Roll forming is a metal forming process used to produce long sections of sheet metal. A roll forming machine incrementally forms the sheet metal through a series of rolling stations until the desired cross-section profile is achieved. Roll formed parts have a wide range of applications across industries like construction, automotive, appliances, and more.
This comprehensive guide will discuss the various components and parts that make up a roll forming machine. We will also overview the working principles, types of roll forming machines, major suppliers, applications, advantages, and limitations.
Overview of Roll Forming Machine Parts
A roll forming machine consists of a series of stations each with a set of rolls that progressively form the sheet metal as it passes through the machine. The major components and parts of a roll forming system are:
|Uncoiler||Feeds the flat sheet metal coil into the roll forming machine|
|Feeder||Controls the feeding of material into the roll forming section|
|Roll forming stations||A series of stations with rolls that bend and form the material into desired profile|
|Cutoff||Cuts the formed profile to desired lengths|
|Stacker||Stacks the cut parts for easy handling|
|Controls||Computerized controls to set and monitor process parameters|
|Drives||Provides power transmission to the rolls and material feed|
|Frame||Houses the roll stations and other components|
These main sections consist of numerous custom machined parts that make up the roll forming system. The key components in each section are:
|Coil mandrel||Expandable shaft on which coil is loaded|
|decoiler arms||Supports and guides the sheet into the machine|
|Leveler||Corrects coil set and initial deformation|
|Feed roll||Drives the metal sheet into the machine|
|pinch roll||Applies pressure to grip and feed the sheet|
|Sheet guides||Maintains sheet alignment|
|Coil car||Allows loading and unloading of coils|
Forming Section Parts
|Forming rolls||Progressively bend the sheet to desired profile|
|Housings||Supports the forming rolls|
|Roll shafts||Drive the forming rolls|
|Gearboxes||Transmit power to the roll shafts|
|Bearings||Enable low friction rotation of roll shafts|
|Roll spacers||Set roll spacing and material opening|
Cutoff Section Parts
|Shear blade||Cuts the formed profile|
|Hold down||Clamps the part for clean shear|
|Conveyor||Moves cut parts away|
|Guards and covers||Ensures safety by covering moving parts|
|Sensors||Monitors machine operation|
|Hydraulic system||Provides actuation for machine sections|
|Lubrication system||Applies lubricant to reduce wear|
The exact configuration of parts varies across different types and sizes of roll forming machines. But the core components outlined here form the backbone of any standard roll forming line.
Working Principle of Roll Forming Machines
The working principle of roll forming machines is quite straightforward. Essentially the process incrementally forms the sheet metal by bending it through a series of stations until the final cross-section is achieved.
Here are the key steps:
- Sheet metal coil is loaded on the uncoiler mandrel.
- The decoiler feeds the flat sheet into the roll forming section.
- The sheet passes through a series of rolling stations each with a set of rolls.
- At each station, the rolls make contact with the sheet causing plastic deformation.
- The incremental bending action gradually forms the material into desired profile.
- Cutoff shears the completed parts to length which are collected on a conveyor or stacker.
- The scrap skeleton is recycled back into the process.
The roll forming action relies on the principles of bending metal plastically beyond its yield point. As the sheet travels through the machine, the transverse rolls induce bending stress while the longitudinal rolls control material flow between stations.
The key variables that determine the forming action include:
- Roll geometry
- Vertical roll spacing
- Horizontal roll spacing
- Material thickness
- Material properties
- Inter-station spacing
- Roll rotation speed
- Material feed rate
By optimizing these parameters, roll forming machines can produce accurate, high-quality profiles continuously and efficiently. The modular forming stations can be flexibly configured to produce a wide range of profiles.
Major Types of Roll Forming Machines
Roll forming machines can be categorized based on chassis design, degree of automation, and direction of material flow. The main types of roll formers are:
Based on Chassis
|C-frame||Open center design allows easy roll changing|
|O-frame||Fully enclosed design for safety|
|U-frame||Good rigidity suited for heavy profiles|
|Multi-radius||Specialized for complex curved profiles|
Based on Automation
|Manual||Basic models with manual controls|
|Semi-automatic||Automated deformation with manual material handling|
|Fully automatic||Complete in-line automation|
|Customized||Tailored solutions for specific applications|
Based on Material Flow
|Horizontal||Horizontal material flow suitable for long parts|
|Vertical||Compact footprint for space savings|
|Inclined||Adjustable installation angle|
By selecting suitable roll former types based on production needs, optimal machines can be implemented for each application.
