Few machines in a modern spinning mill are as critical as the roving frame. Building a solid and reliable roving frame is not an easy task and yet again it is absolutely necessary for the spinner as this machine can feed, depending on the count being produced, thousands of spindles at the spinning frames.

Marzoli, the only European manufacturer of the full line of machines for spinning of short staple fibers with over 150 roving frames being sold every year worldwide, is the ideal referent for whoever wants to choose the best technology. Its FT6E and FT7E represent a state-of-the-art solution, yielding the best results for efficiency, reliability and quality. The article aims at presenting from a technical and technological point of view these machines.

The FT6E and FT7E are driven by independent drives for the drafting system, the flyers, the spindles and the bobbin rail. Every drive is coordinated by the central CPU which ensures perfect synchronization of all the movements involved in bobbin formation.

Marzoli roving frames can be equipped with a 3-over-3 or 4-over-4 top-of-the-class drafting system. There are two options for the cylinder diameters: the standard solution has a diameter of 32mm; however, in case there is a high percentage of short fibers in the processed material, cylinders with a diameter of 27mm can be used to reduce the gauge between nipping points. This guarantees a better control of short fibers during draft.

Marzoli drafting system can also rely on highly efficient cleaners for both top rollers and bottom drafting cylinders. For top rollers there are two options: rollers with rubber fins and revolving felt belts. For the bottom cylinders there are rubber scrapers. These solutions guarantee that at every turn both top rollers and bottom cylinders are always cleaned. This, along with the high quality of each and every component, entails the perfect control of fibers during draft and top quality of the roving.

As bobbins on modern roving frames are arranged in two rows, rovings can have different angles at the delivery of the drafting system and at the entrance of the flyers’ top. It has been argued that these different angles can entail differences in the spinning triangle at draft delivery and different tensions of the rovings thereby causing an uneven take up of twist and variations in roving count.

On Marzoli machines all rovings lay parallel to one another: they have the same angle at the delivery of the drafting system and at the flyers’ entrance for both the front row and the back row of bobbins.

The creel is equipped with hexagonal aluminum rollers to prevent false drafts, a very important aspect especially when working with combed slivers.

One of the most crucial aspects on modern roving frames is automation especially on doffing since doff is costly, frequent, has a quite-important negative influence on efficiency (especially on long roving frames) and, if done manually, can damage the roving bobbins.

Nowadays several options for automatic doffing are available. One of the simplest, most reliable and fastest, automatic doffing systems is the one that Marzoli has implemented, tested and refined in the last twenty years. With this solution in less than 3 minutes full bobbins are replaced with empty tubes and the machine is restarted. During the new doffing cycle, the full bobbins are forwarded to the transport system which carries the packages to the spinning frames.

About company:

Marzoli, a leading supplier of textile machinery and components for short-staple fiber processing. The company is located in Palazzolo S/O (Italy) where it has been developing and manufacturing its machinery since 1851.