siegling prolink
modular belts

Fitting andmaintenance Instructions

for Prolink modular belting in drum-driven spiral systems

Content2

Prior to belt fitting

3 	Fitting belts to adrum-driven spiral4 	Initial start-up andmaintenance instructions
5

Belt tensioning

6 	General belt cleaning
instructions
9 	Troubleshooting
on spiral systems

Siegling – total belting solutions

Prior to belt fitting

The customer ultimately remains responsible for the overall
safety of the work environment and work crews throughout
the installation and start-up process. This includes training
installation and work crews on all company safety rules andprocedures as well as insuring that appropriate safety lockout discipline is maintained.
Inspect the spiral system to insure it is ready before proceeding with the installation of the new belt.
Inspect the unit’s support rail wear strips and cage bar cap
material. Replace worn, broken and damaged material asnecessary. Forbo-Siegling strongly recommends new wear
strip and cage bar cap material be installed when using new
Prolink Series 5 or Series 9 belt for the first time.
Before any work is started, it is assumed that;–	A full engineering evaluation of the system has been
undertaken and that the design have been made in orderthat the spiral is suitable for use with a Forbo Siegling
Prolink modular belt.
–	A physical check on the belt and sprockets has been
undertaken to ensure that the products are as ordered.
– The spiral system has been checked thoroughly for possible snagging or binding points and all snagging andbinding points have been eliminated.
It is of the utmost importance that belts are allowed to
run free without binding or snagging on any part of thefabrication
Note: All belt widths quoted are nominal and are subject tomanufacturing tolerances and material shrinkage (details oftolerances are available on request).

2

Fire warning for
Prolink plastic modular belts
Prolink belts are made of various high-quality plastic materials that can burn. If ignited, products made from POM material, will emit toxic fumes. During operation, storage andinstallation never expose Prolink belts to an ignition source,
such as flames, sparks, burning or very hot objects, or excessive heat. Special care should be taken when undertaking
repair work particularly when welding on or near a conveyor
if the conveyor is equipped with a Prolink plastic modular
belts.
Hazards from burning Prolink belts vary depending onmaterial composition and environmental conditions such astemperature and oxygen availability. Hazards may include
dense smoke, toxic gases or fumes, a flame that is difficult to
detect, and spreading of fire due to movement of the burning belt and/or dripping, burning, molten plastic.
Suitable fire extinguishing media include: water spray, foam,
and dry chemical.

DANGER
Flammable

Fitting of belts
to a drum-driven spiralIf fabrication work has taken place that would cause contaminates to imbed into the UHMW wear strips then careneeds to be taken to washout this foreign matter prior topulling the belt round the system.
Ensure all plastic guides have tapered leading edges so as
not to snag the belt.
Before the belt is installed, the belt path should be checked
for snagging and binding points. Clearance should be confirmed by pulling approx. one metre of belt through the system. This belt needs to move freely through both supportand return sections to ensure optimum performance.
Prior to fitting the belt, ensure that the Belt is fed onto the
Spiral the correct way up and in the correct running direction (see below). Ensure that the belt when fed through thesystem will locate correctly onto the sprockets.
Use a rope or cable to attach to the spiral belt to the cagefor installation.

Cleaning and lubricationof wearstrips during installation
Attach two rows of clean shop rags to the underside of thebelt directly over the area wear the belt support rails. The
first row of rags should be dampened with clean water. The
second row of rags should be spaced approx. 1 – 2 m directly behind the first row of rags. This second row of rags
should be lightly dampened with food grade mineral oil.
These rags should ride the belt completely through the spiral system during the installation process only.
This “ragging” procedure serves two purposes:
1) the water dampened rags will clean the support surfaceof the support rails, and2) the mineral oil will lubricate the belt as it slides throughthe system, easing the installation process. The foodgrade mineral oil will evaporate within a few hours after
the installation of the belt.
Each section of belt should be added by using the pins provided. Pins are held in correct position by two clips thatsnap over a groove in the pin at each side. When fitting pins
ensure that the clips are correctly installed by verifying thatthey are flush with the belt module.

