Cap Sealing with Induction Heating

Cap sealing with induction heating
red_tubes Cap sealing with induction heating (video)

Foil seal prior to and after inductive bonding
Read our article in Process Heating Magazine

Click to read one of our many cap sealing application notes (after a brief, free registration); learn more about:

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  • Overview
  • Using Induction
  • The Seal

The food and medical industries require high-speed hermetic sealing between the cap and the container. Induction heating with Ameritherm equipment provides the following benefits for cap sealing applications:

  • high reliability seals
  • easy integration into production lines
  • high process speeds

diagram 1

A cap- to-container seal is made with the aid of a laminated disc composed of a wax layer, aluminum layer, and a polyethylene (PE) layer (illustration).
The aluminum layer acts as a susceptor, heating to about 125-150°C in the electromagnetic field produced by the induction coil. It then heats the wax and PE layer sufficiently to produce a hermetic seal between the cap and container. Heating times are in the order of 100 milliseconds, supporting a high-speed automated process.

Typical RF power supplies for cap sealing range from 1 to 20 kW, depending on the parts and application requirements.

diagram 1

A cap seal liner is comprised of a multi-layered board:

  • the first and thickest layer of material is the board re-seal

  • next is the layer of wax used to hold the aluminium foil to the board re-seal

  • next is the aluminium foil

  • last is a heat seal film compatible with the type of container to be sealed

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capsealing   cap_sealing_6 Sealing an aluminum disk onto a plastic cap Induction heating enabled the aluminum to seal to the plastic cap quickly without the cap being damaged. The customer desired a quick rate which would make in-sourcing the process worthwhile, and induction heating exceeded the targeted production rate thanks to its fast heating. apps_able.php cap-sealing.php     db_capsealing.html    
capsealing   cap_sealing_5 Heating pre-assembled plastic tube and cap for cap sealing application Customer currently has Ameritherm equipment and would like to increase their run rate. apps_able.php cap-sealing.php     db_capsealing.html    
capsealing   cap_sealing_3 Cap Sealing 3.5” Lotion Container Power is applied directly to the foil; no energy is wasted heating the cap or the surrounding air or parts. apps_able.php cap-sealing.php     db_capsealing.html    
capsealing   cap_sealing_2 Cap Sealing; Shampoo Container A three-turn two-position helical coil is used to heat the aluminum foil in a tunnel style assembly. Product (containers) passes easily under the induction coil. apps_able.php cap-sealing.php     db_capsealing.html