SGIA Journal Graphic November/December 2016 - 72

have been made to improve screen output
that would greatly influence the lowering
of PUC? The point is businesses with both
screen and digital capabilities may be
pleasantly surprised to learn they can get
a lot more mileage and perhaps untapped
benefits from screen, merely by increasing
productivity to become much more
competitive towards the smaller-volume
range. Doing so is a win-win strategy for
all and without the necessity of new hefty
capital investments.
Swim With or Against the Alligators?

What pressure does for tires
is identical in every respect to
what tension does for screens.

The objective of this article is not to
switch any company's alliance to digital
back to screen. It is about making screen
more proficient and profitable with lower
quantities to increase business. While there
are a several ways this can be achieved, the
two most significant is either embracing
CTS - computerization of the image
rather than costly film positives, as alluded
to easier - or increase productivity by
enhancing production output typically at
no additional cost. While incorporating
either one alters the playing field, our focus
will be the latter as the former requires
capital equipment investment.
One of the biggest pitfalls that prevents
screen printing operations reaching high
productivity rates is to be found not on the
production floor, as most people believe,
but in screen making, from routinely
making do with grossly under tensioned
screens. This part of the process is a major
drawback with any screening operation
and one that constantly separates them
from top performers. In many instances,
screen tension is not even close to where it
ought to be, either for the fabric grade or
to aid critical elements of the job.
Promising from the outset that this
would not be a technical article, it is
nonetheless an inspirational message
a b out a n a mu si n g e ve nt , w h ic h
appropriately says much about why
suitable screen tension should be used
to excel productivity and more. Astute
printers have known for the longest
time the direct relationship between
proper tension levels, as defined by fabric
manufactures, to the sheer quality and
hassle-free production it naturally returns
right out of the gate, simply by adopting
them as standard regardless of job.
Car Tires and Screen Tension

Before we go any further about qualifying
suitable tension levels, let's change
direction a by asking a question about
two seemingly unrelated things, from an
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November/December 2016

analogy standpoint. What does a car tire
share in common with screen tension?
Moreover, how important is having the
correct air pressure in a tire? The question
relates to an event that happened a long
time ago about someone's unfortunate
experience from my neighborhood, who
inadvertently created a mini-disaster of
his own making while mowing his lawn.
He admitted his embarrassment about
the incident taking place, particularly as
a truck driver himself and should have
known better about tire pressure.
When asking attendees during my
training sessions what is the difference
between the two, they invariably look
around the room at one another, drawing
a long puzzling blank stare, then suddenly
realize it must be something crucial. On
occasions the right response is given,
"correct pressure and tension are both
very important," or subtle variations.
In other words, what pressure does for
tires is identical in every respect to what
tension does for screens. Read that again
if not digested.
The reality is we drive on tires daily
without ever giving pressure a second
thought. Well, that is exactly what this
poor feller did. He did care about pressure,
but for a compelling reason he did not
bother with it this time - an inaction he
painfully lived to regret. I conveniently use
this incidence frequently because it says so
much about tire pressure being effectively
one and the same to screen tension -
except for one major difference.
The overall performance of a car suffers
considerably; safety among other things
are immediately compromised when
driving on underinflated tires. In a huge
class-action lawsuit regarding loss of tire
pressure, it was claimed that a mere drop
of 4 psi (0.275 bar) tire pressure resulted
in a safety reduction by the factor of
12 percent! Safety would then begin to
deteriorate rapidly thereafter, to a point
of losing complete control of the vehicle.
This is comparable with the declining
performance of what under-tensioned
screens typically yield; the only difference
between that of a tire is the screen drives
print quality, and ultimately productivity
as a result rather than a vehicle.
Printing with lower tension than
desired for the fabric grade, or crucial
demands for which the job may require,
immediately throws productivity and
more into jeopardy. It has been verified
time and again that screen tension in
production is often less than half than
what fabric manufacturers' state in their
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