SGIA Journal Graphic November/December 2016 - 42

stack of fabric...it costs a lot less money
this way - for us. For the dye-sublimated
pieces, we use a different process, but
it still manual. I think the laser cutters
are super cool, but they still require an
experienced operator."
A large manufacturer of custom flags
had the same basic process. Textile flags
were placed on a large table, and then an
employee would cut out the graphic using
a rotary blade. Both of these operations
have looked at the newer laser or rotary
knife (drivel wheel) cutters that will be
covered here. They think that they will
one day be in place in their facilities, but
for now their process remains unchanged.
However, rotary knife flat-bed cutters
have been around for a while and are the
way to go if you are cutting anything
besides polyesters. The lasers are newer
and will catch on, if for no other reason
than they will end up being more efficient.
Sewing and Welding

For a different perspective about sewing
and welding, Jordi Carbonell, CEO,
Matic S A*, had an excellent point about
how it comes into play at the end of the
process. At this stage, you have already
invested significant time, materials and
ink, and a misstep at this juncture costs
not only the rework of the job, but the risk
of missing a deadline, which can lead to
the loss of a client. His takeaways were
to concentrate on the workflow (how the
material is handled and how efficiently
can the operator manage each job) more
so than machine speed, and that there is
no unique machine for all of your needs.
Knowing your application, including
material types, will go a long way to
prioritizing which piece of equipment
will best serve your needs.
Before looking at some of the options
to consider when looking at sewing
and welding, it's important to cover the
different technologies that come into play.
I'll start with hot air welding, which
is probably exactly what you think it is.
It a specially designed heat gun (or hot air
welder) that produces a jet of hot air that
softens the parts that you want to join.
Some advantages are that it is a low-cost
option. In theory, the length of the weld
is endless, you can start and stop through
the process, and it certainly takes up little
space. Some of the disadvantages is that it
can create waves because it has no cooling
bars, you need a very experienced operator,
and the quality of the weld is not as good.
Next up is hot wedge welding, which
uses a heated steel wedge positioned at the
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November/December 2016

seam point providing heat for melting the
fabric. The advantages and disadvantages
are the same as the hot air welding with
one additional disadvantage - the steel
wedge will allow the heat to build up when
not in use, and when you initially reapply
to the fabric it can sometimes burn the
fabric at the initiating point.
High-frequency welding is the joining
of materials by supplying high-frequency
energy in the form of an electromagnetic
field (27.12 MHz) and pressure to the
material you want to join. The electrical
energy causes the molecules within the
material to start moving, which generates
heat and causes the material to soften and
then fuse together. This is more typically
used for PVC; however, it can also be used
for polyurethane, and it can weld more
than two layers at the same time. Some
advantages are a very homogeneous heating
and it is easy (and fast) to changeover to
different welding widths. Disadvantages
are that it is a very expensive technology
and not always successful for fabrics, but it
is used on awning materials, canvas, tents
and automobile mats.
Lastly is impulse welding, which is
a process where layers are heated and
fused to form a welded seam by pressing
them together in close contact with a
shielded electric heating element. The
heating element (or electrode) is heated
up by control led pu lsed cu rrent.
Advantages are that it is one of the easiest
to handle, welding of different textiles,
PVC or polyurethanes without welding
tape is possible, reasonably priced, low
energy consumption, and automatic
guides and folding systems are available.
Disadvantages are that it is not as strong a
weld as high frequency, and the machine
is stationary with a max electrode width of
30 millimeters (mm).
For sewing, Matic offers the Cronos
in three varieties from basic to the
ultimate. The Cronos has auto-feeding
and cutting along with guides to help
produce banners quickly and efficiently.
The automatic conveyor belt helps the
operator manage larger banners or silicone
edge graphics (SEG). Another feature is
the conveyor lock for producing curved
seams for teardrop flags. Matic also has the
Hercules, a unit designed to join and hem
canvas with a mobile sewing head that is
synchronized with the sewing speed. The
Zeus is designed for automatic finishing
for curtains, as it will do the lateral seams
and sewing the tape with rings all in one
machine. Lastly is the Orion, which is
good for PVC-coated fabrics.
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SGIA Journal Graphic November/December 2016

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