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DESCRIPTION

Technical field

The present invention relates to a carding machine and a carding method.

Background art

In the textile industry it is known to carry out carding operations by means of carding machines, also known as "cards", having a main rotary swift cooperating with a plurality of worker rollers and stripper rollers. The swift and the rollers, or cylinders, are equipped, on their outer surface, with pointed elements (also called "card clothings" or "carding teeth"), such as points, sawteeth, and further per se known elements. Such cards are mostly used for working textile fibres of any nature.

Notoriously, the main functions carried out by cards are to disentangle, to parallel, to homogenize and to arrange the fibres coming from a fibre agglomeration, such as wool cloth or fleece. Generally, cards also perform the function of removing most impurities contained in the raw fibres, such as vegetable impurities, e.g. seeds or straws.

Known cards suffer from a few drawbacks.

One drawback is that, in order to provide a worked product of sufficient quality, the cards that use worker rollers and stripper rollers require a large number of rollers, or it may even be necessary to employ multiple carding assemblies. In fact, because the carding action exerted between the swift and the worker rollers is limited to a minuscule area of tangency between such elements (which is theoretically one carding point), the prior art attempted to make up for this problem by increasing the number of rollers or carding assemblies, thus creating very bulky machines. As is often the case in the prior art, fibre carding is carried out by using, instead of a single machine, multiple machines arranged in series and constituting the so-called "carding set". The result is enormous machines that are heavy and complex because of the large number of moving mechanical members; consequently, such cards are subject to high energy consumption.

A further drawback of known cards is that long times are needed for cleaning the card clothings and for changing the colours or compounds of the fibres to be processed, resulting in low productivity.

Summary of the invention

It is one object of the present invention to provide a mixed-technology carding machine with worker rollers and a rolling band, which can overcome this and other drawbacks of the prior art, while at the same time being simple and economical to manufacture.

It is a further object of the present invention to provide a carding process capable of conjugating a high- quality product with numerous merits, including high production efficiency and the capability of creating fine counts .

In particular, some advantages offered by the present invention are due to the use of a reduced number of mechanical parts, resulting in smaller dimensions and lower energy consumption. The efficiency of the carding machine and method is thus improved.

A further advantage is given by the possibility of producing fine counts with a high stretch percentage.

According to the present invention, this and other objects are achieved through a carding machine and a carding process having the features set out in the appended independent claim.

It is to be understood that the appended claims are an integral part of the technical teachings provided in the following detailed description of the invention. In particular, the appended dependent claims define some preferred embodiments of the present invention, which include some optional technical features.

Brief description of the drawings

Further features and advantages of the present invention will become apparent from the following detailed description, which is supplied by way of non-limiting example with particular reference to the annexed drawings, wherein:

- Figure 1 is a side view of a machine created in accordance with a particular exemplificative embodiment of the present invention; and

- Figure 2 is a schematic and enlarged view of a detail of the machine shown in Figure 1.

Detailed description of the invention

With reference to Figure 1, there is shown by way of example a carding machine 1 (which may also be abbreviated as "card") designed in accordance with an exemplary embodiment of the present invention. Said carding machine 1 comprises :

- a swift 10 susceptible of rotating, equipped with a plurality of points on its outer surface 12;

- a loading area C (or feeding area), for arranging a plurality of fibres on outer surface 12 of said swift 10;

- at least one worker roller 20 susceptible of rotating, equipped with a plurality of points on its outer surface 22, for cooperating with said swift 10;

- at least one stripper roller 24, equipped with a plurality of points on its outer surface, and cooperating with respective worker roller 20 and said swift 10 for taking the fibres that are present on outer surface 22 of said worker roller 20 and arranging said fibres on said swift 10;

- an unloading area S for removing the fibres from outer surface 12 of said swift 10 after said fibres have been worked;

- a rolling band 30, equipped with a plurality of points, and cooperating with said swift 10, through a working surface 32, for carding the fibres.

The term "points" refers to any pointed element per se known in the textile industry, such as, for example, hooked elements, sawteeth, carding teeth, card clothings, which are suitable for carding textile fibres.

The preferred variant illustrated herein includes multiple worker rollers 20 that cooperate with swift 10.

The axis of rotation of worker rollers 20 is parallel to that of swift 10.

In proximity to loading area C, or feeding area, means are conveniently provided for arranging a plurality of fibres on outer surface 12 of swift 10; for example, the fibres can be fed onto swift 10 through a taker-in roller 34, also conveniently fitted with points on its outer surface .

