Originally Published EMDM November
2004
Equipment News
Recent developments in tube-processing equipment |
Tube expander facilitates precise assembly of tube sets
A versatile tube expander supplied with standard straight and 90° jaw sets
is designed to simplify and accelerate the assembly of medical tubing and fittings.
Offered by Lakeview Equipment Inc. (Northbrook, IL, USA), the production-ready
Model 595AC also comes with a gauged and regulated foot pedal that allows smooth,
infinite control. A threaded stop on the expander enables expansion width to
be adjusted to precise requirements.
The straight jaws are appropriate for most standard tube expansion applications
involving polyethylene, polyurethane, vinyl, PVC, and other elastomeric tubing,
in which the fitting is assembled with the tubing after the tube has been removed
from the expander. The right-angle jaws are suitable for rubber, latex, and
silicone tubing and situations where the fitting must be assembled while the
tubing is still expanded on the jaws.
Six straight jaw sets can accommodate tubing sizes of 0.062–0.500 in. ID,
and five 90° sets handle tubes with inner diameters of 0.062–0.375
in. The latter are Teflon coated to allow the tube with fitting inserted to
slide off the jaws easily as an assembly. Special jaw sizes meeting custom specifications
can be supplied in either configuration.
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Die stretcher prepares extruded tubing for catheter production
An extrusion die stretcher performs hot-die drawdown of plastic tubing that
is to be used in catheter production. Interface Associates (Aliso Viejo,
CA, USA) designed the machine so that catheter manufacturers could enhance the
strength of their tubing materials and optimize outside diameter tolerances.
Typical applications of the die stretcher include neck-down processing, balloon
tubing preforming, and heat-setting of sheathed, wrapped balloons. The ma- chine
is able to process as many as three plastic tubes simultaneously.
Other catheter production equipment available from the specialty manufacturer
includes balloon-forming machines, balloon-folding fixtures, a laser measurement
system, a wrapper-crimper, pressure testers, a tube-welding machine, and custom
moulds. The company provides balloon production services as well.
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Automatic tube cutter is engineered for biomedical accuracy and precision
A high-performance cutting machine specialized for tubing wound on reels is
especially suitable for tubing destined for biomedical applications, where the
precision of cut length, the accuracy of cut, and the quality of the machine
materials that come in contact with the tubing are critical. The Tecnocut automatic
cutting machine is manufactured by Tecnoideal S.r.l. (Mirandola, MO,
Italy). It features a top line speed of 75 m of tubing per minute and a maximum
cutting speed of 30 cuts per minute. The machine can be programmed with cutting
sequences consisting of as many as 20 tubing lengths. Programmable cut length
can be anywhere from 5 to 9999 mm.
The machine includes an interface for connection to a personal computer or programmable
logic controller. In order to accommodate various customer requirements, it
can be equipped with a discharge conveyor for orderly collection of the cut
tubing into bundles, and with a blade-wetting system that deposits a few drops
of alcohol on the blade to maximize cut quality with such sticky tubing materials
as EVA and silicone. Also available to accessorize the machine is a mechanism
that facilitates the pulling and cutting of very-small-diameter or elastic tubing
so as to achieve a desirable level of repeatability.
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Flexibility of catheter extrusion lines matches the variety of catheter
tubes
Extrusion lines for medical catheters are designed to be highly flexible, so
as to accommodate variances in tube diameter, wall thickness, polymer material
of construction, and, in the case of coextrusions, layer thickness. Lines engineered
by Dr. Collin GmbH (Ebersberg, Germany) produce catheter tubing with small diameters
of 0.5–5 mm, thin walls of 0.07–0.5 mm, narrow tolerances, and single-,
double-, and triple-layer structures. They feature takeoff speeds as high as
100 m/min and offer fast product changeovers.
Finely tuned extruders 16, 20, 25, 30, and 45 mm in diameter cover a wide throughput
range of 0.05–10 kg/hr. Exchangeable feed bushings allow a wide range of
polymers to be processed. Other line elements include melt pumps; gravimetric
feeding units; dies designed for short flow length, fast purging, no dead spots,
temperature homogeneity, and individually adjustable tube-layer consistency;
and a vacuum calibration and cooling system. All in-line components comply with
appropriate cleanroom standards. The lines are governed by a central unit that
controls the acquisition, documentation, and validation of all process data.
Catheters formed precisely, efficiently
The application parameters of a series of systems designed to weld, tip,
and form catheters have been widened through the refinement, improvement, and
diversification of tooling designs. PIRF systems from Sebra (Tucson,
AZ, USA) precisely control the flow of a broader range of plastics and accommodate
more sizes and forming dimensions than previous models did. The systems, which
can be teamed with a variety of tipping, welding, and forming moulds, provide
cost-efficient semiautomatic production of complex assemblies.
PIRF II systems are designed specifically to form complex small-profile catheters.
They concentrate heat in bands less than 1 mm wide, a precision that enables
tips with a smooth surface finish and strong welds to be created, even from
braided materials and materials with differences in durometer. A CE-marked version
meets international safety and emissions standards.
Introduced to form large-profile catheters for tracheal, urinary, and other
applications quickly and accurately, the high-power PIRF III system improves
operator efficiency in performing multiple-part tipping.
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