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Frequently Asked Questions
- Lead Times?
- Warranty?
- Terms
- Samples available?
- How do we return a Defective,
Incorrect or Undesirable Product?
- Is Representation
and Technical Support available in my area?
- What other Products
does U.S. Supply sell?
- Which Belt is
suitable for our process?
- Are Tracking problems correctable?
- What causes Ghosting?
- Why is our Rubber Belt
cracking?
- Why is our Felt
Blanket cracking?
- What causes Seam failure?
- How can we obtain our desired
Shrinkage?
- Why is our Rubber Belt surface
sticky?
- What causes Premature
Belt failure?
- Why does our Felt
shed fibers?
- Why
are our Stainless Blades Delaminating? What causes Serrated edges?
- When and
how do we Grind our Rubber Belt?
- How
do we determine the proper Rubber Belt Tension?
- Is it
possible to Repair our Belt?
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Lead Times?
United States Supply maintains a stock of our most frequently ordered
products; particularly with regards to Squeegee, Rubber Belts, Felts,
Conveyors, Cheesecloth, Dalo markers, Roll lagging, and Leader tapes.
If the product ordered is a stock item, we pledge to ship Domestic orders
the same day ordered, if the order is placed before 2:00 PM, EST.
(Note: Export shipments generally require additional time for paperwork,
scheduling bookings, transit to port, etc.)
If the product ordered is not in stock, we can generally ship within a
week, unless the product ordered is a special or unique product design.
For lead times on any specials, please contact us at sales@ussupplyinc.com.
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Warranty?
United States Supply Co., Inc. warrants all its products to be free
from manufacturing defects or we will replace or repair them at no charge.
This Warranty is valid only if the product, in part or in whole, is returned
for analysis. No claim will exceed the invoice value of the product.
Beyond this, please understand that due to all the variables involved
in the use of our various products, set warrantees for certain time periods
or meters run are simply not possible.
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Samples available?
YES we welcome the opportunity! Please e-mail us at sales@ussupplyinc.com.
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How do we return a Defective, Incorrect, or Undesirable
Product?
Please contact us through Tech Support
or by calling 704-399-4276; faxing us at 704-393-5628; or e-mail at sales@ussupplyinc.com.
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Is Representation and Technical Support available
in my area?
Agents are strategically located throughout the world to provide prompt
delivery and service. Please contact us through Tech
Support or e-mail us at support@ussupplyinc.com
for the name and address of a U.S. Supply Agent near you.
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What other Products does U.S. Supply sell?
Since our inception in 1947, U.S. Supply has tried to meet the product
requests of its customers. Basically, we supply any product related to
the mechanical aspect of Textile Finishing and Printing or any product
related to Rotogravure Pre-press. For a specific product request, please
contact us through sales@ussupplyinc.com
and/or visit our Complete Products
Listing
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Which Belt is suitable for our process?
Please indicate which operation or application you are currently involved
with when you contact us.We will then ask specific questions to help determine
which product is best for you.
____Transfer Printing _____SANFORIZING ____Decating
____Compacting _____ Dryer Ovens ____Polishing
You may also contact us through our Tech Support
form or e-mail us at sales@ussupplyinc.com.
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Generally this is due to a shifting of paper and fabric. The shifting is
typically due to non-uniform tension of the paper, fabric, or both. To eliminate
the problem, vary the paper and fabric tension until optimum results are
achieved. In rare instances, some fabrics and papers are not compatible
and one or the other must be changed.
Shifting may also occur when using an extremely slick grade of paper, defective
paper, or even old paper - especially if stored in an area without climate
control. In this case, extra care in pressure, tension, and speed selection
must be used to reduce or eliminate the shifting. Otherwise, the paper may
have inherent register defects and require substitution.
Additional check points as follows:
- Bearings.
- That all rolls have been reinstalled, correctly pinned or bolted, turn
freely, and are parallel.
- That there is enough tension.
- That there is enough heat in the main cylinder to create sufficient friction
such that the felt holds to the heated cylinder as opposed to slipping against
a cold cylinder (352° C / 200°
F).
