottle using the Pro/Mechanica finite element analysis (FEA).
POLYMER ORIENTATION IN POLYPROPYLENE-TALC COMPOSITES
STRETCHED BELOW THE MELTING TEMPERATURE
Solid-phase die-drawing of composites with semicrystalline
polyolefins and particulate filler is a new
process for producing expanded and oriented structural
materials1-2. The objective of this work was to investigate
the maximum draw ratio attained with composites of
isotactic polypropylene and talc and the polymer chainaxis
orientation obtained over various draw ratios at 10°C
below the melting temperature. The maximum attainable
draw ratio with the PP-talc composite was considerably
greater than with the neat PP. The extent of debonding
and void growth was well advanced before significant
orientation was developed in the crystalline lamellae of
the polypropylene matrix.
POLYMER ORIENTATION IN POLYPROPYLENE-TALC COMPOSITES STRETCHED BELOW THE MELTING TEMPERATURE
Solid-phase die-drawing of composites with semicrystalline polyolefins and particulate filler is a new process for producing expanded and oriented structural materials1-2. The objective of this work was to investigate the maximum draw ratio attained with composites of isotactic polypropylene and talc and the polymer chainaxis orientation obtained over various draw ratios at 10?øC below the melting temperature. The maximum attainable draw ratio with the PP-talc composite was considerably greater than with the neat PP. The extent of debonding and void growth was well advanced before significant orientation was developed in the crystalline lamellae of the polypropylene matrix.
THE INJECTION MOLDING OF NANOSTRUCTURED POLYSTYRENE
TEMPLATES TO INVESTIGATE THE CONTROL OF HUMAN MESENCHYMAL
STEM CELL DIFFERENTIATION
The injection molding of nano-structured polystyrene
(PS) surfaces and its application in the stimulation of stem
cell differentiation is described. PS was selected as a base
substrate for in vitro human mesenchymal stem cell
(hMSC) culturing due to its bio-compatibility and wide
use as a cell culturing medium. The approach was adopted
to improve upon current biochemical differentiation
methods. A customized mold was designed where a nanopatterned
silicon wafer served as the insert for injection
molding. The effect of a nano-pillared PS surface in
comparison to planar control on hMSC cell response was
observed.
THE INJECTION MOLDING OF NANOSTRUCTURED POLYSTYRENE TEMPLATES TO INVESTIGATE THE CONTROL OF HUMAN MESENCHYMAL STEM CELL DIFFERENTIATION
The injection molding of nano-structured polystyrene (PS) surfaces and its application in the stimulation of stem cell differentiation is described. PS was selected as a base substrate for in vitro human mesenchymal stem cell (hMSC) culturing due to its bio-compatibility and wide use as a cell culturing medium. The approach was adopted to improve upon current biochemical differentiation methods. A customized mold was designed where a nanopatterned silicon wafer served as the insert for injection molding. The effect of a nano-pillared PS surface in comparison to planar control on hMSC cell response was observed.
REACTION KINETICS STUDYUSING SPECIALIZED BATCH MIXER
Although reactive extrusion is an important process component in many industrial applications no convenient method to determine reaction kinetics exists in extrusion literature. Batch mixer torque versus time" relationship reflecting reaction kinetic contributions at various melt tem- peratures and shear rates can be used to study reactive sys- tems. This work aims at developing a rapid batch mixer test to differentiate reaction kinetic mechanisms. In order to demonstrate the validity of the test we will be presenting experimental studies of PET polymer degradation model system. Reaction kinetic information obtained from batch system will be linked to previously-reported continuous extrusion process characterization studies."
INTEGRATION OF FORMING AND INJECTION MOLDING PROCESSES ON IN-MOLD DECORATION PRODUCT DEVELOPMENT
Decoration processing for injection molded parts such as painting printing hot stamping electroplating and so on is commonly applied to enhance the surface quality and product value. Due to extra processes cost and pollution problems increase. One of great solutions which is performed in-mold decoration has been utilized to minimize the processes for years. However since it is so complicated from film forming to injection molding how to realize the process mechanism is the crucial factor. In this study the integration of forming and injection molding processes is proposed and performed both experimentally and numerically.
