The Panel Bender: Your Ultimate Guide

Looking to improve production efficiency and reduce labor costs? Look no further than panel benders.
These machines, which have been around for over 40 years, offer a range of benefits over traditional press brake machines, including labor-saving and speed, good repeatability and consistency, and the ability to smoothly complete the positioning of the sheet in a single pass for four-sided bending.

The Salvagnini P4 panel bender, which was introduced in 1977, revolutionized the industry with its flexible, automated sheet metal forming technology. Since then, Salvagnini has continued to innovate with models like the P1 Lean panel bender (the smallest in the family with a large forming length of 1250mm and an average power consumption of only 3 kWh per hour) and the P2L-21 compact panel bender (used in the commercial kitchen industry with a forming length of 2180mm and an average power consumption as low as 5 kWh per hour).

While the high one-time investment cost may deter some sheet metal processing users, the efficiency and intelligence of panel benders make them a revolutionary alternative to traditional press bending machines. With their highly intelligent operating control system, panel benders can efficiently bend different workpieces, making them ideal for companies looking to automate and improve their production processes.

Panel bender history

In Europe and the United States, companies often face a higher proportion of human resources costs. Especially in Northern Europe, the vast majority of companies are eager to address the high cost of labor.

Therefore, European and American enterprises have long prioritized “improving production efficiency and reducing manpower” and have launched a series of automatic and intelligent initiatives. More companies are beginning to consider purchasing smarter equipment and even embracing automated, unmanned production lines.

It has been 40 years since Salvagnini introduced the world’s first P4 panel bender in 1977. The Salvagnini P4 panel bender’s revolutionary universal bending tools and robots introduced flexible, automated sheet metal forming technologynbsp;to the industry in the late 1970s.

salvagnini panel bender

P1 Lean panel benders
The P1 Lean panel bender (Fig. 1) is the smallest model in the family of Salvagnini Panel Benders, with a large forming length of 1250mm, full servo drive, fast speed, and an average power consumption of only 3 kWh per hour.

The small size of the machine allows for the production of small parts, making it very cost-effective.
Lean panel benders

P2L-21 compact panel bender
The P2L-21 Compact panel bender (Fig.2) is the main machine used in the commercial kitchen industry, with a forming length of 2180mm.

The new generation P2L adopts servo motor direct drive, which can meet most of the processing requirements of panel products, covering an area of 6m×3m. The cylinder hybrid drive ensures the long-term stability of the equipment and reduces the maintenance workload, with an average power consumption as low as 5 kWh per hour.

P4-2116 HPT standard panel bender
The P4-2116 HPT is a standard panel bender with semi-automatic loading and unloading (Figure 3), which can be used during machine production. The loading and unloading operations can be carried out without interrupting production, resulting in a significant increase in machine availability.

As a standard panel bender, the P4 can be loaded with additional options to expand production capacity, making it the ideal machine for several major refrigerator manufacturers.

standart panel bender
standart panel bender

S4+P4 flexible manufacturing system
S4+P4 FMS can accommodate the production of more variety and smaller quantities of products that are not yet available.

What is a panel bender?

Previously, panel forming was done on dedicated production lines or manually operated pressure-bending machines. Panel benders have natural advantages over press brake machines for panel processing, including labor-saving and speed, as well as good repeatability and consistency of the workpiece.

panel bender legend

With the arrival of the Salvagnini panel bender, sheet metal forming has entered the era of complete automation for the first time.

There are three main types of conventional sheet metal bending and forming:

  • manual bending
  • semi-automatic bending
  • robot cell bending

However, despite the increasing level of automation, the efficiency bottleneck has not been eliminated.

In a panel bender, there is no need to change the die, the working stroke is short, the feeding is fast, and only one operator is needed to “put in” and “take out” the sheet.

A single machine can smoothly complete the positioning of the sheet in a single pass for four-sided bending… order, efficiency, and intelligence can be so simple.

The combined efficiency of the panel bender is 3 to 4 times that of a manually operated bending machine.


Panel benders can meet all user bending needs with their lean, fast, and energy-efficient capabilities.

The highly intelligent operating control system enables efficient bending of different workpieces, making the panel bender a revolutionary alternative to traditional press bending machines.

However, due to the high one-time investment cost, it has not been widely adopted by the majority of sheet metal processing users.

Working principle of panel bender

The panel bender has a new design concept, which involves downward bending with the upper knife and upward bending with the lower knife, with no limit on the number of bending times.

Bending forces are distributed transversely and generated by oscillating components, namely the bending knives.

The binding reaction force is generated by two components that are strongly locked to the sheet.

Downward bending (negative bending)

Negative bending

Upward bending (positive bending)

Positive bending

The bending length can be adjusted automatically, making it easy to realize unmanned production, which is shown schematically in Figure 8.

Panel bending diagram


Panel benders structure

Panel bender structure

1. Universal tooling and bending knife

The panel bender uses a universal, adjustable tooling with upper and lower bending knives, eliminating the need for a large number of bending tools based on the shape and size of the workpiece. This significantly reduces the cost and manufacturing time of molds and tools, as well as the preparation time of upper and lower molds and tools.

