Textile Conveyor Belts
Rubber conveyor belting is the cheapest system to convey bulk solid materials over any distance. It is the topic item of a conveyor system that allows the material handling. All Rubber Conveyor Belts are composed by two different elements:
- A central resistant carcass, which gives the mechanical characteristics to the product, as tensile strength andelongation. Two main belting families exist: textile - as shown in this catalogue - and Steel Cord Conveyor Belts.
- Two rubber covers, named top and bottom covers, which protect the resistant carcass and characterize the belt, asdescribed in this page. In order to guarantee safety and long life, also under hard working conditions, all type of rubber covers are antistatic and ozone protected. These pages aim to help you for the selection of the proper covercompounds according to the specific use and the characteristics of the conveyed material.
CL (L grade ISO 10247 - Y grade DIN 22102 - RMA II grade) - Standard abrasion resistant compound. CL is a cover rubber recommended for all ground applications and for the majority part of the materials, where resistance to abrasion is required. Conveyor belts with CL compound are suitable to handle heavy and/or abrasive materials such as gravel, stone, sand, aggregates, coal, cement, etc.
EC (D grade ISO 10247 - W grade DIN 22102 - RMA I grade) - Extra abrasion resistant compound. EC is a superior quality cover rubber, especially designed where maximum resistance to abrasion is required. The characteristics of resistance to cut, tear and ozone cracking, together with long duration, improve the quality of this cover. EC is expressly recommended for steel works and iron mines; however, it is recommended for heavy lump ore, coke, salt, limestone too.
SC (H grade ISO 10247 - X grade DIN 22102) - Superior cutting resistance compound. SC is a cover rubber designed for specific use when the resistance to cut and tear is the most important requirement. SC also guarantees high abrasion resistance. Main applications are quartz and cullet conveyance.
AS - Rubber cover for extreme applications. AS rubber cover is studied to offer the maximum abrasion resistance in all the applications, where an increase in the standard abrasion resistant conveyor’s service life is required. Moreover, its excellent mechanical characteristics allow a superior tearing and cut resistance, which permits its use with heavy materials, i.e. big-sized minerals, bauxite, etc. or in critical working situations characterized by atypical loading/unloading systems. AS grants and surpasses grade W - DIN 22102 and D - ISO 10247 assuring an abrasion resistance of 30-50 mm3.
BS - Self-extinguish compound. BS is a cover rubber designed to service both underground and above ground application where safety is fundamental and fire risk is high. It is recommended in particular for coal and potash applications. BS compound is self-extinguish and antistatic according ISO 340 and ISO 284, equivalent Grade K DIN 22102.
TS - Selfexstinguish compound. TS is a product typology designed to service both underground and above ground applications. It is highly recommended for the belt conveyors located in the back areas of the tunnels. TS is designed according to ISO 284 and ISO 340, equivalent Grade S DIN 22102.
TV - Fireproof compound. TV is a belt typology designed to work in underground applications where it is necessary that the belt does not burn and does not trigger centres of fire. It is recommended for the belt conveyors located close to the permanent work-stations in the tunnels. TV is designed according to ISO 284, ISO 340 and DIN 22100-1.
AG - Self-extinguish and oil resistant compound. AG is a nitrile rubber suitable for conveyor belts and bucket elevator systems of cereal terminals and silos. AG cover rubber provides superior resistances to vegetable oils and animal fats; it is also self-extinguish and antistatic according to ISO 340 and ISO 284, equivalent to K grade of DIN 22012 in order to guarantee high safety to the conveyor plant.
OM (G grade DIN 22102) - Vegetable oil resistance compound. OM is a cover rubber that guarantees a good belt resistance against the chemically aggressive effects due to the transport of materials with moderate oil presence, like corn, fertilizers and general vegetable oily materials. OM is expressly designed to resist the terpene of wooden chips and to convey solid urban waste materials.
OH - High oil resistance compound. OH is a premium quality cover rubber with maximum resistance to oils and characterized by low volume variations after immersion in highly aggressive mineral oils. OH is expressly realized for belts conveying materials sodden with mineral oils, as for example the mechanical manufacturing rejects.