- That there is no build up of any type either on the cylinders or the inner
surface of the felt.
Felt tracking problems may also cause ghosting. Please see: Are
Tracking Problems correctable?
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Please indicate which Felt type you need help with:
These felts are the most susceptible of all felts to cracking simply due
to the application. Transfer Printing Felts are typically run under a lot
of tension, high temperatures, travel around small diameter rolls, and are
constantly subjected to sublimation inks, finishing oils and fiber treatments
such as Soil and Flame retardant.
Ink is the main reason for shorter felt life. It penetrates the
felt and impregnates the fibers. When the felt is subsequently stopped off,
for any appreciable time, the ink dries. Because the ink hardens when dry,
the felt becomes stiff, brittle, and loses its resiliency. At this point,
the felt becomes highly susceptible to the breaking of its brittle fibers
once start up begins again. The felt, stiff and lacking pliability, must
now traverse around cylinders which causes a lot of fiber movement, particularly
on the felts surface. The result, sooner or later, is surface cracking.
Generally, the cracks begin small and grow with subsequent machine stops.
NOTE: If cracking is the result of a defective felt, the cracks
will occur across the entire width of the felt and not just under
the fabric/paper line.
Preventive Measures to help avoid or prolong surface
cracking
Many things have been tried over the years and some people claim greater
success than others. Listed below, however, are those ideas deemed most
beneficial:
- Run "backing" paper. Note: Many weights are available
and some applications will require a heavier weight than others to prevent
or minimize the bleed through of inks. The standard weight used is 10-12
lbs., but each application is different, so experimenting with several
weights to find the best balance between cost and effectiveness is suggested.
In addition, it's important to note that the backing paper should have
a "glazing" on one side to be most effective. For help in selecting
the premium paper for your operation we suggest you contact Mr. Steve
Microulis at Micrographics via e-mail: stmic@aol.com
or PH 401-722-9498.
- Periodically clean the felt with a commercial grade carpet-cleaning
machine. The cleaning solution provided with this type machine has, historically,
been effective in helping to remove some of the residual inks without
being detrimental to the felt's fibers. Approved solutions contain either
"Heptane", "Isopropanaol", and/or "1,1,1 Trichloroethane".
(Note: For safety reasons, many plants have now stopped using such
chlorinated products as "1,1,1 Trichloroethane". Please use
extreme caution when using such products.)
- U.S. Supply now offers a non-chlorinated product for this purpose called
"Kwik-Solv". Note: Kwik-Solv is flammable and therefore not
available for air shipment. Please allow ample time when ordering to receive
via UPS-Ground. For additional information on this product, please contact
us via one of the following options: PH 704-399-4276; Fax 704-393-5628;
e-mail support@ussupplyinc.com
- Periodically sand the felt with either a disc or belt sander. This is
meant to be a superficial process only and obviously requires a delicate
approach. NOTE: Extreme caution is warranted to prevent
personal and/or felt damage.
- Prior to printing, be sure the fabric has been scoured to remove spinning
oils.
- Apply "Flame or Soil Retardant" chemicals after printing
or apply as little as possible of these chemicals, if they must be applied,
prior to printing. These chemicals will unequivocally shorten the life
of a felt.
- Remove the felt from the machine, turn it inside out, and reinstall
at the first sign of cracking.
If, after checking these variables, you still desire assistance, please
notify us immediately via one of the following options: PH 704-399-4276;
Fax 704-393-5628; Tech Support form; e-mail
service@ussupplyinc.com.
Although this process is tough on a felt, as it is subjected to plenty
of heat and steam - two prequisites for hydrolysis
- we have developed two primary apron styles
that resist hydrolysis extremely well.
Should cracking occur, however, its probably due to hydrolysis as
there is very little else that can cause it in this application. We would
therefore suggest you contact us immediately via one of the following methods:
PH 704-399-4276; FAX 704-393-5628; Tech Support form;
or, e-mail us at service@ussupplyinc.com.
