Conceiving doctoring solutions from scratch for a new tissue production line undoubtedly offers greater freedom, allowing you to avoid pre-existing constraints and manage dimensions without particular restrictions. However, when the challenge becomes more complex, Oradoc’s technical department stands out: it is in rebuilding operations that it excels, finding effective solutions even in already structured spaces, optimizing overall dimensions without altering the existing line and integrating new technologies and improvements, even when the machine is already operational. A recent example of rebuilding saw the intervention of ORADOC for a multinational customer, which brought a significant improvement in the performance of the tissue machine in cut-off and creping position.
Specific technical solutions tailored for different production and process needs
Cut-off position
The existing old rigid blade holder installed on the cut-off doctoring system (image 1) was removed to make room for the OraSlick 20, the new concept of Oradoc’s rigid blade holder. The old holder was a rigid one that did not allow profiling and required a high stick out in order to guarantee the correct detachment of paper from the Yankee. The new OraSlick 20 supplied (image 2), made of stainless steel, is equipped with fixing holes and screws for profile adjustment and is supplied with 3 cartridges for stick-out adjustment according to the different blade heights that may be required. The open design ensures less accumulation of dust and dirt, as well as facilitating easier cleaning, avoiding problem of different balde stick-out between FS and BS, while the new cartridge makes changing the blade stick-out easier.
Creping position
The most significant rebuilding activities were focused on the creping position: in order to increase the opening capacity and the reliability of the creping doctor and therefore facilitate the extraction of the blade, the old torque arms were removed (image 3) and in their place two new pneumatic cylinders were installed, with two new adjustment brackets fixed to adapter plates welded directly onto the structure of the primary cantilever. In order to make room for the new OraCrepe pressure system and install the new OraCrepe 30 pressure plate (flexible blade holder with cartridge design), the previously installed OraCrepe 20 blade holder and the pressure tube with relative lateral clamps were removed. In its place, using the existing holes used to fix the steel plate that serves to contain the pressure tube, no longer needed, the metal sheet cover with the new pressure tube was installed and the new OraCrepe 30 blade holder was subsequently mounted.
The new pressure kit integrates the ELV (Edge Load Variation) system, used to independently manage the pressure (and consequently the blade load) on the edges of Yankee (out of paper sheet), compared to the central area. An electropneumatic control cabinet (for new pneumatic cylinders and ELCV system) was also supplied and integrated with existing one. As a result, the rebuilding not only improved the performance of the doctoring systems, but it also improved the safety and the overall runnability, allowing for a smoother production process.
Widespread business reach: thousands of Oradoc products are installed all over the world
Here below the results and feedbacks after four months from installation and startup:
- Considerable reduction of the problem of threading paper to the cut-off doctor, thanks to the new blade holder and its profiling capacity.
- Improved Yankee cleaning on the edges, thanks to the ELV system that allows independent loading on the edges.
- Operators particularly appreciated the easier creping blade change, thanks to the greater Yankee blade distance created by the pneumatic cylinders.
The success of this rebuilding project is the result of the long-standing collaboration and the trust this international player in paper production placed in Oradoc as a partner for doctoring and dewatering systems. Proud of this trust and daily committed to meet customers’ expectations, Oradoc is up for the next challenge!