It also reduces the mold and tool stock, which facilitates production management. Furthermore, the absence of the need to design and manufacture special molds and tools for each product reduces the development cycle of new products, improving the competitiveness of enterprises in today’s increasingly competitive market.

2Fast and efficient automatic mold adjustment systems

When folding box-shaped parts, you need to adjust the length of the mold according to the length of the inner edge of the workpiece. There are three methods of adjustment.

The first one is manual adjustment and takes 3 minutes.

The second type is semi-automatic adjustment and takes 90 seconds.

The third type is Automatic Adjustment (ALA), which coincides with the other work steps, so no adjustment time is required.

3A simple and logical method of 1-time positioning

Before bending, positioning is carried out by the two cutting corners of the sheet instead of the edges of the sheet, which completely avoids the positioning error caused by the shearing of the sheet and improves positioning accuracy.

The sheet only needs to be positioned once in the process of panel bending, avoiding the cumulative error caused by repeated positioning of the sheet.

This greatly improves the final accuracy of the finished product.

4High precision and multifunctional robots

The manipulator can move the sheet forward and backward, as well as make discontinuous rotations of 90°, 180°, or 270° during multilateral bending. When the user needs a special angle of rotation, it can also be equipped with a CNC rotary device.

As shown in Figure 3, the panel bender clamps the workpiece with a rotating manipulator, which then clamps the workpiece to the upper and lower presses of the sheet. Between the upper and lower bending knives, the upper and lower bending knives act on the part of the sheet to be bent, making the necessary movements to obtain the bend angle and radius of the arc required by the program.

When one side is bent, the robot automatically rotates the sheet 180° so that the opposite side is bent, followed by the other two sides. When all four sides of the sheet have been bent, the manipulator exits. The panel is released and can be removed by the operator.

If equipped with an automatic loading and unloading system, the panel bending machine can also automatically bend the sheet placed in the designated location, which is after punching and shearing. After the bending is completed, the workpieces will be automatically taken down and stacked neatly. This can realize the automation of the bending process, reduce the labor intensity of the workers, and also avoid the quality accidents that occur due to workers.

The accuracy of the bending parts largely depends on the movement of the manipulator. Therefore, the manipulator of the panel bender has a high degree of positioning accuracy to ensure the accuracy of the bending parts.

5Advanced CNC system

The CNC systems of panel benders are based on Windows NT, with a user-friendly interface and an intuitive, easy-to-use human-machine dialogue. They offer powerful simulation, intervention, and documentation functions, as well as self-diagnosis and remote service functions.

In addition to providing fault codes, they can also be displayed graphically. The remote service function allows software engineers to access the customer’s control system remotely and intervene, diagnose, or modify programs. In most cases, the system can be returned to normal operation, eliminating the need for a repair service visit, or basic normal operation can be maintained until a service technician arrives.

6Variety of configurations

To meet the requirements of different users and products, panel benders are available in a variety of models and configurations. For example:

a) They can be manually loaded or unloaded.

b) They can be equipped with an automatic loading and unloading system, allowing for unmanned operation.

c) They can be connected with the punching and shearing system, to become a punching, shearing, and folding integrated FMS (flexible manufacturing system).

7Advantages of the panel bender


(1) There is no need to change molds, upper and lower tools, which saves running costs, manufacturing costs, and management costs, and greatly improves production efficiency.

(2) Due to the advanced design structure and dynamic compensation of the bending knife, it has very good bending accuracy. Its angular accuracy is ±0.5°, and the parallelism of the two opposite sides after bending is ±0.1mm/m.

(3) Since its bending mechanism is different from other similar machines, it can perform bending processes that other bending centers cannot do. Therefore, it can greatly simplify and rationalize product structure. For example, a box-shaped part that originally required 8 plates to bend after welding can be made from 1 plate using P4 panel bender, thus reducing the weight of parts and processing time. It also reduces product design time, manufacturing costs, and improves product market competitiveness.

(4) It has the function of bending from the bottom to the top, which can avoid the indentation phenomenon that occurs when bending some workpieces with very high surface requirements (such as mirror stainless steel) and long lengths, and when the two ends are machined, greatly improving the appearance of the bent workpiece.

(5) In the machining process, the sheet feed and rotation are continuous and automatic, so its machining time is much shorter than other bending centers, especially for folding box-shaped parts, greatly improving efficiency.

(6) It has strong software functions for the automatic adjustment of the sheet compactor and the automatic generation of the bending program, thus reducing the preparation time considerably.

(7) It is extremely advantageous not only for small-batch production of many varieties but also for mass production of a single piece, and is suitable for production applications in sheet metal processing enterprises.

Pander bender features

Panel benders are characterized by the following:

(1) For companies whose parts require foam processing (such as refrigerators, rice steamers, etc.), the consistency of the parts provided eliminates the need to clean up leaks, resulting in significant improvements in processing efficiency and product quality.

