#Industry News
Robotic automation to optimize the production of tissue paper
The combination of an automatic rewinding machine and a Comau Racer 7 1.4 robot has allowed United Converting to provide an internationally important client with a faster and more efficient system for the industrial production of toilet paper rolls
United Converting, a system integrator and manufacturer of paper processing machinery based in Lucca, reached its objective by increasing the efficiency of the production process of paper rolls for an international supplier of products for the professional hygiene sector.
This was possible thanks to an automated system featuring a small-size articulated robot, namely a Comau Racer 7 1.4. The robot, through a fast handling application, is connected to a rewinding machine designed by United Converting for the large-scale production of toilet paper and kitchen towel rolls starting from simple paper reels.
Increasing the efficiency of a “special” production process
The United Converting system winds a thin layer of paper around a rigid core, forming logs of a predetermined length and diameter which are then processed depending on the final product to be made. With Comau Racer 7 1.4, the system integrator could fully automate every phase of the working cycle of the plant, consequently maximizing its speed and efficiency and simplifying its use at the same time.
As explained by Gianluca Giometti, Owner and Vice President of United Converting, “in order to increase the line efficiency for a factory located in Singapore, we combined our automated system, the S70 Industrial line, with an articulated Comau robot which could perform specific operations that were usually performed by hand.
Many years ago, the client had patented the production of a special tissue paper roll to be used exclusively on their devices. Therefore, unlike standard products, the rolls to be manufactured are composed of two internal half cores, which were previously hand made by an operator. As a result of the project, which was developed together with the client, these operations can now be controlled mechanically by our system and the support of a handling application executed by the Comau Racer 7 1.4 robot.”
Fast and precise handling
The working cycle of the plant developed and integrated by United Converting is divided into several phases. By means of a machine which unwinds the reels coming from the paper mill, the paper is prepared for processing. The paper required to make the rolls is then loaded onto a series of cylinders designed for the production of paper cores made of multiple strips. These are helically wound around a spindle, creating a single tube which is cut to measure by a servo-controlled cutter. The rolls are then loaded on special spindles which cut grooves inside the rolls. Essentially, the operation is performed by carbon tubes which carve a thin groove inside each paper roll.
“Racer 7 1.4, which is positioned at 45° above the other machine, quickly and accurately handles the spindles on which the paper roll is wound, then it loads them on the robot and takes them to the laminator”, further explained Gianluca Giometti. The laminator joins the layers of paper and starts winding the paper on the roll. The rolls are then subjected to gluing, to the cut of the log – which is performed by a mechanical cutter – and to all the final phases of processing needed to give the roll its final shape.
More efficient and easier to use
Before the complete automation of the system, performed by implementing Comau Racer 7 1.4, the mechanical work performed by the rewinding machine of United Converting was combined with the work of operators, who cut the groove by hand with a special tool with which they removed a small portion of the core.
“Racer 7 1.4 handles the spindle by means of a specific tool we designed, a small clamp mounted on the wrist which allows it to perform the mechanical operation required to cut the core. In this way, we went from needing three operators to work near the machine on multiple shifts, to a single operator who performs control operations over the production cycle, but can safely engage in other tasks at the same time.”
The result is a production with lower cycle times and simple programming steps used to manage the robot handling. “When the operations carried out by Racer 7 1.4 are not performed by hand, they are usually implemented by machine tools, but less efficiently and with more complex programming than with an articulated robot.”
The ideal robot: small yet powerful
Racer 7 1.4 is a compact and efficient articulated robot, the ideal robotic solution for reduced operating spaces and for handling, assembly, machine tending and packaging applications.
“We chose Comau Racer 7 1.4 because its technical and structural features – from its size to its payload – made it perfect for this particular application,” explained Gianluca Giometti. “The possibility to mount the robot at 45° above our machine also optimized the layout of the plant and the space needed for the entire process, making the client’s production cycle even more efficient.”
Designed by Comau to ensure a 7-kg payload (extendable up to 10 kg) with a limited excursion of axis 5 to handle extremely fast pick&place applications, Racer 7 1.4 is now the fastest robot in its category. It is characterized by a reduced but more rigid mechanical structure, which is useful to perform applications that require extreme precision. The small size of the machine and of the controller also allow minimum power consumption, together with the lower amount of power installed, in compliance with the principles of eComau Energy Management System. Moreover, the E-motion software is able to optimize its movements and make them more fluid, allowing the robot to achieve a cycle time reduction up to 25% compared to the robots of the previous generation.
