Scientific Ethylene Conversion & Condensation Management
VAMSA Fresh Keeper liners combine active catalytic silver nano particles into food-grade polyolefin resins to actively convert ethylene gas and balance relative humidity inside export crates.
Active Ethylene Conversion
Imbedded catalytic silver nano agents convert ethylene gas ($C_2H_4$) produced by climacteric fruits directly into harmless oxide compounds, suppressing yellowing, softening and stem browning.
Dewpoint Condensation Control
Engineered micro-porosity and anti-fog surface chemistry prevent free water droplet condensation on liner walls, eliminating gray mold (*Botrytis cinerea*) and bacterial soft rot.
Food Contact Certified
100% compliant with US FDA 21 CFR 177.1520 and EU Regulation 10/2011 for direct food contact. Free from migratory plasticizers, heavy metals, or toxic chemical coatings.
Available Fresh Keeper Film Grades
Tailored permeability and barrier profiles designed for low, medium, and high respiration rate produce.
Standard MAP Liner
Balanced O₂/CO₂ permeability for table grapes, pomegranates, and stone fruits.
- Thickness: 20µm – 35µm
- OTR: 4,500 cc/m²/24h
- WVTR: 12 g/m²/24h
Anti-Fog Clear Liner
High optical clarity with internal anti-fog agent for retail display crates & punnets.
- Thickness: 15µm – 25µm
- OTR: 5,200 cc/m²/24h
- Zero fogging at 2°C
Micro-Perforated Liner
Laser micro-perforated for high respiration leafy greens, mint, coriander and broccoli.
- Thickness: 18µm – 30µm
- Custom hole density
- Prevents anaerobic fermentation
Heavy-Duty Sea Liner
High puncture resistance for 15kg–20kg bulk export crates and long sea voyages.
- Thickness: 35µm – 50µm
- Tensile MD: >45 MPa
- Puncture: >18 N
Technical Specification Summary
| Property / Metric | Test Standard | VAMSA Fresh Keeper Specification |
|---|---|---|
| Base Polymer Resin | ISO 1043 | Food-grade LLDPE / mLLDPE co-extruded matrix |
| Active Agent | VAMSA R&D Patent | Imbedded Silver Nano Catalytic Compound (0% chemical leaching) |
| Thickness Range | ASTM D374 | 15 µm to 50 µm (±5% tolerance) |
| Oxygen Transmission Rate (OTR) | ASTM D3985 | 3,800 – 6,500 cc / m² / 24h @ 23°C, 0% RH |
| Water Vapor Transmission Rate (WVTR) | ASTM F1249 | 8.5 – 14.0 g / m² / 24h @ 38°C, 90% RH |
| Tensile Strength (MD / TD) | ASTM D882 | ≥ 38 MPa (MD) / ≥ 32 MPa (TD) |
| Elongation at Break | ASTM D882 | ≥ 480% (MD) / ≥ 620% (TD) |
Frequently Asked Questions
How does VAMSA Fresh Keeper convert ethylene gas?
VAMSA Fresh Keeper liners feature patented active silver nano particles embedded inside the polymer film structure. When ethylene gas ($C_2H_4$) emitted by produce comes into contact with the liner wall, the catalytic silver nano particles oxidise the gas into harmless oxide molecules, preventing the gas from triggering ripening pathways.
Is VAMSA Fresh Keeper safe for direct contact with organic produce?
Yes, 100%. The silver nano active agents are permanently bound into the polymer matrix and do not migrate or leach onto produce surfaces. It is certified compliant under US FDA 21 CFR 177.1520 and EU 10/2011 for direct food contact.
Can Fresh Keeper liners be customized to match our specific box dimensions?
Absolutely. We manufacture pre-cut gusseted box liners, flat bags, continuous roll stock, and large pallet covers according to your packhouse box specifications (e.g. 5kg, 8kg, 10kg, 18kg export crates).
Do we still need pre-cooling before sealing produce in Fresh Keeper liners?
Yes. Pre-cooling produce to remove field heat prior to sealing is critical. Sealing warm produce inside any liner bag creates excessive condensation that compromises cold chain management.