CX - Medium temperature resistance. CX is a rubber compound assuring a medium degree of abrasion resistance; it is formulated for continuous service with hot coarsematerials at a temperature of 130 °C with peaks of 150 °C.
MX - High temperature resistance. MX is a rubber compound assuring a good abrasion resistance. It is
designed for continous service at temperature of 150 °C with peaks of 180 °C.
TX - Superior temperature resistance. TX is a cover rubber that assures the maximum heat resistance for a rubber compound. It is designed to resist with coarse materials at a maximum working temperature of 200 °C with peaks of 300 °C.
All types of conveyor belts produced by SIG SpA are realized according to ISO standards; furthermore, they meet also the requirements of equivalent UNI, DIN, BS, NF, ASTM and RMA standards.
|Cut & tear||★★★||★★★★||★★★||★★||★★||★★||★★||★★||★★||★★★|
|Animal & vegetable oils||N.A.||N.A.||N.A.||N.A.||N.A.||N.A.||★★★★||★★★★||★★★★||N.A.|
|CONTINUOUS WORKING SERVICE °C|
|MAXIMUM PEAKS OF TEMPERATURE °C|
|MINIMUM WORKING TEMPERATURES °C|
N.A. not applicable; ★ fair; ★★ good; ★★★ very good; ★★★★ excellent.
• Polyester - Nylon carcass
• Reinforced cut edges
• Excellent adhesion between plies and covers
• Complete tension style
• Wide selection of cover compounds
• Very low permanent elongations
• Maximum load support
• High resistance to tear and cutting
• Good impact resistance
• Apt to mechanical fasteners
• Humidity proof
Total thickness = Carcass thickness + Cover thickness
Total weight for m2 = Carcass weight (above table) + cover weight (below table)
|1 mm||2 mm||3 mm||4 mm||5 mm||6 mm||7 mm||8 mm|
The transition distance is the length of the section between head or tail pulley and the first troughing idler.
In some cases, intermediate idlers are placed along the transition distance to favour the passage of the belt from the flat to the trough shape.These conveyor sections are the most critical points of the whole plant as the elastic performances of the belt during the time depend on them.
If the transition distance is not correctly designed, high overtensions on the edges and abnormal compressions along the central axis of the belt are generated. Such phenomenon is the cause of unexpected defects, sometimes mistakenly attributed to the belt as wave on the edges and longitudinal fold of the belt carcass.
According to the recommendation of the international standard ISO 5293/81, the calculation of the transition distance is performed in order to prevent belt centre from buckling and edge tension from exceeding 30% of the maximum recommended belt tension (RMBT). These conditions can be respected adopting the following formula:
LT = 14,14 x V x K
Experimental trials, calculations and experiences have shown that average conditions of tension and compression are carried out with values of V equal to 1/2 V1.
Nevertheless, with larger sizes there is the tendency of backward rolling of the materials, for which in most cases values of V included between 2/3 and 4/5 of V1 are assumed.
So, the value of the transition distance LT can be easily calculated for TEXTER belts in the most typical installations, with idlers of equal length, by means of the following formula:
LT = L1 x B x K
L1 = unitary transition distance
B = belt width
K = reduction factor depending on the working tension on the belt.
UNITARY TRANSITION DISTANCE L1
|V =||Idler inclination|
|K multiplier factor||1||0,93||0,82||0,74||0,71||0,83||1,22||1,74|
RMBT = Recommended Maximum Belt Tension
MINIMUM RECOMMENDED PULLEY DIAMETER (mm)
|60% up to 100%||30% up to 60%|
Safety factor > 17
|up to 30%|
Safety factor > 33
A = Drive and tripper pulleys;
B = Tail, return and take-up pulleys;
C = Snub pulleys.
ELEMENTS FOR THE ORDER
To avoid errors or misunderstandings, we suggest using the belt designation of these examples:
Belt lenght Belt type Belt style/nr. plies Cover thick. Cover Belt width
(m) (KN/m) (mm) quality (mm)
1000 m TEXTER 1250/5 10+4 EC 2000
REEL DIAMETER (m)
|Total belt thickness (mm)|
REEL WEIGHT from 1m wide (Tons)
|Total belt thickness (mm)|