Fabrication of dissolvable film tabs requires an adhesive solid support like PSA
(Fig.5.17). First, the knife cutter is used to cut out the inner holes and the chads are
manually removed. Next, the upper layer of PSA is removed exposing the adhesive
surface of the PSA. A sheed of dissolvable film is rolled onto this layer and pressure
is applied to the film to ensure a good seal over the hole. The outer edge of the DFs
is then defined by using the second CAD file above. The force used by the knife
cutter should be lower than used for the inner DF cut; this results in the DF tabs
remaining mounted on the backing film such that they can be peeled off for
placement into the discs (Fig.5.18).
6.4 Cutting PMMA
The cutting of sheets of PMMA is relatively simple in comparison to that of PSA,
sheets of PMMA are firstly cut by hand to the size required by the laser cutter being
used, in this case the laser cutter is a 30 W Carbon Laser. Once the laser is set up the
DXF files, shown in Fig.5.19, can be opened in the controlling programme Corel
DRAW X5 or an alternative programme if using a different piece of equipment.
Once this is complete the laser can be activated.
Fig. 5.17 The DXF files showing the inner and outer cuts made in a sheet of PSA (Left) and a
graphical representation of the procedure required to create dissolvable film tabs
Fig. 5.18 30 W Carbon
Laser
136 B. Henderson et al.