Fiber-optic extrusion line

4-Creels, 96 unwinders, for fiber-optic extrusion line made in Spain – Catalonia

The line assembles 96 single strands of optical fiber and drive them into a single extrusion line to produce a very particular type of optical fiber cable.

Intech realized:

• the design of electrical and control part
• the connection with the pre-existing line
• the commissioning
• verification of performance with live wire

The unwinders must continuously and reliably exchange information with the pre-existing extrusion line.

Each single unwinder is a small semi-machine, with its own operating logic that regulates the position of a dancer which has the particularity of having little accumulation and very light load, and therefore it is critical in the regulation.

Each group of 6 unwinders is controlled by a unique activation / deactivation from the line, as needed by the Customer, as well as each creel (which groups 24 unwinders). This allows the operator to quickly configure the line, which can be used with flexibility in the most diverse configurations (e.g. 24 reels, 48, 96, or any other combination) and quickly change a process in order to reduce tooling times.

The pre-existing line also controls the general safety of the system, and the use of a safety CPU has been specifically chosen for a lean and reliable management of the safety signals to each individual unwinder.

The use of a communication field bus that supports safety protocol made it possible to reduce the wiring and therefore speed up the installation of the system. But above all it increases the overall reliability of the system, reducing the connection points and therefore the possibilities of a hardware fault.

The control of the dancer signals, and the logic of activation, takes place locally, thus relieving the CPUs of calculations, making the reaction of the dancers quick and effective. Upon activation, the dancer smoothly moves to the chosen working point, thus avoiding to load the optical fiber of any abnormal stretch or tension.

Each dancer has a fiber break recognition system, setting off an alarm which is communicated to the main line and then show, indicating which unwinder has lost its fiber, to the operator, who will choose the appropriate reaction (e.g. stop the line or continue to produce with product derating).

The unwinders can work with a rather wide range of pull, from a few tens of grams to several hundred, thanks to a precise and low-friction realization of all the rotating axes involved. The unwinders can work up to over 1000 m/’ (55 ft/”), each individual reel can be started and accelerated to production speed in a matter of seconds, thanks to a particular management of the PID that controls the dancers.

Our experience in the design and construction of similar machines has allowed a rapid and effective testing and commissioning, with satisfaction of the final Customer.

The project phase of the project involved 3 months of work.

The commissioning process of the plant that we took care of in all the details lasted 1 month, providing the customer with a tested and compliant system matching and surpassing production needs.