Page 34 - February-March-2017

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Few machines in a modern spinning cleaned. This, along with the high quality of each and
mill are as critical as the roving frame. every component, entails the perfect control of fibers
Building a solid and reliable roving during draft and top quality of the roving.
frame is not an easy task and yet
again it is absolutely necessary for the False twist area
spinner as this machine can feed, As bobbins on modern roving frames are arranged in
depending on the count being two rows, rovings can have different angles at the
produced, thousands of spindles at delivery of the drafting system and at the entrance of
the spinning frames. the flyers’ top. It has been argued that these different
angles can entail differences in the spinning triangle
Marzoli, the only European at draft delivery and different tensions of the rovings
manufacturer of the full line of thereby causing an uneven take up of twist and
machines for spinning of short staple variations in roving count.
fibers with over 150 roving frames
being sold every year worldwide, is On Marzoli machines all rovings lay parallel to one stems from the amortization of the cost of the head
the ideal referent for whoever wants to another: they have the same angle at the delivery of and rear stocks on a higher number of spindles per
choose the best technology. Its FT6E the drafting system and at the flyers’ entrance for machine. However, the higher the number of
and FT7E represent a state-of-the-art both the front row and the back row of bobbins. spindles, the smaller the benefit stemming from a
solution, yielding the best results for further increase in machine’s length.
efficiency, reliability and quality. The Individual sensors ensure that each and every roving with a diameter of up to 24” which allow to reduce Besides permitting an easy collection of the full
article aims at presenting from a break is properly detected and the machine securely Machines exceeding a certain number of spindles machine stops and increase its efficiency. bobbins, this solution allows an easy and cost
technical and technological point of stopped, even in case of roving overlap around the also entail higher costs for electronics and efficient upgrade of the machine to the
view these machines. cylinder/top roller. On the other hand, if dust passed drafting drive. Doffing fully-automatic version.
One of the most crucial aspects on modern roving
where motion is transmitted through toothed belts. In in front of the sensors the machine would not stop, it frames is automation especially on doffing since doff Energy efficiency
Drive system traditional machines spindles are moved by one would continue to run. Individual sensors also make Last but not least a higher number of spindles per is costly, frequent, has a quite-important negative To succeed in the highly competitive and globalized
motor which, through a long shaft, transmits motion suction not required. This, along with the IE3 motors machine causes a reduction in efficiency. The FT6E influence on efficiency (especially on long roving sector spinners must minimize production costs of
to bevel gears which drive pulleys that drive belts and an overall design meant to minimize energy (110mm gauge) can reach 224 spindles and frames) and, if done manually, can damage the whom energy consumption represents an important
which ultimately make spindles rotate. A group drive consumption, allows to save up to 4 Kwh. produce bobbins of 16” x 6”. The FT7E (130mm roving bobbins. component.
allows to substantially simplify this transmission gauge) has a spindlage up to 168 spindles and can
system. The drive comprises several motors, each produce packages of 16” x 7”. These numbers Nowadays several options for automatic doffing are Marzoli roving frames represent an outstanding
one driving a limited number of spindles. Each motor, represent the limit in terms of number of spindles and available. One of the simplest, most reliable and fastest, machine from the energy consumption point of view.
through a pulley, drives toothed belts which transmit dimensions of bobbins to maintain top efficiency automatic doffing systems is the one that Marzoli has This machine is the only one available on the market
motion directly to the spindles. Shafts, gear boxes standards. A higher number of spindles per machine implemented, tested and refined in the last twenty years. that does not need suction. In fact thanks to the
and bevel gears are eliminated. Therefore it is would not give an additional benefit to the spinner as With this solution in less than 3 minutes full bobbins individual sensors installed as standard any roving
possible to: the decrease in machine efficiency would not be are replaced with empty tubes and the machine is break can be promptly identified. No suction is
- reduce maintenance costs: fewer transmission counterbalanced by the reduction in the average cost restarted. During the new doffing cycle, the full required to capture the broken roving and make it
components are needed and lubrication is no longer per spindle. bobbins are forwarded to the transport system which pass in front of the photocell.
required; Roving tension is kept constant within a pre-set carries the packages to the spinning frames.
- reduce noise; range through sensors that constantly monitor The flyers installed on Marzoli’s roving frames are This, along with the IE3 premium efficiency motors, the
- reduce vibrations: lower mechanical transmission roving’s fluctuations between the delivery of the made of ultra-light alloy and are dynamically Also a semi automatic doffing option of the machine light weight components (e.g. the bobbin rail in
entails lower wear of transmission components and drafting system and the flyer’s top and adjust the balanced so that even when working at high speeds, is available. With this version ergonomics has been aluminum) and an overall design meant to minimize
therefore lower vibrations. This enables the machine speed of the spindles accordingly. These sensors vibrations are kept to a minimum. Marzoli’s roving substantially improved if compared to standard friction and transmission inefficiencies, entails an
to work at higher speeds; play an important role in ensuring that there are no frames can reach up to 1,500 rpm mechanically and manual-doffing machines. After bobbin formation is energy saving of over 4 Kwh for every hour of operation.
- increase transmission efficiency: transmission false drafts in the roving and that roving breaks are the roving can be wound on standard tubes, with a completed, the bobbin rail lowers and tilts out for an
system comprises only a pulley and toothed belts: no 27mm can be used to reduce the gauge between kept to a minimum. diameter of 53.5 mm, or on thinner tubes , with a easy bobbin collection. Furthermore, there is a
The FT6E and FT7E are driven by shafts, no bevel gears are included. This allows to nipping points. This guarantees a better control of diameter of 48mm, to have a further slight increase in
independent drives for the drafting reduce energy consumption. short fibers during draft. Winding area bobbin capacity. parking rail in front of the bobbin rail with empty
system, the flyers, the spindles and It is argued that to increase productivity and lower tubes so that substitution of full bobbins with empty
the bobbin rail. Every drive is Drafting system Marzoli drafting system can also rely on highly investment costs, spindlage and dimension of The creel tubes is as easy as possible.
coordinated by the central CPU which Marzoli roving frames can be equipped with a efficient cleaners for both top rollers and bottom bobbins should be increased. This is only partially The creel is equipped with hexagonal aluminum
ensures perfect synchronization of all 3-over-3 or 4-over-4 top-of-the-class drafting system. drafting cylinders. For top rollers there are two true: a higher number of spindles per machine rollers to prevent false drafts, a very important aspect With the release of the FT6E and FT7E Marzoli offers
the movements involved in bobbin There are two options for the cylinder diameters: the options: rollers with rubber fins and revolving felt reduces the cost of the investment as the total especially when working with combed slivers. Optic also a third option: the roving frame with the
formation. standard solution has a diameter of 32mm; however, belts. For the bottom cylinders there are rubber required number of spindles can be reached with sensors positioned between the rollers ensure that in prearrangement for automatic-doffing upgrade.
During doffing the bobbin rail lowers and slides out
in case there is a high percentage of short fibers in scrapers. These solutions guarantee that at every fewer machines. From a unit cost (cost per spindle) case of sliver break the machine is immediately horizontally, just like the fully-automatic model.
The spindles drive is a group drive the processed material, cylinders with a diameter of turn both top rollers and bottom cylinders are always point of view, there is an economic advantage that stopped. Marzoli roving frames can be fed with cans