belt

2. What is a Conveyor Belt?
Of all the methods invented for the continuous
transportation of materials, the conveyor belt has
proved to be most versatile and in long term, the
most economical.
It is designed for handling of products, such as
coal, sand, ores, minerals, chemicals to foodstuffs.
Thus, virtually, almost in every field of industry
there is use of conveyor beltings and conveyor
system involving bulk transportation.

4.  Conveyor belt consists of a load supporting tension
members (carcass), protected from wear and tear, chemical
action, heat etc. by an elastomeric cover.
 Carcass, which is basically fabric or steel cord, considering
to be the main tension bearing member.

5.  High strength : to be able to carry the load
 Low growth: so that belt does not become slack
 High impact resistance : In order to take care of shock
loads
 Good troughability : to convey lumps/granular materials
 Low bending resistance & no buckling : for low power
consumption
 Effective mechanical splicing : to be able to be repaired

6.  Good adhesion between components : to be able to carry
the load
 Resistance to atmospheric condition : for durability
 Longer life
 Good flexibility
 Low creep & high compression resistance

7.  High capacity in handling material.
 Economic transportation.
 Least degradation of materials.
 Lowest power requirement.
 Faster transportation.

8. Conveyor Belt consists of – 3
Elements
COVER RUBBER
A CARCASS
(REINFORCING MEMBER)
 INTERPLY RUBBER

9. IT IS USED FOR THE FOLLOWING
PURPOSES:
 To protect the belt from being damaged by the
materials conveyed.
 It protects the carcass from external abrasion
and impact injuries.
 Covers are designed to resist adverse service
condition, like Abrasion, Heat, Oil, Fire, Static
Electricity, Chemicals etc. depending upon
application.

10. Cover RubberCover Rubber : Designed to suit different purpose
 M-24 : Compound can be based on NR or synthetic
polyisoprene
 N-17 : Here Tensile strength is needed is 17 MPa. NR
can be blended with rubber of cheaper quality.
 Heat ResistanceHeat Resistance
 Type I : Upto 120 deg C (NR, SBR can be used)
 Type II : Upto 150 deg C (SBR can be used)
 Type III : Upto 200 deg C (Chlorobutyl / bromobutyl,
EPDM can be used)
 Oil ResistanceOil Resistance : Compound can be based on NBR, CR,
depending on the nature of oil contact

11. IT IS USED FOR THE FOLLOWING PURPOSES:
 To provide the body to a belt.
 Carcass can be defined as the tension and strength
bearing member consisting of either Textile Material
or Steel Cord.
 It primarily provides resistance to tension forces that
build up in the conveyor system.
 It also provides strength to resist belt tear and loading
impact.
 For load support, it gives troughing.

12.  Textile fabrics are the most common reinforcing materials in
flat belting.
The type of fabric used:
 Cotton
 Viscose Rayon
 Glass
 Nylon
 Polyester
 Aramid
 Steel

13.  COTTON
 Low tension
 Light duty service
 COTTON-NYLON
 Better resistant to impact damage
 Tear strength is higher than cotton
 Better troughabllity and greater flexibility
 Increased tesion rating
 Longer flex life

14.  NYLON FABRIC
 Reduction in belt weight
 High tension rating
 Greater troughability and better flexibility.
 Better moisture resistance
 Excellent impact resistant
 Superior durability
 No fatigue during bending
 POLYESTER FABRIC
 Better moisture resistance
 Low stretch
 Less dependability on temperature
 Other properties similar to Nylon

15. Steel CordSteel Cord
 High Strength
 Low bending stress
 Superior troughing characteristics
 High splice efficiency
 Adhesion
 High Impact resistance
 Good flexibility
 Less creep
 Higher fatigue resistance

16. Interply RubberInterply Rubber
For textile BeltFor textile Belt
 Improvement of adhesion between plies & ply to cover
 The load support is improved by greater Inter-ply rubber
 Damage to fabric can be avoided by increase of Inter-ply
rubber

17. For Steel Cord Belt
 Good bonding to metal, i.e, higher adhesion with metal
 Bonding strength should be retained upon repeated
dynamic flexing
 Higher hardness with adequate tear resistance & rigidity

