SANDVIK PROCESS SYSTEMS
Service Instructions
Bonding of Rubber V-ropes
PS-SB-4457-ENG 09.2013
Procedure
Prefered at site bonding is TESA tape.
Bonding procedure valid for:
• On-site bonding of a V-rope over a welded joint.
• Repairing bonded V-rope.
• If bonding a V-rope to a new belt on-site, please
contact SPS technical support.
1.
The ends of the undamaged V-rope should be cut square
(i.e. 90˚ to the belt edge).
Tools and materials
• Heating plate
• V-grooved clamping bar
• Thermometer
• Screw clamps
• Drilling machine / Multitool
• Abrassive flap wheel, 80 grits
• Etched rubber V-rope or V-rope with applied glue ”Onestep”
• TESA tape (formerly Technicol) if not ”Onestep” is used
• Super glue
• Chisel
• Iron (when using TESA tape)
• Solvent, which does not leave a film
• Rags
2.
For repairs only. Remove the loose parts of the V-rope
together with any contamination from the area of the belt
where the bonding is to take place.
3.
Clean the area of the belt to be bonded using clean rags and
solvent. It is essential that the belt surface is completely clean
and dry.
4.
5.
Grind the area in a longitudinal direction to the belt. Roughen
the area with an abrassive flap wheel, 80 grits, fitted to a
power drill. A drilling machine is recommended for this
purpose.
Cut a piece of new V-rope 1% longer than the required
length. The ends must be cut square to precisely match the
ends of the existing V-rope on the belt.
7.
Clean the V-rope and the area to be bonded using clean rags
and solvent. For the ”Onestep” remove the plastic cover.
8.
Cut a piece of TESA tape to the same length as the new section of V-rope, if not ”Onestep” is used.
9.
The following procedures should be used to apply the
bonding tape:
• TESA tape should be attached to the V-rope using heat
(a normal domestic iron is recommended). After ironing, remove the plastic interleafing which protects the
TESA tape on the topside.
10. Place a couple of drops of super glue on each end of the
new section of V-rope. Place the new V-rope on the belt and
hold the ends together until they are securely bonded.
6.
2
The flat surface of the V-rope (i.e. the surface to be bonded)
must be etched with sulphuric acid. To test the effectiveness
of the etching, bend the V-rope and check for surface cracks
in the rubber. If no cracks are visible, do not use the V-rope.
Note: this test is valid for nitrile and natural rubber (not
L-28742, ”Onestep”).
11. Place the heating plate under the belt.
Trouble shooting
Any of the following conditions can result in poor-bonding results:
12. Place the V-grooved clamping bar on top of the V-rope and
press down gently.
13. Clamp the assembly together with screw clamps.
• Insufficient cleaning and degreasing of the belt and V-rope.
• Insufficient roughening of the belt at the bonding area or to rough.
• Dirty or greasy fingermarks on the belt or on the rubber after
they have been degreased.
• Use of old (brittle) TESA tape.
• Bonding with the interleafing plastic still attached to the bonding
tape. To rough surface.
• Failure to etch the V-rope – the rubber surface must contain fine
cracks (TESA tape).
• The V-rope not having been properly clamped.
• Curing at the wrong temperature.
• Moving the belt while the V-rope is still warm.
• Old (to long storage) V-rope for ”Onestep” (L-28742).
Specification
TESA tape
”Onestep”
Surface Roughness
≈ Ra 1.0
≈ Ra 1.0
Temp
150 °C
> 180 °C
15 min until
11 min
colour reddish- no colour
brown
Pressure
Evenly
> 45 N/cm²
Evenly
> 45 N/cm²
Nitrilie Rubber
L-28711 (EUR)
L-28712 (US)
L-28742 (EUR)
15. When the curing process is complete, carefully remove the
V-grooved clamping bar.
Chloroprene Rubber
(Neoprene, CR)
L-28741
16. When the V-rope has cooled down, check the bond by
carefully twisting it with pliers.
Natural Rubber
(Grey, NR)
L-28791
Nitrile Rubber (25 mm)
High Belgium
L-28710
14. TESA tape is cured at 150 °C (300 °F) for approximately
15 minutes until the colour darkens to a reddish-brown.
V-rope with ”Onestep” at 180 °C (356 °F) for approximately
11 minutes no colour.
V-rope
17. For repairs only
A belt installed on a meat cutting line should be heated to
150 °C (300 °F) for 15 minutes before curing the V-rope in
order to remove any fat from the material.
3
Sandvik Process Sys tems
SE-811 81 Sandviken, Sweden, Phone +46 26 26 56 00, Fax +46 26 25 86 75
www.processsys tems.sandvik.com