Questions and Answers – Bending Film (bending foil) for press brakes

We have prepared this Questions and Answers page to address the most common questions about bending film, based on information collected from our potential customers. We hope this page will help you better understand the main topics and will also save time by providing a single link that contains important and useful information.

Some of the information below may repeat what is written on our main page. Bending film (in US market also used as "bending foil") is made of polyurethane and is one of the most cost-effective and universal ways to reduce or eliminate marks on the metal surface during bending. These marks are typically caused by contact with the die shoulders. Due to its flexibility and high resistance, bending film is much more effective than paper, surface foil, standard plastic sheets, or similar solutions commonly used by customers.
Bending film can be used with any type of material, any press brake, and with all types of bending tools and configurations. It is considered a low-cost solution because it does not require any changes to daily production, tooling, or existing bending programs. The only adjustment usually needed is to add the bending film thickness to the material thickness in the CNC program. After that, the film is simply placed on the die during bending.
Surface marks after bending are a serious issue for applications where visual appearance is important. Such marks cannot be eliminated by adjusting machine or tooling parameters. Removing them afterward is complicated, requires additional equipment, and adds extra technological steps after bending.
However, bending film also has some minor disadvantages. These include the need to fix the film on the die, regularly checking its condition before bending, small deviations in the bending angle, minor CNC program adjustments, and potentially different results when bending different radii or angles.

We usually encounter two types of customer requests. The first group already knows the bending film parameters they want and is mainly interested in pricing and delivery conditions. The second group has never used bending film before and does not know what specifications to request.
We have a production program that includes all available dimensions and technical data. We also provide theoretical recommendations. However, we would like to clearly state that we do not operate a sheet metal workshop and do not perform bending tests with our film, materials, or tooling. Therefore, our recommendations are theoretical only, and we cannot guarantee optimized performance in real production conditions. We strongly recommend that customers determine the most effective setup based on their own experience, production processes, and bending programs.
Some sources suggest using thinner bending film for softer materials such as aluminum or copper.
here is no “universal” bending film thickness that works optimally for all material thicknesses and applications. While some users attempt to use one thickness for everything, the results are usually not optimized and may increase wear, create programming issues, or cause inaccurate bending angles.

We frequently receive requests such as: “Bending film for metal thickness 1–5 mm—please provide an offer.” We have already provided theoretical recommendations. If you are unsure about which thickness to use, please keep in mind that we also cannot determine the exact thickness for your application.
We supply bending film, but we do not collect detailed case studies, and many companies prefer not to share specific information about their technology or processes.
If you want to test your conditions, please refer to Clause 8 on this page.
As a small recommendation, we suggest that potential customers focus on one or two of the most commonly used thicknesses for bending. Conduct thorough testing to achieve optimal results for these, and then verify other thicknesses and solutions as needed.

Yes, in theory, there are several alternative solutions to reduce or eliminate marks during bending. However, bending film is one of the most universal options because it can be used immediately with existing tooling.
Other solutions include polyurethane dies, nylon dies, and roller dies. Roller dies reduce friction during bending thanks to moving rollers. In some cases, solid lubricants are also applied to dies to reduce scratching. These alternatives are generally more complex and more expensive. It is also difficult to say which solution will be the most effective for eliminating marks, as this strongly depends on the application.
We have encountered cases where customers completely solved marking issues by switching to roller dies. However, like any bending tooling, roller dies are suitable only for specific thickness ranges and are not a universal solution for all bends in a workshop. Investment cost is also an important factor when choosing between different solutions.

We do not provide a single recommended method for fixing bending film to the die. In practice, we have seen customers use magnets, rubber bands, duct tape, manual clamping devices, special fixators, or no fixation at all. Special fixators or supports installed on the bending die are also available and can be supplied by us. If bending film is used in daily production, it is important to choose a fixation method that minimizes operator time and prevents frequent readjustment of the film.
Each roll has a cardboard core, which allows it to be used with bending film holders or unwinders offered by some manufacturers.
If special holders are used, we recommend checking in advance that they do not interfere with the press brake’s safety systems, such as light or laser beams.

We have identified several points that should be taken into consideration. These are not suggestions or recommendations, but factors to keep in mind:

• Fixation should prevent any displacement in order to reduce the risk of scratches caused by movement.
• It is better to spend additional time on preparation and ensure correct setup of the bending film than to produce a metal part with defects.
• The bending film does not have a sticky surface. If duct tape is used, it should be applied only on the sides of the die to prevent displacement, and not between the die and the bending film.
• If fixation problems persist, it is recommended to use dedicated holders.

