What causes multiple seams in the roll film of composite packaging bags? Is it related to the manufacturer?

I once received a large batch of roll films from a supplier that looked perfect—until my client’s pouch machine kept stopping. The problem? Multiple seams.

Multiple seams in roll film usually come from the manufacturer using split rolls or forcing film splices¹ to reduce waste. While this saves costs for them, it causes huge problems for pouch-making clients.

Clients expect smooth production. But seams in the film break that flow. Once I understood why these seams happen, I changed the way I judged film suppliers.

Why does composite roll film have multiple seams²?

Seams don’t appear by accident. They are almost always a manufacturing decision.

The main cause is that the raw film³ is not from a single continuous roll. Many suppliers use second-cut film⁴ or leftover film reels and splice them together.

What is second-slit film?

Some factories buy or keep leftover rolls from other jobs. Instead of wasting them, they cut and join these pieces.

Benefits for the factory:

• Lower raw material cost
• Less downtime
• Less material wasted

But for the buyer:

• More seams
• Higher machine stoppage
• Greater risk of pouch failure

Internal cost-saving strategy

Another reason is intentional splicing⁵ during production.
Some factories try to:

• Avoid stopping machines to reload new rolls
• Reduce film waste from roll ends
• Speed up job transitions

They connect film ends by heat or adhesive, creating visible seams inside the roll.

From their view, this saves time and money. But the cost is passed to you.

Why are seams a problem for pouch-making machines⁶?

Clients who buy roll film often have automated bag-making machines.

Seams in roll film force machine stops. Each stop creates waste, uses labor, and risks equipment misfeeds.

How a single seam affects workflow

Let’s say you’re running a pouch-making line at 80 bags/min. One seam hits the blade:

• Machine stops instantly
• Operator manually resets
• Around 5–10 bags wasted
• Production delay of 3–5 minutes

Multiply this by three seams in a roll, and you’re looking at:

• Lost time
• Higher labor
• Customer delivery delays

Real cost of a seam

That’s why most roll film buyers clearly say: “No seams.”

Can manufacturers avoid seams in composite film rolls?

Yes, but only if the factory is willing to do it.

Factories can avoid seams by using continuous primary rolls and planning production carefully. It requires more material and more machine stops, but gives cleaner output.

Why most factories don’t do it

Many manufacturers are focused on reducing internal costs. Avoiding seams means:

• Using full-length original film rolls
• More roll changes (downtime)
• More waste at reel ends

They avoid it unless the buyer insists. That’s why it’s rarely standard practice.

What we do at IMIPAK

At IMIPAK, we take the client’s side.

We understand that:

• One seam can ruin hours of production
• Some high-speed machines can’t detect seams
• Clients don’t want excuses, just results

So we control our film roll cutting with three principles:

1. Use only original master rolls when possible
2. Splice only when necessary, with client consent
3. Guarantee zero seams⁷ or maximum one splice per roll

That’s why many pouch makers trust our films for smooth, high-speed production.

How to check if a supplier is adding seams?

You can’t always see it until the film arrives.

To check for seams, ask for roll production details, request a splice-free guarantee, and inspect roll ends before use.

Ask the right questions

When sourcing:

• Is the film from original rolls?
• Do you splice rolls during slitting?
• Can you limit splice count?

Good suppliers give honest answers. If not, that’s a red flag.

Request documentation

Ask for:

• Slitting report per batch
• Film roll length confirmation
• Splice map if applicable

These show how many cuts or joints exist in each roll.

Visual check at arrival

Before loading film:

• Inspect both roll ends
• Feel for adhesive points
• Mark any splice found for QC

Some clients set a rule: reject any roll with more than one seam.

Why do we prioritize zero-seam film at IMIPAK?

Because we think like the end user.

Every stop at the client’s pouch machine is our problem too. That’s why we commit to either no seams, or at most one seam—carefully done.

What clients say

A large coffee packer in Singapore once said:

"We don’t mind paying a little more, as long as we never have to stop the machine mid-run.”

Since then, we’ve adapted our slitting lines:

• Shorter runs = easier to control seam points
• Dedicated QC check for splices
• “One-seam maximum” label on each roll

Trade-off we accept

Yes, our waste rate is slightly higher.
Yes, machine operators change film more often.

But our customers gain:

• Better yield
• Less downtime
• Higher trust

Conclusion

Multiple seams in roll film usually mean the factory is cutting corners. Choose suppliers who prioritize your machine's performance.