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Global
Trends in Medical Plastics Technology and Applications
Processing: The
processing of the plastic components is usually done by
standard thermoplastic processing techniques such as
extrusion and injection molding. Other techniques, such as
thermoforming, laser ablation, solvent processing and
silicone rubber processing, may be used depending on the
material and the device requirements.
As an example, catheter
extrusion is one of the common devices that are used for a
variety of different devices and purposes. Various
configurations are possible within the extrusion of this
tubing geometry. Catheters with multiple lumens, lumens
with different geometries and curved or straight tubes are
some of the variants in the design, this is illustrated in
Figure 5. Catheter production requires an extrusion line,
water bath, dimensional control, a winder and an annealing
oven.
Figure 7: Various catheter geometries
and shapes
Medical device assembly
is done in a cleanroom. A cleanroom is defined as A room
in which the concentration of airborne particles is
controlled, and which is constructed and used in a manner
to minimize the introduction, generation, and retention of
particles inside the room and in which other relevant
parameters, e.g. temperature, humidity, and pressure, are
controlled as necessary.
The greater the
criticality of the device, the greater the restrictions
placed on the construction of the cleanroom. Medical
plastics, in general, are the components of the device
rather than the device itself and consequently, most of
the medical plastic processing can be done in less
stringent environments.
Sterilization: All
medical devices have to go through the process of
sterilization. Sterilization is the process of killing of
all micro-organisms (bacteria, virus and fungal) by use of
either physical or chemical means. Human skin can never be
completely sterile, hence covering the human skin is an
important aspect of a sterile environment. The inside of
the human body is devoid of bacterial growth and is termed
aseptic. Transfer of germs into an aseptic environment is
contamination Sterilization of all items used in surgery
is essential to the maintenance of asepsis.
There are different
methods of sterilization. The method could be based on
thermal elimination of contamination, either using Dry
heat or Steam. The method could be based on chemical
means, using an Ethylene oxide (ETO) environment, or the
method could be based on the use of high energy radiation.
Conclusion
As the importance of
the use of medical devices in healthcare is increasing,
the worldwide market for these devices is forecast to
increase robustly. Plastics form the core of many medical
devices and therefore the use of plastics in medical
applications is a fast growing market.
Plastics have a great
range of properties and this huge variety of plastics
properties means a number of different medical device
applications can be satisfied by plastics. However, many
times the applications are not fully satisfied as the
properties of the plastic material are not completely
exploited. There is clearly a distinct need for plastics
expertise to be involved in the further development of the
medical field.
The selection of a
particular plastic material is dictated by the needs of
the device and application. Many aspects of the behavior
of the material in different conditions and environments
are taken into account in order to select the right
material.
The production of
plastics components for the medical industry requires
discipline, certain extra procedures and controlled
methods.
Plastics production for
medical applications is, however, not onerous and
difficult.
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