In proximity to unloading area S, means are conveniently provided for removing the fibres from outer surface 12 of swift 10. Advantageously, a flywheel roller 38 is included, which is susceptible of rotating about its axis at a peripheral speed higher than that of swift 10, and which is fitted with a plurality of long and flexible points that blend with the points of swift 10, for lifting the fibres from surface 12 of swift 10. In the illustrated example, a doffer roller 36 is conveniently used, which is conveniently fitted with points on its outer surface, for picking up the fibres from outer surface 12 of swift 10. Flywheel roller 38 prepares the fibres for doffer roller 36, which removes them from swift 10. Thus, during the rotation, the portion of swift 10 exiting from unloading area S has substantially no fibres and is therefore ready for receiving the fibres being fed from loading area C.

As aforementioned, carding machine 1 further comprises at least one stripper roller 24, equipped with a plurality of points on its outer surface, and cooperating with respective worker roller 20 and said swift 10 for taking the fibres that are present on outer surface 22 of said worker roller 20 and arranging said fibres on said swift 10 (i.e. on its outer surface 12) . In particular, there are a plurality of stripper rollers 24, each one cooperating with the respective worker roller 20.

In fact, with reference to Figure 2, worker roller 20, while turning, takes a part of the fibres that are present on outer surface 12 of swift 10; then stripper roller 24, while turning, takes such fibres and transfers them again onto swift 10. At this point, the points of worker roller 20 will have no fibres and will be ready again to come in contact with the fibres on outer surface 12 of swift 10 in order to card them.

With reference to the flow of fibres, said at least one worker roller 20 is located upstream of said rolling band 30 (Fig. 1) . Therefore, the fibres enter from loading area C, are first carded by the at least one worker roller 20, are then carded by rolling band 30, and finally exit through unloading area S. In the preferred example illustrated herein, a plurality of worker rollers 20 are arranged upstream of rolling band 30. As an alternative, at least one worker roller 20 may be located downstream of rolling band 30.

By way of example, the figures show the directions of rotation of the various rotary members: swift 10 turns in a direction of rotation, e.g. clockwise; worker rollers 20, stripper rollers 24, rolling band 30 and doffer roller 36 turn in the direction opposite to that of swift 10, e.g. counterclockwise .

Preferably, the tangential speeds of said worker roller 20 and of said rolling band 30 in the area of cooperation with said swift 10 are concordant with the sliding direction of the flow of fibres. With reference to the illustrated variant, the flow of fibres starts in loading area C and follows outer surface 12 of swift 10, thus covering an arc of circle in a clockwise direction up to unloading area S.

For more clarity, the area of cooperation between swift 10 and worker roller 20 corresponds to the point of contact or tangency between them; in this area, with particular reference to Figure 2, the points that are present on outer surface 12 of swift 10 cooperate with the points that are present on outer surface 22 of worker roller 20. The area of cooperation between swift 10 and rolling band 30 corresponds, instead, to working surface 32; in this case as well, the points that are present on outer surface 12 of swift 10 cooperate with the points that are present on the surface of rolling band 30. This cooperation between points results in a large fibre carding area .

Working surface 32 is essentially an arc of circumference, as schematically shown in Figure 1. In other words, a more intense carding process takes place on this working surface 32, through which the fibres are directed towards unloading area S.

The tangential speed of said swift 10 is different from the tangential speed of said worker roller 20 and of said rolling band 30. This means that the tangential speed (or peripheral speed) of outer surface 12 of swift 10 is different from the tangential speed of outer surface 22 of worker roller 20. Likewise, the tangential speed of outer surface 12 of swift 10 is different from the tangential speed of the surface of rolling band 30. This allows carding the fibres.

Advantageously, the tangential speed difference between swift 10 and worker roller 20 is different from the tangential speed difference between swift 10 and rolling band 30. In this manner it is possible to obtain a high percentage of fibres having the same direction, as well as a good homogenization of the same. For example, carding machine 1 of the invention can be designed in a manner such that the tangential speed difference between swift 10 and worker roller 20 is less than the tangential speed difference between swift 10 and rolling band 30. In fact, when the fibres enter from loading area C, they are in an extremely disorderly and uneven condition, and are not mutually oriented in the same direction (e.g. they show in the form of flocks), and therefore it is advantageous that the difference in tangential speed between swift 10 and worker roller 20 is relatively small, in order to avoid breaking/tearing such fibres. On the contrary, when the fibres arrive at rolling band 30, i.e. after they have been carded by one or more worker rollers 20, they are more homogeneous and mutually oriented in the same direction; it is therefore possible to apply a greater difference in tangential speed between swift 10 and rolling band 30, so as to increase the fineness of the fibre carpet exiting carding machine 1, thereby improving its quality and stretch percentage during the next step of the spinning process .

