MRO Multi Roll Opener
History of the MRO
In the 1950ies Herbert Hergeth got a license from SRRL, Texas, to produce a multi roll opener. This machine was very narrow, 500 mm.
As it had multipoint suction, this choked and caused fires.
Herbert Hergeth modified the machine to a wider model and with only one suction point.
This machine performed well and was also part of the HERGETH cotton cleaning line.
Also in the non-wovens industry this machine was a success.
In 1981, Hubert Hergeth changed the belt feed, that often got damaged, to slide feed.
This type has often been copied and is mostly used in the non-woven industry today.
The production of big non-woven lines demanded higher production. The old design was not suitable for wider versions as the rolls had to be taken out to the side. Access for cleaning was not very good. The pick-up of the final roll needed enournmous air volume at wide frames. That was not only costly but it was also difficutl to accommodate these volumes in following machines.
Therefore, in 2016, Hubert Hergeth re-designed the machine with the following features:
- Except for the 200 mm feed roll, all cylinders have the same diameter. This allows less spare parts.
- The cylinders are identical to those of the Compact Card. So at 3000 mm frame width, the cylinders and bearings are the same and can be used in the card, too.
- The 400 mm diameter cylinders have an advantage over the previous small cylinders. At a given surface speed, the large diamter creates less centrifugal force so more fibers get lifted to the opening points, resulting in a higher production.
- All drives in the machine, except for the opening roll of the reserve tower, are driven by frequency inverters, so the speed can be adjusted.
- In the old design, the rolls had to be taken out by the side, which was difficult and is impossible at 3000 mm working width. At this width, it was also impossible to get access to the opening rollers for cleaning.
Our aim was that customers could roll off the clylincers on a fork lift and insert the rolls with a fork lift. For cleaning, there should be plenty of space and also the reserve tower should be accessible. We did not want to take the structure holding the cylinders apart, so all the settings could be kept. We also did not want to disconnect the suction tube.
These targets were achieved by placing the reserve tower above the opening roll structure.By this, only the slide has to be wheeled away to give full access to the opening rolls. The MRO rolls stay in place and all the settings can be kept. When wheeling way the slide, also the opening section of the reserve tower is accessible. As there is unlimited space, the rolls can be changed with the help of a fork lift. To roll the cylinders out, a bracket arm is fixed on both sides and the cylinder can be rolled out without touching the setting of the bearing block.
- Old designs either had propeller sealings and/ or needed wooden side plates that restricted the active opening area and someitmes failed. The new design uses our modern h-type sealing like int he Compact Card. This results in a good sealing even at high surface speeds and can easily be changed without removing the cylinder.
- A special design of the suction and special wire result in a reliable suction at low energy consumption.
- The MRO is successfully used to eliminate hard pieces from fibers. Especially fused fibers and fibers forming plastic blocks are elininated. These particles cannot be detected by optical foreign matter detectors as they are the same material and colour like the fibers. Also cyclones only occasionally get these pieces. The special arrangement of the rolls and the clampless opening kicks the hard pieces back to the slide. /li>
- Big pieces are detected by a sound sensor. The feeding is then stopped, a flap opens and the big piece is eliminated. After that, the feeding starts again. Small pieces drop through a slot. (optional)
- All eliminated pieces are automatically pushed to the side of the machine where they can be picked up or sucked away. The elimination feature is an extra (optional).