Many variables occur in the finishing end of textiles that can greatly
affect a felts life span. The predominant variables include the finishing
chemicals used, heat and moisture levels, speed, tension, and the dwell
time against heated cylinders.
In addition, there are many different felt fibers available which can greatly
affect the performance of the felt. For example, although Polyester has
been used for years as a staple fiber, it is not the best choice when the
pH level is alkaline (8+ pH). In this case, Nylon is the preferred fiber
while Polyester lasts best in a neutral to slightly acidic environment.
We have still other fibers available for specific conditions, such as moist/heat
and/or chemical resistance(Note: pH values generally range from 0 to 14,
with a pH value of 7 being the neutral point, or the value of "pure"
water).
United States Supply constantly tests new fibers, blends of fibers, and
chemical treatments. Our purpose is to achieve the absolute best product
possible for any foreseeable condition on a SANFORIZING range. Since 1995,
for example, U.S. Supply has developed two new Felt styles (ULTRA 4000®
and RYNO 9000®) that have greatly improved the life span of a felt,
regardless of the environment it's used in. Both fibers are extremely successful
in moist/heat and/or chemical resistant applications.
For specification sheets and product descriptions, please see our Felt
Blanket section.
Should a crack occur on a Palmer felt, it is most likely the result of
one of the following:
- Accidental cut during shipping, installation, or fabric change.
- Hydrolysis.
- A tear on the felts edge due to tracking
problems.
NOTE: It is advisable to keep a record book containing the installation
date, meters processed, and any other pertinent data for future reference
and comparison. By so doing, a company is better able to determine what
style felt best suits its process. (A free
copy of our SHIELD® Rubber Belt and Felt
Record - Excel Spread-Sheet may be downloaded from our web-site).
PH 704-399-4276; FAX 704-393-5628; Tech Support
form; or, e-mail us at support@ussupplyinc.com.
Preventative Measures to help avoid surface cracking
As cracking is most often the result of hydrolysis,
we highly recommend that you contact us for guidance on the next style felt
used. We may suggest some lab work in order to advise you correctly. Other
factors that may be beneficial:
- Periodically clean the felt with a commercial grade carpet cleaner.
(Please see added notes to this affect under Transfer Printing Felts).
- Apply our Release Wax (see Products)
to the heated cylinder to keep it properly conditioned; keep the cylinders
clean.
- Be sure to apply as little tension as absolutely necessary to operate.
- Apply only enough heat to operate efficiently, generally 155°
C (311º F).
- Be sure the tracking mechanism is working properly.
- During shutdown and start up, run the felt whenever the temperature
is 60° C (140º F) or more.
Please contact us for additional information via any one of the following
means:
PH 704-399-4276; FAX 704-393-5628; Tech Support
form; or e-mail us at support@ussupplyinc.com.
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Seam failure relates principally to Oven
Conveyor Belts. These belts are joined in various ways, but most often
with a synthetic coil seam and pintle.
This pintle is pushed through an opening formed when joining together opposite
ends of a conveyor. It helps constitute the seam or splice, which is the
weakest part of the conveyor. As such, it is usually the first part of the
conveyor to fail. What Preventive Measures can be considered to help?
Preventive Measures to insure the best possible seam life for your conveyor:
- That the guiding mechanism is working and calibrated properly. (NOTE:
Perhaps the biggest reason for seam failure is tracking related. If the
conveyor tracks off the machine, particularly once it has some age on
it, the seam area is highly prone to being ripped).
- Run as little tension as absolutely necessary to successfully track
the conveyor.
- Avoid prolonged intervals of excessive heat, especially to the seam
area. Run the lowest temperature possible to successfully process your
fabric. When "stopping-off", be sure the seam is located outside
the oven.
- Be sure to remove the metal pintle or joining wire from the seam
after installation of the conveyor. This metal wire is used only
to guide the mono-filament pintle that follows it. The metal pintle
must be removed from the coil seam, leaving only the mono-filament
pintle to join both ends of the belt. Otherwise, premature seam failure
will likely result. (For a detailed explanation, please see our Installation
Instructions T-457).
