Plastic vs. Laminated vs. Aluminum Tubes: Which Sealing Method Suits Your Product?

For New Product Development (NPD) managers in the cosmetic and pharmaceutical industries, choosing the right packaging is a balancing act between aesthetics, barrier protection, and cost. You might have selected the perfect Aluminum Barrier Laminate (ABL) tube for your new toothpaste, or a premium Soft-Touch LDPE tube for a face wash.

But here is the critical question: Is your manufacturing line equipped to seal it correctly?

Different tube materials require fundamentally different sealing physics. Using a hot air gun on a metal tube will do nothing, while mechanical crimping on a plastic tube will result in immediate leaks. At Wenzhou Kxite Machinery, we guide our clients to match the correct tube filling and sealing machine types to their specific packaging materials.

1. Plastic Tubes (LDPE/PE/PP): The Hot Air Standard

Extruded plastic tubes are the standard for lotions, creams, and cleansers. They are flexible, bounce back after squeezing, and offer a seamless look.

The Sealing Method: Internal Hot Air Sealing

Plastic tubes must be melted to seal. The most advanced method (used in our NF-120 model) is Internal Hot Air Sealing. A nozzle enters the tube, blows precisely heated air to soften the inner wall, and then chilled jaws press the tube shut.

• Why not external heat? External heating is slow and risks damaging the artwork on the tube's exterior.
• The Result: A strong, hermetic seal that can be trimmed into various shapes (curved, straight, or with a hanging hole).

2. Laminated Tubes (ABL & PBL): The Versatile Choice

Laminated tubes are made of multiple layers.
ABL (Aluminum Barrier Laminate): Has a thin aluminum layer inside for oxygen protection (ideal for toothpaste/pharma).
PBL (Plastic Barrier Laminate): Uses EVOH as a barrier, fully recyclable.

The Sealing Method: Hot Air or High Frequency

For most modern laminated tube sealing methods, Internal Hot Air is still the preferred choice, especially for PBL. However, for thick ABL tubes, careful temperature calibration is needed to melt the plastic layers without delaminating the aluminum foil.

3. Aluminum Tubes: The Mechanical Fold

Pure aluminum tubes are rigid and offer the absolute best barrier against air and light. They are collapsible (they don't bounce back), which prevents air intake.

The Sealing Method: Mechanical Folding (Crimping)

You cannot heat seal metal. Instead, the machine uses a series of mechanical stations to fold the open end of the tube. This is a cold process.

• Fold Types: Double Fold, Triple Fold, or Saddle Fold.
• Key Requirement: The machine requires a metal folding workstation instead of a heating system.

4. Matching Material to Technology: A Quick Guide

Use this table to determine the configuration you need for your cosmetic tube packaging guide.

5. How the Kxite NF-120 Adapts to Your Product

Many manufacturers worry: "If I buy a machine for plastic tubes today, can I run aluminum tubes tomorrow?"

The answer lies in the modular design of the Kxite NF-120 Tube Filling Machine. While the core transmission (powered by advanced Norden technology) remains the same, the sealing station is configurable.

Configuration Flexibility

• For Plastic/Laminates: We configure the NF-120 with a Leister Hot Air Generator and cold-pressing jaws.
• For Aluminum: We replace the heating module with a precision mechanical folding station (2-fold or 3-fold).
• Hybrid Capability: For contract manufacturers (OEMs), we can provide a "Combo" machine that allows skilled technicians to swap the sealing units, giving you maximum versatility on a single chassis.

Conclusion

Choosing the right sealing method is just as important as choosing the tube itself. A mismatch leads to leaks, product spoilage, and brand damage.

At Wenzhou Kxite Machinery, we don't just sell machines; we ensure your product is packaged perfectly. Whether you are filling delicate eye ointments in aluminum or premium sunscreens in LDPE, our Tube Filling & Sealing Machines are ready for the task.