Overview
EN ISO 4167:2006 (ISO 4167:2006) defines the principal properties, test methods and delivery requirements for polyolefin agricultural twines (commonly called baler twine). Prepared by CEN in collaboration with ISO, this standard covers twines made principally from polypropylene (PP) and high-density polyethylene (PE) and specifies material, mechanical and sampling requirements needed to verify product suitability for agricultural baling and binding.
Key topics and requirements
- Scope and designation
- Specifies how to designate twine (e.g., “agricultural twine ISO 4167 - PP - 350” where 350 is the nominal runnage in m/kg).
- Raw materials
- Polyolefin base (PP, HDPE) with UV stabilization and non-toxic pigments; colour must be distinguishable from straw/grass.
- Manufacture
- Twine must have a Z twist (ISO 2) and be wound to allow continuity from the center of the spool.
- Technical properties
- Linear density (tex), runnage (m/kg), minimum twine breaking force and minimum average knot breaking force are defined.
- Runnage tolerance: ±8% (rounded to nearest integer).
- Formulae given for minimum breaking force (F) based on nominal runnage and for knot breaking force (Fk = 0.55·F).
- Sampling and batches
- Batch and laboratory sample selection rules; sampling formula S = 0.025·N (number of spools).
- Test methods
- Detailed procedures for determining linear density and runnage (weighing 30 m specimens), tensile breaking force and knot strength, conditioning (ISO 139 atmosphere), and acceptance/retest rules.
- Form of delivery and marking
- Requirements for spool presentation, marking and batch make-up for sale.
Applications and users
- Agricultural twine manufacturers - for product design, production control and compliance.
- Quality assurance and testing laboratories - to perform standardized runnage, tensile and knot-strength tests.
- Equipment manufacturers and farm operators - to specify compatible twine for balers, round/conventional/big bales.
- Purchasers, distributors and regulators - for procurement specifications and conformity assessment.
- Standards bodies and certification schemes - for harmonized requirements across CEN/ISO member countries.
Related standards (if applicable)
- ISO 2 - Direction of twist designation for yarns.
- ISO 139 - Standard atmospheres for conditioning and testing (used in ISO 4167).
- EN 906:1996 - Superseded by EN ISO 4167:2006.
Keywords: EN ISO 4167, ISO 4167:2006, polyolefin agricultural twines, baler twine, polypropylene twine, HDPE twine, runnage, breaking force, knot strength, sampling, test methods, CEN.