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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Scope of our work has been development
of a new type of coupling agent by which
processing of long carbon fibre reinforced
composites by injection moulding will be
possible since hindering the fibres from
breakage and simultaneously improving
the mechanical properties. Resistance of
LLDPE of 1-10% carbon fibres against
tensile and flexure stresses has been
investigated. Tensile strength has increased
by 30% and flexure strength has gained
90% related to the neat polymer.
Fibre/matrix interaction has been studied
on SEM graphs and a polymer layer has
been observed to be connected to the fibre
in additive treated fibre containing
composites.
Akihiko Nemoto | Hiroshi Ito | Yasuhiko Murata | Nobuhide Ito | Hitoshi Ohomori, November 2011
To cope with increasing demands on ultraprecision
profiling and finishing of aspheric lens molds, we have
implemented an ultra nanoprecision aspheric grinding
system to be mounted with an ELID(ELectrolytic Inprocess
Dressing)-capability and on-line feedback
capability of profile accuracy. A cemented carbide mold
has successfully ground and finished to be with several
nanometric surface smoothness and with ultraprecise
profile accuracy by just grinding process with ELID
mechanism. Some specific conditions have been
investigated to achieve better accuracy and quality on
molds. This paper presentation introduce those R&D
activities and also discuss on the latest achievements on
this topics, with showing injected aspheric lenses by the
molds.
Peter Allan | Ali Ahmadnia | Rob Withnall | Jack Silver, November 2011
Acoustic properties of polymer compounds are an important consideration for many applications. Currently there is a standard test method for the determination of the sound impedance and absorption properties of materials but there is no such test for the property of sound transmission loss (STL). The equipment used for the impedance and absorption standard test can, however, be adapted to measure the sound transmission property. The objective of this project was, therefore, to assess this testing method for STL and to carry out an initial investigation on the relationship between the structure of plastic compounds and their acoustic transmission property.
We describe the steps necessary to establish a stable extrusion process of physical foaming of poly(lactic acid) (PLA) with carbon dioxide. The low melt strength and poor thermal stability of PLA plays a role in optimizing processing conditions. Up to 10 wt% supercritical CO2 was added. The effect of a chain extender was also tested. Low density, microcellular foams with density down to 20-30 kg/m3 were obtained for three different PLA grades. Foams were characterized by density, cell structure, crystallinity and mechanical compression properties.
Aleksander Prociak | Slawomir Michalowski | Tomasz Sterzyński | Dariusz Bogdal, November 2011
Microwave heating has a number of advantages in comparison to the conventional method due to the ability to heat a part of polymeric material directly through specific interaction of electromagnetic radiation with selected types of materials. Most thermoplastics are relatively transparent for microwave irradiation and they do not absorb microwaves to a sufficient extent to be heated. In such case, enhanced microwave heating can result from the use of fillers such as carbon black.
In this paper, the ability of different thermoplastic polymers as polyurethane, poly(vinyl chloride) and carbon black filled polypropylene to absorb microwave irradiation and to be foamed using chemical blowing agents is discussed. The temperature changes of such materials as the heating effect under microwave irradiation with various power were investigated. Selected polymeric materials with additive of chemical blowing agents were foamed under microwave irradiation and the influence of foaming conditions on cell structure and apparent density of porous products was analyzed.
Polyamides are widely used in many applications. There is a vast amount of recycled polyamide coming from the carpet and textile and other industries. Due to degradation and loss of viscosity, this recycled polyamide has reduced performance and limited its use. The unique chemistry of alternating copolymers of ethylene and maleic anhydride provide several advantages for upgrading recycled polyamide. This paper discusses the results obtained with compounding prime grade polyamide as well as recycled polyamide with the addition of small quantities of this copolymer and specific property improvements for applications in injection molded compounds.
