Trouble with Tube Sealing? Here's Why the End Looks Uneven

When producing cosmetic tubes, one of the final steps is sealing the tail end of the tube. While it may seem simple, improper sealing can lead to unattractive finishes—wrinkled edges, uneven seams, or even partial openings. These not only affect your brand's image but can compromise the product's shelf life and integrity.

Two key factors play a critical role in achieving a clean, professional seal:

1. Heat Sealing Temperature
If the sealing temperature is too low, the plastic layers may not fuse completely, leading to weak seals or visible gaps. On the other hand, excessive heat can cause over-melting or burning, resulting in deformed or bubbled edges. The optimal temperature varies depending on the tube material (e.g., PE, laminated, co-extruded) and wall thickness.

2. Tube Wall Thickness
Thicker-walled tubes require higher sealing temperatures and longer sealing times. If the settings remain the same as for thinner tubes, the heat may not penetrate evenly, causing incomplete bonding or inconsistent results across production batches.

Pro Tip:

• Always test sealing parameters when switching tube materials or wall thickness.

• Regularly calibrate your sealing machine to maintain consistency.

• Monitor visual cues like seam straightness, clarity, and feel for quality control.

A well-sealed tube doesn’t just look better—it builds consumer trust in your brand. Paying attention to these details can save you from costly reworks or packaging failures later on.