PET binding film

PET Binding Films as Protection for Various Printed Products

Printed materials can be well protected by using PET binding film as a transparent cover sheet. At the same time, the title page remains clearly visible through the crystal-clear or finely matte films.

optimont® binding films are made from heat-resistant BOPET material. These films are characterized by high UV stability, which prevents yellowing and makes them more durable than other plastic films.

PET binding films are suitable for both thermal binding and spiral or wire comb binding, also known as Wire-O binding.

The PET binding films are antistatically discharged and can therefore be used without problems in machine processing.

Advantages of BOPET Material for PET Binding Films

The term BOPET—sometimes also written as BO-PET or, in English-speaking countries, BoPET—is the abbreviation for biaxially oriented PET film. Biaxial orientation refers to polyester film that is stretched first in the longitudinal direction and then in the transverse direction.

The technical term for this process is stretching, meaning the film is biaxially stretched. This treatment leads to an improvement in the mechanical properties of films.

These reinforced films show better values in tear resistance, impact resistance, and abrasion behavior compared to comparable unstretched films.

However, the most important property of BOPET material is the dimensional stability of the PET binding film produced from it. The films can be processed perfectly without waviness or distortion.

PET Binding Film for Thermal Binding

Thermal binding is a popular type of bookbinding, for example for thesis papers, master’s dissertations, and similar academic works. It is especially popular among students because it quickly and affordably meets the requirements for academic submissions.

In this type of binding, also known as adhesive binding or perfect binding, the pages to be bound are stacked together and aligned precisely at the edges using a vibrating alignment machine. During this step, the PET binding film is already processed as the front cover sheet, and a cardboard sheet is used as the back cover.

In a binding machine, the pages are joined together under the influence of heat using a special fabric adhesive strip, known as the binding strip. Under pressure and heat, the adhesive on the synthetic fiber strip is activated in the binding press, firmly bonding the pages together along with the PET binding film. At the same time, the outer side of the adhesive strip forms the book spine.

The good heat resistance of PET binding film made from BOPET material is an essential requirement for its use in this heat-based binding method.

Afterwards, the edges can be trimmed to create a perfectly finished book block.

PET Binding Film for Spiral Binding

Spiral binding, also known as ring binding, is familiar from notebooks, instruction manuals, and similar products. Spiral binding is simple and inexpensive.

Holes are punched along the edge of the pages to be bound, as well as through the PET binding film and a cardboard sheet used as the back cover. The spiral is then inserted through these holes along the spine of the book.

Since the binding wire winds through the pages in a spiral shape, the opened pages shift upward or downward along the spiral. At the end of the spiral, the wire must be bent to prevent the spiral from slipping out.

The spirals used for this binding method can be made of metal, coated metal, or plastic. When stacking documents or placing them on shelves, the spirals along the spine can sometimes be somewhat inconvenient.

PET Binding Film for Wire Comb Binding

PET binding films are also commonly used as cover sheets for printed materials bound using wire comb binding. Unlike spiral binding, wire comb binding does not involve twisting a spiral through the punched holes. Instead, the wire comb consists of parallel loops of wire into which the punched document is inserted.

Afterwards, the wire comb is closed using a press, ensuring that the pages can no longer fall out of the binding.

Wire combs are available for punch patterns with 34 holes or 23 holes along a DIN A4 sheet length. These are referred to as 3:1 punching or 2:1 punching, meaning three or two holes per inch.

With this binding method, books up to a thickness of 31 millimeters can be bound. Book sizes from DIN A6 up to DIN A3 are possible, including intermediate formats.

Cookbooks are often bound using this method, as are notebooks and instruction manuals. For wall calendars, a hanger can be easily integrated into the wire comb.

In addition to PET binding film and paper, other materials can also be effectively combined with this binding method, including different material thicknesses.

PET Binding Films in the Bleher Product Range

There are two quality grades of PET binding film in the Bleher product range. Both are heat-resistant, made from BOPET, and therefore UV-stable and resistant to yellowing. They are more durable and more robust than comparable plastic films and are free from plasticizers.

optimont® Binding Cover CC is supplied as a crystal-clear, transparent PET binding film. It is available in thicknesses of 125 and 175 µm.

optimont® Binding Cover FM is coated on both sides with a fine matte finish and is translucent. This makes it resistant to fingerprints. This PET binding film is available in a thickness of 175 µm.

Both films are supplied in the standard formats A3 and A4, and special formats are also available on request.

Which Films Can PET Binding Films Serve as an Alternative To?

Transparent cover sheets for printed materials are often made from PVC or polypropylene. PET binding film made from BOPET material makes it possible, thanks to the excellent mechanical properties of the material, to use thinner films.

This saves resources, is therefore more environmentally friendly, and also reduces costs.

The durability and abrasion resistance of binding film made from BOPET, as well as its UV stability, also ensure a long service life for printed products. This is especially important for items that are used frequently and remain in use for a long time, such as cookbooks or instruction manuals.

The Importance of Antistatic Treatment for PET Binding Film

Static charging of films is a recurring problem. On the one hand, statically charged films attract dust from the air and therefore become easily soiled. This is, of course, undesirable for printed products that are intended to create a visually flawless impression.

In addition, static charge can cause significant problems, especially during machine processing of films. Due to the electrostatic effects caused by the charge, films can “stick” together and become difficult to handle in automated production.

The antistatic treatment of PET binding films from bleher prevents both of these effects, ensuring visually perfect printed products as well as optimal machine processability of the films.

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