Processes to print, stamp, mark, label or otherwise deposit graphics onto molded plastic products
are collectively known as plastics decorating. Given decorating processes, graphic types and
production requirements, no single decorating method fits all projects and, conversely, most
projects have more than one viable decorating method. For your latest new product design or
redesign, one challenge is determining which decorating processes are options. This challenge is
an equation of sorts with several factors to consider including: 1. graphics details required; 2.
molded plastic part characteristics; and 3. production demands. The following pages guide a
discussion of these factors.
Although the process of selecting the right polymer for new medical devices has not changed very much in the last 10 to 15 years, the degree of complication seems to have grown exponentially. The variety of specially designed materials, the number of suppliers, some under the same name or others with a new corporate moniker, and the availability of reference databases puts a glut of information into the hands of the design engineers. But how does one successfully navigate through this information and decide on the one material that is best for their particular application. It is much more difficult to find live technical support from either suppliers or from database providers. With staff reductions and department consolidations, many companies have also lost experts from their library of specialists that in the past have led the selection of the optimum polymer for new applications. No longer do companies have the historical databank of material expertise or on-staff resources for guiding new project efforts. The level of experience in many companies is down while the breadth of knowledge is much more focused. This coupled with the evolution of far more complicated devices that often combine advances in multiple new technologies such as conductive polymers, shape memory materials, drug eluting devices and polymers that dissolve in the body all complicate the process of selecting the right polymer for the application.
Medical devices designers and engineers are tasked with selecting just the right polymer for their devices; and this requires keeping in mind all the various requirements that must be satisfied including functional requirements, chemical and biological requirements and manufacturing, assembly and sterilization. Collectively, results of the evaluation of the materials used in the construction of medical device and the function of the devices together contribute to what many refer to as the biocompatibility of the device.
Composites of poly(caprolactone) (PCL) and multiwalled carbon nanotubes (MWCNTs) were produced by melt-mixing in a small scale compounder by varying the screw speed between 25 and 400 rpm at a constant mixing time of two minutes. By that, different levels of dispersions, as assessed by quantitative analysis of area ratio of remaining primary agglomerates from light microscopy, were achieved. With increasing screw speed the state of dispersion increases and levels off starting at about 100 rpm.
Melt rheological properties were measured in frequency sweeps. Interestingly, distinct differences in the complex viscosity * and the storage modulus G’ were found in dependence on the agglomerate area ratio, whereas the loss modulus G’’ was not much influenced. The storage modulus at 0.1 rad/s initially increased with decreasing area ratios, showing that especially the storage modulus is very sensitive to the nanotubes dispersion state. It increased up to a mixing speed of about 75 rpm illustrating improved dispersion followed by a decrease when further increasing the speed. As GPC investigation showed no significant differences in the degradation of the PCL matrix depending on the rotation speed, the effect of decreasing rheological parameter was assigned to nanotube shortening. Both effects improved dispersion and nanotube shortening are also reflected in the electrical resistivity values of compression molded samples. Here, up to 75 rpm a decrease in resistivity due to the better dispersion was observed, whereas above 75 rpm, where dispersion had leveled off, again an increase was found reflecting the reduction in nanotube aspect ratio.
Thus, it could be shown that rheological measurements are suitable to detect differences in the dispersion state in composites with a fixed type of CNTs and concentration but also the effect of nanotube shortening reflected in lower aspect ratios.
E. Calvo González | Jean-Marc Gonnet, November 2011
In cable industry, the ease with which a piece of jacket can be removed (stripped) from insulated multiwires
is called strippability. A low stripe force is not only requested by customers and installers but it also makes
the cable more flexible. The purpose of this paper is to present a method based on numerical approach to reduce
the stripe force for a cable during extrusion. A correlation between the numerical parameter (pressure applied
around the wires) and the stripe force measured on samples has been demonstrated afterwards it is used to design
future extrusion pressure tooling.
