WINTER 1998
Volume 4 • Number 1
MATERIALS:
Why Test?
Why is plastics material testing so important?
There
are many reasons to consider conducting material testing, but
the answer to the question "Why test?" depends on what you hope
to discover about your materials and products. Are the results
expected to provide you with information about the material's
mechanical, chemical, or flow properties? They will. But these
answers are often dependent upon the intended application. In
many cases, testing also can help resolve a problem with an existing
design and material.
Typically,
mechanical properties testing includes tensile strength, flexural
modulus, or impact strength. These properties are often important
in determining the load carrying capability of a part or assembly,
or to provide useful and accurate data in a finite element structural
analysis.
The
chemical makeup of a plastic material can be tested to determine
the type of material to be used, the percentage of a single component,
or percentages and types of fillers and reinforcements. Material
identification can be important in deciding whether or not the
proper material was used in molding the parts, and to determine
if the material supplier shipped the correct material grade.
The
flow -- or rheological -- properties of a material generally refer
to how a molten material flows. These flow properties can be determined
from the plastic's melt index or viscosity, which is measured
using a capillary rheometer. This information is necessary to
help determine the material's effect, how the part will fill,
and what kinds of pressures may be developed during filling. The
rheological data can be used to compare the flow properties of
several materials, or to perform a predictive process simulation
via a computer filling analysis.
After
determining the types of properties or results you are looking
for, focus on locating a resource capable of performing the necessary
tests. In northwest Pennsylvania, two sources for plastics material
testing are the Plastics Technology Deployment Center and OSRAM
SYLVANIA Products, Inc. The PTDC, which is located at Penn State
Erie, is capable of performing many physical, mechanical, and
rheological tests. OSRAM SYLVANIA Products, Inc., located in Warren,
PA, can perform a wide range of tests including mechanical properties,
physical properties, material identification and environmental
testing.
The
cost of testing varies depending upon the type and number of tests
to be performed, the material to be tested, and the quantity of
specimens. The following is an expanded list of the capabilities
of the PTDC and OS-RAM SYLVANIA; for a more detailed list and
cost information, contact the staff member at the number provided.
Plastics
Technology Deployment Center
Tye
S. Sonney
(814) 898-6499
- lzod
impact
- Dart
impact
- Moisture
content
- Tensile
properties
- Flexural
properties
- Melt
viscosity using a capillary rheometer
- UV
weathering (accelerated weathering)
OSRAM
SYLVANIA Products, Inc.
Jim Kuenzie
(814) 726-6977
- Thermal
shock
- Glass
transition temperature
- Plating
thickness
- UV/VIS
spectroscopy
- Coefficient
of linear thermal expansion
- Dynamic
mechanical analysis (DMA)
- Differential
scanning calorimetry (DSC)
- Scanning
electron microscopy (SEM)
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The
Vector is Coming
Question:
What weighs 70,000 pounds, has eighteen wheels, and conference
seating for 20?
Answer:
GE Plastics' VECTOR truck.
And
you thought your pick up was loaded with options. When parked,
GE Plastics' VECTOR truck converts into a 700-square-foot conference
center and exhibit area featuring sophisticated audio-visual equipment,
modular displays, and a conference table able to seat 20 people.
This 18-wheel mobile innovation center literally brings solutions
to customers' doors by offering a high-tech environment for GE
Plastics representatives to develop and discuss answers to their
clients' material and processing problems.
The
PTDC has invited VECTOR to roll into Erie this spring for a visit.
Stay tuned for more information about touring this unique facility
on wheels.
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Rapid
Commercialization Consortium Forming
If the buzz words rapid prototyping, rapid tooling, rapid inspection,
reverse engineering, and process optimization pique your interest,
perhaps it's time to try the Rapid Commercialization Consortium
on for size.
The RCC is a new entity forming under the direction of Brad Johnson,
a Penn State Erie plastics engineering technology faculty member
affiliated with the PTDC. The RCC, which will be located at Penn
State Erie, met for the first time January 16 to discuss potential
strategies for success.
