Ultra-light packaging paper enters the market, but real-world performance remains the key question

German manufacturer Koehler Paper has introduced a new heat-sealable packaging grade, NexPlus Seal Pure 36 gsm, positioning it as the lightest flexible packaging paper currently available in its category.

At first glance, the value proposition is clear:
less material, lower weight, reduced resource input.

But in practical converting and packaging environments, the real question is not weight.

👉 It is whether such a thin structure can maintain:

• sealing consistency
• mechanical strength
• runnability at industrial speeds

What makes 36 gsm significant — and why it’s not just about weight

At 36 grams per square meter, this material pushes the lower boundary of what is typically considered stable for heat-sealable paper.

In standard packaging operations:

• lighter grammage often means higher risk of web instability
• tension control becomes more sensitive
• sealing windows narrow

Koehler states the material can run on:

• flow wrap systems
• horizontal and vertical form-fill-seal lines

From a machinery standpoint, this is not trivial.

👉 Thin paper behaves very differently under:

• high-speed unwinding
• thermal sealing zones
• multi-lane packaging systems

Production challenge: Speed vs stability

One of the most telling parts of this development comes from inside the mill.

Joachim Uhl, mill director at Koehler Paper’s Kehl facility, pointed directly to the core issue:

Maintaining stability at high operating speeds was the main production challenge.

This aligns with what converters experience daily.

In thin-gauge materials:

• web flutter increases
• edge tracking becomes unstable
• wrinkling risk rises during sealing

👉 In other words:

Reducing weight is easy on paper. Running it at 300–600 m/min is where the real engineering begins.

The company credits its success to:

• upgraded production lines
• internal technical expertise

But the real validation will happen downstream—on customer machines.

Printing compatibility: A strategic advantage for converters

Koehler positions the material as compatible with:

• flexographic printing
• gravure printing
• digital printing systems

From a converter’s perspective, this is critical.

Because in flexible packaging:

printability is not optional—it defines product value.

However, low grammage introduces new variables:

• ink absorption consistency
• drying behavior
• dimensional stability under heat

👉 Especially in flexo printing:
thin substrates can amplify:

• dot gain variation
• registration challenges

Transparency effect: A feature or a limitation?

One distinctive characteristic of this material is its low opacity.

This creates a semi-transparent effect, enabling:

• visibility of contents
• QR code scanning without opening
• new applications in direct mailing

According to Koehler’s packaging division:

The ability to see inside the package creates new communication opportunities.

From a marketing standpoint, this is valuable.

But from a packaging engineer’s perspective, it raises trade-offs:

• reduced privacy for contents
• limited suitability for certain food categories
• potential light exposure concerns

Sustainability claim: Reduction vs real impact

The central narrative behind NexPlus Seal Pure 36 gsm is material reduction.

And technically, this is valid:

• lower grammage = less fiber usage per square meter

However, this is only one part of the equation.

Real-world sustainability depends on:

• transport efficiency (more units per shipment?)
• product protection (damage rate in logistics?)
• recyclability within existing systems
• performance lifespan

👉 A critical industry reality:

If lighter packaging leads to higher product damage, the environmental benefit disappears quickly.

Material composition: Where it fits in food packaging

The product is made from 100% certified virgin fiber pulp, making it suitable for:

• food-related applications
• primarily secondary packaging layers

This positioning is important.

Because at 36 gsm:

• the material is unlikely to replace barrier layers
• it functions more as outer wrap or secondary protection

Industry perspective: Thin is a trend—but not a universal solution

Across the packaging sector, there is a clear movement toward:

• downgauging materials
• reducing fiber or polymer usage
• optimizing logistics weight

But experienced converters understand:

The success of lightweight materials is not defined in the lab—it is defined on the packaging line and in the distribution chain.

Editorial insight: What converters and machine suppliers should watch

For companies working in:

• paper converting
• slitting and rewinding
• flexible packaging production

this development signals several practical shifts:

1. Tension control becomes more critical

Thin materials demand:

• precise load cell calibration
• stable unwinding systems
• responsive braking

2. Slitting accuracy tolerance tightens

At lower grammage:

• edge quality becomes more sensitive
• blade condition directly affects output quality

3. Machine adaptability becomes a selling point

Converters will increasingly ask:

“Can this material run on my existing line without modification?”

Final takeaway

Koehler Paper’s 36 gsm heat-sealable paper is not just a product launch.

It is part of a broader industry direction:

pushing material limits while testing the boundaries of real-world performance.

Whether it becomes widely adopted will depend on one thing:

Not how light it is—
but how reliably it runs.

Last Updated on 30/03/2026 by Jota Machinery