Overview
EN ISO 1805:2006 specifies an internationally accepted method for determining the breaking force and knot breaking force of netting yarns used in fishing nets. The standard covers tests in both the dry and wet states and highlights wet knotted-yarn testing as particularly representative of in-use behaviour. EN ISO 1805:2006 supports reproducible tensile performance data that can be used for quality control, material selection and product specification.
Key Topics
- Scope and purpose: Measurement of breaking force, knot breaking force, tenacity and breaking length for netting yarns.
- Apparatus: Tensile testing machines (preferably constant-rate-of-elongation) with suitable holding devices, facilities for conditioning (standard atmosphere) and water immersion, and timing/recording instruments.
- Sample preparation:
- Condition dry samples in the standard atmosphere (ISO 139) until equilibrium.
- For wet testing, immerse samples in tap water at (20 ± 2) °C for at least 12 h; an agreed wetting agent may be used to shorten immersion to 1 h.
- Avoid altering twist when removing samples from packaging or when making knots.
- Knots: Use the weaver's knot for knotted tests; all four ends are secured in the grips and knots are made immediately before testing and gently tightened by hand.
- Test geometry and timing:
- Free gauge length between grips: at least 250 mm.
- Target mean test duration (time-to-break): (20 ± 3) s. Where not achievable, (30 ± 3) s or (60 ± 6) s are acceptable if recorded.
- Repeatability: At least ten valid single tests per sample package; discard and record any invalid tests (e.g., slippage or breakage due to grips).
Applications
EN ISO 1805:2006 is valuable for:
- Quality control: Routine verification of incoming yarn lots and finished net components against specified breaking and knot strengths.
- Product development: Comparing materials, yarn constructions and finishing processes for tensile performance in both dry and wet conditions.
- Specification and procurement: Providing objective, reproducible data for contracts, material datasheets and regulatory compliance.
Practical benefits include improved reliability of nets in service, clearer acceptance criteria for suppliers, and traceable test records for dispute resolution.
Related Standards
- ISO 139 - Standard atmospheres for conditioning and testing (referenced for sample equilibration).
- ISO 858 - Designation of netting yarns in the Tex system (used for reporting linear density and twist).
Test reports prepared under EN ISO 1805:2006 should state test conditions, machine and grip type, number of tests and any deviations, and report average breaking force, and where required, tenacity and breaking length. This ensures test results are comparable, auditable and useful for engineering decisions.