Overview
ISO 20299-3:2008 specifies requirements for non-strippable film used in wrapping general-purpose synthetic rubber bales. Developed by the International Organization for Standardization (ISO), this standard ensures effective separation of bales, especially for industrial storage and transport. The covered rubber types include:
- Ethylene-propylene-diene rubber (EPDM)
- Acrylonitrile-butadiene rubber (NBR)
- Hydrogenated nitrile-butadiene rubber (HNBR)
- Acrylic-ethylene rubber (AEM)
- Acrylic rubber (ACM)
The primary goal is to avoid rubber-to-rubber adhesion during storage, enabling easy bale handling throughout the manufacturing supply chain.
Key Topics
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Material Specifications
The film must be composed of low-density polyethylene (PE-LD), PE-LD blended with ethylene-vinyl acetate copolymer (EVAC), pure EVAC, or certain copolymers of ethylene. The use of suitable antioxidants and agents is permitted to improve film performance.
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Physical Property Requirements
The wrapping film must meet strict thickness standards, typically ranging between 0.040 mm and 0.085 mm, depending on the material used. Proper thickness is essential for handling stresses during bale processing and storage.
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Thermal Properties
The standard defines maximum limits for Vicat softening temperature-ensuring that the film will disperse efficiently into rubber compounds during mixing. This reduces manual removal requirements and enhances operational efficiency.
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Non-strippable Film Focus
Films specified by ISO 20299-3:2008 are intended to remain on the bales during compounding, as they are designed to disperse under typical mixing conditions. The standard does not cover strippable (removable) films.
Applications
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Rubber Processing and Manufacturing
The film is widely used in the synthetic rubber industry for wrapping bales prior to distribution and storage. It maintains separation, preserves bale integrity, and prevents contamination.
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Automated Packing Operations
Given that the film must endure the heat and pressure of automatic bale packing, ISO 20299-3:2008 ensures its suitability for high-throughput environments.
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Rubber Compound Mixing
Because the film disperses during high-temperature internal mixing, there is greater efficiency in production pipelines using EPDM, NBR, HNBR, AEM, and ACM rubbers.
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Logistics and Storage
With the risk of rubber-to-rubber adhesion reduced, storage and handling are more manageable, minimizing the creation of large, undividable bales and facilitating seamless downstream usage.
Related Standards
ISO 20299-3:2008 is part of a broader set of ISO standards concerning films for wrapping rubber bales:
- ISO 20299-1 - Film for wrapping butadiene rubber (BR) and styrene-butadiene rubber (SBR) bales
- ISO 20299-2 - Film for wrapping natural rubber bales
Additionally, key referenced standards support compliance:
- ISO 306 - Determination of Vicat softening temperature for plastics
- ISO 4591 - Determination of film thickness by gravimetric techniques
- ISO 11357-3 - Differential scanning calorimetry for plastics
- ISO 1872-1 - Polyethylene material specifications
By following ISO 20299-3:2008, manufacturers and supply chain specialists ensure optimal protection and processing of synthetic rubber bales, aligning handling, safety, and quality with international best practices.