Orthopedic Fiberglass Casting Tapes Gained Widespread Commercial Acceptance (3)
Many of the printing inks which can be used to print orthopedic fiberglass casting tapes substrates were solvated and bled after the polyurethane resin was applied. Sometimes the printing ink itself provided chemical instability to the system. That is, the chemical interaction between the printing inks and the polyurethane resin may cause premature gelling of the resin or a color change in the ink. As used herein, the term "gelling" has the same meaning as that used in U.S. Patent No. 4,433,680.
Many printing substances cause a significant loss in the conformability of glass fiber casts. The printing is such that the conformability of the fiberglass substrate should not be compromised significantly after printing inks are dried and cured. This is the obvious need for the conformability of the substrate in order to provide good fracture immobilization. Because the glass fiber surface would not readily absorb the pigments, large quantities of inks must be applied in order for the inks to become locked in the interstices of the fabric. However, in the case where the cured inks become hard, the interstices of the substrate become locked which causes a loss in stretchability and conformability of the orthopedic fiberglass casting tapes. It is therefore desirable to have systems which remain flexible after curing and permit the application of thin layers of prints to the surface so that there is little effect on the conformability of the casting tape.
