What Is a Release Liner

on January 10, 2019

What Is a Release Liner?

What do diapers, roofing shingles, and postage stamps all have in common? They all use release liners to preserve their adhesion potential for their desired end use.

Release liners use polymer- or paper-based material to keep adhesive materials unstuck while simultaneously holding them in place until their final intended application. Think of the backing material for stickers: liners keep the stickers sealed to the roll without affecting their adhesion when users peel them off. 

Two Types of Release Liner Suppliers

In the adhesive and sealant industry, release liner suppliers fall into two basic categories: liner producers and in-house producers. What are the differences between the two?

  • Liner producers manufacture standalone release liners intended for a wide variety of uses and work with a broad range of backing materials and release agents. Liner producers can tailor their products to their customers’ requirements, and once the contracted liner has been produced, customers can further modify the liner with their specific product and branding requirements.
  • In-house producers don’t consider themselves liner producers, but their products still incorporate liners that they produce in their own facilities. Generally, these companies use a limited amount of substrates and release agents because they only intend their liners for specific end goals.

Release Liner Uses

Companies can use several different varieties of liners depending on their desired end products, budgets, and preferences.

To produce most kinds of liners, workers apply a coat of silicone on one or both sides of the base material. However, even though most companies use silicone-coated release liners, others rely on specialized materials according to their product’s needs.

Below are some of the most effective types of release liners:

  • Polypropylene liners provide increased strength due to their biaxial orientation, resulting in high tensile strength and dimensional stability. These liners come in different thicknesses.
  • High-density polyethylene liners provide higher heat resistance than other liner types. They also come in varying thicknesses according to customer specifications.
  • Polyester liners resist heat better and are tougher than all other liners, and therefore, many heavy-duty applications rely on them for increased support.
  • Paper liners are one of the most cost-effective liner solutions available. They provide a wide range of adhesion strength, from low adhesion for sticker rolls and display racks to high adhesion for home and vehicle insulation.

These categories contain many subvarieties and incorporate many different kinds of material. For example, paper release liners include Super Calendered Kraft paper, used for labels in the United States, which differs from Glassine paper, which incorporates a PVOH polyvinyl alcohol coat on top and appears on European labels.

Release liners have come a long way over the years in both their manufacture and their applications. For example, the medical industry relies on them for wound dressings, EKG monitors, and dermal patches. The shipping and mailing industries use liners to better seal packages, and homes and vehicles use them to section off insulation materials.

Release Liners for All Occasions

Tee Group Films provides our customers with high-quality release liners tailored to their needs. We’ve provided customized liners for clients across the country from our Illinois plant for years, and we’ve helped rubber manufacturers, automotive manufacturers, construction businesses, and aerospace assemblers achieve the sealing solutions their products need. 

If you would like to learn more about release liners and their applications, contact us and request a free quote today.

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Advantages to Using Heat Activated Adhesive Films

on December 27, 2018
in Blog

Heat Activated Adhesive Films

Adhesive films are thin layers of high-performance bonding agents supported by a backing material. Despite their relative thinness, they offer a level of bonding performance similar to fasteners, screws, rivets, and welding for many applications.

The backing of adhesive films – also known as the carrier – may be constructed from several types of materials including paper, plastic, cloth, foil, foam, and more. The backing may be coated with an adhesive on one or both sides and can be integrated with a release liner if required. Adhesive-coated backings are typically wound in rolls and die cut into desired lengths and shapes. These films can also be formulated with varying adhesive chemical compositions to provide beneficial properties for unique applications.

Unlike liquid glues, adhesive films are applied as solids and do not ‘squeeze out’ when compressed between two surfaces. Additionally, since adhesive films contain no liquids, they have no pot life or gel time, allowing them to be stored indefinitely. These attributes make adhesive films ideal for automated processes and industrial applications where time-consuming messes and maintenance issues need to be avoided.

Different Types of Adhesive Films

There are three main types of adhesive films, as follows:

1. Pressure Sensitive Adhesive Films

Pressure sensitive adhesive films (PSAs) are adhesive tapes activated with the application of external pressure. The films consist of a pressure-sensitive adhesive compound coated onto a backing material (usually on one side). The other side of the backing typically has a release liner to facilitate manual pressure application.

PSAs are tacky at room temperature and can be used to bond a variety of materials, including paper, plastic, metal, and concrete. These adhesives can achieve bonding pressures of up to 30 psi depending on the specific application.

PSAs are best applied in environments with temperatures between 59º F and 95º F. Lower temperatures can lead to insufficient wetting or coverage of the adhesive on the substrate. Whereas, extremely high temperatures may cause the adhesive film to stretch or warp during final application.

2. Heat Activated Adhesive Films

Heat activated adhesive films, unlike pressure sensitive adhesives, remain tack-free until activated by an external heat source. Elevated temperatures – usually 180º F or higher – must be maintained for a specific length of time on the film to achieve adequate bonding.

During the cooling process, the microstructure of the adhesive begins to crystallize, significantly increasing the bond strength.

Heat activated adhesives are particularly aggressive and enable the bonding of difficult surfaces, including rubber and polymer-based materials. Heat activated adhesives are also customizable and are available with numerous backing materials.

3. Moisture Activated Tape

Moisture activated tape, as its name suggests, is an adhesive compound that becomes sticky when moistened with water or any other liquid solution.

This type of adhesive film is usually backed by kraft paper and is relatively inexpensive compared to other adhesives.

Benefits of Heat Activated Adhesive

Relatively high bonding strength and superior chemical resistance are major benefits of heat activated adhesives. The cross-linking reactions that take place during the curing of thermoset adhesives result in a rigid bonding structure that is unmatched by pressure sensitive or moisture activated adhesive films.

Thermoplastic heat activated adhesive films can be used continuously or in batch bonding processes for precise and piecemeal application on large surface areas. This characteristic is especially useful for automated processes with high production speeds.

These films are also compatible with surfaces that resist bonding by other adhesive solutions, such as:

  • Aluminum foil
  • PVC
  • Polyurethane
  • EPDM rubber

This compatibility makes heat activated adhesives a popular choice for laminating, molding, and thermoplastic welding in a broad range of applications.

These films are experiencing increased usage, especially in the textile industry. Heat activated adhesives for fabrics are used to create various types of high-performance composite and waterproof garments with increased speed and efficiency.

Heat Activated Adhesive Films from Tee Group Film

Tee Group Film’s TALON line of heat activated adhesive film products are designed to create bonds between a wide range of materials and surfaces. Our films can also be customized with myriad features, including water vapor barriers, enhanced tensile strengths, and improved heat resistance.

If you would like to find out more about our heat activated adhesive films and how they can benefit your application, feel free to contact us for more information.

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