Major Roll Forming Machine Manufacturers
There are a number of leading global manufacturers that supply roll forming equipment and machinery. Some of the major players are:
|Formtek||Complete range of C-frame and O-frame roll formers|
|Electro-Mec||USA based leading supplier since 1959|
|Bradbury Group||Full portfolio of roll forming solutions|
|Dimeco||Heavy-duty roll forming machines up to 10000 kN|
|Samco Machinery||Taiwanese manufacturer of economical roll formers|
|Shanghai Rollforming||Chinese manufacturer exporting worldwide|
|T&H Lemont||Specializes in tube and pipe roll forming|
|Metform||Australian manufacturer focused on metal forming|
|Ensalco||India based manufacturer exporting globally|
These companies offer standard as well as customized roll forming equipment to suit different production needs across industries.
Applications of Roll Formed Parts
Due to its continuous, efficient, and versatile forming capabilities, roll forming is used to mass produce a wide array of parts and profiles.
Some of the most common applications are:
|Construction||Roofing panels, door frames, studs, cladding|
|Automotive||Window frames, railings, anti-intrusion bars|
|Appliances||Panels, housings, door handles, frames|
|Furniture||Racks, storage units, shelves, frames|
|Infrastructure||Highway crash barriers, drainage profiles, utility poles|
|Packaging||Racks, pallets, trays, totes|
Nearly any open profile section that requires continuous production can be efficiently roll formed to save time and costs compared to other processes like fabrication or casting.
Advantages of Roll Forming
Roll forming provides several benefits that make it advantageous for high productivity forming of metal profiles:
|Lead time||Shorter time from design to production|
|Efficiency||High material usage and line speed|
|Flexibility||Quick roll changeover between profiles|
|Quality||Excellent dimensional accuracy and surface finish|
|Automation||Suitable for automated mass production|
|Versatility||Wide range of materials and thicknesses can be formed|
|Cost||Lower initial and operating costs|
Key factors like minimal material waste, low tooling costs, and reduced finishing result in lower overall part costs compared to other methods.
Limitations of Roll Forming Process
Despite its advantages, roll forming also has certain limitations:
|Profile complexity||Cannot produce highly complex shapes|
|Size restrictions||Limited to relatively narrow width and radii|
|Strength||Lower strength than wrought or forged parts|
|Holes||Cannot pierce holes along the profile length|
|Batch size||Suited for long production runs, not small batches|
|Material type||Only ductile metals like steel alloys can be roll formed|
For some applications that require complex 3D profiles, tight tolerances, or short production runs – other processes like stamping, fabrication, or casting may be better suited.
Roll Forming Machine Pricing
Roll forming equipment represents a major capital investment for a manufacturing facility. Prices vary substantially based on factors like:
|Factor||Impact on Price|
|Line speed||Faster machines cost more|
|Degree of automation||Manual models are least expensive|
|Type of material||Machines for thicker/harder metals cost more|
|Line length||Longer lines with more stations cost more|
|Brand||Premium brands command higher pricing|
|Customization||Standard machines cheaper than custom machines|
Typical price ranges for new roll forming equipment are:
|Machine Rating||Price Range|
|Light-duty||$50,000 – $150,000|
|Medium-duty||$150,000 – $500,000|
|Heavy-duty||$500,000 – $2,000,000|
Purchasing used equipment can significantly reduce investment costs. But productivity may be lower on older machines.
Choosing a Roll Forming Machine Manufacturer
When investing in roll forming equipment, choosing the right supplier is critical. Here are key factors to consider:
|Technology||Advanced 3D modeling, precision machining, controls|
|Experience||Proven track record, years in business|
|Capability||Range of machine sizes offered|
|Customization||Ability to modify for special needs|
|Production capacity||Adequate to meet demand|
|Service||Installation support, training provided|
|Pricing||Competitive pricing commensurate with features|
|Lead time||Ability to deliver within schedule|
|Certification||ISO certified quality management system|
|Support||Responsiveness for problem resolution|
Reviews from industry peers, site visits, and discussions with suppliers can help assess these parameters to make the optimal machine selection.