- The larger the diameter of all the cylinders, the easier it is on the
seam as it traverses.
Please contact us for additional information via any of the following:
PH 704-399-4276; FAX 704-393-5628; or e-mail us at support@ussupplyinc.com.
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Please choose one of the following products:
- Rubber Belt Thickness - As Rubber Belts become
thinner, they lose their ability to effectively shrink. This is because
a thinner Belt has less surface movement and thus, less recoil action.
Therefore, at some point, as Belts become thinner, they lose their ability
to effectively shrink fabric. If you require substantial shrinkage (12
- 16%), particularly when processing heavier fabrics like denim, this
point usually occurs when a 2 5/8" (67mm) thick Belt reaches 2"
(50mm)*.
NOTE: When processing heavier fabrics that require substantial shrinkage,
we highly recommend the SHIELD I-Câ Rubber
Belt. (Please see under Product Listing).
* Since there are so many variables and differences from mill to mill,
determining the best time to remove a Rubber Belt is largely a matter
of experience.
- Rubber Belt needs Regrinding - In general, you
should consider grinding the surface of the Rubber Belt if any or all
of the following conditions exist:
- Rubber Belt hardness varies
more or less than 10% (15% maximum) of its original reading. (NOTE:
If forgotten or unknown, this original reading can be approximated
by checking the hardness of the Belt on its edge, as this area does
not come into direct contact with the heated steam cylinder and finishing
chemicals.)
- The surface of the Belt becomes shiny or glazed. In this condition,
the belt loses its grip on the cloth and thus, its ability to effectively
carry water.
- Penetration of chemicals and finishes in the surface of the rubber
that reduce the natural ability of the Belt to shrink fabric.
- Surface cracks or other blemishes on the face of the Belt. These
will worsen if not removed. We strongly recommend immediate
action.
- Excessive Tension on the Fabric - Excessive
fabric tension can exist in many different areas throughout the machine
set up, but is generally at fault in the following areas:
- Between the A-Frame or J-Box and the Sky House or Cole Spray (Moisturizer).
- Between the Moisturizer and the "nip" area of the Rubber
Belt.
- Between the Rubber Belt and Palmer units.
- Between the exit end of the Palmer and the take up roll on the exiting
A-Frame or J-Box.
REMEMBER: A SANFORIZING machine
is meant to shrink cloth, not stretch it.
NOTE: The use of a shrinkage indicator (a transducer connected to a shrinkage
monitor) at any critical point mentioned above is beneficial in determining
whether or not shrinkage is being pulled out at that particular point.
- Fabric Finish -
The use of certain fabric finishes, for example, resins, starches and/or
water repellencies or proofs, can reduce the ability of the Rubber Belt
to shrink fabric.
These finishes simply limit the ability of the Rubber Belt to compressively
shrink the fabric. Water or moisture serves as a lubricant and is necessary
for shrinkage to take place. The lack of proper moisture penetration in
the fabric may result in "false shrinkage" where the fabric
is really being "crimped" and not shrunk. In this case, the
dry core of the yarn actually acts as a spring and pushes out the mechanical
shrinkage applied. The result is "elongation" or "creep"
of the fabric after shrinking. In such cases, it may be necessary to add
a re-wetter, softener and/or lubricant to the finish to achieve
the desired shrinkage.
NOTE: Fabric moisture is an extremely critical factor while compressive
shrinking. Either too much or too little will affect the fabric, both
in terms of appearance and the ability to shrink the fabric. If you suspect
a moisture problem, we suggest you first determine how long it takes to
"wet out" the fabric you are having trouble shrinking. A simple
test is to cut a square inch (millimeter) swatch and drop it into a cup
of water. The fabric swatch should sink instantaneously. If not, consider
using a re-wetter and/or lubricant.
- Excessive Tension on the Rubber Belt - Too much
tension reduces the relative compression that exists on a Belt. In
essence, a tighter belt means less recoil and less potential shrinkage.
