Coiling on drum coilers / uncoilers / recoiling line is required by specific types of extruded pipes or by special fields of application. In fact, basically the drum is a reel on which the pipe is coiled and it can be made of cardboard, wood, plastic, or iron. In general, the drum coil needs no strapping unless to lock the initial coupling and the end piece of the pipe, or to make intermediate fastenings.

There are applications in which the drum is necessary and/or recommended. For example, many installers who use optical fiber pipes prefer having a wooden drum rather than a coil wrapped with straps. In this way, unwinding at the construction site is simpler to manage. On the other hand, a coil without reel can become more complex to handle once the straps are cut.

DRUM COILERS / UNCOILERS / RECOILING LINE

In terms of costs, the drum falls under the additional coiling costs item. The very cost of the drum can range from a few euros to several hundred euros. Higher transport costs than those for returning the empty spool are to be considered. Last but not least are the maintenance costs since a reel undergoes a deterioration process both at the construction sites and in handling, which can make it unusable for subsequent coilings.

To meet the specific requirements of several manufacturers, FB Balzanelli has developed a series of drum coilers designed to optimize the production processes of the different types of pipes and their applications.

The technology of coiling/uncoiling on a drum called drum coilers / uncoilers / recoiling line applies to all productions in which pipes, due to processing requirements, have to be coiled immediately after extrusion and then be uncoiled to perform an additional process, and lastly be packaged in coils of the final length.

One characteristic of the uncoiler consists of its two tailstocks (two pins that go inside the drum and lift it so it can turn freely). It is a machine able to reach high speeds, up to 200-300 meters a minute, and is built with highly resistant structures since it is designed to uncoil reel that might weigh even several tonnes.

The uncoiler is synchronized with the coiler, which demands speed variations established by the different coiling phases to always provide maximum productivity without the pipe touching the ground, and becoming damaged. When changing the pipe guide from one reel to the other, and before cutting, the uncoiler decelerates for about 3-4 seconds, preventing the pipe from resting on the ground. After being coupled, the coiler sends a new signal with the instruction to re-establish the planned speed, in this way creating a perfectly synchronous movement between the two machines. The result is high-quality coils and optimized processing time.

Coiler/decoiler technology is crucial in production lines running for subcontracted work, where there is the need to print the logo of the different customers on the same product. In this way, a pipe ready for subsequent ink-jet printer marking and packaging in coils ready for the end market is coiled on drums and stored. Also companies that manufacture PEX pipes for the large-scale retail trade and do-it-yourself stores find the coiler/decoiler process useful. This pipe is extruded at a speed of about 60 meters a minute, but is sold in small coils 5 to 50 meters long. It is preferable to coil at high speed on drums and then uncoil the product and form coils in shorter lengths.

The drum coiler/uncoiler technology is necessary for products requiring intermediate processing steps, such as PEX pipe, or material ageing before being packaged in end coils, such as the polybutylene pipe. In this case, the product has to be stockpiled on drums and then undergo the processing and final packaging.

When coiling the extruded pipe, there may be moments when the coiler pauses while the extrusion process continues, such as when the pipe guide is transferred from one reel to the other. In this case, devices such as the accumulator or compensator are used. Their purpose is to prevent the pipe from touching or from accumulating too much of it on the ground.

The compensator is used on the recoiling lines or in production lines up to 20-30 meters a minute, where the few extra meters of pipe generated by the speed oscillations between extrusion and coiler must be compensated. It is indispensable for pipes that must not touch the ground and become damaged, such as the PEX tubing with EVOH.

The accumulator, on the other hand, is used in very fast productions, up to 150-200 meters a minute. In fact, several meters could be generated when transferring from one reel to the other, which would fall onto the ground with the risk of kinks and breakage that would damage the product or stop the line. The accumulator manages the excess meters in an orderly manner to return them during the recovery phase performed by the coiler at a higher speed. This solution is used, for example, in the production of dripper irrigation tubing.

Using an accumulator to meet any potential problems or coiler standstills is an improper, although widespread, use of this piece of equipment. It is, indeed, a conceptual error to think that it is possible to amass the pipe production on the accumulators while trying to rectify the causes of the interruption by hand. FB Balzanelli coilers are built to solve the problems without supervision, always and promptly, and the presence of redundancies such as the double reels or double strapping machines let the machine continue to operate in the case of faults on some components.