BO-PET Release Films

Release films for various technical applications and packaging solutions

Release films are films equipped with a non-adhesive surface. They are also known as separation films and serve as a separating medium between two surfaces at the point of application. One of the best-known applications of a release film is adhesive tape, which features a protective film covering the adhesive layer. The release film protects the adhesive, and the tape can only be used once the film has been removed. Many DIY users are familiar with such tapes from construction applications or as double-sided adhesive tapes. In industrial environments, release films are widely used for numerous specialized applications.

Materials for Release Films

Materials used for release films include polypropylene (PP), polyethylene terephthalate (PET), primarily in the form of BO-PET, and polyethylene (PE). These materials are coated with anti-adhesive layers such as silicone, fluoropolymers, or other specialized release agents. This coating provides the non-stick properties that make the films suitable for use as release films.

BO-PET Release Films

The separation films in the Bleher portfolio are manufactured from BO-PET material. Some of the technical films from the Bleher range can be used as BO-PET release films. Our service team will be happy to advise you on which film is suitable as a release film for your specific application. BO-PET release films are heat-resistant, dimensionally stable, and highly tear-resistant. As a result, they can be used as release films in a wide variety of applications.

Types of Release Films

Release films can be equipped with different coatings to achieve non-adhesive properties. Silicone-based release layers are frequently used. Fluoropolymers or other release agents may also form the non-stick layer. Depending on the application, release films can be produced in various thicknesses. The surface structure of release films is also important, as it influences the surface texture of the workpiece and thus affects its appearance and tactile properties.

Applications for Release Films

• Adhesive Tape and Label Production

In adhesive tapes and labels, release films protect the adhesive layer.

• Composite Materials

During the curing of composite materials such as glass fiber reinforced plastics or carbon fiber components, release films are used to separate the finished components from the molds.

• Construction and Laminating Processes

When laminating surfaces such as wood, metal, or plastic, release films are used to prevent unwanted adhesion of adhesives.

• Electronics Industry

In printed circuit boards or flexible displays, highly precise separation processes are required to ensure flawless functionality – these are enabled by release films.

• Baking Films in the Food Industry

Release films serve as packaging for frozen foods that can be prepared in the oven or microwave together with the packaging.

• Medical Applications

As separation films, release films simplify the handling of self-adhesive plasters, electrodes, or medical devices.

• Printing Industry

In printing applications, release films protect the transfer material until it is used in the printing process.

Advantages of Using Release Films

In aerospace, shipbuilding, the automotive industry, and many other sectors, components or reinforcements are manufactured from composite materials. To improve resin curing within these composites, molds are lined with release films. This facilitates the removal of finished components and protects the molds from adhesion. Cleaning the molds becomes significantly easier and more environmentally friendly. Similar benefits apply to laminating processes or the printing of electronic circuits. In adhesive tapes, release films prevent the tape from sticking to itself, and the same principle applies to labels and medical products. In printing, the transfer material is protected until the printing process. A baking film protects food until consumption, eliminating the need for additional cookware during preparation – an important advantage, particularly in catering. In all cases, release films help simplify production or working processes, save material and time, accelerate operations, and ultimately reduce costs.

BO-PET as a Material for Release Films

BO-PET release films are manufactured from biaxially oriented polyethylene terephthalate film. After the extrusion process, BO-PET films are stretched both in the machine direction and transversely. This stretching process alters the crystalline structure of the film. The result is high mechanical strength, heat resistance, and dimensional stability. All of these properties are essential prerequisites for the successful use of a release film.

Alternatives to Release Films

Instead of using release films, certain applications may also employ traditional release agents. Depending on the application, these may be oil-based, water-based, or solvent-based release agents. Silicone-containing release agents as well as wax- or lacquer-based systems are also available on the market. These agents are applied manually or by spray equipment and allow components to be removed from molds.

Advantages of Using BO-PET Release Films Compared to Release Agents

• Cleanliness and Precision

BO-PET release films leave no residues, neither on the surface of the component nor on the mold.

• Efficiency

BO-PET release films reduce the time required for mold cleaning and post-processing of the workpiece.

• Material Protection

BO-PET release films prevent scratches, deformation, cracks, or other damage to the component during the separation process.

Quality Requirements and Selection Criteria for Release Films

Selecting the appropriate release film for a specific production process is crucial for functionality, process reliability, and cost efficiency. One key criterion is the release force – the film’s ability to separate the product from the mold. Temperature resistance, chemical resistance, and mechanical strength are also important decision factors. The so-called peel force – the force required to remove the film from an adhesive or resin surface – must be precisely matched to the respective process. If the release force is too low, unintended detachment may occur and significantly disrupt the production process. If the release force is too high, handling of the BO-PET release film and the workpiece becomes more difficult. Sensitive materials may be damaged by BO-PET release films with excessive peel force.

Impact of the Surface Properties of BO-PET Release Films

Another important selection criterion for BO-PET release films is the surface finish. A smooth BO-PET release film surface ensures an even, smooth, glossy finish of the final product. Textured BO-PET release films modify the surface structure of workpieces and can create a specific, desired tactile and visual effect. In sectors such as interior design or product design, these effects play an important role. Film thickness also influences the production process. Thin release films are flexible and material-efficient. Thicker versions offer greater stability and, under optimal conditions, can be reused multiple times.

Optimized Process Reliability and Automation Through BO-PET Release Films

In modern, highly automated production processes, BO-PET release films make an important contribution to process stability. By simplifying demolding and separation processes, they enable scalable production steps and consistently high quality. They reduce scrap rates and minimize machine downtime. Thanks to their BO-PET base material, BO-PET release films offer excellent flatness, low elongation, and consistent material properties even under changing temperatures. These characteristics are essential for ensuring precise positioning of the workpiece during production, as well as clean edges and consistent final product quality.

BO-PET Release Films for Adhesive Tapes and Labels

In label printing, the tear resistance of BO-PET release films is a key property, as any film break at high web speeds results in significant machine downtime. Considerable time is required to clean the machine of all film residues. A similar situation applies to adhesive tape production. Although adhesive tapes are not always printed, adhesive coating is also carried out at high speeds, and a torn tape causes similar issues as in label printing. For multi-stage production processes, the dimensional stability of BO-PET release films is equally important to ensure that each production step is executed precisely at the intended position.

Sustainability and Reusability of BO-PET Release Films

Sustainability is becoming increasingly important in the field of BO-PET release films. They are a good choice in this regard because they are durable and can be reused multiple times in certain applications. Their high resistance to mechanical stress enables repeated use. In molding processes for composite manufacturing, reuse can significantly reduce material consumption and waste volumes. If single-grade, uncoated BO-PET is used as a BO-PET release film, the used material can also be fed into the well-established PET recycling stream. As a petrochemical product, BO-PET release film therefore offers several sustainability advantages.

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