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Medical Polymer Tubing :
Applications & Extrusion Technology Highlights
Tubing quality is affected by a number
of factors, including raw material selection, material
handling, and the many parameters of the tubing extrusion
process.
Advances in extrusion technology are
aiding the evolution of plastic tubing with the latest
developments that include special formulations offering
unique combinations of desired properties such as
strength, flexibility, a high gas-barrier rating and
lubricity. The extrusion process is only as good as the
manufacturer’s ability to control it.
A tube’s dimensions can affect the
performance characteristics of extruded medical tubing.
However, process parameters, equipment, and material
characteristics also play an important role in determining
the end properties of an extruded tube. Tubes have
also shrunk dramatically in recent years, to the point
where a human hair is thick compared with some tube walls.
Manufacturing such products poses considerable challenges,
requiring special extrusion equipment, precise process
control, and painstaking inspections.
Designing and developing complex
multiplelumen tubing can spur innovation, provided that
the designer understands the latest technology and how
best to work with a tubing manufacturer.
The extrusion process is only as good as
the manufacturer’s ability to control it.
Medical Tubings : Common Applications
| Sr. |
Materials |
Common Applications |
| 1 |
Polyvinyl Chloride PVC |
Containers used for blood and blood
components for urine or for ostomy products and tubing
used for blood taking and blood giving sets,
catheters, heart-lung bypass sets, haemodialysis set
etc. |
| 2 |
Polytetrafluoroethylene, PTFE |
Catheter liner, Electrical Insulation,
Fluid transfer, Telecommunication |
| 3 |
Fluorinated Ethylene |
IV catheter, Regional Anesthesia,
Vascular access |
| 4 |
Ethylene Tetrafluoro ethylene, ETFE |
Fluid transfer, IV catheter,
Electrical insulation |
| 5 |
Perfluoroalkoxy, PFA |
Fluid transfer, In Vitro diagnostics |
| 6 |
NYLON, 6, 11, 12 |
Angiography, Choloecstectomy, Epidural
catheter, Laparoscopic instruments, Radiology |
| 7 |
Polyether Block Amide, PEBA |
Angiography, Cholangeography, Epidural
Catheter, Radiology |
| 8 |
Polycarbonate PC |
Laparoscopic instruments, IV therapy,
Laparoscopic cannulae, Tube packaging, Microtubes |
| 9 |
High Density Polyethylene LDPE |
Embolectomy, Guidewire dispensers,
Introducers, Protective tubes, Thrombectomy, Sheaths
and dilators for introducers, Coextruded perfusion
tubing, Aspirator tips |
| 10 |
Low Density Polyethylene LDPE |
Embolectomy, Guidewire dispensers,
Introducers, Protective tubes, Throbectomy |
| 11 |
Polyurethane PUR (Aliphatic) |
Angiography, Cardiac catheters,
Central Venous catheters, Dialysis, Epidural
catheters, IV catheters, Epidural probes, Catheters,
Highpressure lines |
| 12 |
Polyurethane PUR (Aromatic) |
Angiography, Cardiac catheters,
Central Venous catheters, Dialysis, Epidural
catheters, IV catheters |
| 13 |
Polypropylene PP |
Guidewire dispenser tubes and
Protective tubes |
| 14 |
Ethylene Vinyl Acetate EVA |
Endotracheal, Embolectomy, IV therapy,
Suction catheter |
| 15 |
ACETAL |
Laparoscopy, Guiding catheter |
About Catheter Tubing :
Number of variables affect the performance
of a finished catheter – the most paramount being the
properties of the raw material and the extrusion process.
Careful consideration of the extrusion process is
essential to ensure consistency and repeatability.
Single- or dual-screw extrusion is used to
manufacture catheter tubing.
During the extrusion process, air at a
specific pressure is used to obtain the intended tubing
shape. A heat-transfer process begins as the polymer exits
the die. Air is used as the initial cooling medium,
followed by water in a cooling bath. A belt or wheel
hauloff (puller) pulls the tube from the die and through
the cooling bath
at a controlled speed.
Because of the complexity of catheter tube
manufacturing, several parameters associated with the
extrusion process may affect the properties of the
finished product.1 These parameters include:
• Temperature profile.
• Initial method of drying the polymer granules.
• Temperature of the cooling bath.
• Tubing dimensions.
• Screw geometry.
• Rotational speed of the screw.
• The distance between the die head and the cooling bath.
• Polymer choice can also affect the finished product's
properties.. |
