Liner Lessons - Learn about the liners in our closures

LINER LESSONS – Learn a little about liners with Waterloo Container

What is the Liner? 

When you choose a cap or closure for your product, you are determining how the wine will be opened and how the top of the primary package will look.  Inside screw caps and continuous thread closures there is often a liner.  Some liners tend to withstand chemicals better then others, while other liner material types are better used for moisture barriers. As the liner is the component that actually touches and affects your product, Choosing a liner type and style is one of the most important factors of cap selection.

Why is the liner important to you?

Since liners have direct contact with the bottle contents, their composition can affect how the contents are preserved, oxygenated (aged)or protected.  Liners can also play a key role in secondary fermentation, helping to regulate CO2 loss and O2 entry.  In short, your liner choice will affect your product.  You need to make sure the affect is positive!

What is OTR (Oxygen Transfer Rate)?

OTR is the measurement of the amount of oxygen gas that passes through a substance over a given period.  OTR of the closure is one of several factors that control the total package oxygen in a bottle of wine.  The liner is a significant determiner as It is the barrier between the headspace (which can contain up to 65% of the total package oxygen) or product and the capsule itself.  In recent years, closures with liners have become increasingly technical, allowing for increased control of OTR after packaging. 

LINERS COMMONLY USED IN BOTTLE CAPS AND CAPSULES

Foam  Liners:  FDA approved Olefin Polymer suitable for food and beverage contact.  An ideal general-purpose liner material, the compressible PE foam creates a stable seal.  Excellent chemical resistance with low moisture transmission rate and good taste and odor resistance. Good resistance to acids, alkalis, solvents, alcohols, oils, household cosmetics, and aqueous products.

• EPE 3217: A single layer of low density expanded polyethylene foam laminated with polyethylene film on both sides
• Use:  Use with products with low sensitivity to oxygenation.  Commonly for Alcohols and Spirits.   Any alcohol product with greater than 50% alcohol should consider these liners.
• Find it:  EPE 3217 liners are found in our 30-1610 ROPP caps

• EPE 4020 (Corelen) Liner:  A single layer of low density expanded polyethylene foam.
• Use:  Use with products with low sensitivity to oxygenation.  Commonly for Alcohols and Spirits.   Any alcohol product with greater than 50% alcohol should consider these liners.
• Find it:  Corelene liners are available with orders of Stelcap Liquor Caps.

• PE F217 Foam Liner:  Three ply liner consisting of foamed Low Density Polyethylene core sandwiched between two solid layers of Low Density Polyethylene
• Use:  Closure designed for use with food, household, cosmetic and liquor containers.   Works with acidic contents like vinegars.  Excellent sealing properties.
• Find it:  Our plastic hand applied CT caps are lined with F217 (or generic equivalent) PE foam liners.

Oxygen Scavaging Liner : Granulated PVC based polymer compound  (FDA compliant) applied to underside of cap to reduce oxygen migration from atmosphere into container/contents

• Use: Choose this liner to decrease oxidation of the beverage when using a crown cap application.  Reduces signs of staling in beer and related beverages.  Pasteurization resistant and good for acidic and low alcohol content liquids.
• Find it:  We offer several metal crown caps with Oxygen Scavenging barrier

Plastisol Liner:   FDA Compliant synthetic resin made from the polymerization of vinyl chloride. This liquid PVC compound (plastisol) material is injected into interior surface of metal cap and cured to create airtight ring.

• Uses:  Hot fill items that create a vacuum and pasteurized products.  Excellent resistance to mild acids (as in food products).  Can add tamper evidence and creates a hermetic seal (preventing the passage of air, oxygen or other gases)
• Find it:  Our 28 and 38mm metal caps are plastisol lined.

Polyethylene Injected Liner:  PVC-Free virgin polyethylene heat molded into the cap.  This is enhanced by special additives to improve elasticity and to reduce osmotic permeability.

• Use:  Flexible and pliable liner boasting excellent mechanical sealing against pressure. Ideal for medium-term ageing up to approx. 48 months.
• Find It:  Many of our sparkling crown caps offer this pressure resilient liner

Saranex™ Liner-Proprietary FDA approved liner specifically designed for STELVIN® capping technology.  A single central layer of low density expanded polyethylene foam (EPE) laminated on both sides with SX film (PE-PVDC-PE)

• Use:  Best for products with light sensitivity to oxygen.  Allows oxygen permeability. Your wine will do best with some aging and controlled oxygen transfer.  Your wine will be consumed in 1-3 years.
• Find it:  All of our stock STELVIN® brand caps are designed for wine and lined with either Saranex™ or Saran™tin liners.  

Saran™tin Liner-Proprietary FDA approved liner specifically designed for STELVIN® capping technology.A single layer of low density expanded polyethylene foam (EPE) followed by two layers of  low density polyethylene film (LDPE)  with Aluminum foil layers and PET film barrier.

• Use:      If your wine or spirit is ready to drink when you bottle it (requires no aging), this is the liner for you.  It creates a strong Oxygen barrier.
• Find it:  All of our stock STELVIN® brand caps are designed for wine and lined with Saranex™ liners or Saran™tin liners. 

• Note:    STELVIN® caps can be customized with special PVDC-free Saranex liners created for targetted Oxygen Transfer Rates.  These STELVIN INSIDE capsules and liners are a custom order item.
• STELVIN® P Liners are recommended when carbonation is used (will maintain up to 6 bars of internal pressure)
• STELVIN® Lux capsules are available with Saran™tin, Saranex™ or Optimex Liners for O₂ Ingress control

SUMMARY

Your liner is Busy!  It is a performing aspect of your packaging:

• Liners provide a leakage barrier or sealing surface
• Liners acts as a barriers or control mechanisms for atmospheric transfer between contents and the outside world
• Liners protect contents, in all conditions of storage, without causing undesired effects or changes to taste, odor or appearance.

IMPORTANT:  Compatibility with specific beverages and post lining closures treatment processes should be verified by the user