Overview
ISO 23560:2015 - Woven polypropylene sacks for bulk packaging of foodstuffs sets international requirements for woven polypropylene (PP) sacks used to transport and store foodstuffs such as cereals, sugar and pulses. The standard applies to typical commercial sack capacities of 50 kg (Type 1) and 25 kg (Type 2) and defines construction, materials, testing, marking and sampling criteria to ensure safe, food-compatible bulk packaging.
Key Topics
- Scope and materials
- Applies to woven PP sacks (tube woven from PP tape ~2.5 ± 1 mm) for food contact use.
- Raw materials must meet food contact requirements.
- Dimensions and weights
- Typical internal dimensions: Type 1 (50 kg) - inside length 100 cm, inside width 57 cm; Type 2 (25 kg) - inside length 65 cm, inside width 48 cm.
- Typical sack mass: ~135 g (50 kg) and ~67 g (25 kg) with specified tolerances.
- Construction and stitching
- Bottom seams stitched with two rows of chain stitches (ISO 4915), minimum seam width and stitch density specified to prevent failures during handling.
- Closure design must prevent leakage during transport and handling.
- Liner option
- Unlaminated sacks may include a loose polyolefin liner for additional protection; liner width and seam placement are specified.
- Mechanical and durability tests
- Fabric breaking strength and elongation requirements (e.g., average breaking strength ≥918 N for 50 kg sacks lengthwise; ≥816 N for 25 kg).
- Bottom seam strength requirements (average ≥377 N for 50 kg; ≥337 N for 25 kg).
- Drop testing (Annex C) and conditioning per ISO 291 to simulate handling and storage.
- UV resistance and ash content
- UV-stabilized fabrics must retain ≥50% breaking strength after accelerated UV weathering (ISO 4892-3).
- Ash content for UV-stabilized fabric limited to 3% max (ISO 3451-1).
- Marking, packaging and bales
- Sacks are wrapped into circular bales (typically 500 sacks/bale) with specified bale marking (manufacturer, sack type/size, gross/net mass, date).
- Sampling and conformity
- Sampling plans and acceptance criteria (including allowable defects and strength minima) are defined for lot conformity.
Applications
- Ensures consistent quality for bulk food packaging, handling and export/import of grains, pulses, sugar, rice and similar commodities.
- Used by: PP sack manufacturers, quality managers, procurement teams, logistics and warehouse operators, exporters/importers, and regulatory bodies verifying food-contact packaging compliance.
- Practical benefits: improved stack stability, reduced leakage/spoilage, predictable mechanical performance in transport and storage.
Related Standards
Normative references cited include:
Keywords: ISO 23560:2015, woven polypropylene sacks, bulk packaging, foodstuffs, PP sacks, seam strength, UV resistance, drop testing, food contact.