Check the Rubber Belt Tension Instructions for the proper guidelines.
- Steam Cylinder Temperature - Excessive or inadequate
temperature can adversely affect the shrinkage. Although the correct temperature
will vary per process, depending on the fabric, finish, and a host of
other factors, a standard operating range is between 270 and 290° F (133
- 145° C).
- Calibrate the Compression Plate - Be sure to
calibrate this setting after the installation of a new Belt and after
every grinding session. Without proper calibration, it's difficult,
if not impossible, to know how much compression is actually being applied
to the Belt. Obviously, if insufficient compression is being applied,
the result may easily be less shrinkage than desired. Conversely, excessive
compression will degrade the rubber surface faster. Please see our instructions
on how to properly Calibrate The Compression
Plate.
- Proper Heat Setting - Be sure the fabric is
being properly dried on the Palmer unit before put-up. If too wet while
framed, "elongation" or "creep" will likely result.
Several factors should be checked: the temperature in the steam drums
of the Palmer, the processing speed, and the type of felt blanket used.
We recommend checking both steam drums. The purpose of the main drum
is to shrink the fabric, while the smaller drum is to dry the felt. Either
or both could be too cool and thus, ineffective.
The overall machine speed may be too fast for the Palmer section to properly
work as described above. Try slowing down.
Not all felts are created equal. Some are designed to wick moisture away
faster than others. For more information concerning this, please see our
SANFORIZING Felts Product
Listing.
NOTE: These are the most common reasons for shrinkage failure,
but, certainly, not the only ones. Variables in environment, fabric, moisture
quantity and quality, and a myriad of other factors can result in poor shrinkage.
If, after checking the above variables, you still have trouble obtaining
and/or maintaining the desired shrinkage, please contact us through any
one of the following methods: e-mail: support@ussupplyinc.com;
PH 704-399-4276; Fax 704-399-4276.
Several prominent variables warrant discussion.
- Moisture in the fabric.
- Thickness of the Felt.
- Quality of the fabric.
- Temperature.
- Tension.
Moisture is a significant variable whenever shrinking
fabric for the following reasons:
- It allows for greater shrinkage of the fabric by lubricating the fibers.
- It makes the shrinking process easier in general, as well as, on the
belt and machine.
- It can affect the fabric appearance and "hand".
- It can affect fabric elongation or shrinkage loss. If the fabric is
compacted without sufficient moisture, the amount of compaction may
easily be removed by the slightest amount of tension. In affect, the
fabric has not been properly set and is unstable.
Thickness of the felt has a direct bearing on
the amount of surface movement occurring on its face. The more movement
(stretching and recoil) of the felts surface, the greater potential for
shrinkage. The density of the felt and its overall construction also play
a part.
For options or specification sheets on the styles currently made, please
see Compacting Felts or contact us
at support@ussupplyinc.com.
The Quality of the Fabric can greatly affect
shrinkage. The following variables should be considered:
- Quality of the fabric off the knit machine.
- The blend of fabric.
- Preparation of the fabric before its compacted.
- Whether or not the fabric has the ability to absorb proper moisture.
There are a number of related problems related to each of the above which
we will address in time. For now, however, as this part of our site is
still under revision, please feel free to contact us via PH 704-399-4276;
FAX 704-393-5628; or, e-mail us at support@ussupplyinc.com.
Temperature is significant in that it helps the
felt slip against the cylinder, assists in the recoil action of the felt,
affects the fabrics appearance and "hand", and helps set the
shrinkage as it wicks moisture from the fabric.
Tension is always the arch enemy of shrinkage.
All processes leading up to and including the actual shrinking of the
fabric are for naught, if excessive tension is then applied. The tension
will only serve to remove some of the shrinkage just achieved. Likewise,
if excessive tension is applied prior to shrinking the fabric, then over-shrinking
the fabric (which means shorter felt life and undue machine wear) is necessary
to compensate.
Extra care to insure proper tension throughout
and after the shrinking process is critical.
