Overview
ISO 20299-2:2017 specifies material and physical property requirements for non-strippable low density polyethylene (LDPE) film used to wrap natural rubber bales. The standard covers film used with block natural rubber (typical bale weights 33.33 kg or 35 kg) and ribbed smoked sheets (bale weights 33.33 kg, 35 kg, 50 kg and 111.11 kg, or other mutually agreed weights). The film is intended to keep bales separate during transport and storage and to be compatible with downstream rubber processing.
Key topics and technical requirements
- Material: Film must be manufactured from low density polyethylene (PE-LD / LDPE). Surfactants, antioxidants and antiblocking agents are normally not included.
- Thickness and density: Measured with a micrometer, film thickness shall be 0.03 mm to 0.05 mm. Density is 0.92 ± 0.01.
- Thermal properties: Compliance can be shown by satisfying one of two tests:
- Vicat softening temperature (ISO 306, method A50): Vicat temperature ≤ 95 °C.
- DSC melting peak (ISO 11357-3): Differential scanning calorimetry melting peak ≤ 113 °C.
- Note: The film’s melting/softening characteristics are chosen so the film will disperse during internal mixing (mixing cycle temperatures typically 120–160 °C).
- Marking: Each bale must be marked with manufacturer and retailer identification-manufacturer name in yellow (1 cm characters) near the right-side junction; retailer name in red (5 cm characters) centered on both sides. Specific marking details can be agreed between parties.
- Test report content: Test reports must reference ISO 20299-2, identify the sample, record any unusual events, include results for the physical tests (clause 5) and provide test dates.
Applications and who uses this standard
- Natural rubber producers and packers: to specify compliant LDPE bale film for export and storage.
- Packaging film manufacturers: to design and certify LDPE film formulations meeting thickness, density and thermal criteria.
- Quality control and testing laboratories: to perform Vicat and DSC testing and document conformity.
- Buyers, logistics and traders: to ensure packaging protects bales, prevents sticking/mould and does not contaminate mixes.
- Practical benefits include hygienic, cost-effective packaging that avoids the drawbacks of ball coatings (ash contamination, product quality impact).
Related standards
- ISO 306:2013 - Plastics - Vicat softening temperature (VST)
- ISO 11357-3 - Plastics - Differential scanning calorimetry (DSC)
- Other parts of the ISO 20299 series (rubber bale packaging)
Keywords: ISO 20299-2:2017, film for wrapping rubber bales, natural rubber, LDPE film, Vicat temperature, DSC melting peak, film thickness, rubber bale packaging, packaging standards.
