Overview
ISO 1532:1973 is an international standard developed by the International Organization for Standardization (ISO) that specifies methods for cutting knotted fishing netting into specific shapes, a process known as "tapering." This standard details the proper techniques to achieve various tapered shapes by making precise cuts in the netting. It replaces the earlier ISO Recommendation R 1532-1970 and is instrumental for ensuring uniformity and quality in fishing net production.
The document establishes terminology, cutting types, and designation rules to assist manufacturers and users in shaping netting efficiently and consistently according to desired final geometries.
Key Topics
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Cutting Types
- N-cut (Vertical cut): A cut at right angles to the general direction of the netting yarn, performed just beyond the knots.
- T-cut (Horizontal cut): A cut parallel to the general yarn course, also just beyond the knots.
- B-cut (Bar-cut): A cut parallel to a line of sequential mesh bars. This cut severs one or more mesh bars along the cutting edge.
- K-cut (Knot cut): Cuts made close to the knots, sometimes used interchangeably with N- or T-cuts when the yarn direction is less significant.
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Cutting Rate
- The rhythmical alternation of N-, T-, and B-cuts, determining the tapering pattern required to produce the shape of the netting piece.
- Designated by combinations like "1N2B" (one N-cut followed by two B-cuts) or "1T2B" (one T-cut followed by two B-cuts).
- Cutting rates help control the final shape by specifying how many meshes or bars are cut consecutively.
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Tapering Shapes
- The standard supports creating trapezia, triangles, parallelograms, and other polygons.
- By tapering one or two edges of the net, shapes such as right-angled trapezia, isosceles trapezia, isosceles triangles, and asymmetrical trapezia can be formed.
- Guidelines include how to combine cuts on opposite edges to create parallelograms or join cuts from different edges for more complex shapes.
Applications
ISO 1532:1973 is essential for professionals involved in the design, manufacture, and repair of fishing nets. Its applications include:
- Fishing Net Production: Enabling precise shaping of knotted netting adapted to various fishing conditions and vessel requirements.
- Net Repair Work: Providing a standard method to taper and fit replacement net sections seamlessly.
- Quality Control: Assuring consistency in tapered net shapes across different manufacturers through standardized cutting rates and methods.
- Custom Net Fabrication: Facilitating custom net shapes tailored to specific fisheries or environmental regulations.
By following these standardized cutting procedures and designations, net manufacturers can minimize waste, improve the structural integrity of nets, and optimize fishing efficiency.
Related Standards
- ISO 1107: Fishing nets - Netting - Basic terms and definitions, which provides foundational terminology referenced in ISO 1532.
- Other ISO standards developed by Technical Committee ISO/TC 38 (Textiles), which address fishing net materials, properties, and testing methods.
Integrating ISO 1532 with these complementary standards ensures comprehensive harmonization across fishing net production and application processes.
Keywords: ISO 1532, fishing nets, knotted netting, tapering, net cutting, N-cut, T-cut, B-cut, cutting rate, fishing net shapes, net manufacturing standard, fishing net repair, ISO fishing net standards.