Flexible packaging bag making, what is lamination curing time and why it matters?

When lamination isn’t cured properly, it may ruin the entire batch of packaging bags. That means wasted time, lost money, and even lost clients.

Lamination curing time usually takes 24 to 48 hours. It depends on material types, and it directly affects bonding strength, odor control, and barrier performance¹.

I’ve learned this the hard way. Once, a shipment got returned because the bags smelled like solvent. That was when I knew: curing isn’t optional. It’s essential.

What is lamination in flexible packaging?

We can’t talk about curing time without understanding what lamination is in the first place.

Lamination is the process of bonding two or more layers of films together using adhesives to create multi-layer flexible packaging².

Dive Deeper: Why do we need to bond multiple films?

Lamination allows us to combine the best properties of different materials. For example, PET gives strength, aluminum foil offers excellent barrier, and PE brings sealability.

Each layer does a job. Without lamination, we can’t make packaging that looks good, keeps food fresh, and seals properly.

What is the purpose of lamination?

Many buyers only ask about thickness or print. But lamination is the silent hero behind a bag’s performance.

The main purpose of lamination is to enhance mechanical strength, barrier properties, and heat resistance by combining functional films.

It’s not just about sticking films together. It’s about making sure the bag performs in real-world conditions.

Dive Deeper: How does curing time affect lamination quality?

Without enough curing time, the adhesive won’t fully crosslink. That leads to:

• Delamination during sealing or filling
• Solvent odor that ruins food safety
• Poor barrier performance, especially for oxygen and moisture

On the other hand, over-curing isn’t good either. After a certain point, curing doesn’t improve anything. It just delays delivery. So the goal isn’t curing longer—it’s curing fully.

What temperature should laminating pouches be?

Many buyers ask about lamination temperature, but what they really need to understand is how it works with curing.

Laminating temperature ranges between 60–90°C, depending on material and adhesive type³.

This heat activates the adhesive and allows initial bonding. But it’s only the first step.

Dive Deeper: Heat is just one part—time and pressure matter too

Temperature must match the adhesive type³:

But curing happens in the warehouse, not during lamination. After lamination, we store the rolls under controlled temperature and humidity⁴ to allow chemical crosslinking.

This stage helps:

• Reduce residual solvent
• Stabilize layers
• Improve pouch quality during pouch-making and sealing

Skipping this step leads to higher complaints and returns.

What is the process of lamination wrapping?

Lamination sounds complex, but the process is straightforward when broken down step by step.

The process of lamination wrapping involves unwinding base films, applying adhesive, bonding layers through rollers, and curing in controlled conditions.

Dive Deeper: The curing time is not just a number

We often get asked: can we ship faster if we reduce curing to 12 hours? My answer is always no. Not unless you want solvent odor⁵ or complaints about bags opening up during filling.

Here’s why I insist on a 24–48 hour curing window:

• Material matters: PET+PE may cure faster, but PET+AL+PE needs longer.
• Adhesive matters: Solvent-based adhesives usually cure faster than solvent-free, but both require proper setup.
• Thickness matters: Thicker films take longer to release residual solvents.

It’s not about picking a number. It’s about analyzing every order.

Curing checklist I follow in my factory:

• [x] Check room temp: 25–40°C ideal
• [x] Maintain 50–60% humidity
• [x] Log adhesive mix and lot number
• [x] Use solvent retention test after 24 hours
• [x] Smell check: no odor = ready for pouch-making

This checklist helps us deliver bags that are clean, strong, and ready for sealing—even on automatic machines.

Conclusion

Curing isn't about time—it's about doing it right.