(2) By using the corner-cut positioning method, it is possible to maintain the exact size of the exterior reference surface and ensure a high degree of consistency of the exterior part.

High accuracy can be maintained even if the sheet edge straightness deviates after unloading.

For workpieces with limited working envelopes that need to be refolded with a conventional bending machine, the size of the workpieces remains under control due to the exact outside dimensions.

Positioning methods

Fig.10 Comparison of positioning methods

(3) For thin stainless steel plates (0.8mm thickness or less), manual bending can result in inconsistent offset bending due to operators prioritizing efficiency and synchronization.

The panel bender does not require lifting the plate during the bending process for larger panels, which eliminates the issue of offset bending caused by the plate not being lifted into place.

Compared to a press brake machine, the panel bender greatly improves surface quality and production efficiency, with an average increase of over 40%.

(4) The highly flexible processing capabilities of the panel bender allow for small batch and multi-mix production.

The unique ABA technology of the panel bender enables quick press length adjustments, even during robot edge changes.

As a result, it only takes an extra 2 to 3 seconds to complete the process of folding the long edge first and then the short edge (short wrap long).

The panel bender is also capable of processing products that require frequent press length adjustments.

(5) The panel bender offers advanced technology to develop new products and can complete most processes that are not possible with a press brake machine.

Compared to conventional bending machines, the panel bender has a relatively powerful processing capacity.

For example, Figure 11 illustrates the contoured shape of a refrigerator door handle developed for a customer.

Two different shapes were designed for the customer to choose and evaluate.

Previously, the customer was producing a similar product on an assembly line with five press brake machines and no quality control.

By using the P4 panel bender, the product’s quality was controlled, and the processing time was reduced to one minute.

refrigerator door handle contouring

Figure 11 Refrigerator door handle contouring

(6) The panel bender offers a wide range of bending tools for customers to choose from, and it is recommended that the thin red circle type bending tool be used for thin plates in general.

The configuration of the panel bender can be targeted to meet specific professional requirements.

Bending tool selection

Figure 12 Bending tool selection

(7) Industries that heavily utilize “201” chrome manganese series stainless steel often encounter difficulties due to the material’s high hardness and bending rebound.

Panel benders with new material property compensation technology as a standard feature have significantly improved product processability and first-piece success rates.

(8) Panel benders are available in various configurations based on customer requirements and investment size.

Panel bender applications

The panel bender is suitable for producing professional kitchenware for the catering and food industry, as well as ovens, cooking systems, cleaning systems (such as dishwashers and glassware washers), refrigerators, instant freezers, refrigerator counters and freezers, stainless steel furniture, and air handling systems (such as extractor hoods and exhaust fans).

Additionally, it is suitable for bending electrical industry cabinets, elevators, and lifts.

Panel bender applications


Panel Bender vs. Press Brake

Simplification of bending processes

In , the handling of a panel often requires more than one person, and it becomes difficult for one person to handle a panel longer than 1500mm, as it moves during the bending process.

In the panel bender, the handling of the panel concerns only its loading on the working table, its rotation on the sides to bend, and the unloading of the final product.

The operator only needs to load the metal sheet to be bent and unload the final product.

In the case of an advanced panel bender, the operator only unloads the final product.

Furthermore, traditional bending systems require the operator to memorize the bend sequence to execute.

In the semi-automatic panel bender, the operator only needs to turn the panel into the position that the machine requires.

Traditional bending systems

Handling of a panel with the pess-brakes

Overturning of the panel on the ball table of a panel bender.

Overturning of the panel on the ball table of a panel-bender

Reduction of labor costs

Press brakes require skilled laborers with specific experience and the ability to follow and control the bending stages.

The panel bender can be operated by only one person without any specific skills: the machine automatically executes all the bending stages.

This can lead to reduced personnel costs (hiring unqualified personnel) and higher production flexibility (multiple people can use the machine).

Reduction of labor costs

Panel benders are suitable for the following product areas

For the stainless steel industry, the company manufactures or supplies the following types of products: ovens, cooking systems (stoves, grills, etc.), cleaning systems (dishwashers, cup washers, etc.), refrigerators, flash freezers, stainless steel furniture, air handling systems, electrical equipment and accessories, elevators, and more.

For other metal sheets, the company manufactures and supplies the following types of products: elevators, freight elevator products, painted cabinets, security doors, engineered doors (fireproof partitions, etc.), inside or outside covers, and more.

Who needs the panel bender?

  • Enterprises mainly engaged in the production of stainless steel products.
  • Product quality-oriented enterprises
  • The products are small-batch or custom-made.
  • Companies whose products are concentrated in the production and processing of press brake
  • Enterprises whose products have complex processing processes

Final Thoughts

Panel bender is an advanced and modern bending machine that completely separates the quality of the product from the skill level of the workers, ensuring the production of high-quality products.

At the same time, the panel bender greatly reduces the labor intensity of the workers. Additionally, it provides sub-engineers with new design ideas and has significant advantages for the development of new products, giving the enterprise a head start in the ever-changing product market.

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