For more support regarding any one of the above issues, especially while
this part of our site is being revised, please contact us via PH 704-399-4276;
FAX 704-393-5628; or, e-mail us at support@ussupplyinc.com.
NOTE: This section is under construction. In general, however, many of
the principals are the same as those listed above in SANFORIZING/COMFIT.
If this overview is not helpful though, please contact us via the following
for immediate support: PH 704-399-4276; FAX 704-393-5628; or, e-mail us
at support@ussupplyinc.com.
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The surface of a Rubber Belt can
become sticky or gummy in the "selvage" area, or the area outside
of the cloth line. This usually occurs for the following reasons:
- Improper and/or Infrequent Grinding - After
periods of prolonged use, the surface of any Rubber Belt tends to deteriorate
because of the effects of finishing chemicals, heat and compression.
Usually, this deterioration results in a softer Rubber surface (as measured
using a Shore A durometer). It is especially prevalent in the area of
the Rubber Belt outside of the cloth line. This area is more susceptible
to problems because the natural rubber is directly exposed to the heated
steam cylinder.
If this softer or "dead" rubber is not ground away, it has
a tendency to become sticky (as the rubber is actually reverting back
to its original "gum" state) and, eventually, will begin to
"peel" or "pick" away in sheets or pieces from the
surface of the Belt. At this point, the Belt obviously needs immediate
grinding.
* See our recommended Grinding
Instructions for guidelines as to when and how to properly grind
a Rubber Belt.
- Excessive Temperature -
Temperatures in excess of 290° F (145° C) will speed up the deterioration
process of the rubber.
- Lack of Water - Improper application
or lack of water is a common cause of a sticky or "gummy"
Rubber Belt.
NOTE: Make sure that all water spray pipes are operating properly and
check the condition of the felt or brush doctor blade. Please see additional
comments found under question #10 Why does
our Rubber Belt Crack? Or, contact us for help via e-mail: support@ussupplyinc.com
; PH 704-399-4276; Fax 704-393-5628.
REMEMBER:
WATER SHOULD ALWAYS BE THE FIRST THING TURNED ON AND THE LAST THING
TURNED OFF.
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There are typically three explanations: 1) the Felt manufacturing process,
2) the application the Felt is under, and/or 3) the type fiber used to manufacture
the felt is not suitable for the application.
The Felt Manufacturing Process : requires a set
"needling" procedure to insure interlocking of the fibers so they
will not "pull" out or simply "lay" on the surface.
In addition, the "density" of the felt can be too great, not
allowing proper set of the fiber. Check with your supplier/manufacturer
by furnishing them the Felts serial number.
The Application : under which the Felt is used
may not be suitable for the type Felt being used. For example, certain applications,
such as "polishing" require the Felt withstand much more abrasion
than other applications, such as conveying or SANFORIZING. We suggest checking
with us to insure the correct fiber is used to manufacture the Felt being
used in your application.
The Fiber Type : used to manufacture the Felt may
be incorrect either for the application or for Felt manufacturing. Obviously,
certain fibers withstand certain elements that others will not. One fiber
type may perform exceptionally well at 175° C
(347° F), while another becomes brittle, breaks,
and sheds. Or, certain finishes, like silicone, may have been used on the
fiber allowing it to be too slippery and shed. Another consideration may
be the length of the fiber staple - too short and it resists proper locking
during the needling process.
The importance of selecting the correct fiber for a specific job application
and working with a quality manufacturer, can not be ignored. We welcome
the opportunity to lend our expertise in this selection process. Please
contact us by any of the following means for support: Ph 704-399-4276; Fax
704-393-5628 or e-mail us at support@ussupply
inc.com.
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Stainless Steel
Depending on the type stainless steel used and the amount of pigmented
inks used, this may or may not be a common problem. Over the years we have
witnessed attempts by others to enter this market. As they are the newcomers,
they are trying to offer a lower price incentive to win business. When it
comes to manufacturing quality stainless steel, however, all reputable shortcuts
have been discovered by the worlds leading manufacturers. The end result
is that a necessary step in the manufacturing process is usually skipped,
resulting in a stainless steel that has insufficient "microstructure"
and/or "hardness". This, then, results in a stainless steel that
has inadequate abrasion resistance.