Correct running direction for spiral belts

Final belt length adjustment is generally undertaken at thetension roller. The change in belt length due to belt tension
and temperature changes must be allowed for. The initialbelt length will “grow” during the first few days or weeks as
the pins and modules seat together.
Insure that the inner edge hold down rail in down go spirals
is not pinching the belt, nor should it be more than approx.
6 mm above the belt.
Check that the belt has enough clearance on leaving thedrum for the swing effect. Leave approx. 25mm for every
300 mm of belt width

3

Initial start-up andmaintenance instructions
Insure that all Safety Equipment is in working order (emergency stops, etc.) for spiral belt.
It is of the utmost importance that the admissible belt pull
during operation and at rest is not exceeded, (Refer to
Prolink data sheets).
In a low tension spiral the drum (or cage) is always turning
faster than the inside edge of the belt and is therefore
always in overdrive. The aim is to set the amount of overdrive relative to the desired belt speed in order to achieve
the least amount of pull needed to move the belt.

High tension

Operating

Low tension

Smooth operation

Range

Surging

Measuring overdriveThis can easily be accomplished with the following four
steps;
1) Face the spiral at a convenient point and identify a particular cage bar or a point on the solid drum with a markerpen.
2) When the spiral is rotating, place an object on the insideedge of the belt in line with the mark on the cage bar or
drum.
3) After one revolution of the “mark” (on cage bar or drum)note how far the “mark” is in front of the product (product will appear on the next tier) previously placed on thebelt. This distance can be expressed in equivalent ofdrum bars passed or measured in mm.

Belt tension [N]4) The number of cage bars times their pitch or the measured distance has to be divided by the Tier pitch. Thisratio equates to the amount of overdrive.

What is the correct overdrive?

1

2

3

4

5

6

7

8

This always has to be adjusted to each particular spiral, but
as a general rule a plastic belt using smooth plastic cagebars will require an overdrive of 4 – 5 tiers.

Overdrive expressed in tier heights

It is important that the optimum overdrive be set for a particular spiral, as each unit will vary slightly in respect to thefriction coefficients in the system. Too little overdrive will
result in high belt tension that will cause the belt to flip up(Christmas tree) and result in greatly reduced belt life. Toomuch overdrive will cause the belt to surge and result inexcess product movement.

It is better to initially have high overdrive for the reasons previously discussed. It is suggested that the overdrive is “finetuned” when the system is fully loaded and operating at theusual speed and temperature. When setting up the user
should try for overdrive of 4 to 5. If the belt does not surgethat is probably a good setting. If the belt surges, reduce theoverdrive a little and the surging should stop.
Extremely high overdrive will cause the cage bars to wear
very quickly and in the event of an emergency, the system
will be much harder to stop. However, plastic belts do notgive any appreciable cage bar wear.
Remember: Too little overdrive creates too much tension
and ruins belts; too much overdrive will not significantly
lower belt tension compared to the ideal settings.

4

Belt tension

The modular spiral belt is like a stiff rubber band and will
therefore stretch as the tension increases. As the belt
stretches, it will accumulate in the take up loop.
The increased tension will be apparent as the take up roller
drops in the take up loop.
The following conditions are some causes of increased tension in a belt.
1) System previously running empty but now full of product(Higher loads).
2) The systems originally clean but as the support, wear
strips and belt become contaminated tension increases(Friction between wear strips and belt increases).
3) Overdrive reduced (for example to eliminate unacceptable belt surging).
4) In freezers as the temperature increases the friction due
to contaminates increases (Cooking oils and fats that are
hard on wear strips and belt at -35 °C become very sticky
and increase friction at -5 °C)
Note: A dropping take up roller in normal operations correlates to higher belt tension, which correlates to higher motor
current.
By noting the position of the take up roller over a period oftime it can be seen whether the tension in the belt has
increased or decreased. It is suggested that after the controls have been set a reference mark be made on the frame
to indicate the centre line of the take up roller. Any movement up by the roller signifies a drop in tension whilst adrop in the tension roller will indicate an increase in belt tension (Readings should be taken when the belt is at the sameenvironmental temperature).
After all installations carried out the belt tension can bechecked with the Forbo Siegling belt tension device and agraph of results provided.

Take up tension roller
The tension take up roller must be of a weight just sufficient
to counter balance the weight of the belt (remember the
belt length will vary). Any excess weight in the take up roller
will result in over-loading the belt with unnecessary tension.

5

Cage and take up/tension motors
The Cage motor speeds must be adjusted to produce thelowest belt tension possible without belt surging.

Belt lubricators
With Forbo Siegling modular spiral belts, it is generally notnecessary to use a lubricant. If however in unusual situations
where a lubricant is felt necessary, the lubricant must be
checked to ensure it is compatible with the belt material.
The lubricant must not get on to the inside edge of the beltor the cage bars as this would reduce friction and lower thecage drive.

