Compostable packaging bags are mostly made from natural raw materials.
Under industrial-standard compost surroundings, they fully turn into carbon dioxide, water and organic humus without plastic waste left behind. Their breakdown creates no harm to microbes, wildlife or plants.
Common options cover kraft paper, PLA, PBAT, plus barrier-enhanced VMPLA. Its thin vapor-deposited aluminum layer degrades alongside the base film, without ruining the bag’s compostable trait.
The core purpose of packaging bags is to keep contents in proper storage conditions, so picking the right material matters a lot. Different materials block light, moisture and oxygen to varying degrees. (Higher scores mean better barrier performance)
Kraft/PLA
Kraft/PBAT
Kraft/VMPLA/PBAT
Makepac can provide various kinds compostable material to make pouches.
Made from unbleached wood pulp, this thick paper has natural rough texture. It brings eco-friendly visual sense, good stiffness, but poor moisture and oxygen barrier performance, needs composite films for food storage.
Polylactic acid made from plant starch, fully compostable. It features high transparency and rigidity, yet turns brittle under low temperature, with average barrier against water vapor and oxygen.
Polylactic acid made from plant starch, fully compostable. It features high transparency and rigidity, yet turns brittle under low temperature, with average barrier against water vapor and oxygen.
Aluminum vacuum-coated PLA film. The thin aluminum layer greatly boosts light, oxygen and moisture blocking ability, keeps full biodegradability, a substitute for non-degradable aluminized PET.
The thicker the material, the better its barrier properties.
OTR (Oxygen Transmission Rate)
@ 23℃, 0% RH, Unit: cm³ / (m²・24h・Atm)
WVTR (Moisture Vapor Transmission Rate)
@ 38℃, 90% RH, Unit: g / (m²・24h)
| Material | OTR | WVTR | Est. Shelf Life |
|---|---|---|---|
| Kraft/PLA | 100 ~ 180 | 80 ~ 120 | 2~3 Months |
| Kraft/PBAT | 180 ~ 260 | 100 ~ 160 | 2~3 Months |
| Kraft/VMPLA/PBAT | 4.6 | 4.7 | 4~6 Months |
This table describes the different characteristics of PLA and PBAT. Please select the appropriate material according to your product. If you have any questions, please contact us.
| Comparison | PLA | PBAT |
|---|---|---|
| Raw Material Source | Derived from corn/cassava starch, bio-based & renewable | Petroleum-based copolyester, non-renewable |
| Handfeel | Rigid, brittle; easy to crack after folding | Soft & elastic, resistant to repeated folding and low temperature |
| Heat Sealing | Narrow sealing temperature window; brittle seal prone to breakage; poor oil resistance | Wide stable heat sealing range; flexible seal, resistant to grease & acidic contents |
| Barrier Property | Better oxygen & moisture barrier performance | Weak barrier performance; VMPLA layer required to extend shelf life |
| Temperature Resistance | Max 50℃; softens & deforms under high temperature | Stable from -20℃ to 60℃, suitable for refrigerated storage |
| Suggested Structures | Single coated Kraft/PLA flat small pouches only | Kraft/VMPLA/PBAT stand-up pouches & Flat Bottom Bags |
| Degradation Condition | Only decomposes fully under industrial conditions. | Degrades rapidly in industrial compost, normal soil or seawater |
| Disadvantages | Prone to cracking at folded edges, poor oil resistance, easy melt-through during heat sealing | Low transparency, higher raw material cost |
The carbon-to-CO₂ conversion ratio of the materials is ≥90%
Each component accounts for ≥1% of the raw material degradation rate≥60%; the total proportion of trace auxiliary materials is ≤5% and they are biodegradable.
After passing through a 2mm sieve, the mass of residual large pieces of material is less than 10%, and there are no intact packaging bag fragments.
Heavy metals such as lead, cadmium, mercury, and chromium are below the national standard limits for fertilizers, and the residue from the aluminum-plated VMPLA aluminum layer does not exceed the standard.
The compost residue does not inhibit seed germination, does not poison earthworms, and causes no ecological pollution.
Natural decomposition often takes a long time, so scientists have tested environmental conditions that accelerate decomposition—industrial degradation.
This significantly speeds up the rate and extent of degradation, making the large-scale use of biodegradable packaging bags possible.
| Control Parameter | Standard Value Range | Description |
|---|---|---|
| Constant Temperature | 58±2 ℃ | Optimal temperature for thermophilic microbes to break down polymer chains of PLA and PBAT |
| Sustained Temperature | 55 ℃ for 28 consecutive days Or 60 ℃ for a total of 7 days |
Eliminate pathogens, parasite eggs and weed seeds to realize harmless treatment |
| Moisture Content | 50%~55% | Support microbial metabolism; overly dry conditions make flora dormant while excessive moisture triggers odorous anaerobic fermentation |
| Oxygen Level | ≥10% | Maintain full aerobic environment and stop methane generation from anaerobic reaction |
| Aeration Rate | 0.05~0.1 m³/(h·kg dry compost) | Supply steady fresh air and carry away carbon dioxide produced in degradation |
| Carbon-Nitrogen Ratio (C/N) | 25±5 : 1 | Balance nutrients for microbes and keep a stable degradation speed |
| pH Value | 7.0±0.5 | Neutral surroundings to avoid acid or alkali suppressing activity of thermophilic microbes |