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Newsletter (PDF)
Engineering Support
FLX-P™ Innovation
US Office:
31 Winterbrook Road
Mechanic Falls, ME 04256
Phone: 207-998-5140
Fax: 207-998-5143
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Frequently Asked Questions
About Static Control Devices
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Will
static control devices work if not grounded? - An ungrounded static control
device will remove charge for a short period of time.
Eventually the static control device will self charge
and stop working when the electric field between the
fiber tips and the charged surface is reduced to a level
which cannot support ionization. Electro Static Technology
recommends grounding static control devices to ensure
proper operation.
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What
wire gauge is necessary for grounding a static control
device? - The
ion currents are very low (microAmp range) therefore
22 gauge will be more than adequate. The ground wire
gauge is usually specified for its mechanical strength
rather than the current carrying capabilities.
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- What
is the ideal fiber pitch in a static control device? - Experimental data has shown that a 5mm pitch is ideal
for a static control device. A tighter pitch does not
increase the effectiveness while increasing the cost.
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What
should be the maximum gap in a static control device? - The ions are very mobile and
will easily travel 10mm from a fiber tip. Therefore,
the gaps on the ends of the static control device can
be 10mm and a gap inside the static control device should
not exceed 20mm. Larger gaps will limit the effectiveness
of the static control device.
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What
is the life expectancy of a static control device? - A static control device
will work for millions of cycles if the charged paper
does not touch the fibers. Electro Static Technology
recommends a distance of 2mm to 7mm between the fiber
tips and the charged paper.
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Will
a static control device work if the fibers are in contact
with the charged paper? - Yes, but the life expectancy
of the static control device will be reduced.
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Will
a static control device work if the fiber tips are greater
than 7mm away from the charged paper? - Yes, however, the effectiveness
of the static control device will be reduced. A static
control device will need a greater static charge to
induce ionization when the distance of the fiber tips
from the charged surface is increased.
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Does
a static control device remove all the charge from a
charged surface? -
No, the electric field between the fiber tips and the
charged surface will be reduced as the charge is reduced.
At some point, the electric field will be reduced to
a level that will not sustain ionization. All passive
static control devices leave a residual charge. The
objective of a static control device is to reduce the
charge to a level that will not cause a paper process
flow problem.
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What
degree of charge removal will eliminate problems in
paper transport equipment? -
This has to be determined by testing the paper transport
equipment in an environmental chamber with the relative
humidity level below 15%. Variables such as paper composition,
mechanical support of the paper through the equipment,
and thickness of the paper will affect the results.
The correct location of static control devices in the
paper transport equipment will be determined by experiment.
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Will
grounded rollers and conductive plastics remove charge
from paper? - No,
paper is an insulator and the paper will leave the grounded
rollers and conductive plastic surfaces with a static
charge due to charge separation. The static charges
generated on the grounded rollers and conductive plastic
surfaces will flow to ground, but the paper surface
will remain charged. The only way to remove a static
charge on an insulated surface is with a static control
device.
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Is
the adhesive on the peel and stick static control device
conductive? -
No, the adhesive is not conductive. Conductive adhesives
are not very aggressive. The peel and stick static control
device uses an aggressive adhesive with a space at the
top and bottom of the holder to allow the fibers to
make direct contact with a conductive surface under
the static control device.
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How
can I measure the amount of static charge on a surface? - Static charges are difficult
to measure directly. An indirect method is to measure
the surface voltage with an electrostatic field meter.
The surface voltage can be measured before and after
the installation of a static control device. The amount
of voltage reduction is an indicator of the static control
device effectiveness.
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What
is the best fiber material for my application? - This depends on where the static control device is
to be used. Carbon fiber is the most effective static
reduction material. However, carbon fiber is a brittle
material and will shed if the paper makes occasional
contact with the fibers. We recommend carbon fiber at
the exit trays of machines or anywhere that fiber shedding
will not cause mechanical or electrical problems. Stainless
steel should be used if the paper makes regular contact
with the fibers of the static control device. Stainless
steel is very resilient and will tolerate the abrasion
of paper contact. Conductive acrylic should be used
anywhere that fiber shedding cannot be tolerated. Conductive
acrylic is the most robust fiber material and is often
used inside paper transport equipment.
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Why
is carbon fiber the most effective material? - Carbon fiber has the smallest diameter filaments of
the common fibers used in static control devices. A
small diameter filament concentrates the electric field
and produces ionization at a lower static charge density
than a larger diameter filament. Both stainless steel
fiber and conductive acrylic fiber have larger diameter
filaments than carbon fiber. However, stainless steel
and conductive acrylic are still very good static reduction
materials and are recommended anywhere that fiber shedding
will cause mechanical or electrical problems inside
machines.
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Can
static control devices remove static charges from materials
other than paper? -
Yes, static control devices will reduce the charges
on the surfaces of any insulated material. Static control
devices are often used to reduce static charges from
rubber rollers, plastic surfaces, and ungrounded conductive
material.
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Email: sales@est-static.com |