Roll Forming Machine Installation
Proper installation is vital for smooth functioning of roll forming systems. Here are key considerations:
|Site preparation||Level concrete foundation, space for coils/conveyors|
|Lifting equipment||Crane, forklift to position machine sections|
|Assembly||Bolt machine frames, addguards, covers|
|Alignment||Precision alignment of roll shafts and stations|
|Calibration||Set and test all sensor switches, controls|
|Trial runs||Confirm forming quality before production|
|Operator training||Review operating procedures, safety|
Vendors usually provide supervision during installation. But in-house personnel should participate to understand the process and equipment details.
Roll Forming Machine Operation
Efficient operation of roll formers requires training and adherence to set procedures for:
|Coil loading||Use appropriate mandrel and loading method|
|Threading||Feed sheet through machine gradually|
|Parameter setting||Enter recipe values for feed rate, cut length etc|
|Starting||Run machine at slow speed to confirm forming|
|Monitoring||Observe process for any issues, sensors|
|Speed adjustment||Ramp up to required production speed|
|Quality checks||Take measurements, verify part accuracy|
|Shutdown||Stop feeds, allow machine to clear stock|
|Safety||Follow safe operating practices at all times|
Operators should have full knowledge of machine controls and emergency stop procedures.
Maintenance of Roll Forming Machines
A comprehensive maintenance program is essential for peak performance of roll formers. Key aspects include:
|Inspections||Check roll wear, backlash, loose parts daily|
|Lubrication||Grease bearings, gears, per schedule|
|Line clearance||Remove scrap buildup, dust, dirt often|
|Roll change||Schedule roll sets change as per tonnage produced|
|Drive service||Inspect chains, sprockets, couplings periodically|
|Hydraulics||Check fluid level, leaks, cylinder seals|
|Electricals||Inspect wires, controls, sensors periodically|
|Records||Document all maintenance activities|
Roll replacement is a major activity to restore profiling accuracy once wear exceeds tolerances.
How to Choose Between Roll Forming and Other Metal Forming Processes
Roll forming provides unique advantages for high volume production of metal parts. But for some applications, other processes may be more suitable depending on factors like:
|Comparison Factor||Roll Forming||Stamping||Extrusion|
|Part shape||Open profiles||Complex 2D shapes||Simple solid profiles|
|Production volume||High||Medium to high||High|
|Tooling cost||Medium||Very high||Medium|
|Dimensional accuracy||High||Very high||Medium|
Understanding application requirements and comparing process capabilities is necessary to select the optimal method. Roll forming, stamping, and extrusion complement each other for wide-ranging metal fabrication needs.
Q: What types of materials can be roll formed?
Most ductile metals like low carbon steel, stainless steel, and aluminum alloys can be roll formed. With sufficient power heavier sections of high strength steels, copper, and brass are also possible.
Q: What are common roll formed profile shapes?
C-sections, Z-sections, channels, square tubes, roofing panels, angle sections are among the most popular roll formed shapes. Special profiles like curved panels, railings, door frames are also possible.
Q: How are holes and notches incorporated in roll formed parts?
Holes and notches perpendicular to the length can be punched in a separate press station before or after roll forming. Slots and holes along the length require post operations like milling.
Q: What thickness range can sheet metal be roll formed?
Roll forming is highly effective for sheet thickness between 0.3 mm to about 3 mm. Sections up to 8 mm thickness can be formed with heavy-duty machines.
Q: What affects the line speed of roll forming?
Machine power, material thickness, profiling complexity, number of stations, and desired quality determine maximum line speed. Speeds of 15 m/min to 200 m/min are typical.
Q: What defects can occur in roll formed parts?
Twisting, bowing, flaring, and longitudinal curling are common defects due to non-optimized process parameters or worn tooling.
Q: What safety is required for roll forming operations?
All moving components must be fully guarded. Emergency stops, pull cords along length are necessary. Personnel should wear protective gear and stay clear during running.
Q: How to calculate cost savings with roll forming versus fabrication?
Roll forming can provide 20-50% savings in material, labor, and energy costs compared to fabrication of equivalent profiles. But design and tooling costs may be higher.
Roll forming enables efficient, precision production of metal profiles vital for construction, automotive, and other industries. The modular design using specialized machined components makes the process highly flexible and scalable. By understanding key roll forming machine parts, working principle, types, applications, and operational best practices, manufacturers can gain maximum value from this versatile metal forming technology.