Should "Delamination" (sometimes also referred to as "de-chroming"
or "shearing") occur with our Stainless Squeegees, we would
like to know immediately. Please keep a sample of the blade(s) that have
delaminated and make note of any common variables that may serve as a clue
to explain how or why the delamination occurred. For example, has the amount
of "pressure" applied to the Squeegee changed? Has the Squeegee
size changed? Does the "delamination" occur with various
Squeegee sizes? Does it occur when you use a particular type of ink(s)?
When you process a specific type fabric(s)?
Obviously, the more input provided us the more we can help. We may suggest
a different chemical composition, hardness, Squeegee material, or adding
a Teflonâ edge to the existing blade. Whatever
the choice, we will expediently strive to find a solution.
PLASTIC
"Delamination" occurs when the wrong polyethylene or similar
type material is used to make a so-called "Plastic Squeegee".
The proper material and process of joining the material must be used for
this product to be successful.
Typically, a Plastic blade will reduce wear on rolls and screens by virtue
of the fact that the blade is softer and more flexible than stainless. This
allows the Plastic blade to be run with less pressure minimizing the friction
and thus, wear that occurs.
Plastic Squeegee is also compatible with the majority of solvents, coatings,
lacquers, varnishes, water and alcohol based inks commonly used in flexographic,
gravure, and rotary screen printing. (Please see a specific listing located
under PRODUCTS
/ PLASTIC SQUEEGEE). Should you suspect
a "contamination" problem, however, from any outside factor affecting
the Plastic Squeegee, please contact us immediately via Ph 704-399-4276;
Fax 704-393-5628; or e-mail us at support@ussupplyinc.com.
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When to Grind
You should consider grinding a Rubber Belt if any of the following
conditions exist:
- You can no longer achieve the required shrinkage.
- Rubber Belt hardness varies more or less than 10% of its original
reading (15% maximum). (If forgotten or unknown, this original reading
can be approximated by checking the hardness of the Belt on its edge.)
- The surface of the Belt becomes shiny or glazed. In this condition,
the belt loses both its grip on the cloth and its ability to effectively
carry water.
- Surface cracks or other blemishes exist on the surface of the Belt.
These will worsen if not ground out. Pay particular attention
to the area outside of the cloth line. The Rubber Belt is directly exposed
to the heated Steam Cylinder in this area and is more susceptible to
problems.
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How to Grind a Rubber Belt
Please see our Rubber Belt Grinding
Instructions for a complete explanation. The required steps
are too numerous to list here.
REMEMBER: IT IS BETTER TO GRIND MORE OFTEN THAN NOT ENOUGH.
If properly ground, and ground at the optimum time, a more frequently
ground Belt will not only outperform an infrequently ground one, but
will also last longer.
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Fine tuning the correct amount of tension on a Rubber Belt is largely
a function of experience. Several variables, including the current thickness
of the belt, the style of fabric being processed, etc., need to be taken
into account for an accurate determination.
In general, however, the proper tension on a 67 mm (2 5/8") thick
Rubber Belt can be approximated as follows:
- With the rubber blanket tension set at the minimum position, draw
two (2) lines*, 30.5 cm (12") apart, on the edges of the blanket.
Make these lines on BOTH belt edges, that is, on both sides of the belt.
*NOTE: On a new SHIELD® Belt this has been done for you,
although, with wear, the marks may need to be reapplied.
- Turn the belt (4 - 5) complete revolutions. Stop the machine with
the line markings between the tension and guide-rolls. Confirm that
the amount of stretch is still 31 cm (12 1/8") preferably, to a
maximum of 31.3 cm (12 1/4").
*NOTE: Thinner Rubber Belts, 51 mm (2")
or less, may need up to 8 mm (5/16") additional stretch per each
30.5 cm (12").
