Food Grade Induction Liners

Big Brand Cosmetic and Food Companies value their product being produced in Western Countries like the USA, Canada, Australia, New Zealand, The UK, Germany and France.

For example, a Salt Scrub that says produced in Canada carries a lot more appeal to clients and Brand owners alike than a product that says “Made in China”; Especially a product that you will Ingest or put into Direct Contact with your Body.  The reasons are really quite obvious – it is common knowledge that in some parts of Asia where there is a huge ether of manufacturing, completely regulating all practices to be safe is a very difficult task. This leaves open an unacceptable risk for many consumers who will understand that “somewhere” in the chain of processes that go into the finished product something can more easily go wrong.

It is not uncommon to source packaging from Asia and then produce the contents in a more controlled and higher profile country or location.

If the brand (and clients) see value in knowing the contents are produced in a safe and controlled location then Induction Liners should NOT be considered as separate from the contents or as simply “inert” packaging.

Safe Induction Liners

The sealing layer of an induction cap liner that comes into contact with the inside area of your packaging is a plastic polymer and or an adhesive. Often cap suppliers will provide this lining material without paperwork to identify and qualify the material fit/safe for purpose. For example the liner may only be suitable for industrial chemical contents.

During the induction sealing process, the lining material is heated to a point where their sealing polymers and adhesive are in a liquid/molten state. This can OFTEN mean liners from unknown suppliers in China will have a polymer cocktail that can leach into your (your clients) product*.

The process of induction sealing could therefore result in some nasty compounds becoming an extra unintended ingredient in the product.

Please be assured that we are only raising this point to make sure you are aware of this possibility and to allow your client and you to complete a due diligence for the manufacturing of a product that will be in contact with people’s skin.

From our experience, the least that can be expected from a supplier of caps with lining material is to be given a cap lining certificate of compliance with food and commodities; supplied, on the letter head of the manufacturer of the lining material. It is not sufficient to have such a document issued by the cap supplier or a lining material agent that simply puts their letter head at the top of a generic declaration.

“Food for thought”

All our liners are manufactured using lining materials that have a cap lining certificate of compliance with food and commodities; supplied, on the letter head of the manufacturer of the lining material.

*Even the Foam we supply for fitting behind induction liners is resistant to the heat process of the Induction Sealing and this foam comes with it’s own certificate of compliance with food and commodities.

Often the first thing our clients realized with respect to how things can go wrong with Seals from Asia or India is inconsistency of sealing results. That problem , while a practical problem is a relatively minor problem. That is a relatively safe issue and it is well-known that this will often be due to variations from batch to batch of liners produced in these regions.

The safest way to treat induction lining material (and source it) is as if it were the contents.

A cap liner is a piece of material that sits between the cap and the bottle. Its traditional primary purposes are to offer proper sealing of the product to prevent leakage and optionally to provide tamper evidence.

New technology is now turning this humble piece of packaging into a multimedia gateway for brands to reach out to their consumers through the Tribe Platform.

Since the cap liner is something only seen by the consumer after the product has been opened, the cap liner can essentially facilitate a “cap coupon”.

Since the cap liner is in direct contact with the product, chemical compatibility and correct certification for contact with your kind of product is crucial. Using the wrong seal can lead to expensive and sometimes dangerous mistakes that can jeopardize your product brand and integrity.

Chemical products and consumer/food products can require liners that differ significantly in their properties. The varying liner materials have different jobs. They may be used as any combination of moisture barriers, oxygen barriers, chemical resistant barriers, consumer tamper evidence safety and for preventing leakage.

The cap liner material alone can significantly affect the cost of the cap, not to mention the impact on the finished product.

Compatibility of the caps, liners and bottles has to be tested; as well as the compatibility of these packaging materials to the product inside.

Selecting the Right Seal

Novice producers may find it difficult to decide which cap liner is the right solution for their product. With all the different liner types available, choosing the correct liner for your product and container is an important step.  If considering cap lining material it may be worthwhile looking at how a practical packaging initiative and a practical marketing initiative can be combined.

A wide range of cap seals are available but by focusing on these key questions, we should be able to narrow down the field:

• Level of tamper evidence required?
• Type of product: liquid, powder, or solid?
• After opening the product is a reseal important?
• Will the Seal be used to promote the Brand?

Some Popular Cap Liners

1. Plain Expanded PE foam. Providing both a seal and reseal, this is one of the lowest cost cap lining materials available.  When produced using C02 Gas the cell structure of this material can be tight and present and perform close to that of some laminated foams produced with less sophisticated methods.

2. Laminated Expanded PE foam. As per the Plain foam this material has added layers often on both sides to provide a smoother and more chemically resistant sealing surface. With the right laminates this material can have Good resistance to acid, alkalis, solvents, alcohols, oils, household cosmetics, and aqueous products. Aluminum, Tin or Saran are common coatings used for alcohol with Tin being particularly popular for Wine bottles with screw caps.

3. Pressure Seal Foam Liner. Coated with torque-activated adhesive, the action of applying the cap causes this seal to bond with the bottle or product opening; there is no need for an outside heat source. Historically this type of seal was applied to provide tamper evidence and often printed with words that would infer that the seal was a form of tamper evidence. You will now notice that on any credible supplier’s specification sheet they will go out of their way to state this is NOT a seal to provide tamper evidence.  This is to avoid potential legal claims associated with the possibility this type of seal can be tampered with and reapplied without any special equipment. The Moisture and oxygen barrier of this type of material is also generally lower than laminated foams.

4. Induction Liners – When passed through an induction process, the foil layer heats up in a process that will bond all or part of the lining material to the top of the product. Induction liners can only be applied using an Induction Sealing Machine.

There are 2 types of Induction Liners:

1. One-piece Foil. Since it “sticks” to the bottle after sealing, this single-use foil is one of the most common forms of sealing. Side tabs and Lift ‘n’ Peel™ options add to the experience of easy removal from the lid for items like milk and juices. An added barrier layer can also provide protection against aggressive products. An air and watertight hermetic seal prevents leakage in packaging for edible oils, water, juices, condiments, shampoos & conditioners, gasoline treatments, additives, food & beverages, nutraceutical products, health & beauty products, vitamins, spices, and pharmaceutical products.  Often a one piece Foil will need to be applied over a softer and thicker foam based liner to insure a good distribution of pressure from the cap over the entire opening of the product to be sealed.

2. Two-piece Heat Induction Liner – The benefit of using two-piece heat induction liners is that they eliminate the need for lining the closure in two separate stages: The base foam or cardboard layer of the  liner is temporarily bonded to the foil with either a wax and paper layer or a separating polymer layer.