Safeties
Before starting the spiral, it must be verified that all belt-lifting detectors and other safeties switches are installed andfully functional.

Cage bars/wear strips
Cage bars and wear strips should be checked periodicallyfor damage and wear. Damaged, worn or missing cage bars
or wear strips may cause the belt to bind or snag therefore
they should be replaced.
It is important to check all return wear strips for wear as thiswill cause extreme tension if worn through to metal.

Belt damage
The belt should be periodically checked for damage. Anydamaged modules or pins should be replaced and thecause of damaged determined and rectified.
The above points to be checked at all spiral start up to
ensure that the Prolink modular belt is run at the lowest tension and this will give the optimum belt life for the system.
The most common form of belt damage is caused by
objects left on the spiral belt, which cause a blockage in the
spiral system.

Belt washing general instructions

Introduction

When should the belt be cleaned?

Hygiene standards for food production are constantly
improving. For Forbo Siegling, being a major supplier in thismarket segment, hygiene has always been a key factor. A
plastic spiral belt is a big step forwards in hygiene and in theimplementation of HACCP. Compared with stainless steel
the main advantages are no black wear debris caused by
the metal components and the clean top surface.
However, for a proper functioning spiral, the belt underside,
support rails and cage drum/bars are important.

This will depend on the types of product fed through thespiral; the more spillage on the belt will result in more frequent cleaning times.
The less contamination on the belt will extend times
between cleaning.
A product in a sealed carton will offer little contamination to
the belt but a flour-covered product may require daily belt
cleaning.

Why clean the belt and cage
To maintain the spiral belt at the lowest system tension possible it is required that the friction between the rail wear
strip and belt is kept to a minimum.
It is also required to maintain a high friction drive between
the cage and the belt so the friction of the cage bars is kept
as high as possible.
Both rails and cage must be kept clean.

What happens if the installation
is not cleaned?
If the rails are not cleaned, the friction will increase between
belt and wear strip and the system tension will increase.
The effect will be seen in several ways;
1) The cage drive will begin to use more power to overcome the frictional forces; in extreme cases, the cage
motor could trip on overload.
2) As tension increases the take up weight will lower, andcould activate take up low switches.

The best indicators of a contaminated belt are, droppingtake up weight and increased current on the cage drive.
With regard to wear strips which are also a good indicator ofcontamination within the system. The spiral is first stopped
and if a clean white cloth is wiped over the wear strip shows
black contamination this indicates the wear strip requires
cleaning.
The above indicators will eventually show the frequency forcleaning.

General points with regard
to keeping a spiral belt clean
1) Ensure that the product is fed into the spiral in a regularway, if product touches due to incorrect speed it may
damage and produce contamination on the belt. It could
also cause a blockage on the spiral tiers.
2) Any conveyor feed to the spiral must be synchronised tothe spiral controls, i.e. when the spiral stops feed systems
must not carry on feeding3) Transfers on and off the spiral must not cause productbuild-ups, which may damage or spill product on to thespiral belt.

3)	At points of highest tension on the spiral, which is oneither the first tier on up drums, top tier on down drums
or the first tier of the second drum on double drum systems the belt may lift, known as a Christmas tree. This will
result in possible damage to the belt but certainly a loss of
production, as the tier lift detectors will stop the spiral.

4) When a product, which is coated with flour or other coatings, is fed into a spiral it is advised to remove any excess
coatings by use of an initial transfer conveyor to the spiral.
The removal can be done by the use of compressed air or
vacuum systems.

4) It has to be remembered also that excessive tension willcause excessive belt wear, which will shorten belt life.

Contamination increases friction and hygiene problems.

5) If a belt is not cleaned on a regular basis hygiene considerations could become an issue.

6Ways of cleaning spiral belts5) First Stage – Remove excess contamination and carry out
a pre-rinse with water to soften any contamination.

There are several methods presently used for the cleaning ofspiral belts.

6) Second stage – Dose the belt with the approved detergent, it is advisable to leave this on for a period to aid thebreakdown of contaminates.

