Sealing Machines

Sealing Machine Types by Pack Format

The pack format decides the machine. Bag and pouch sealers close flexible film — from pre-made sachets and stand-up pouches to liner bags in cartons. Tray and cup sealers press a film or lid onto a rigid rim, the format behind ready meals, yoghurt cups and portion packs. Tube sealers close and crimp the open end of filled tubes, the standard for creams, ointments and adhesives.

Induction sealing is the fourth family: it seals a foil liner inside a cap, on a filled and capped bottle, without touching the product. The machine passes the closed container under an induction head and the liner bonds to the jar or bottle mouth — the tamper-evident, leak-proof closure common in pharma, chemical and food liquids.

• Bag and pouch sealers — sachets, stand-up pouches, liner bags
• Tray and cup sealers — film or lid sealed to a rigid rim
• Tube sealers — end crimping for creams, ointments and adhesives
• Induction sealers — foil liner bonded inside the cap, tamper-evident

Impulse, Continuous and Band Sealing

Heat-sealing machines differ in how they deliver energy to the film. Impulse sealers heat only while the jaws close — a pulse, then cooling under pressure — which suits thin films and occasional sealing without a machine that runs hot all shift. Continuous band sealers keep moving: the bag rides between heated bands that seal as the pack passes, then through cooling elements, discharging a finished seal at line tempo.

Vacuum sealing adds a step before the jaws close: air is drawn from the bag first, then the seal locks the reduced-atmosphere pack in. For products where oxidation or bulk is the enemy — some foods, some chemicals — the vacuum function is the specification; for everyone else it is an option that complicates the machine. The sealing method is chosen against your film, your output and whether the pack must exit the machine ready for coding and case packing downstream.

Seal Materials and Integrity

A seal is a welding of two film surfaces, and it only works when heat, pressure and time match the material. Polyethylene seals at one behavior; multi-layer laminates — PET, PP and aluminum-based composites — each bring their own seal layers and windows. The machine's temperature control, jaw pressure and dwell settings exist to hold that window despite film batch variation and running heat.

Seal integrity shows up downstream or in the customer's hands: a leaker on the filling line is a nuisance, a leaker in a shipped case is a claim. Where your application demands proof, seal testing — burst, dye or vacuum-bubble methods — belongs in the acceptance conversation, and the sealing configuration is documented against it.

• ✓Aluminum (as foil and ALU-based composite films) is documented across packaging-machinery platforms as a packaging material handled by packaging machines

Sealing Within a Packaging Line

Sealing rarely works alone. Upstream, the filler hands over a filled-but-open pack: the sealer's infeed has to accept that handoff without spills or misaligned film. Downstream, coding and case packing expect a closed, stable pack. Inline sealing — the sealer as a station in the line — keeps the product moving continuously; offline sealing moves filled packs to a separate machine, which suits short runs and multi-format production.

The integration question is buffer and tempo: a sealer that pauses for each pack caps the line the same way a slow filler does. Tell us what runs upstream and downstream, and the sealing station is specified to the neighbors, not in isolation.