Recent statistics on building fires show that smoke and toxic gases emitted due to burning of materials are much more harmful than the fire itself posing serious health hazard and sometimes fatal to the occupants1. It is for this reason, that many governing and regulatory bodies have laid Fire, Smoke and Toxicity (FST) standards for the use of plastics in public buildings and transportation in Europe, as well as the rest of the world. High-end engineering plastics like polysulphones are well known2 for their low smoke and flame retardance performance according to various standards, but their high cost could limit their use in certain areas of application. This work is an attempt to overcome these cost limitations by using an innovative technology and presents the development of a new poly(arylene ether) resin (PPE) based low smoke, flame retardant, halogen free, Noryl® NI-160 I OB resin (from here-on refe1Ted to as PPE+PS blend) that meets many of the FST requirements applicable to building codes and mass transit bodies in Europe and America. PPE resin is usually modified with polystyrene (PS) [ either crystal polystyrene (CCPS) and/or High Impact Polystyrene (HIPS)]. The PPE+PS blend utilizes a proprietary eco-friendly smoke suppressant technology that helps build robust char during its combustion. The robust char is believed to play a role in reducing smoke while maintaining outstanding flame retardancy and low toxicity. In addition, the PPE+PS blend offers advantages in terms of good proccessability, good mechanical and them1al properties, and low specific gravity.
Rudy A.C. Deblieck | D.J.M. van Beek (Linda Havermans) | Klaas Remerie, November 2011
The occurrence of two brittle ductile transitions is
explained in terms of craze propagation and craze-crack
transition models. The first and most familiar transition
occurs at low temperatures and high strain rates and it is
linked to chain scission. The other less well known
transition occurs at elevated temperatures and low strain
rates and is linked to molecular disentanglement. The
importance of the entanglement network for these
transitions is highlighted. The relation between these
transitions and the molecular mobility transitions such as
the glass transition and the -relaxation are discussed.
Strategies for increasing the crack propagation resistance
are reviewed. The present paper is taken from the authors’
feature article that appeared recently.
Aluminum has a high thermal conductivity which
make them less suitable for window frames unless the
inner and outer skin are separated by a thermal break.
Currently glass reinforced Polyamide66 is used for this
application. Noryl GTX* however has a thermal
conductivity, measured on a extruded sample which is
clearly below the thermal conductivity of Polyamide.
Noryl GTX is also capable to withstand the high powder
coating curing temperatures and meets the mechanical
requirements for thermal breaks. By the upcoming, more
stringent regulations on energy saving using Noryl GTX
will help to meet these requirements.
Anton Ginzburg | Tibor Macko | Robert Bruell | Klaas Remerie | Lars-Christian Heinz, November 2011
High impact polypropylene (hi-PP) shows consistent growth
rates, with the automotive industry being a main driver
behind this. The fractionation of hi-PP into the individual
components is essential to establish structure«property
relationships. High temperature two dimensional liquid
chromatography (HT 2D-LC), which couples a separation
according to composition by high-temperature high
performance liquid chromatography (HT-HPLC) with a
separation according to molar mass by size exclusion
chromatography (SEC) opens fundamentally new
perspectives to characterise the molecular heterogeneity
present in hi-PP. For the first time a separation of the
amorphous EP rubber fraction according to its chemical
composition becomes possible. The HPLC separation uses
porous graphite as stationary phase and gradients of high
boiling solvents as the mobile phase. Starting from the
separation of EP model copolymers it is shown how
commercial hi-PP can be chromatographically separated in a
comprehensive way.
Robert Brull, Guru Geertz, Raquel Maria, Karsten Rode, Tobias Schuster, Benjamin Baudrit, Martin Bastian, Mirko Wenzel, Jurgen Wuust, November 2011
The loss of stabilizing additives is a crucial elemental step in
the ageing of polymers. However, the approach currently
used to determine the spatial distribution of antioxidants in
finished or semi-finished products of polymers is extremely
limited with regard to spatial resolution and reproducibility.
Infrared microscopy offers an extremely powerful alternative
with regard to both these criteria: Using infrared microscopy
the extraction of the phenolic long term stabilizer Irganox
1010 from the wall of polypropylene pipes can be
monitored. Carrying out IR-microscopy in a quantitative
manner enables to determine the temperature and pressure
dependent diffusion constants of the stabilizer. The same
approach also allows to monitor the loss of Irganox 1010
from the surface of polyethylene pipes as a result of
weathering. A quantitative relationship between the loss rate
and the radiation dose can be established.