1) In line belt washers- these generally use high-pressure
sprays combined with an air knife system for drying thebelt. Can incorporate hot and cold water plus detergents,
plus a mechanical rotating brush. Used on both ambientand freezers2) C.I.P. systems these are generally total system cleaners,
which try to clean all the surfaces of the spiral belt, rails
and cage. Use hot and cold water plus detergents. Only
used in an enclosed spiral system such as a freezer.
3)	Manual system incorporating a high-pressure hose andoperator.
Whichever system is used the aim is to clean the belt modules, rail wear strip and cage.

The cleaning of theSpiral Modular plastic belt
1) The first stage of any cleaning process is to find out what
the belt material is, as this will affect the temperatures ofwater to use and what types of detergents which can beused. Also check on wear strip and cage bar materials asthese too will be affected by cleaning, some wear strips
may have lubrication impregnated in them and somedetergents can wash it away.
2) Consider the type of contamination to decide on which
method of cleaning is appropriate and also what detergent is most suitable. Suppliers of detergents will give
direction on detergent types if the above information is
given.
a. Plastic belts are resistant to most forms of chemical
attack see the attached chemical resistance list.
3) As cleaning is also a hygiene requirement it may be thatthe spiral belt is to be disinfected, a real clean surface isthe result.
4) When using hot water check on the allowable temperatures the plastic belt can withstand generally do not use
water temperatures in excess of 80 °C.

77) Third stage – Wash the belt with hot water to remove all
the contaminates,
8) Final Stage – Rinse with cold water, to remove all trace ofdetergent.
a. If the belt is not clean, repeat the last three stages.
After the belt is clean, which may be checked by eye orswab tested the spiral may be disinfected.
It is important that any detergents used are not too viscousor applied too much as they could create a tension problem,
also detergents must not smear or leave deposits on therails or belt as this will cause tension build up on spiral startup.
9) With most systems an air knife can be used to ensure thebelt is dry before use, this is a priority with belts on freezer spirals as any free water could freeze the belt and damage modules when the refrigeration plant is switched on.
In extreme cases the belt could freeze to the rail wear
strip.

Rail and Cage cleaning
The above methods have mainly concerned cleaning thebelt but it is important as mentioned to ensure clean railwear strip and cage.
There will be partial cleaning of the rails and cage by theaction of the belt but for extra cleaning there are two othermethods.

Important!
–	Never use an acid cleaning agent in combination with achlorine-containing agent: Dangerous chlorine gasses willdevelop.
– Chlorine can affect process equipment such as stainlesssteel and rubber parts.
–	Acid agents can affect aluminum and galvanized steel
parts.

1) The rail wear strip can be cleaned by hand by the use of acloth soaked in a cleaning agent. This will involve lifting
the belt off the rails with the belt stopped and rubbing
the wear strip clean. In some cases on wide belts this it
may not be possible to reach the inner wear strip.

– Temperatures above 70 °C must be avoided to prevent
proteins sticking to the surface. Fats can be removed atlower temperatures, if proper cleaning agents are used.

2)	Where the belt is too wide for rail cleaning it is possible toplace a piece of cloth between the belts and wear strip
and the belt weight will keep the two in contact. The spiral is then operated and the action of the belt will movethe cloth around the system cleaning the rails. This may
have to be repeated several times to ensure the rail isclean.

Manufacturer notification

It is very important to remove the cloth before it can tangle
on sprockets.
Collect all used cloths (count the number before you start)
when one is left in the spiral it could cause a possible blockage of the system when the spiral is in operation with product.
Cleaning of the cage is usually carried out with the cage
stopped as the use of water and detergents lowers the friction of the cage to belt to such a limit that little drive is
imparted to the belt and can cause tension increases andbelt lift.
The usual method is to spray the drum with the use of ahigh-pressure hose plus the use of detergent. The cage isusually not required to be cleaned very often unless the
product is in constant contact with the drum and is of anoily nature.

8

Please consult local suppliers in your area for their recommendation on cleaning detergents/chemicals based on thebelt material.
Recommendations:–	Never exceed the concentration, temperature, and dwell
time indicated of the cleaning agent’s directions for use.
– Wash-off cleaning agent thoroughly to prevent agent
residuals from affecting the conveyor.
– Keep safe and sufficient distance between high-pressure
nozzle and belt surface.
– To avoid bacterial resistance against the used disinfectant,a regular disinfection with another disinfection agent (likea chlorine containing disinfectant or a different disinfectant) is advised.
If the above cleaning recommendations are carried out, theForbo Siegling Prolink modular spiral belt will operate correctly.
Should you have any questions with regard to the operationof Prolink belts on spirals please contact your local Forbosales representative.

