How Does commercial appliances panel bender Work?

As is commonly known in the sheet metal fabrication industry, the bending operation typically represents a bottleneck in the production process. Panel bending technology can be useful in helping metal fabricators streamline this process while significantly increasing manufacturing capacity and velocity. The ROI for a panel bender can be quick when the application and annual usage for the part mix are a good match.

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How Does a Panel Bender Work?

To gain a better understanding of the technology, it is important to note that panel benders work on an entirely different principle than press brakes. The speed of a panel bender is based on how the technology works.

The part remains stationary while the bending tool forms flanges both up and down. The part then is rotated as the machine continues through the bending process for all sides, allowing for a very efficient bending process averaging four to five seconds per bend. Typically enclosure and flat panel parts are an excellent fit for panel benders. Large parts that are difficult to handle on a press brake can be especially good applications as well.

How Can Panel Bending Increase Bending Capacity and Speed?

It is generally agreed that the average setup time on a press brake is 15 to 30 minutes, which explains the push for automatic tool changeover systems that many press brake OEMs now offer. In fact, the setup time can be so excessive that fabricators will overproduce just to amortize the setup back into the production run. Unfortunately, the parts that are not needed right away can end up sitting around somewhere as inventory, work-in-process (WIP), or worse yet, get lost or thrown away by mistake.

Setup on a panel bender is much quicker because a panel bender can use common tooling to process a variety of part geometries and material thicknesses. The operator is not required to exchange tooling physically when going from one job to another. Setup for the next job simply involves sliding the clamping tools to the new positions as needed. This can be done manually, which takes about five minutes, or with an automatic tool changer, which further decreases the setup to about 90 seconds.

The reduction in setup time that a panel bender provides is advantageous for fabricators that wish to embrace the principles of lean manufacturing—making only what they need when they need it and reducing WIP.

Panel bending technology works according to the transfer line principle, so that parts are always moving ahead as different stations work simultaneously. By using a modular approach, fabricators can combine multiple bending units to reduce the bending cycle time further.

This method is especially useful for achieving a 1-1 ratio between the blanking and bending operations. Once a balanced ratio is achieved, the blanking and bending processes can be integrated into one complete line without one machine or process waiting on the other. The entire process can be further optimized by feeding the finished parts directly to the assembly area, eliminating additional handling and WIP.

How Can More Parts Geometries Be Processed?

As with all technologies, panel bending has some caveats to its advantages. Many fabricators get excited about adding this technology to their operation only to find they do not have the right mix of parts to keep such an efficient machine busy. In many cases, complex part geometries or narrow parts can be a misfit for panel bending if the machine cannot process these types of parts with the common tooling and manipulator concept that the machine design is based on.

The idea behind the multitool panel bender was inspired by relentless research on how to expand the capability so that more types of part geometries could be processed to completion without additional manual tooling changeover.

A console is incorporated into the multitool panel bender’s design so that it can accommodate multiple bending tools. This enables it to bend intricate part profiles that previously were not good candidates for panel bending. An additional manipulator device on the backside of the multitool panel bender allows fabricators to process narrow channel-type parts that had been considered a challenge for traditional panel bending.

The multitool panel bender works with mild steel sheet thicknesses from 0.020 to 0.118 in. and lengths up to 13 ft. for a single machine and up to 26 ft. with two machines in tandem. Additional features such as moving tools, visual inspection devices, grippers, and custom tools can be incorporated into the final system.

The multitool panel bender is designed to be simple to program, control, and maintain, all while powered using electric drives for low energy consumption.

How Can Panel Bending Streamline the Entire Process?

It is important to note that panel bending addresses not only the bending bottleneck but downstream operations as well. An analysis of the different processes in an average sheet metal fabrication shop shows that welding and assembly are by far the most expensive processes on the shop floor, with one of the main culprits being poor fit-up. How much time does the welding operator have to spend trying to make the part fit in the welding fixture rather than weld? How often does the assembly operator struggle to get the parts to fit together? This happens more often than not.

Panel benders can help streamline these downstream operations by producing parts with high flatness and accuracy. Superior flatness is achieved because unlike a press brake with dynamic crowning, minimal tonnage is placed across the bending line.

Accuracy improvements are attributable to how the part is referenced. It is referenced from a single datum point, eliminating what is known as tolerance error accumulation. When making multiple bends on a press brake, the operator often is required to gauge from previously bent flanges. This opens the opportunity for the tolerance error to accumulate, leaving the welding or assembly operator as the last line of defense to correct the problem. A quick overview of the welding and assembly departments is a good place to start when evaluating the bending process.

When Is a Panel Bender a Good Fit?

Panel benders are a good fit for large, boxy, flat, straight, and rectangular parts that are difficult to bend and handle by a single person using a press brake or when dealing with highly cosmetic parts.

Panel bending is commonly used to form:

• Appliances such as refrigerators

• Electrical appliances such as electric cabinets and lighting.

• HVAC equipment

• Construction components such as panels, doors, elevators, cable trays, platforms, and profiles.

• Metal furniture for commercial kitchens, offices, storage, and lockers

• Truck trailers

Panel bending is especially applicable for bending cosmetic, or appearance, parts. Supported by a brush table underneath, the bending tool’s interpolated movement in the X and Y axes maintains a single point of contact to the flange during the bending process, thereby significantly reducing scratching and marring.

Panel bending technology offers many benefits in modern sheet metal manufacturing. While panel benders do have some limitations in the types of parts they can process, they can be a most efficient bending method when the application fits.

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.

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.

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.

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)

Upward 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 bender’s 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.

2. Fast 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.

Further reading:
A quiz on bending sheet metal and plate

For more information, please visit commercial appliances panel bender.

3. A 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.

4. High 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.

5. Advanced 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.

6. Variety 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).

7. Advantages of the panel bender

Advantages:

(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.

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.

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.

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 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.

Handling of a panel with the pess-brakes

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).

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.

The company is the world’s best stainless steel panel bender supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.

Source: www.machinemfg.com