Mark van der Mee | Roland Assink | Peter Vollenberg, November 2011
Trends in Automotive Lighting towards increased design
freedom, weight reduction and lower system costs have
resulted in an increased usage of thermoplastics. SABIC
Innovative Plastics recently introduced its Lexan* XHT
resin portfolio, a family of new transparent high heat
polycarbonate copolymers. These resins can withstand
elevated temperatures existing in close proximity to the
light source and, as such, are suitable for usage in both
metallized bezels and transparent lens applications. This
paper will demonstrate the excellent metallization
characteristics, weatherability and long-term color and
property retention of these resins. Finally, other potential
applications of Lexan* XHT resins will also be discussed.
A fast method was develop to predict the macroscopic
properties of molded resin specimens tested in the
Underwriting Laboratories (UL®) Relative Thermal Index
(RTI) test (tensile strength retention) with microscopic
properties that can be easily measured (molecular weight).
By using higher temperatures than employed in the UL
RTI protocol, accelerated ageing can be achieved in
pellets.
Polyetherimide (PEI) resin was spiked during
extrusion with common stabilizers. The analysis focused
on melt stability, rheology and long-term heat ageing
performance. Hindered phenol stabilizers were detrimental
under accelerated thermo-oxidative ageing of PEI. The
use of new stabilizers should be carefully considered.
Polypropylene impact copolymers are widely used in
automotive applications. They are required to comply with
many criteria. Customers demand high-performance
materials which also exhibit good aesthetical properties.
The challenge is to balance properties as high impact
strength, good flow ability and absence of surface defects,
like tiger stripes.
It is known that peroxide modification whilst
increasing the flow ability of polypropylene impact
copolymers deteriorates the basic mechanical and
aesthetical properties.
Work was performed in which a PP-impact
copolymer was subjected to peroxide aided chain-scission
under simultaneous presence of the co-agent 1,4-
butanedioldimethacrylate (1,4-BDDMA). Results show
that samples made with 1,4- BDDMA exhibit superior
cold impact resistance and tiger stripe performance
compared to the materials made with only peroxide. In
addition, morphology, molecular weight distribution, and
rheological behaviour of the continuous and dispersed
phases of the modified PP impact copolymer were
studied.
André J.P. van Zyl | Robert D. van de Grampel | Tapan Chandra, November 2011
Lexan* copolymers offer new performance attributes in comparison to conventional polycarbonates by combining building blocks from different monomeric species. In doing so the application space of polycarbonates are expanded to include e.g. weatherability and scratch performance. By improving these attributes on an intrinsic level unique value propositions can be realized which include non-hardcoat or paint-out solutions. This can lead to cost-out opportunities and environmentally friendlier solutions. To emphasize application possibilities in the automotive industry, attributes are considered with regards to scratch, chemical and UV resistance for both Lexan* DMX and SLX resins.
Novel theory and methodology were developed to
increase and intensify competitiveness and business
activities of companies at plastics industry type SME. As
result of research work the model for R&D – Tampere
Model - was created. This model is based on four main
components - research, networking, university-enterpriseco-
operation and technology transfer.
This paper describes the Model, its main results in
economical and technological terms using a Finnish SME,
Vesita Ltd., as business case. The process has developed
the company and its business from small local to research
orientated and international. This has also led to new hightech
products and increasing use of plastics components.
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Any article that is cited in another manuscript or other work is required to use the correct reference style. Below is an example of the reference style for SPE articles:
Brown, H. L. and Jones, D. H. 2016, May.
"Insert title of paper here in quotes,"
ANTEC 2016 - Indianapolis, Indiana, USA May 23-25, 2016. [On-line].
Society of Plastics Engineers
Available: www.4spe.org.
Note: if there are more than three authors you may use the first author's name and et al. EG Brown, H. L. et al.
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