BENDING WITH BALL MANDREL AND WIPER DIE

When the radius of the bend is smaller and/or the wall is thinner, it becomes necessary to use a

ball mandrel and wiper die. The wiper die is used to prevent wrinkles. The ball mandrel performs like a plug mandrel. The balls are used to keep the tube from collapsing after it leaves the mandrel shank.

Bending issues are enlarged when making tight bends or with thin wall tubing. It becomes more difficult to retain the material during compression.

The pressure is so intense the material is squeezed back past tangent and buckles. This area must be supported so that the material will compress rather than buckle; this is the prime purpose of the wiper die. Note, the wiper die cannot flatten wrinkles after they are formed; it can only prevent them.

Bending thin wall tubing - requirements for the bending of thin wall tubing with tight radius bends of centerline radius equaling the tube outside diameter have become more common in recent years.

To increase the problem, new alloys have been developed that are extremely difficult to bend. The proper bending machine, good tooling, and a trained operator can make all the difference.

To facilitate this type of tube bending, the material to be bent should receive special consideration. To help maintain the consistency of the tubing dimensions and characteristics, the entire material required for a given job should be acquired from one supplier, preferably even from the same lot or heat number. Premium-priced close-tolerance tubing should be considered. It often saves many more times its added cost. It may be necessary on occasion to size certain tubing before bending.

There are many pipe bending machines but only a few are capable of thin wall, 1 x D bending.

Even those machines best suited for this special bending must be in excellent condition and of a size large enough to assure rigidity. The machine must be capable of retracting and advancing the mandrel with the clamp and pressure dies closed. A hydraulically actuated pressure die is desirable. One feature of this system is that it provides identical pressure on the tube regardless of wall variation.

A pressure die boost counteracts the drag of the pressure die, mandrel and wiper die. It pushes the tube into the bending area, preventing excessive wall thin out.

Without a pressure die boost, the thinning that normally can be expected is about three quarters of the elongation of the outer wall. Companies specialized in steel bending automation for a broad array of fabricated products, includes CNC tube benders, tube measuring equipment and complete cellular integrated systems.

BENDING TUBE

A bend die, clamp die, and pressure die are the minimum essentials for tube bending. The bend die helps to prevent the tube from flattening and forms a given radius of bend.

The clamp die holds the tube in position while bending. The pressure die forces the tube into the bend die.

Springback is excessive when a mandrel is not used. This should be considered when selecting a bend die. Springback is the term used to describe the tendency of metal that has been formed to return to its original shape. Springback will cause the tube to unbend from two to ten degrees depending on the radius of bend, and may increase the bend radius of the tube. The smaller the radiuses of bend the smaller the springback.

The tube may kink or buckle, this may be due to hard material which will not compress on the inside radius of the bend. The material, not being able to compress, pushes in toward the centerline of the tube. This condition can be corrected (provided the tube is not too hard) by proper set up of the tooling. A plug mandrel is indicated if the tube buckles and is still within the wall factor and the diameter of the bend.

The purpose of a plug mandrel is to prevent the tube from flattening and to bend without wrinkles or kinks. The mandrel is held in a fixed position while the tube is pulled over it. The tube stretching process is localized on the outer radius of the bend and the material is work hardened to retain its shape and not flatten. The material stretching is done on the forward tip of the mandrel. This force, acting on the mandrel tip, supports the inner radius of the bend, holding it firmly into the bend die groove. CNC bender is used on CNC benders from 0.25" inch to 6" inch tube bending machines.

The pressure die should be adjusted for a light pressure against the tube. The purpose of the pressure die is to keep the tube against the bend die through the duration of bending. The pressure die also keeps the mandrel from bending and maintains a straight tube between tangent points of bends (the portion of ubing left on the mandrel after steel bending). The location of the mandrel affects the amount of springback. The mandrel in a forward position (toward tangent) will stretch the material on the outside of the bend more than is necessary. This increases the length of material on the outside beyond that which is required to make a bend. When the bent tube is removed from the bend die, it will conform to the die and there will be little or no springback.

TUBING BENDERS

Tubing benders come in many sizes, for use in everything from heavy construction to auto building to home landscaping. They range from a 16-ton hydraulic pipe bender to a handheld bender for small-gauge copper and aluminum tubing. All of them, however, use one of four basic methods. Ram bending is the cheapest and easiest method. Tube benders are restrained at two ends and a ram deforms the pipe in the middle. This is suitable for light gauge tubing only. Rotary draw bending is the most commonly used method, and maintains the diameter of the pipe without deformation. In this method, the tube is drawn through a stationary counter-bending die onto a forming die of a specified radius. These tube bending machines are used in the formation of exhaust pipes, process pipes, and any aluminum or stainless steel application where interior deformation can't be tolerated. Bending is similar to rotary draw bending, except that the interior of the tube is supported by a flexible mandrel. The mandrel bends with the tube, ensuring that the interior diameter is not deformed. Ring roll bender is used for bending pipes and tubes with a large diameter. There are three rollers, two on the bottom and one on the top. As the pipe is rolled through, the top roller exerts a downward pressure, bending the pipe. The pressure of the top roller can be adjusted manually or hydraulically, and either two or all three rollers can be powered. This method is used to make drum barrels, awnings, and other circular shapes.

