Overview
ISO 505:2017 specifies a test method for measuring the propagation resistance of an initial tear in textile conveyor belts, either at full thickness or of the carcass only. The test is intended for applications where there is a risk of longitudinal tearing and provides repeatable data for safety assessment, quality control and belt selection.
The principle of the test is a tensile measurement: a pre-cut tear is extended under controlled separation speed while the tearing force is recorded graphically. The method applies to textile conveyor belts used in installations exposed to longitudinal-tear hazards.
Key Topics
- Scope and purpose: measurement of tear-propagation resistance for textile conveyor belts (full thickness or carcass only).
- Apparatus: dynamometric tensile testing machine sized so measured forces fall within the upper 90% of rated capacity, separation speed adjustable to (50 ± 10) mm/min, and a free jaw distance of at least 300 mm. A device for graphical recording of tearing force is required.
- Sampling and test pieces:
- Samples cut in the longitudinal direction, at least 50 mm from belt edges.
- Rectangular test pieces: length 300 mm; width (100 ± 1) mm (increase to 300 mm if weft threads pull out rather than break).
- Thickness: full belt thickness or carcass only (covers may be stripped or buffed where required).
- Two test pieces are used, one in sense A and one in sense B.
- Preparation: special handling if a breaker ply is present; tapering of edges permitted to match jaw grip width.
- Conditioning: tests start not less than 24 h after manufacture (including at least 8 h conditioning). Acceptable conditioning atmospheres include:
- 20 ± 2 °C and 65 ± 5 % RH; or
- 23 ± 2 °C and 50 ± 5 % RH; or
- 27 ± 2 °C and 65 ± 5 % RH.
In disputes, conditioning shall be 72 h. Tests are performed in the same atmosphere.
- Procedure and results:
- Mount the cut ends in the machine so the inner cut edges are centered in the jaws.
- Separate jaws at (50 ± 10) mm/min and continue until the tear has extended at least 100 mm.
- Record tearing forces graphically; analyse multi-peak traces in accordance with ISO 6133. The median peak force is defined as the mean tear resistance. Report values for each piece and the mean of both.
Applications
- Acceptance testing and quality control of textile conveyor belts.
- Comparative assessment for belt selection where longitudinal tear risk exists.
- Design validation and troubleshooting of conveyor installations subject to tearing hazards.
Related Standards
- ISO 6133 - referenced for analysis of multi-peak tear-resistance traces.
- ISO 505:1999 - previous (third) edition cancelled and technically revised by ISO 505:2017.
This concise guidance reflects the practical requirements and reporting elements specified in ISO 505:2017 for consistent measurement of tear-propagation resistance in textile conveyor belts.
Open preview (PDF)Conveyor belts — Method for the determination of the tear propagation resistance of textile conveyor belts
