Discussing material selection at the earliest
design stage of the project not only saves
time and cost, but also provides options the
designer may not be aware of.
Often, designers specify tight dimensional
tolerances or utilize the title block tolerances,
either of which may add unnecessary cost to
the component. With early collaborative discussions, areas of the product that require close
tolerances, can be identified and have realistic
tolerances specified. This maximizes production
success and minimizes tooling cost.
Product Design Considerations
Design engineers who lack knowledge in basic
plastic design principles may be prone to design
a component or device with challenges that
directly affect the mold and molding process.
This results in potential product failure and
increased manufacturing costs. Early discussions between designers and their molders can
focus on the basic rules of part design and help
the designer significantly reduce costs while
achieving a “quicker to market” introduction.
Some of the most fundamental of these
• Sharp corners should be minimized and
radiused to reduce potential stress areas
• Nominal walls should be designed with
uniform thickness to reduce the likelihood
of warping or distortion during cooling
• Generous draft should be designed in to
facilitate part removal from the mold and
to reduce the molding cycle time
• Extremely small or thin areas in the
product should be avoided to reduce the
likelihood of product failure
The Benefits of Collaboration
In conclusion, this article provides a brief
overview of the benefits of early collaboration
between designers and their molders, and the
unique challenges that are presented to both
when designing plastic components for efficient
manufacturing and maximum performance.
More importantly, it is meant to help all par-ties involved profit from the availability of the
latest innovations in materials that enable the
production of high-performance components
and devices efficiently and cost-effectively.
For those interested in increasing their
knowledge of plastic part design and mold-
ing, there are informative seminars available
online, and many local community colleges
offer training courses in plastics molding
technology. The knowledge gained will
be extremely valuable in guiding designers
toward designing components that take full
advantage of today’s molding technology.
It is the nature of the medical device market
that has proven each device has its own
unique challenges, some involving the physical
design itself and some involving the choice of
the most appropriate materials. In each case,
investing time in collaborative discussions with
a knowledgeable molder will pay dividends in
making the best, most informed choices, lead-
ing to a successful product in the marketplace.
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