For a tube bending, two things happen to metal. The outside wall is reduced in thickness due to the stretching of the material and the inside wall becomes thicker due to the compressing of the material. The material actually is formed approximately about the centerline of the tube. The material that forms the outside of the bend has further to travel and therefore is stretched; the inside of the bend has less distance to travel and is compressed.

When the ratio of the tube diameter to wall thickness is small enough, the tube can be bent on a relatively small radius. Excessive flattening or wrinkling of the bend should not occur. The outside and inside of the bend tend to pull towards the centerline of the tube. Two factors that help prevent this from happening are a grooved bend die, which supports the tube along the centerline and the natural strength of the tube.

Tube and pipe rollers

The tube and pipe roller or roll bender machines consists of manual or electronic driven single pinch ring roller machines (noting some have a hydraulic top roll with DRO) and hydraulic driven double pinch models with two hydraulic bottom rolls. The company has a very diverse line of angle roll bender machines to bend tube, pipe, angle iron, solids, squares, and much more.

The manual pipe bender machines consists of two manually driven ring roll benders for bending up to 1-1/4" tubing. These are great tube roller machines for the hobbyist or metal artist. The company also has several ring roller machines that are electronically driven with variable speed inverter drives. These ring roller machines have greater capacities and are easier to operate with two driven bottom rolls. These powered tube roller machines can bend vertically or horizontally for larger section angle bends. All versions in this category have manually adjusted top rolls and are considered single pinch style machines.

The single pinch angle rolls bender line with hydraulic down feed of the top roll has digital positioning readouts for repeatability. The tube benders in this category have three driven rolls for extra power. These roll bender machines are perfect for production fabrication settings where the fabricator is making hay hoops, spiral stair cases, and much more.

Finally the company offers two versions of double pinch angle rolls, hydraulically driven roll benders with hydraulic positioning of the two bottom rolls that are coupled to two separate digital readouts. These angle roll machines have three hydraulically driven rolls. We also have two angle bending machines that have hydraulically driven rolls, hydraulically positioning bottom roll, as well as hydraulically driven lateral guide rolls. These ring roller machines are for bigger section bending projects or for more structural applications. A double pinch bender allows the operator to pre-bend and post-bend the material saving the fabricator time and money. These roll bender machines are easy to use, cost effective, and built for decades of service.

Features:

· Bending capacity to 6″

· Bend any angle to 180° with independent material spring back compensation for each bend

· Bend to CLR as small as 2.5D

· Ideal for producing consistent quality bends in large diameter pipe, tube, squares, rectangular, solids and other profiles

· PLC touch screen control offers easy access to operating modes, programming, system diagnostics and multiple language capability

· Patented quick-change tooling system with multiple radii available

· Remote foot pedal for hands free operation

TOLEXPO – 15-18 November 2011

A partnership with the Midest and Maintenance Expo to create:

· a communication synergy promoting the sector

· a technological showcase bringing together subcontractors' and equipment manufacturers' know-how

The 4^th edition of TOLEXPO, the international show for sheet metal, coil, tube and section

equipment, organized by DBR Event will be held at Paris-Nord Villepinte Exhibition Centre from 15 to

18 November this year. As the economic recovery begins, Tolexpo confirms its position as an

industrial event firmly dedicated to the sector and confirms the success it has achieved, with both

exhibitors and visitors, since its creation in 2005.

6 months before the show opens, Tolexpo already has more than 200 exhibitors, among them both French leaders in the sector and the majority of foreign manufacturers, between them there is also Tauringroup which is a world leader in tube and pipe bending machines.

Almost 11,000 targeted visitors looking for new equipment will discover the products and technical innovations offered by suppliers at the show.

At Tolexpo, visitors will find solutions to all their needs, whether they are looking to renew or modernize their equipment, begin using new technology, improve their productivity, bring their businesses into line with standards and regulations, etc.

For the first time this year, in partnership with the Tolexpo show, Tôlerie magazine is organizing a

competition for students in the various areas which involve sheet metal working.

A Challenge which will bring students together: the Tol&Design Challenge has been created to put the spotlight on the expertise of young people who have chosen the various subjects which involve sheet metal working, and aims to promote these subjects and the production chain itself, by bringing students together to work on an industrial project.

It is also an opportunity for the students to present their expertise to industry professionals by

creating finished products - in this case a chair - using precise specifications.