TO FINE-TUNE BLANKET TENSION:
If the fabric shows any corrugation, it may be necessary to
increase the tension or stretch slightly.
Have a worker on each side of the tension roll tighten or raise the
tension roll one turn at a time, while watching the fabric. As soon
as the corrugation disappears, increase the tension by one more turn.
REMEMBER: IT IS VERY IMPORTANT THAT THE RUBBER BELT IS RUN
WITH THE LEAST AMOUNT OF TENSION POSSIBLE. EXCESSIVE TENSION REQUIRES
AN INCREASE IN COMPRESSION TO ACHIEVE THE DESIRED SHRINKAGE. THIS RESULTS
IN DECREASED RUBBER BELT LIFE.
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The answer to this question obviously depends on the severity and type
of problem and, sometimes, what odds one is willing to take. Some patches,
for example, are a high risk, but, nonetheless, still performed as the Belt
has a lot of useful rubber remaining.
Some of the more typical repairs associated with rubber belts are as follows:
- Surface - Cracks on the surface of a Belt,
if they are not too numerous or extensive, can be patched using a special
repair compound available from United States Supply Co. Please see our
Rubber Belt Repair Instructions.
Note: The Repair Kit is designed to be user friendly,
as well as, easily and economically shipped. This way, the end user
is able to perform his own repairs, instead of paying for and/or having
to wait for a specially trained service technician. As always, however,
if you desire additional help, we encourage you to contact us via
e-mail: service@ussupplyinc.com;
PH 704-399-4276; or, Fax 704-393-5628.
- Edge of Belt - Cuts on the edge of a Rubber
Belt can also be repaired. There are several options including hand
grinding, trimming, and/or patching the problem area(s). Please contact
us for assistance in determining the most viable option and/or see additional
information under Proper Grinding
Procedure and Rubber Belt Repair
Instructions.
- Inside Cracks or Cuts - Usually, if there
is one crack on the inside of a Belt there are many. Most Belts in this
condition can not be repaired because the damage is too extensive. This
photograph serves to demonstrate just such an example.
NOTE: For preventive maintenance of this problem, please
see #10 Why does our Rubber Belt have Cracks?
and #14
Why is our Rubber Belt Sticky?
- Burns - As the belt is made of
natural rubber, it is susceptible to being burned if not properly cared
for. To safeguard the belt from being burned, we recommend a watchful
eye be kept on the following:
- If the Rubber Belt is "stopped off" against the hot steam
cylinder for more than a minute or two, it is extremely important
that the pressure on the "compression roll" be removed.
In addition, if at all possible, jog the belt periodically - even
if just a little.
- When shutting down, we recommend turning the rubber belt while the
steam cylinder cools until the cylinder is basically "cool to
the touch". (100° F; 212° C)
More specifically, the following
procedure should be followed when "shutting down":
NORMAL SHUT-DOWN PROCEDURES
AFTER PRODUCTION CLOTH HAS PASSED THROUGH MACHINES
- Slow machine, turn off steam, supply valves fully closed. By-pass valves
fully open.
- Back off on Compression Roller-fully.
- Release pressure on Water Removal Rollers.
- Continue to run machine at slow speed.
- After machine is cooled, stop machine until further processing is desired.
- Cut off water to Rubber Belt.
- WATER SHOULD BE THE FIRST THING TURNED ON AND THE LAST THING
TURNED OFF WHEN OPERATING THE MACHINE.
If compression is left on the compression or pressure roller after the
machine has been stopped for a lengthy time, this will cause a mark on the
rubber belt that will cause a defect in the cloth. This is especially true
if the steam is left on the cylinder.
Running the machine without water will cause the belt to deteriorate
much quicker, especially on the inside; which in most instances, cannot
be repaired except by the supplier.
Should the Rubber Belt become burned, the only solution is to grind. Hopefully
the burn is not so severe that a grinding can not rectify the damage. Please
see our Procedure For Grinding a Rubber
Belt.
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