In the packaging industry, heat induction liners are used to secure products within a container as well as implement tamper evidence. Heat induction liners come in many forms. Both one- and two-piece liners are available for different applications. In this blog, we will delve into the different types of heat induction liners as well as applications for each.
What are heat induction liners?
Heat induction liners are a thin layer of material that resides inside of a closure. This liner is applied to containers after they are filled to ensure the integrity of the product inside as well as offer barriers against the elements and tamper evidence. Each heat induction liner is made from several different layers. These different layers will vary, depending on the needs and applications for the container as well as the product inside. The main components of a heat induction liner are:
- Foil layer: These foil layers are often made of aluminum that act as a barrier. The foil layer is the portion of the liner that adheres to the container and will need to be removed by the customer prior to use.
- Sealant layer: The next layer in the process is the sealant layer. Under the foil layer is an adhesive that will bond to the lip of the container when applied.
- Backing layer: This is typically the last layer in the liner and can be made from foam, pulp, or other suitable materials as needed for the project.
How to use heat induction liners for bottle caps?
Heat induction liners are applied to containers with the use of an induction sealing machine. An induction sealing machine generates an electromagnetic field that travels through the closure and causes the liner to adhere to the container. The entire process of cap lining is quick and with efficient induction sealing liners for large production a customer’s costs can be reduced greatly. The process works as follows:
- Cap placement: after a container is filled with its product, the cap is then placed on the container and prepared for induction sealing.
- Induction sealing: The container with the applied closure is then passed through an induction sealing machine which generates an electromagnetic field. This electromagnetic field then seals the liner to the closure.
- Heat transfer: The electromagnetic field transfers energy to the aluminum foil layer of the liner causing it to heat up and create a bond to the container.
- Bonding: When the foil layer of the liner cools it then bonds to the lip of the container.
Types of heat induction liners
There are several types of heat induction liners and these will depend on several requirements. Some of the requirements may be that the products inside of the container are wet or dry, they may need venting of the air inside of the container or they may need to be printed to let customers know that the bottle is sealed for their protection. Some common types of liners are:
- One piece foil liners: A one-piece foil liner is a single liner that will adhere to the container and not leave behind any foam or paper backing inside of the closure. These are commonly used with dry products as there is no concern for leakage. The heat induction liner is removed from the container.
- Two-piece foil liners: Two-piece foil liners are often used with wet products. This is because once the heat induction liner is applied to the container there is an additional layer that has left behind inside of the closure ensuring that the bottle is sealed even after the liner is removed from the container.
How do heat induction liners improve packaging quality?
Foil liners have many advantages that make them a great addition to packaging. Some key advantages are:
- Induction liners for tamper-evident packaging: When heat induction liners are applied to a container, they must be removed prior to use. If the heat induction liner is ripped or removed entirely prior to use it offers a form of tamper evidence in that a customer knows not to use the product if it has been removed.
- Improving shelf life: Cap sealing liners for air-tight packaging greatly improve the products being sold as it offers a hermetic seal for the container itself. This reduction in air transfer allows the products inside containers to have a longer shelf life.
- Leak prevention: These liners make it so that products inside of the container do not leak either in transit or before they have arrived to the customer.
Conclusion
Heat induction liners play a large role in many industries. Induction sealing liners for food and beverage, pharmaceuticals, cosmetics and personal care and cleaning products all use heat induction liners to improve shelf life and create a hermetic seal for their containers and the products inside. At Bay Area bottles, we can answer your HIS liner questions, as well as provide in stock and ready to ship heat induction liners for bottle caps. Reach out today for pricing or samples.
