Tensioning Conveyor Belts
How do I tension my PVC , PU and Silicone Conveyor Belt with textile wefts (plies)?
Adjusting and determining installation tensions for Conveyor Belts with Polyvinyl Chloride (PVC), Polyurethane (PU) and Silicone coverings with textile plies (polyester weft)
Conveyor Belts are used for conveying.
Conveyor belts are the key elements of a conveying system, their primary function being to move a product or an isolated load from one point to another.
During initial installation, tension adjustment is essential to ensure optimum operation of your installation.
When the Conveyor Belt is installed, it is essential to determine and adjust the tension to ensure that your installation runs smoothly.
The Conveyor Belt is made up of textile weave and PVC or PU coating on 1 or 2 sides.
Lightweight Conveyor Belts are made up of textile weft (ply), often polyester, with a PVC, PU or silicone coating on one or both sides.
The type of fabric (polyester, cotton, etc.), the number of plies and the width of the belt all affect the initial tension at which it is laid.
Textile pleated tapes are generally made of polyester weft (pleats). The number of plies varies from 1, 2 or 3.
The number of plies (1, 2 or 3) and the width of the belt determine the stiffness or, more commonly, the elongation ratio at 1%. This value is the basis for determining the tension at which the belt is laid.
The 1% elongation tension corresponds to the value in Newton per mm of width required to elongate the strip by 1%.
The value at 1% corresponds to the elongation tension in N (Newton) / mm (width) to elongate the Conveyor Belt by 1%.
Ex = 8 N/mm To lengthen a belt by 1% of its length, a load of 8 Newton per mm of width is required.
Ex 15 N/mm to lengthen the belt by 1% of its length a load of 15 N per mm of width is required
The greater the number of plies, the greater the value of 1%.
IF the number of textile layers (plies) is greater, the greater the value of the stiffness expressed in 1%.
The value of the initial laying tension is expressed in % and is generally between 0.1 and 0.5 %.
Width greater than 1000 mm
Narrow width (- 150 mm)
1% elongation greater than 15 N/mm
1% elongation less than 5 N/mm
% voltage
0.1
0.5
0.2
0.4
How do I tension my monolithic Conveyor Belt without textile wefts (plies)?
Adjusting and determining mounting tensions for Conveyor Belts without weft (Monolithic Belt)
Monolithic belts have no textile weft, just a layer of polyurethane (PU).
Elastic belts are mainly used for applications with a fixed centre-to-centre distance (no mechanical tensioning system).
A new range of Conveyor Belts has recently appeared on the conveyor market: weftless belts (plies).
Elastic or monolithic belts are designed for applications with reduced tension travel or on installations with fixed centre-to-centre distances (no possibility of tensioning).
Shore A hardness, thickness and width have an influence on initial installation tension.
The length, thickness and especially the shore hardness (A) determine the stiffness of the belt and therefore the value of the laying tension.
Monolithic belts are joined endlessly according to a manufacturing dimension (length L0 at rest).
Length L1 corresponds to the length of the belt with tension (belt under tension on the conveyor).
To obtain the LO dimension, we need to deduct the % of initial elongation of the belt, generally referred to as pre-tension.
Example: for a tensioned length of 1000 mm with an initial elongation of the belt of 5%, we obtain a manufacturing dimension of 950 mm (1000 - 5%).
For this type of belt, the manufacturing dimension is called L0 (or length without tension at rest). The L1 length corresponds to the dimension of the belt under tension (tensioned or raised dimension).
The ratio between L0 & L1 is called the tension value in % or, more generally, % tension.
To obtain the rib L0, deduct the % of initial elongation of the belt.
Example: for a tensioned length of 1000 mm with an initial elongation of the belt of 3%, we obtain a manufacturing dimension of 970 mm (1000 - 3%).
Monolithic belts are generally short, less than 10 metres.
Monolithic belts are often short belts, less than 10 metres long.
The value of the initial laying tension is expressed in % and is generally between 0.2% and 5%.
Shore hardness from 65 to 85 shore A
(Maximum length = 3000 mm)
Thickness 0.5 to 0.9 mm
Thickness 1 to 1.9 mm
Thickness 2 to 3 mm
Width 10 to 100 mm
6 à 10 %
2 à 6 %
1 à 2 %
Width 100 to 399 mm
2 à 6 %
2 à 4 %
0.5 à 1 %
Width 400 to 750 mm
-2 %
-1 %
-0.5 %
Shore hardness from 86 to 100 shore A
(Maximum length = 10000 mm)
Thickness 0.5 to 0.9 mm
Thickness 1 to 1.9 mm
Thickness 2 to 3 mm
Width 10 to 100 mm
2 à 4 %
1 à 2 %
0.5 à 1%
Width 100 to 399 mm
1 à 2 %
0.5 à 1 %
0.2 à 0.5 %
Width 400 to 750 mm
-1 %
-0.5 %
-0.2 %
The % stresses indicated are given for information only. It is necessary to make a precise calculation, taking into account the shaft load, to determine the stress on the axles or bearings.
Method for applying the tension value
Make an empty mark (without tension) 1000 mm long on the belt
Apply a tension of 0.1 to 0.5 %, depending on the size of the strip
Move the tension roller to lengthen the mark
The initial mark will lengthen to 1003 mm
(for wide tapes, it is advisable to measure on both sides to avoid too great a difference in tension, which would lead to poor guiding of the tape).
Methodology for assembling a Conveyor Belt with weft
Make an empty mark (without tension) 1000 mm long on the belt
Draw a mark without tension with a dimension of 1000 mm
Apply tension of 0.1 to 0.5 % depending on the belt
Once the correct tension has been determined, tension the belt and move the roller using the adjustment screws
Move the tensioning roller to lengthen the marked area
The belt will lengthen and the initial mark will lengthen
The initial mark will lengthen to 1003 mm
For a strip with a tension of 0.5%, for example, the mark will lengthen by 5 mm
The initial rib from 1000 to 1005 mm
(for wide tapes, it is advisable to measure on both sides to avoid too great a difference in tension, which would lead to poor guiding of the tape).
(For narrow belts, we recommend that you take several measurements to check the tension, as tension disparities can occur on belts with narrow widths, resulting in poor belt operation and the risk of rapid deterioration).
ATTENTION :
The data and voltage values are given for information only. Tanals cannot be held responsible for any misinterpretation or misuse.