Does the thickness of the bag affect its barrier effect?

Most buyers think thicker packaging means better protection. But is that always true?

Yes, the thickness of the bag can affect its barrier properties¹—but not in the way most people think. It's not just about thickness, but material type and structure.

Once, a client asked me to double the thickness of their snack pouch, assuming it would extend shelf life². But the result? Higher costs, harder sealing, and no real improvement. Let’s look deeper.

What is the effectiveness of using thicker plastic bags?

Many buyers believe thicker bags³ provide stronger barriers. Is it really that simple?

Thicker plastic bags can offer better durability and tear resistance, but barrier effect mainly depends on material, not just thickness.

Dive Deeper: Barrier Effectiveness vs. Thickness

When we talk about the “barrier effect” in packaging, we usually mean how well the bag protects the contents from outside elements like:

• Oxygen
• Moisture
• UV light
• Aroma loss

Each of these threats can spoil food or reduce shelf life². While thicker bags³ may seem like the obvious choice, they don’t always provide the best barrier. That’s because different materials have different permeability levels.

For example, a 50-micron PE bag will still offer lower oxygen protection than a 12-micron EVOH laminated bag⁴. That’s because EVOH is designed to block gases—even in thin layers.

Sometimes, we use multi-layer structures⁵ to combine strengths. A 3-layer laminated pouch with PET/VMPET/PE might only be 100 microns thick, but its barrier performance is far higher than a 150-micron single-layer PE bag.

Real-World Case

I once worked with a roasted coffee bean distributor in Australia. They used a 150-micron PET/PE pouch. After switching to a 3-layer 110-micron pouch with AL foil, their shelf life² extended by 30%, while their logistics cost dropped due to lighter packaging.

How thick should a bag be?

Choosing the right thickness is tricky. How do you know what’s enough?

Bag thickness should match the product’s weight, fragility, and barrier needs—usually between 60-150 microns for most food packaging.

Dive Deeper: Guidelines Based on Product Type

There’s no one-size-fits-all thickness, but here are some common ranges we use at IMIPAK:

Besides product type⁷, here are three more things I consider:

1. Logistics – Thicker bags weigh more and cost more to ship.
2. Printing Finish – Some finishes like matte or soft-touch need thicker films.
3. Filling Machines – Some automatic machines can't seal very thick films well.

I always recommend testing first. We offer free samples so our clients can try different thicknesses with their product and filling process.

What are the disadvantages of thick plastic bags?

Most think “more is better,” but what do you lose with thicker bags³?

Thicker bags cost more, use more raw material, increase waste, and can reduce sealing efficiency⁸ or machine speed.

Dive Deeper: Hidden Costs and Environmental Impact

When customers request thicker bags³, I ask them: What is your goal? Sometimes they think thickness equals quality, but the downsides include:

1. Increased Material Costs

Thicker bags mean more raw material—PET, PE, or others. This raises unit cost.

2. Worse Sealing Performance

On automatic filling lines, thicker films may seal slower or unevenly. This can cause leaking or burnt seals.

3. Environmental Load

Sustainability matters. Thicker bags are harder to recycle and produce more waste. If we use a smart structure instead of just “more film,” we reduce impact.

4. Poor Folding and Storage

Thicker bags are harder to fold or roll, increasing storage and transport volume. Some bags even bounce back or fail to stay flat.

Let me share a story: A client in Europe used a 140-micron bag for protein powder. The problem? During sealing, the thick edges curled. Switching to a 100-micron laminated structure fixed the problem and cut material costs by 12%.

What is the difference between thin and thick plastic bags?

Can thickness alone define quality and performance?

Thinner bags are lighter, cheaper, and easier to recycle. Thicker bags are stronger but not always better in terms of barrier.

Dive Deeper: When to Go Thick vs. Thin

Let’s compare:

When Thin Wins

• Light products like chips or tea
• Short shelf life²
• Budget packaging
• When using barrier materials like EVOH

When Thick is Better

• Heavy items (liquids, big volumes)
• Rough handling during shipping
• Premium feel (luxury snacks or supplements)

I always advise my customers to not focus only on thickness. Instead, I help them pick a film structure that matches their product, machine, and market.

Conclusion

Thickness affects barrier, but material and structure matter more.