Preferably, the tangential speed of swift 10 is higher than that of worker rollers 20 and of rolling band 30.

Carding machine 1 also comprises drive means capable of putting in motion at least swift 10, worker rollers 20 and rolling band 30.

Conveniently, carding machine 1 is prearranged for individually varying the revolution speed of swift 10, worker roller 20 and rolling band 30. This is possible, for example, through the use of dedicated motion transmission means, per se known. As an alternative, it is possible to associate respective drive means with swift 10, worker rollers 20 and rolling band 30.

Conveniently, a plurality of plates fitted with points for cooperating with said swift 10 are associated with said rolling band 30. As an alternative, said plurality of points is directly fixed to the surface of rolling band 30, in particular to the outer surface thereof.

Preferably, the carding machine comprises a cleaning device for cleaning rolling band 30 (not shown) . In this manner, that portion of rolling band 30 which is about to come in contact with the fibres on outer surface 12 of swift 10 will have substantially no fibres or any other types of impurity, and the carding can be carried out correctly, thus further improving the quality of the worked product. In fact, after a portion of rolling band 30 has carried out the carding at working surface 32, it is possible that fibre residues or other impurities might remain trapped on the points of rolling band 30; hence it is convenient to remove such residues before that portion cooperates again with swift 10. Advantageously, the cleaning device comprises an aspirator for removing such residues from rolling band 30. Alternatively, a brush may be employed, e.g. a rotary brush operating on rolling band 30, in particular on the points thereof.

In accordance with a further variant (not shown) of the present invention, card 1 comprises a further worker roller, and possibly also a respective stripper roller, located downstream of said rolling band 30, with reference to the flow of fibres.

The present invention provides also an innovative process for carding textile fibres that can preferably be carried out by mixed-technology carding machine 1 of the invention, comprising the following steps:

- creating an input flow of textile fibres to be processed towards a rotary swift 10 of a carding machine 1, said rotary swift 10 being equipped with a plurality of points on its outer surface 12;

- carrying out a first carding of the fibres by means of the points of said rotary swift 10 cooperating with at least one rotary worker roller 20 equipped with a plurality of points on its outer surface 22;

- carrying out a second carding of the fibres by means of the points of said rotary swift 10 cooperating with a rolling band 30 equipped with a plurality of points for cooperating, through a working surface 32, with said swift 10;

- creating an output flow of processed fibres from said rotary swift 10.

Preferably, with reference to Figure 1, the input flow of fibres is created at a loading station C, and the output flow of fibres is created at an unloading station S.

In particular, the step of carrying out the first carding includes the steps of :

- transferring a part of the fibres from said rotary swift 10 to said at least one rotary worker roller 20;

- transferring the fibres from said at least one rotary worker roller 20 to a respective rotary stripper roller 24; said rotary stripper roller 24 being equipped with a plurality of points on its outer surface, for cooperating with said rotary swift 10 and said at least one rotary worker roller 20;

- transferring the fibres from said rotary stripper roller 24 to said rotary swift 10.

Conveniently, a step is included for removing fibre residues from the points of that portion of said rolling band 30 which is not cooperating with said rotary swift 10. In other words, the residues are removed from the portion of rolling band 30 that is not carrying out the carding at working surface 32.

Preferably, the step of carrying out the first carding

(on the at least one rotary worker roller 20) precedes the step of carrying out the second carding (at rolling band 30); i.e. as it happens in carding machine 1 shown in Figure 1.

The carding machine and the carding method of the invention are applicable to numerous types of textile fibres, including, for example, wool, cotton, synthetic fibres, etc.

This process allows obtaining high-quality processed fibre layers at low cost; in particular, it is possible to obtain fine counts having a greater yarn volume than by using the known technology of the combed spinning process. It is also possible to obtain a production characterized by higher stretch and homogeneity percentages than in the prior art .

A further advantage of the present invention consists of shorter interruptions for replacing the fibre lot and for cleaning.

Further advantages are low maintenance, high versatility as concerns the types of fibres that can be processed, possibility of using unskilled labour, possibility of significantly reducing energy consumption.

Of course, without prejudice to the principle of the invention, the forms of embodiment and the implementation details may be extensively varied from those described and illustrated herein by way of non-limiting example, without however departing from the scope of the invention as set out in the appended claims.