Patent Description:
To obtain dimensional stability, within constant and sufficient limits, of the fabrics, of the knit, as well as of the paper, these manufactured products are subjected to forced shrinkage by various methods.

For example, the Sanfor method is known, where a cellulosic fabric is continuously fed between a rubber ring about <NUM> thick and a large heated roller; at the entrance, a pressing roller, which is metallic or covered with rubber, strongly compresses the rubber ring against the textile manufactured product which is pressed against the heated roller; once it comes out of the compression area, the rubber ring recovers its original size, dragging with it by friction and thus contracting the textile manufactured product. The disadvantage of the Sanfor method consists in the limited level of compaction of the textile manufactured product due to the thickness of the rubber belt.

Patent document <CIT> describes a plant for compacting textile manufactured products, wherein a tensioned elastic ring turns around a first motorized roller, then it winds <NUM>° around the surface of a second idle roller pressed against the first roller which turns at the same speed as the first roller, then it turns around a third motorized roller, placed downstream of the second roller, and it completes the loop around various return and tensioning rollers of the ring. The textile manufactured product is continuously fed between the tensioned elastic ring and the second roller, and then exits the machine upstream from the third motorized roller. The higher adjustable speed of the first motorized roller, with the speed equal to that of the second roller, compared to that of the third motorized roller placed downstream of the first two, allows the contraction of the tensioned elastic ring, pressed against the second roller, thus resulting in the shortening of the elastic ring which drags the textile manufactured product with it, by friction.

Document <CIT> describes (the cited references are to this document) a device for continuously compacting a textile manufactured product (device <NUM>), which comprises a first motorized roller, a second motorized roller and a third motorized roller (motorized rollers <NUM> and <NUM> and drum <NUM>) - see paragraphs [<NUM>] and [<NUM>]), arranged in sequence; an elastic ring <NUM> wound around said rollers to transport and support the textile manufactured product <NUM> to be compacted (see paragraph [<NUM>]); at least one roller (idle roller <NUM>)) adapted to act as a pre-tensioning means for applying a predetermined longitudinal tension to the elastic ring (see paragraph [<NUM>]), which is longitudinally elastically deformable; and a further idle roller (idle guide roller 4b) wherein the elastic ring is wound around the first motorized roller <NUM>, then wound around the second motorized roller <NUM> and finally wound around the third motorized roller <NUM> (see <FIG>), the textile manufactured product or the paper are fed between the elastic ring, wound around the first motorized roller and the second motorized roller, and then transported between the elastic ring and the second motorized roller (see figures), and wherein the second motorized roller is heated (see paragraph [<NUM>]). The device of the document <CIT> further comprises means adapted to vary the speed of all three rollers (see paragraphs [<NUM>] - [<NUM>]).

The main drawback encountered with the use of the devices according to these two documents consists in the limited control of the pressure exerted by the elastic ring against the textile manufactured product, pressed against the second heated roller, often generating an uneven contraction of the same ring, wound at an angle of <NUM>° around the second roller, which often results in an irregular shortening of said manufactured product, which makes it difficult to adjust the percentage of compaction of many articles. In addition, the contact surface of the elastic ring against the second heated roller always remains constant, which is why it is not possible to precisely set a certain percentage of compaction.

Other state-of-the-art documents are <CIT>, <CIT> and <CIT>.

The main object of the present invention is to realize a device for continuously compacting textile manufactured products or paper which is more effective than similar devices of the known type.

This is achieved, according to the invention, by realizing a device having the characteristics set out in claim <NUM>. Further features of the invention are present in the dependent claims.

The invention will be better defined by describing one of its possible embodiments, given only by way of non-limiting example, with the help of the appended drawings, wherein:.

