Induction Sealing Machine Suppliers & Manufacturers

How induction sealing works and which containers it suits

Induction sealing creates a hermetic foil seal on the opening of a bottle or jar using electromagnetic induction heating — without direct heat contact. The process: a cap with an inner foil-laminate liner is applied to the filled container and torqued in the normal capping process. The capped container then passes under or through an induction sealing head, which generates a high-frequency electromagnetic field. The field induces eddy currents in the aluminium foil layer of the liner, heating it rapidly. The heat melts a thin layer of polymer wax on the underside of the foil, bonding it to the container neck opening. The result is a hermetic foil seal bonded to the container, providing tamper evidence, freshness seal, and leak protection. Induction sealing is compatible with a range of container materials and is widely used on: PET bottles (cooking oil, juice, sport drinks, pharmaceuticals, supplements); HDPE bottles (chemicals, detergents, lubricants, supplements); PP jars and bottles (food products, cosmetics, chemicals); glass bottles (sauces, oils, beverages) where the neck finish has been designed for induction sealing; aluminium bottles. Induction sealing requires a cap with an induction-sealing-compatible liner. Standard caps without a foil liner will not seal. Foil liners are available in various specifications — single-piece liners (wax/foil/backing) produce a peel-back foil; two-piece liners (foil bonds to container, backing remains in cap) leave the foil on the container when the cap is removed.

Machine configurations and sourcing

Induction sealing machines are available in three main configurations. Bench-top and handheld induction sealers — small-scale units suitable for low-volume or laboratory use; a handheld wand is placed over the capped container for a few seconds; production speed is very low (manual, a few containers per minute). Inline continuous induction sealers — a conveyor carries capped containers through or under a fixed induction head; the sealing time is determined by the conveyor speed and the induction power; speeds of 20–300+ containers per minute; the standard for all commercial production applications. The inline sealer is installed immediately after the capping machine and before the labelling machine in the bottling line. Tunnel induction sealers — the capped container passes through an enclosed tunnel with induction coils surrounding the container neck; provides more consistent sealing of containers that are not perfectly aligned or that vary in neck height. When sourcing an induction sealing machine, specify: container material and neck diameter, liner type (single-piece or two-piece, wax or polymer seal layer), required conveyor speed, available conveyor height, whether inline or separate unit, and whether a seal integrity check (vacuum decay or pressure test) is required downstream. Common issues to avoid: insufficient power for the conveyor speed (leading to incomplete seals); excessive power causing overheating and warping of the container neck or cap; liner selection mismatch with container material; cap torque outside the specified range preventing consistent sealing.

Frequently asked questions