Understanding Cap Liners

How to Choose the Right Cap Liner for Your Products



When browsing the SKS website, you will see PE, F217, pressure-sensitive, plastisol, and induction liners. This is a how-to guide on understanding the features of each cap liner, to help you in choosing the best option for your application needs.

These liners come inserted into plastic or metal caps and are not sold separately. There are key features to consider when choosing a liner: the type of seal the liner creates, application requirements, barriers provided, and long-term use.

How To Choose the Seal for Your Containers

PE & F217 Liners: Available in an array of plastic caps of all sizes, PE liners are highly versatile. These foam liners provide excellent chemical resistance to acids, alkalis, solvents, alcohol, oil, household cosmetics, and aqueous products. They also offer low moisture transmission rates, odor resistance, and do not alter product taste.

PE and F217 liners do not seal the tops of plastic bottles, glass jars, and other containers. Unlike pressure sensitive and induction liners, foam liners are not meant to be single use liners; they create a barrier against the container's neck and remain inside the cap, even after opening.


PS22 & PS113 Liners: Pressure sensitive liners adhere to the rims of plastic and glass containers and provide an additional layer against outside elements, such as oxygen and moisture, which can help to preserve product freshness.

Plastisol Liners: Plastisol liners create an airtight, tamper-evident, hermetic seal with matching glass bottles and jars. Plastisol liners are single use and are popular for canning and hot filling foods and beverages.

Induction Liners: When properly applied, induction lined caps provide a hermetic, leak-proof, airtight, and tamper-evident seal. An induction sealing system is ideal for extending product shelf life and preserving freshness. The FDA states that induction lined caps are one of the most effective methods for tamper evidence.

How To Apply Liners

PE & F217 Liners: No application is required while using these liners. These multilayered liners stay inside the metal and plastic caps and do not require activation.

PS22 & PS113 Liners: To apply pressure sensitive liners, first fill the containers and make sure the rim is clean, screw the plastic caps tightly in place, and then leave the caps in place 24 hours or longer. As the caps set, the pressure sensitive liners adhere to the rim of the plastic or glass containers, creating a seal. To adhere correctly, be sure to store products upright to prevent them from coming in contact with the liners.

Plastisol Liners: Plastisol liners are composed of a plasticized PVC resin sprayed around the inner perimeter. Plasticizing the PVC makes it more flexible and malleable to create the seal. The plastisol liner begins as a solid liner within the caps; as it is heated, via water bath or hot filling, the liner becomes softened and pliable, and during cooling, it solidifies to create the seal.

Induction Liners: Induction sealing machines are required to create this strong seal when paired with plastic or glass containers. For more information on how this activation happens, read Understanding Induction Liners and Induction Sealing Machines, which discusses the sealing of these liners.

How To Choose the Right Size Cap

Selecting the correct size cap is essential for compatibility with your containers. SKS provides Cap Code measurements to match plastic and metal caps to containers. Each cap has a Cap Code listed in the description to easily pair with compatible containers. Cap Codes include the neck finish, inner neck diameter, and several other important factors to pair caps with containers accurately.


Popular Uses for Cap Liners

PE & F217 Liners: Consider PE and F217 liners for cosmetics, hair care products, and much more. Foam liners are available with plastic caps in both small and large sizes, making an expansive product line effortlessly cohesive.

PS22 & PS113 Liners: Pressure sensitive liners are highly versatile and available in plastic and dispensing caps. Black smooth caps paired with clear jars can easily showcase your bath salts, while preserving product freshness. PS22 and PS113 liners are also available in snap top caps paired with eye-catching honey bear bottles for packaging honey, syrups, and more.

Plastisol Liners: The most common uses for plastisol liners is in canning sauces, vegetables, and jellies. The plastisol liner is helpful with long-term storage for seasonal produce or other food preservation. Plastisol liners can also be valuable when packaging juices and brewed teas for optimal freshness before opening.

Induction Liners: Induction liners provide the most substantial seal available and uses vary from food packaging options, like peanut butter jars, to pharmaceutical needs. Induction liners are sold in ribbed and smooth plastic caps, child-resistant caps, and dispensing caps, making them an option for a wide range of industries.

SKS offers samples for testing each of these liners in metal or plastic caps before purchasing to ensure complete compatibility with your product.






Chat with Us

Copyright © 2024 SKS Bottle & Packaging, Inc. All Rights Reserved