An initial analysis of the applications shows that students are particularly committed to this project

which is closely connected with the world of work. Teamwork, together with the students' fabulous

motivation, gives them the opportunity to bring their apprenticeships to fruition by carrying a

project through from A to Z.

The organizers of Tolexpo, Midest, the global sub-contracting show and Maintenance Expo, the

maintenance solutions show, are continuing to work together in order to create communication

synergies and boost their industry sectors.

The major objective is to create a technological showcase which will bring the expertise of subcontractors together with that of production equipment manufacturers.

Further insights:

http://www.tolexpo.com

BATIMAT – 7-12 November 2011

BATIMAT is the essential meeting place for the French and international construction industry. Playing a central role in tackling the energy challenges facing buildings, BATIMAT is the place where the technical solutions emerge that will characterize sustainable construction and renovation projects. BATIMAT is a real springboard for manufacturers who want to launch their technological innovations and massively speeds up the rate at which new ideas and products are adopted, one of these is Tauringroup that offers top quality angle rolls and bending machine.

As well as its professional role, BATIMAT is also the place where the entire profession gets together in a pleasant atmosphere.

BATIMAT 2011 will serve as one of the shop windows for these developments by featuring innovations and model projects by architects and hosting conferences and events. It will enable professionals to find out about the products that will take centre stage tomorrow.

BATIMAT will also speed up progress. For example, another major theme of the 2011 show will be accessibility for persons with restricted mobility. On 1st January 2015, existing buildings that are open to the public and residential buildings will have to comply with the requirements of the new law on accessibility. BATIMAT will feature this theme through conferences, demonstration areas and round tables.

The 2011 show will be right at the heart of developments in the energy efficiency of buildings.

One of the objectives of the Grenelle de l’Environnement (the French environment initiative) is to spread the concept of the “Low Consumption Building” from 2012 onwards through the adoption of a new set of thermal regulations, the “RT2012”, which will replace the current 2005 thermal regulations.

These new regulations will come into force in the second half of 2011, will result in a major development in technical and architectural approaches on buildings. This development will bring an increase of innovative products and an increasing demand for training from professionals.

Editions des Halles presents a modular wood-home prototype. Located at the center of this 6-day event, this is the opportunity to follow-up on the wood industry's desire to answer the environmental preoccupations of construction.

With the support of France Bois Forêt (French Wood Promotion Fund)

The aim of the Zero Carbon Habitat is to prove that, today, one can build and live all while drastically reducing their carbon footprint.

In these times of urban densification and the desire to optimize real-estate resources, the Zero Carbon Habitat delivers simultaneously an economical and environmental answer, two dimensions that are often hard to conciliate.

Further insights:

http://www.batimat.com

BATIMAT – 7-12 November 2011

BATIMAT is the essential meeting place for the French and international construction industry. Playing a central role in tackling the energy challenges facing buildings, BATIMAT is the place where the technical solutions emerge that will characterize sustainable construction and renovation projects. BATIMAT is a real springboard for manufacturers who want to launch their technological innovations and massively speeds up the rate at which new ideas and products are adopted, one of these is Tauringroup that offers top quality angle rolls and bending machine.

As well as its professional role, BATIMAT is also the place where the entire profession gets together in a pleasant atmosphere.

BATIMAT 2011 will serve as one of the shop windows for these developments by featuring innovations and model projects by architects and hosting conferences and events. It will enable professionals to find out about the products that will take centre stage tomorrow.

BATIMAT will also speed up progress. For example, another major theme of the 2011 show will be accessibility for persons with restricted mobility. On 1st January 2015, existing buildings that are open to the public and residential buildings will have to comply with the requirements of the new law on accessibility. BATIMAT will feature this theme through conferences, demonstration areas and round tables.

The 2011 show will be right at the heart of developments in the energy efficiency of buildings.

One of the objectives of the Grenelle de l’Environnement (the French environment initiative) is to spread the concept of the “Low Consumption Building” from 2012 onwards through the adoption of a new set of thermal regulations, the “RT2012”, which will replace the current 2005 thermal regulations.

These new regulations will come into force in the second half of 2011, will result in a major development in technical and architectural approaches on buildings. This development will bring an increase of innovative products and an increasing demand for training from professionals.

Editions des Halles presents a modular wood-home prototype. Located at the center of this 6-day event, this is the opportunity to follow-up on the wood industry's desire to answer the environmental preoccupations of construction.

With the support of France Bois Forêt (French Wood Promotion Fund)

The aim of the Zero Carbon Habitat is to prove that, today, one can build and live all while drastically reducing their carbon footprint.

In these times of urban densification and the desire to optimize real-estate resources, the Zero Carbon Habitat delivers simultaneously an economical and environmental answer, two dimensions that are often hard to conciliate.

Further insights:

http://www.batimat.com