MORPHOLOGY AND PROPERTIES OF EXFOLIATED
GRAPHITE/THERMOPLASTIC POLYURETHANE NANOCOMPOSITES
Functionalized graphite sheets (FGS) and isocyanate
treated graphite oxide (iGO) were incorporated into
thermoplastic polyurethane (TPU) via melt compounding
solvent blending and in-situ polymerization. Transmission
electron microscopy (TEM) indicated that FGS is
exfoliated while iGO forms mixed morphology of partial
intercalation and exfoliation. Their dispersion into TPU
resulted in noticeable enhancements in electrical
conductivity stiffness and gas barrier. Average aspect
ratios of graphitic additives determined by fitting
properties with composite theories agree well with values
from direct TEM imaging.
MORPHOLOGY AND PROPERTIES OF EXFOLIATED
GRAPHITE/THERMOPLASTIC POLYURETHANE NANOCOMPOSITES
Functionalized graphite sheets (FGS) and isocyanatetreated graphite oxide (iGO) were incorporated intothermoplastic polyurethane (TPU) via melt compounding,solvent blending and in-situ polymerization. Transmissionelectron microscopy (TEM) indicated that FGS isexfoliated while iGO forms mixed morphology of partialintercalation and exfoliation. Their dispersion into TPUresulted in noticeable enhancements in electricalconductivity, stiffness and gas barrier. Average aspectratios of graphitic additives determined by fittingproperties with composite theories agree well with values from direct TEM imaging.
ADVANCED RESULTS OF A PROSPECTIVE STUDY ON FLEXIBLE PLASTIC PACKAGING IN ANDEAN COUNTRIES: SCENARIOS AND STRATEGIES FOR THE PERIOD 2003 ƒ?? 2013
A prospective study on flexible plastic packaging was carried out in Andean Countries with the participation of two plastic research institutes and 20 companies including raw material manufacturers processors converters and end users.The inputs of this prospective study were a review of the state of the art on flexible packaging a benchmarking study considering the 10 most important companies a study using the Delphi method with national and international experts who identified the key variables to the development and progress of the flexible packaging in the region and workshops.This study generated new projects and products on the field of barrier smart and active packaging biodegradable materials among others; it shows that the Andean region is applying R&D and technological alliances in its industrial processes.
TRITAN™ COPOLYESTERS
Tritan™ copolyesters are tough transparent
copolyesters recently developed by Eastman Chemical
Company. These new copolyesters have higher glass
transition temperatures than Eastman’s heritage
copolyesters of PETG PCTG and PCTA. The properties
of Tritan™ copolyesters allow it to be used in applications
in a variety of markets from housewares to signs. The
unique properties of Tritan™ copolyesters are achieved by
modifying poly(1 4-cyclohexylenedimethylene
terephthalate) or PCT with 2 2 4 4-tetramethyl-1 3-
cyclobutanediol (TMCD) . The properties of Tritan™
copolyesters can be tuned to meet the demands of
applications by changing the level of TMCD modification.
This paper describes the basic chemistry and structureproperty
relationships of Tritan™ copolyesters. In
addition this paper describes the properties for some of
the commercial Tritan™ copolyesters grades available.
TRITAN COPOLYESTERS
Tritan copolyesters are tough, transparent copolyesters recently developed by Eastman Chemical Company. These new copolyesters have higher glass transition temperatures than Eastmanƒ??s heritage copolyesters of PETG, PCTG, and PCTA. The properties of Tritanƒ?› copolyesters allow it to be used in applications in a variety of markets from housewares to signs. The unique properties of Tritanƒ?› copolyesters are achieved by modifying poly(1,4-cyclohexylenedimethylene terephthalate), or PCT, with 2,2,4,4-tetramethyl-1,3- cyclobutanediol (TMCD) . The properties of Tritanƒ?› copolyesters can be tuned to meet the demands of applications by changing the level of TMCD modification.This paper describes the basic chemistry and structure-property relationships of Tritanƒ?› copolyesters. In addition, this paper describes the properties for some of the commercial Tritanƒ?› copolyesters grades available.