Trouble shooting on spiral systems

Take up roller is low or dropping
The spiral belt is in tension so check the following.
Remember if the take up roller drops there is less belt in thesystem and the belt is tight, if it goes up the system is taking
in belt, and having lower tension.

Belt lifts (Christmas tree) on spiral– If bottom tiers check return for snagging of belt.
Look for belt catching on bearing bolt heads.
– If on top of spiral check for product blockage
or dirt on wear strips.
– Check for worn or damaged belt guides.

– Is there a product block?
– Check product fed into spiral evenly, check for productgap at infeed.

– If none of above check cage drive not trippingor the cage is slowing down.
– If central drive check the gearbox.

– Is product too high, check product height.

– On chain-drive systems check for chain break.

– Is product moving on the spiral belt?

– If sprockets fitted check for alignment.
The belt must not rub against any metal side plates.

– Foreign body on spiral, causing blockage against arms.
– If freezer or cooler is air velocity moving product on the
spiral belt, check at mezzanine floor levels.

– Ensure all rollers turning and that bearings are all OK.

– Is product spillage causing contamination of belt andhence high friction, which will increase belt tension?

Belt lift (Christmas tree)
not on top or bottom of spiral– Check for belt snag on returns.
– Worn wear strip, exposing steel, which causes
high friction.

– Check for product blockage.

– Damaged belt guides.

– Check for rail wear strip damage.

– Check operation of cage.

– Check for raised rail wear strip– Is cage motor overloaded, not large enough drive motor?

– Check for damaged module.

– Seized cage support bearings, top or bottom.

– Check for elongated or loose joining pins
catching on cage bars.

– If a freezer, check that the belt is not frozen to rails, if the
spiral has been stopped.
– Spiral stopped for more than 10 mins could cause belt tofreeze to rails especially if product has high water content.
– Check if spiral stopped at meal times.

9– Check for damaged cage bars.

– If freezer check that, the belt is not frozen to rails,
if the spiral has been stopped.
– Check operation of belt lift sensors.

Belt stops moving– Overdrive gearbox stopped, or tripped.
– Snapped belt.
– Check electrical controls.

Belt surges– Too much overdrive.
– Possible blockage occurring.
– Check operation of any variable speed drive invertors.

Double drum systems
On these systems, the same principals as mentioned above
apply but the most common place for a belt lift is as the
belt leaves the up drum and enters the down drum. This is
usually the point of highest tension.
If this occurs, any of the above points are factors but they
are increased as the belt has a length of crossover to pull the
belt over after leaving the up drum so increasing tension.
Other points to consider are if the up drum is feeding belt at
the correct speed to the down drum.
– Check that the up drum cage is revolving faster than
down drum, usually about 10 % more rpm.
– Ensure the crosses over guides are not snagging the belt.

Belt damage–	No product blockages at this point.

–	Broken outer modules caused by high tension.

– Check product alignment as it leaves up go cage.

– Check for belt snagging on guides, bolt heads.
– Over feeding of product, causing high tension.
– Wear on underside of belt, check for missing rail wear
strip.
– Wear on belt edge, check for missing cage bars
or snagging on belt guides.
– Check belt returns for missing wear strip.

10

Please note the single biggest reason for belt lifts is
usually an increase on system tension caused by the wear
strips or belt been dirty.
As a rule always, check backwards from a tier lift to find the
problem.
If a problem persists contact Forbo Siegling.

11

Siegling – total belting solutions
Committed staff, quality-orientated organisation and­production processes ensure the constantly high standardsof our products and services. The Forbo Siegling Quality
Management System is ­certified in accordance with ISO 9001.

Forbo Siegling service – anytime, anywhere
The Forbo Siegling Group employs more than 2,200 people.
Our products are manufactured in nine production facilities
across the world. You can find companies and agencies withwarehouses and workshops in over 80 countries.
Forbo Siegling service points are located in more than
300 places worldwide.

Forbo Siegling GmbH
Lilienthalstraße 6/8, D-30179 HannoverPhone +49 511 6704 0, Fax +49 511 6704 305
www.forbo-siegling.com, siegling@forbo.com

10/16 · PV · Reproduction of text or parts thereof only with our approval. Subject to change.

Ref. no. 285-2

In addition to product quality, environ­­mental protection is an
important corporate goal. Early on we also intro­duced anenvironmental management system, certified in accordancewith ISO 14001.