The choice of the liner is one of the most important factors in the selection of Metal Closures.
The liner is a round piece of material, situated between the cap and the jar/container.
Its primary function is to offer the proper sealing of the product and oftentimes it guarantees and determines the right functionality and stability of the Metal Closure.
Since the liner is in direct contact with the product, the compatibility is critical.

Liners will help ensure shelf life performance and stop the leakage of the product.
Certain products require specialized liners: they are available for moisture barrier, chemical resistance, consumer safety, or preventing leakage.

Tecnocap Liner Division has developed further specialized liners such as Pressure Sensitive, PVC-free, Plasticizer-Free, ESBO-Free alongside the Heat Seal.

The Heat Seal liner is part of a double liner system.

Heat Seal Liners offer tamper evident protection. When the closure is applied, the adhesive is melted through heat induction, and the liner adheres to the container, providing a tamper evident seal.The opposite side of the liner  is typically printed with “Sealed For Your Protection” or “Safety Seal™”.

The Heat Seal liner can be provided with a custom print.

When the customer removes the Metal Closure, the Heat Seal liner remains on the jar neck ring while the second liner remains inside the cap to seal the container for reapplication.