There has been sustained, long-term
growth in the field of medical polymers, which will be
maintained over the next several decades as
generational population shifts drive the need for
advances in healthcare. This growth is not limited to
just one sector of the medical polymers industry.
Advancements of all kinds will find a niche in this
booming healthcare market.
Quality Of Injection Molded Plastic
Components used for the Medical Applications depends
on factors that include part design, material
selection, quality of machines, the design and quality
of Moulds as well as the processing conditions.
So, you want to be a medical device
Many injection molders currently
serving markets that are slumping are beginning to
recognize the value of diversification, and the mantra
of many has become, “I want to get into medical
molding.” It’s easier said than done.
The medical industry, while it may
look a stable, high-volume segment, is a tough market
to enter. The barriers are primarily regulatory, and
Good Manufacturing Practices (GMPs), clean rooms, and
the high cost of compliance restrict many molders from
A major misconception in the
molding community is that big money is to be made in
medical devices, however, the reality is that the
pricing pressures are just as heavy in medical as in
automotive or consumer products.
While molded components for nearly
all markets require quality, on-time delivery, and
best cost, meeting those requirements in medical
device molding is much different from other markets
because of compliance issues. The overall company
culture requires a different mindset for employees who
need to understand the medical device manufacturing
Molding medical device or healthcare
products tends to require more resources.
The goal of the medical part
designer should be to provide a part that combines
maximum functionality with minimum complexity. Some of
the important principles as enlisted below, when
overlooked results in increased mold costs, a
defective final product, or premature part failure.
The most basic principle of plastic
part design is that uniform wall thickness should be
maintained wherever possible. Thin sections are weak
structurally and difficult to fill; they can restrict
flow and require increased injection pressure. Thick
sections are easier to fill but difficult to cool and
pack out; they are subject to increased shrinkage, and
may cause sink marks, voids, and high levels of
molded-in stress. When thickness variations are
unavoidable, they should be designed with a gradual
transition, which will help reduce the level of
molded-in stress at the transition region.
Corners are often problem areas
because of non uniform thickness. If the outer radius
is too small, a thick section is created in the
corner; this increased thickness then causes cooling
and war page problems. If the outer radius is too
large, the corner will be thinner than its adjoining
walls. Besides being weak structurally, the change in
thickness can serve as a flow restrictor. The best
approach is to have the inner and outer radii
originating from the same point, ensuring a uniform
wall thickness through the corner.