Hot-air sealing is best for laminated and plastic tubes at medium to high speed; ultrasonic sealing suits plastic tubes where instant start-up and sealing through product residue matter; crimp (folding) sealing is the only option for aluminum tubes. Choose by tube material first, then by speed and product.
Hot-air (inner heating) sealing
Hot air is blown inside the open tube end to melt the inner layer, then cooled jaws press the tail closed and emboss a code. It is the standard for laminated toothpaste and cosmetic tubes.
- Pros: fast, low cost per seal, strong hermetic seals, decorative tail patterns.
- Cons: needs a few minutes to heat up; settings depend on tube wall thickness.
Ultrasonic sealing
A sonotrode vibrates at high frequency and welds the plastic layers by friction heat generated only at the joint.
- Pros: no warm-up, very low energy, seals through traces of sauce or gel, no heated parts to touch.
- Cons: higher equipment cost per station; best for plastic tubes up to medium speed.
Folding (crimp) sealing
Aluminum tubes are flattened and folded two or three times, optionally with a saddle fold, then embossed. No heat is used.
Side-by-side comparison
| Hot air | Ultrasonic | Crimp | |
|---|---|---|---|
| Tube | Plastic, laminate | Plastic, laminate | Aluminum |
| Start-up | Warm-up needed | Instant | Instant |
| Seal through residue | Fair | Excellent | Good |
| Typical use | Toothpaste, cosmetics | Food sauces, gels, small runs | Ointment, hair dye, glue |
How to choose
If you only fill laminated tubes at volume, choose hot air. If you fill sauces or run many short batches, consider ultrasonic. If any SKU is aluminum, you need a crimp station — or a dual-sealing machine. Compare models in our tube filling and sealing machine range.