18. Smoked sheet 100
Zinc oxide 5
Stearic acid 2
SRF black 10
Whiting/activated calcium
carbonate
15
Tackifier / softner 5
Antioxidant 1
Accelerator (CBS) 0.6
Sulphur 2.5
(Cure : 20 min. at 1500
C)

19. Smoked sheet 50
SBR 1500 50
Zinc oxide 5
Stearic acid 2
Tackifier / softner 5
ISAF black 40
Antioxidant 1.5
Accelerator (CBS) 1.0
Sulphur 2.0
(Cure : 20 min at 1500
C)

20.  Belt StrengthBelt Strength : Cord strength (KN) X n / Width of Belt in mt.
where, n = Number of cords
 Cord PathCord Path : = P(n -1)+d,
Where, P = Pitch in mm
n = Number of cords
d = Cord diameter in mm
 Belt designationBelt designation
Textile : 2400 x 2000 / 4 x NN x 10 + 6 x M-24 X CE
Width = 2400 mm, Bottom Cover = 6mm
Belt Strength = 2000 KN/mt. M-24 = Grade
No. of Ply = 4, of rubber with TS 24 MPa
NN = Nylon-Nylon CE = Cut edge
Top Cover = 10mm, construction

21. Steel Cord BeltSteel Cord Belt
 2400 x ST4000 x θ 8.8 (7X19) x p-15 x n-157 x 200mt
 Width = 2400mm
 Strength on belt = 4000KN
 Cord diameter = 8.8 mm
 Cord Construction = 7x19
 Pitch = 15 mm
 Number of cords = 157
 Length = 200mt.

22. Breaker Fabric
•Breaker fabric is recommended for critical application.
•It is placed between the cover and the carcass to
improve additional anchorage through locking and to
resist cover against grouping, stripping and tearing.
•It finds particular application where impact due to fall
of lumps from greater height is experienced.

23. TensionTension
 Tension to overcome friction of the belt and conveyor
compound that contact the belt
 Tension to overcome friction of the load
 Tension to raise or lower the load through elevation changes
Minimum PlyMinimum Ply
 A belt has been designed for the minimum number of piles
for load support and it also will have enough carcass tensile
strength to meet the tension requirement
Maximum plyMaximum ply
 The belt must be designed to be sufficiently flexible
transversely to trough properly.

24. ImpactImpact
 The carcass must be “beefed up” through the use of special
fabrics, breakers, and construction so that the belt can be
withstanding abnormal impact
Flex LifeFlex Life
 Rubber quality, pulley diameters, belt speed and length and
troughing flexure all influence carcass flex-life.
CoverCover
 A very small premium for upgrading quality or adding cover
gauge may be well rapid in terms of overall belt life

25. The Core Element – Steel cord

26. The Core Element – Steel cord
The cords may have several types of configurationsThe cords may have several types of configurations
like:like:
7Х7 7Х19 1Х19+7Х7

27. Textile Conveyor Belt
 Fabric is skim coated in calender
 Rubber Cover is sheeted from calender or Roller die
 Fabric is assembled in belt building machine under uniform
tension and consolidated by pressurizing rollers
 The assembled carcass is transferred to main let off station

28.  Rubber is laid on top of the carcass. Similarly, bottom cover
is also laid on the other side of carcass
 The belt is then vulcanized being pre-stretched under high
temperature and pressure with pre-determined compression
 The cured belt is then passed through repair machine,
where defects is determined and repaired accordingly.

29.  Dimension check e.g, width, pitch, edge width, cord
diameter, cord position i.e, vertical displacement, cover
thickness etc.
1. Full Belt T.S.
2. EB at 10 % of Breaking Load
3. Adhesion : Cover to Ply & Ply-Ply
4. Adhesion drop after ageing
5. TS & EB of cover
6. Ageing drop of TS & EB of cover
7. Abrasion resistance of cover

30. 8. Tear resistance of cover
9. Troughability
10. Hardness of Cover
11. Flame resistivity
12. Drum friction test
13. Electrical Resistivity