Depth marks and printing can easily be added to catheters and metal shafts with
heat shrink tubing. Typically thin bands of colored shrink tubing are used for marking.
They can be accurately positioned using the proper techniques. Labeling information
can be added by pre-printing on the shrink tubing, then applying it to the product.
That avoids the need to send the devices themselves to a printer for labeling or
to bring printing inks and solvents into the manufacturing facility for in-house
printing. Some products, such as catheters made from high density polyethylene,
cannot be readily printed without surface treatment, adding more complexity. Manufacturers
who do print on their products can use clear heat shrink tubing over top of the
printing to protect it. The ultra thin wall of polyester heat shrink tubing does
not increase the diameter of the product substantially.
A clear tube (top) is marked with bands of transparent
green heat shrink tube. Pre-printed polyester heat shrink tubing (middle two images)
is shown before and after shrinkage in a labeling application. At the bottom, alternating
white and black bands of polyester heat shrink tubing are shrunk onto a clear catheter
tube.
The key properties of polyester heat shrink tubing influencing marking and printing
are:
- Can be printed with any color and graphic
- Tubing is available in variety of colors
- Thin wall tubing adds little to the size of the product
- High-gloss surface provides quality appearance
- Can be accurately placed using proper techniques
- Clear tubing can be used to protect printing on the product