Labelling Machinery

Induction Cap Sealing Machine – Automatic Induction Cap Sealer, Induction Sealing Liner


The conventional bore sealing (Induction Cap Sealing Machine also called as Induction Cap Sealer or Induction Sealing Liners) has been the most widely preferred practice for sealing of the containers. They have an advantage over other alternatives as such Induction Cap Sealers are not at all expensive to manufacture and relatively easier to fit. These closures can either be inserted in the neck or from a combination of two. Factors that affect the effectiveness of the seal are- temperature, natural relaxation & mechanical properties.

Bore seals have a drawback of not being able to form flexible, reliable, or hermetic seal making them allow leakage after a period of time. The Induction cap sealing technology helps to overcome this difficulty by forming hermetic seals on the neck of the container. The seal formed is strong, flexible and can be removed easily. Induction Sealing Liners are useful in providing protection against cross-contamination and also forms an effective tamper-evident layer.

An Induction cap sealing Machine makes use of induction heating for the purpose of sealing caps which helps the bonding process of thermoplastic material. It includes heating electrically conducting objects; this includes use of electromagnetic induction and the heat generated in the object by eddy currents. This type of induction sealing liner has many applications. One of the most common application is sealing caps by induction method, which involves heating the inner seal and ensure the top of the plastic seal. There is no-contact method performed after the container has been filled with the product.  


Innerseal are suitable for use on the containers which are made of PET, PVC, Polythene, Glass and other thermoplastics. Induction Cap Sealer are also used with screw type Snap On, Child resistant and other customer closures provided that the seal is in positive contact with the neck of container.  A good Induction Sealing requires a uniform neck finishing. The sealing provided should not be very wide. It should be small from 50 ml to the big 200. The Drums having a neck size of 10 mm opening to the wide mouth of 120 mm can be Induction sealed. Induction sealing liners is available in different thickness for HDPE, LDPE, and PET & PP.

The Induction Cap Sealing Machine operates on the principle that a conductive material i.e. Al Foil heats up, when exposed to high frequency magnetic field, which is generated by an Induction Unit. The entire process is a non-contact without any direct heat transfer. This allows the sealable closure liner to be placed in the cap by the manufacturer. The Wad consists of a board packing material, a wax layer, aluminum foil and a sealable film. As the container closes, the screw cap combination passes through the induction unit. As the container is placed under the induction head, the Aluminium layer starts developing heat. The wax layer starts to melt and penetrate into the board layer. The Sealing layer also melt & forms a tight seal against the lip of container. The liner/screw cap combination provides the required pressure. When the container is opened, the board continues to remain inside the cap and it acts as a seal on further use. On the other hand, the aluminum foil is permanently sealed on the rim of the mouth of container.

Salient Features

  • Tamper Proof: The seal applied on containers ensure that the content remains free from getting tampered.

  • Product Freshness: The hermetic seal applied on the containers preserves the taste and aroma of the product keeping intact its freshness.

  • Protection against Leakage: The products in the container are prevented from any sort of leakages during transportation.

  • Sales Promotion: The seals on the product offers an opportunity to the companies for advertising and promotional activities.

  • Maximum Filling Speeds: The entire process is automated without requiring any direct contact allowing full utilization of the plant.

  • Minimum Effort: Usually, the manufacturers put the wad into the cap. Hence, the filling line requires only the Induction Cap Sealing Machine to be installed.

  • Indirect Heating: The indirect heating method employed is very useful in applying seals faster in heat sensitive products, such as- creams, petroleum product, pesticides, etc. as compared to the direct heating method.

  • IGBT Technology: The IGBT technology imparts reliability and improved efficiency at higher line speeds.

The Wad basically consists of four layers :

There are four layers in a Wad:

  • Cardboard or Foam Packing.

  • Wax Layer.

  • Aluminum Foil.

  • Sealing Film.

The pulp board packing material is seen as the retaining wad, the aluminum foil, and the sealing film.  The force lines pass through the foil and hence current is induced in it. As a result, the temperature of the foil is increased. Hence, the sealing film starts to melt and gets adhered to the lip of the container. The cap retains the board or foam packing after the seal is broken.

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