there are more tape debris in Travan5 head ceramic surface
than in LTO in the same experimental conditions indicating
contact pressure effect leading to more debris of the tape
transferred to the head surface. For both systems, increasing
temperature and water content, there is more tape debris
produced indicating tape degradation in the higher temperature
and high water content.
In previous publications [6,7] we have shown that Fe
stain formed preferentially on the metallic poles and on the
TiC phase in the ceramic. The poles in their ‘as received’
state are slightly recesses and as a consequence the contact
pressure is slightly reduced in this area and this might
reduce stain removal rate, once formed. The mechanisms
of stain formation in modern linear data tape systems have
been detailed by Sullivan and co-workers [6–8]. If
adhesive interaction between the outermost polymeric
layer of the tape and the materials of the head is greater
than the internal cohesive bond strength between pigment
particles and binder, material transfer will occur. Sullivan
[8] estimated mean contact temperatures of a Travan5
linear tape system to be over 130 8C. As the contact
pressure for the LTO system is less than one-third of that of
Travan5, mean contact temperatures are likely to be
considerably less than this. Adhesive bond formation is a
chemical process that is governed by temperature, thus the
higher the contact temperature the higher the probability of
adhesive bond formation and the greater the amount of
transferred material (stain). Thus stain in the Travan5
system is more easily formed than that of LTO and
coverage is far more extensive under similar tape
formulation, spread and environmental conditions than
that of LTO.