There are essentially two areas where polymers are used in the medical sector : disposable products/packaging
products and medical devices. The disposable products or packaging products need lesser properties or
performance compared to the sector of medical devices. New research and innovations play a major role
in the field of medical devices where newer materials are required for better performance. To develop
effective and safe devices, design engineers and manufacturers must have access to precise information
on material properties. Several new materials with enhanced properties have been introduced:
Recently a self-bonding silicone rubber that improves product performance and custom thermoplastic elastomers
(TPEs) with enhanced oxygen-barrier properties has been developed. BioSil SB self-bonding silicone rubber that
bonds to thermoplastics reduces scrap and can enhance the overall performance of medical parts made from
multiple materials. A two-shot moulding capability enables the silicone to be efficiently processed with
substrate materials such as polycarbonate, PEEK, polyester, polyamide, and phenolic polymers. The co-moulding
process eliminates the need to mould the silicone and thermoplastic parts in separate operations and manual
assembling. Moulding a multimaterial part in one press, under one process, provides design engineers with
greater design freedom compared with other methods. Seals, caps, septums and soft-touch instruments are among
the medical applications suited for this moulding process. The technology is suited for any silicone and
thermoplastic device component that is typically assembled or over moulded, as well as designs that demand
complex assembly.
Initially engineered for food packaging, custom-formulated TPEs may also have a future in healthcare applications.
These materials are reported to provide 10 times better oxygen-barrier performance, better clarity and cleanliness
than conventional TPEs. Cleanliness is ensured via elimination of the leachable halogens and heavy metals used to
cure thermoset rubber. The products offer numerous advantages over thermosets and silicone, which have
traditionally reigned as the materials of choice for barrier applications. Silicone, despite its rubbery
properties and clarity, is a poor material for barrier applications. Owing to their inert nature, TPEs can
be used for tubing applications and can act as a substitute for silicone. To improve barrier properties in
devices, design engineers could use TPEs in lieu of silicone and butyl rubber. Butyl rubber and TPEs share similar
barrier properties but TPEs do not require multiple production steps.
Because TPEs can be processed by means of high-pressure injection moulding, extrusion, and blow moulding, TPES provide
a great deal of design flexibility because. They are thermoplastics & can be converted by extrusion, injection moulding
as well as blow moulding. TPEs do not require reinforcing fillers, thus allowing them to maintain low specific gravity
and clarity. Moreover, they can bond to PP substrates, which open up opportunities for part consolidation and design
innovation.
Another recent product introduction is of special interest to OEMs that manufacture diagnostic catheters and similar
devices that require a smooth surface and radiopacity. Tungsten-filled thermoplastic urethanes, nylons, olefins, and
other polymers are now available. The materials resist solvents, soften at body temperature, and have high specific
gravity. They are available in Shore hardness ranges from 75A to 75D.
|
|
{{comment.DateTimeStampDisplay}}
{{comment.Comments}}