As one of the most widely used tube forming processes, tube rolling allows for high production rates while also providing enhanced strength-to-weight properties.
Some benefits of tube rolling include high part-to-part consistency and good surface finish. Able to produce a broad range of part shapes, such as cylindrical, oval, rectangular, conical and square, tube rolling is used in diverse industries and products including: sports and recreation, for fishing rods, golf shafts, tennis racquets and ski poles; electronics, for antennas and other consumer applications; industrial manufacturing, for heating elements and machine components; and marine and naval defense, for launcher tubes, telescopes and masts.
Tube rolling is often used in custom tube fabricating, since it offers the ability to place fibers either along or around the part with knowledge of the end application. Able to be performed using various materials such as stainless steel, aluminum, titanium, magnesium and brass, tube rolling can fabricate both large and small diameter tubes with low tooling costs due to the use of affordable and durable mandrels, and the versatility of tube cutting.
There are many different tube rolling techniques, which are most commonly undertaken using a tube rolling mill. A tube rolling mill can either refer to a factory or a machine; however, in either technique, the method typically remains the same. To begin the process, patterns, or flags, are cut out from materials such as epoxy pre-impregnated carbon, aramid cloth or glass, and then rolled around a mandrel, which is typically made from steel or some other type of metal alloy.
It is essential that a very tight roll is achieved, so that air is not trapped and the fiber is properly aligned. Before the tube can be heat cured, it must be pressure-wrapped with heat-shrinkable plastic film or sleeve. Referred to as debaulking, the wrapping increases the compaction of the part. Now able to be heat-cured, the material-wrapped mandrel is placed within an air-circulated oven or furnace at high temperatures.
During heat curing, the outer wrapping functions to squeeze air out of the ends of the wrapped material through shrinkage. When the heat curing is finished, the mandrel can be removed, creating a hollow, tubular part with very thin walls. Typical rolled tube diameters range from .76 – 609 mm (.030 – 24 in.), and can reach maximum lengths of about 7.3 m (24 ft.).