Induction Seal Liner manufacturers

All Induction seal liner manufacturers, no matter if they are producing in China, USA, UK or any other country, they have all a same aim, “leakage prevention”. But, let’s see what is “Induction Sealing” and what can it do for you? Any manufacturer making kind of products that need to be sealed due to leakage prevention or avoid tampering during shipment or shelf time, must have heard about the Induction sealing method. Induction sealing method is a non-contact heating process that accomplishes the hermetic sealing of a container with a closure inserted with a heat-sealable induction foil liner. The typical induction seal liners begins as a multi-laminate liner inside a plastic closure. It consists of a layer of pulpboard, a layer of wax, aluminum foil and a layer of polymer that is compatible with the bottle material and capable of heat-sealing to the lip of the container. There are different types of foil seal liners that will be discussed in another article here.

When the closure is placed onto the bottle and is passed through an electromagnetic field produced by the induction head, several things occur. An electromagnetic current, called an eddy current, is induced into the foil portion resulting in a resistance-type heating effect (only the foil will warm up). The heated foil melts the laminated wax layer and the polymer coating melts, hermetically sealing the foil to the lip of the bottle. If the liner is a 2 pc type, then melted wax will be absorbed by the pulpboard, releasing the foil from the pulpboard. The pulpboard will remain in the bottle closure and will act as an extra liner after the foil is removed from the bottle lid.

Some induction seal liner manufacturers mislead customers by advertising their cap lining materials without informing them the function differences and just focus on the price. There so many different factors that any induction seal manufacturers or consumers should think about beside the price. Some of these factors which may increase or decrease the prices are:


  • Foil Thickness
  • Pulpboard or Foam Thickness
  • Pulpboard or Foam Quality
  • Wax and Polymer Quality
  • The hygiene Production Process
  • Punching or Slitting Quality
  • Packaging Method

Occasionally, we receive emails from some customers who tell us something is wrong with their induction sealers. They go on to tell us they have run 200 containers under the induction sealing head and only 195 of them sealed. We explain that if 195 of them sealed, there is nothing wrong with the induction system and liners and we suggest they look elsewhere for the problem. Further examination usually uncovers the fact that there were other problems with the bottles such as:

A: Insufficient torque on the containers

B: The foil was not in intimate contact with the lips of the containers

C: The lips of the containers were deformed, Greasy or the caps were cocked.

If a series of identical containers are put through an induction field and one of them seals, then all of them should seal. You must realize that when you are dealing with hundreds or thousands, if not millions, of containers and caps, you will experience an occasional bad lip, insufficient torque or cocked cap. When this occurs, poor seals cannot be blamed on the induction equipment or materials. Most of the times the consumers blame the induction seal liner manufacturers for the above mentioned problems that is not really true. Please check our blog here.