EVALUATION OF MOLECULAR ORIENTATION OF WELDLINE
BY POLARIZED LASER-RAMAN SPECTROSCOPY
Molecular orientation in weldline region of
injection molded polypropylene was investigated by polarized
laser-Raman spectroscopy. The intensity ratio of two intrinsic
peaks in a Raman spectrum of weldline was considered to be a
molecular orientation index. By setting the angle of incident
laser beam in two ways so as to be parallel and perpendicular
to the weldline the molecular orientation around the weldline
was able to be clarified in detail. It was found that the
molecules in weldline region oriented along the interface of
the weldline even inside the moldings. Moreover the
orientation degree of the area 0.3 mm away from the interface
was higher than that of the interface itself. These findings are
much different from our expectation obtained from the former
experiments using polystyrene moldings in a similar method
which suggests that the orientation parallel to the weldline is
limited to the area beneath the surface. Although the cause of
this difference has yet to be identified there is little doubt that
crystallinity of polypropylene deeply plays an important role
on it.
EVALUATION OF MOLECULAR ORIENTATION OF WELDLINE BY POLARIZED LASER-RAMAN SPECTROSCOPY
Molecular orientation in weldline region of injection molded polypropylene was investigated by polarized laser-Raman spectroscopy. The intensity ratio of two intrinsic peaks in a Raman spectrum of weldline was considered to be a molecular orientation index. By setting the angle of incident laser beam in two ways so as to be parallel and perpendicular to the weldline, the molecular orientation around the weldline was able to be clarified in detail. It was found that the molecules in weldline region oriented along the interface of the weldline even inside the moldings. Moreover, the orientation degree of the area 0.3 mm away from the interface was higher than that of the interface itself. These findings are much different from our expectation obtained from the former experiments using polystyrene moldings in a similar method which suggests that the orientation parallel to the weldline is limited to the area beneath the surface. Although the cause of this difference has yet to be identified, there is little doubt that crystallinity of polypropylene deeply plays an important role on it.
THE RELATIONSHIP BETWEEN PROCESSING-THERMOMECHANICAL ENVIRONMENT AND STRUCTURE ON INJECTED FLAT PARTS
The microstructure of an injection moulding polypropylene part has been varied through systematic changes on the process conditions. The specimens were mouldedmodifying the holding pressure mass caudaland gate design. The skin-core structure was characterized by polarized light microscopy. The thermo mechanical environment imposed during processing was characterized using simulation commercial software.From the mould filling stage two thermo mechanical indices were calculated. The results show the relationship between these indexes and the micro structural features obtained in the moulded specimens
TOWARDS QUALITY PRODUCTS FROM BIO-BASED PLASTICS
The importance of three inter-dependent factors i.e.
(1) materials (2) manufacturing and (3) design and
engineering is generally recognized. All factors are
indispensable and equally important for product
development. Manufacturing is often the least structured
factor and many designers and materials experts do not
consider themselves capable to deal with it. Fortunately
expertise is sufficiently available and the best
professionals are able to utilize plastics expertise properly
in collaborative product development.
For bio-based plastics which are rapidly emerging in
some specific markets it is already clear that the relation
between the three factors is different and more varied than
for the currently well-known plastics. Critical factors for
increased successful application of bio-based plastics will
be product manufacturing and the expectations of
applicators and consumers. From interviewing a variety of
professionals it was found that clear true and complete
information is currently not accessible for most whereas
some assumptions are not realistic or not correct
particularly the ones related to degradability and to
environmental effects. Better and well-structured
information will be needed resulting in fulfillment of
elementary consumer expectations.
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