As mentioned earlier, bending film acts as an additional layer and must be taken into account in the press brake program. If not, surface marks may be eliminated, but bending angles may become inaccurate. Different film thicknesses affect the bending result differently because the film effectively enlarges the V-opening of the die. If the punch end position is not adjusted, angle deviations may occur. In precision applications, even small deviations can be critical, even if the program worked correctly without bending film. To avoid these issues, the bending program must be adjusted accordingly.
We have also encountered opinions that programming complexity, film wear, and non-constant results make bending film a risky solution, and that nylon dies are more precise and reliable. For highly precise applications, this may be an important consideration. However, thousands of factories worldwide successfully use bending film as an effective solution to protect parts from scratches and marks.
This text is intended to provide a realistic and detailed overview, beyond standard marketing materials, to help customers make informed decisions.

There is no professional or universal answer regarding the service life of bending film. Its lifetime depends on many factors, including bending force, press brake settings, cleanliness of dies and punches, absence of abrasive dust or metal particles, cleanliness of sheet metal, presence of oil, and correct matching of film thickness to the application. We have encountered theoretical data suggesting 30–50 bends on the same spot, but this should be considered only as a rough and theoretical reference.
Correct programming is essential. If the program is not adjusted, excessive force may be applied to the bending film, leading to premature damage and wear. Sharp bends, such as 30° or 60°, cause faster wear compared to standard 90° bends due to higher stress on the material.
Additionally, bending film may positively affect die service life by preventing direct metal-to-metal contact and reducing exposure to abrasive particles.
Since the minimum width of bending film is typically 90–100 mm, it can also be used on small V-openings (such as V6 or V8) by shifting the worn section sideways.
We do not have data proving that our polyurethane bending film has higher or lower wear resistance compared to products from other suppliers or compared to other urethane, polyurethane, or/and other polymer materials.
The presence of burrs on the edges of the material to be bent will definitely have a negative effect on the wear of both the bending film and the bending tooling.

As mentioned earlier, the answer depends entirely on the application.
In the US, several manufacturers offer solid polyurethane bending dies as a mark-free solution. Nylon is generally more rigid, stronger, and less flexible than polyurethane. This rigidity can result in more consistent bending angles. However, using nylon dies requires replacing standard dies, and they are typically available only for smaller V-openings. To reduce cost, many manufacturers offer nylon dies as inserts combined with metal holders.
In summary, the choice depends on application requirements, convenience, and economic considerations. Bending film is a more universal solution, especially in workshops producing a wide variety of parts. For applications where surface marks are not critical (for example, parts that will be powder-coated), the film can simply be removed.

Our company does not provide free samples due to commercial policy. However, we understand that customers who have never used bending film may not want to purchase a full roll for testing. For this reason, we offer bending film in lengths of 1, 2, 3 meters, or more, allowing customers to test it in their own production. Pricing is calculated per meter (usually with a 1.5 coefficient compared to a full roll price) plus delivery costs. Upon request, we can also supply two or three different thicknesses for testing.
Please note that not all thicknesses are available for sale by the meter. For detailed availability and conditions, please contact us.
We do not provide free samples because, as a commercial company, we must operate on a profit basis. However, existing customers who purchase press brake tooling from us are welcome to contact us regarding free samples or special requests.

We cannot provide guarantees regarding results, surface quality, or the percentage of mark or scratch reduction. We consider it unprofessional to make such claims without factory testing.
Even if customers provide detailed information about their press brake, tooling, and materials, we cannot guarantee performance. We encourage all potential customers to perform their own tests and make the final decision based on real production results.

In general, no. We do not offer customized dimensions outside our standard production program.
Custom sizes may be discussed only for large one-time orders of approximately 400–500 meters or more. For single rolls or small quantities, customized dimensions are not available.

We do not compare our products with those of other manufacturers, countries of origin, or suppliers. We offer our product at our price and do not evaluate or benchmark competing solutions.
Some sizes are available for purchase by the meter, allowing customers to test the product without buying a full roll. This is the best way to evaluate performance for your specific application.

For storage, we recommend keeping bending film in a dry indoor environment. The recommended relative humidity is 40–70%, and the storage temperature should be maintained between +10 °C and +25 °C.
Bending film should be stored away from direct sunlight and UV lamps, as UV exposure may cause premature aging of the material. It is also important to keep the film away from solvents, oils, acids, alkalis, and other aggressive chemicals that could negatively affect the properties of polyurethane.
For the disposal of used bending film, we recommend verifying the local regulations and disposal requirements applicable in your country or manufacturing area. Disposal rules may vary depending on local environmental laws and waste management practices.
Used bending film may be contaminated with metal particles, oil, or other process-related materials, and therefore should be disposed of according to the regulations applicable to polyurethane or industrial plastic waste in your region.

In Europe, polyurethane dies as shaped dies for standard bends are not commonly used. Using rectangular or square inserts is not a proper solution—even if with middle holes for increased flexibility.
Traditionally, such inserts were only suitable for radius bends.
If they are used for standard bends, such as 90° bends, numerous problems can arise. Unlike air bending, the material will resist from the bottom, which increases the required force. Additionally, with repeated deep penetration, the wear on polyurethane inserts is expected to be quite high. Therefore, polyurethane inserts are generally not considered a reasonable solution for standard bending operations.