The
consortium will continue to accept new members through April 1;
for detailed membership information, contact Johnson at (814)
898-6148 or by e-mail at bgjl@psu.edu.
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New
Hire: Senior Engineer Joins PTDC Staff
New Senior Engineer Martin J. Dropik brings 19 years of experience
in the plastics industry to the PTDC.
Prior
to joining the center, Marty was senior CAE staff engineer in
Product Development Engineering at Fisher-Price, East Aurora,
N.Y. While with the toy manufacturer, he held a variety of plastics
engineering positions in computer-aided engineering, materials
engineering, processing, and management. Marty also is former
owner of Dropik Design Services, which consulted on flow analysis,
product design mold sourcing, and plastics engineering for the
automotive, medical, and consumer goods industries.
Marty's
focus at the PTDC will continue to be high-technology tools for
plastics processing including structural analysis, flow analysis,
and product design. He is fluent in the use of Pro/ENGINEER, MoldFlow,
ANSYS, Hypermesh, and ADAMS computer software.
"The
PTDC's proximity to the university and local industry excites
me, particularly after working in a corporate environment where
most manufacturing took place in the Far East or South America,"
Marty said of his new position. "I'm going to be able to focus
my efforts on local impact. For the first time I'm talking with
clients who are making their living by processing plastics just
down the road, instead of in Monterey, Mexico, or China."
Marty
holds a bachelor's degree in mechanical engineering from the State
University of New York at Buffalo, where he has also completed
coursework for a master's degree in engineering. He is a member
of the Society of Plastics Engineers and the Society of Mechanical
Engineers.
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Memo
To Manufacturers: Painless Plastic Material Selection
No
pain, no gain, right? Wrong! The variety of compounds and resins
commercially available today seems infinite, we know. And you're
right — there is a better way to select the best of the best for
your applications.
PTDC
offers an impressive array of comprehensive design and engineering
services to our customers. We deploy some of the most advanced
design technology available, make use of extensive CAE modeling
and engineering analysis capabilities, and stand ready to support
every customer and every customer's design, from initial concept
through manufacturing process design and optimization.
One of the biggest challenges our clients typically face in their
quest for product excellence is selection of the most appropriate
material for a particular application. We at the PTDC have a tough
time keeping up with the thousands of materials and blends available
— and this is a key aspect of our job. We can only imagine that
our valued customers are overwhelmed as well.
Many experienced plastics product designers and materials engineers
(our PTDC team included) routinely follow a common-sense, intuitive
process for selecting the preferred material for their applications.
Combining this experience with use of extensive material selection
guides, computerized databases, and the technical resources of
resin producers will often result in an objective, high-confidence
plastic material choice.
But what about those designers and well-grounded experience and
materials information resources? How do these companies ensure
that they are minimizing their risk, maximizing their investment
and on the right path towards making the best material choice
for their application? What's an engineer or a manager to do?
Risk
can be reduced and your chance of getting it right the first time
can be substantially improved by employing the following material
selection process:
- Clearly
identify all the end-use and functional requirements.
- Define
end-use requirements in specific, quantitative terms.
- Translate
the quantitative requirements into ideal plastic material properties.
- Identify
candidate plastic materials generically -- resin family, agency
or customer approval, etc.
- Select
prospective material grades within resin families that best
correlate to ideal properties required.
- Systematically
evaluate the prospective materials in terms of performance,
cost, ease of processing, etc.
- Consult
external resources, such as resin suppliers and the PTDC, to
fully understand material capabilities and trade-offs.
- Select
the best material(s) for your application.
In
the words of my brother (a senior automotive service technician),
"Nothing beats experience and the right tools." But accessing
the right experience and tools and using them to select the best
plastic material is at times a very risky proposition. Far too
often product introduction is seriously delayed or sometimes shelved
because someone did not do his or her materials homework. Hopefully
your material mistakes will be caught before they find their way
to your customers. If not, well, you'll have pain, and still no
gain.
The
PTDC wants to help you avoid pain and the expense associated with
misapplication of plastic materials. Give us a call at (814) 898-6145
and we'll put our tools and experience to work for you.
-
David Thomas-Greaves, Director
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