Chatter Marks Monitoring with BONETTI’s BONVIBES

Over the years we’ve helped numerous customers to improve their creping process taking comprehensive approach spanning from blades to doctoring equipment, them being both part of the current product portfolio. The main areas where Bonetti focused its efforts have been the sheet quality improvement, the increase of the overall efficiency of the tissue machine and the reduction of its operating costs. The approach is diversified and tailored made to the specific demands of the customer and Bonetti accomplished the task bringing to the industry new tools and new products. A good example is BONVIBES, the new Bonetti vibration monitoring system (Figure 1).

Doctoring the World

This new device helps the tissue manufacturer to monitor the development of the creping doctor vibrations during the blade life, thus allowing the blades change to be correctly programmed. This in turn significantly reduces the risk of chattering on the YD surface and better control of the coating distribution. The system consists of an accelerometer mounted on the nose of the doctor back at drive side (Figure 2 – Figure 3) and then connected by cable to a control unit. Signal is then carried via an ethernet or a USB cable to a regular personal computer. Unlike other similar systems, BONVIBES uses only one sensor to detect the vibration data from the creping system. Field tests have shown that the differences in measurement with two or three sensors are negligible. Having only one sensor in the working area guarantees more freedom of maneuver to the operators of the machine.

The display of the BONVIBES on the PC has two graphs and a numbering on the top left, all in continuous reading. The graph at the top (Figure 1) represents the amplitude of the vibration while the graph at the bottom shows the variation in time of the acceleration value that appears as a numerical value at the top left. The four windows at the top right of the display show the instantaneous measurement of the low, medium, maximum and overall frequency. In summary the system:

• Helps tissue manufacturers to monitor the development of vibrations to the creping system;
• Allows the correct management of the blade life;
• Provides valuable support to avoid chattering on the Yankee dryer.

Bonetti S.p.A. is also a worldwide recognized supplier for doctoring systems and blades. Our portfolio offers a complete range of creping, coating and cleaning blades, in various materials and sizes. Focusing on the creping process, BONETTI offers two different types of tip coated creping blades named MIZAR (Chrome Oxide) and SIRIUS (Chrome Carbide). Those two blades compared to traditional carbon steel blades guarantee an extended lifetime and greatly improve the softness of the tissue produced. MIZAR offers the longest possible lifetime, SIRIUS by sacrificing a small portion of lifetime, allows a smoother start-up. Both blades are delivering a higher bulk compared to traditional carbon steel blades and improve the softness of the tissue produced. When it comes to equipment, as one of the most established suppliers of doctors and creping equipment (Figure 4) Bonetti knows what are the needs of the market and is constantly working hard to find the right solution.

One good example is the double doctoring system (Figure 5 – Figure 6) for the suction press roll of tissue machines. This system’s primary target is the removal of as much water as possible from the roll surface and from the holes drilled on it, whether blind drilled or connected to a suction. Major advantages coming from the installation of this equipment are a higher dryness content after the press and a more uniform humidity profile entering the YD. This technology is best practice in some of the biggest tissue groups in the world.