In <FIG>, it can be seen that in its first operating mode an elastic ring <NUM>, which has a thickness that can vary from <NUM> up to about <NUM> even if advantageously the thickness can vary from <NUM> up to about <NUM>, a ring <NUM> composed of a stretchable material such as natural or synthetic rubber with a hardness that can vary from <NUM> Shore up to about <NUM> Shore, said stretchable material can be elongated up to <NUM>%. The ring <NUM> is wound in contact for a stretch around a first motorized roller <NUM> having a rubberized outer surface, and then it is wound, with a winding angle of about <NUM>°, in contact with and around a second motorized roller <NUM>, optionally heatable, whose outer surface has a low coefficient of friction; again thereafter, it is wound in contact for a stretch around a third motorized roller <NUM>, which has a rubberized outer surface; again thereafter, it is tightened (see point Y) between said third roller <NUM> and a pressing roller <NUM> and is then wound in contact around a tensioning roller <NUM> of the elastic ring <NUM>. Finally, the ring <NUM> is tightened (see point X) between the first roller <NUM> and a pressing roller <NUM> and is then wound back into contact around the first roller <NUM>.

The outer surface of the two sides of the ring <NUM> is slightly rough to improve the coefficient of friction between said ring and the surface of the various rollers or between the surface of one side of the textile manufactured product during its compaction phase; moreover, the ring, downstream of point X, is advantageously cooled to maintain its temperature constant.

To ensure a low coefficient of friction, the outer surface of the roller <NUM> is advantageously covered with a mini layer of polytetrafluorethylene or ceramic.

In <FIG> a further operating mode of the device according to the invention is visible, wherein the winding angle of the elastic ring <NUM> around the motorized roller <NUM> is conversely about <NUM>°; by adjusting the raising or lowering of the motorized roller <NUM>, a winding angle of the elastic ring <NUM> around the roller <NUM> is obtained, which varies from a maximum value of <NUM>°, up to a minimum value of <NUM>°; by varying the winding degree of the elastic ring <NUM> around the motorized roller <NUM>, the contact surface of the elastic ring <NUM> against the motorized roller <NUM> varies accordingly.

In a variant of <FIG>, not shown, in order to keep the distance between the rollers <NUM> and <NUM> unchanged, as the value of the winding degree of the ring <NUM> around the roller <NUM> varies, with said elastic ring interposed in contact between the two said rollers, the raising or lowering of the roller <NUM> does not take place in a perpendicular direction, but in an oblique direction.

In a variant of <FIG> and <FIG>, not shown, upstream of the motorized roller <NUM>, there is a series of motorized rollers, around which the elastic ring <NUM> is wound for a stretch, which rollers have the function, by varying the speed difference between them, of adjusting the percentage of elongation of the elastic ring <NUM>.

The pressure exerted by the pressing rollers <NUM> and <NUM> against the motorized rollers <NUM> and <NUM> effectively divides the elastic ring <NUM> into two independent stretches, YX and XY. Along the first stretch YX, the tensioning roller <NUM> adjusts the elongation with the relative tension of the elastic ring <NUM> which, consequently, generates a pressure up to a maximum value of about <NUM>/cm<NUM>, which the same ring can exert for the stretch wound against the surface of the roller <NUM>. The subsequent adjustable contraction of the same ring <NUM>, wound for a stretch around the motorized rollers <NUM>, takes place along the second stretch XY, <NUM> and <NUM>; the diameter of the roller <NUM> can advantageously vary from a value of <NUM> up to a value of <NUM>, but this diameter could also be smaller or larger without departing from the scope of the present invention; furthermore, in order to reduce the length of the second stretch XY, the pressing rollers <NUM> and <NUM> can be placed laterally or above the motorized rollers <NUM> and <NUM>.

As visible in the figures, the device <NUM> provides that a textile manufactured product <NUM>, which can be dried, but also wet or even heated, is continuously fed (inlet A) between the tensioned elastic ring <NUM>, supported by the first roller <NUM> and the second motorized roller <NUM>, optionally heatable, whose outer surface has a low coefficient of friction.

In the second stretch XY, the percentage of contraction of the ring <NUM> is adjusted by the difference in speed between the motorized rollers <NUM>, <NUM> and <NUM>; the lower adjustable speed of the motorized roller <NUM> with respect to the adjustable speed of the rollers <NUM> and <NUM> effectively guarantees the adjustable percentage of contraction of the tensioned elastic ring <NUM>, wound for a stretch around the three rollers, which may be equal to the percentage of elongation applied, in the first stretch YX, to the elastic ring <NUM>, but may also be lower.

By adjusting the percentage of contraction of the elastic ring <NUM>, which rotates with an adjustable winding angle, from a minimum value of <NUM>° up to a maximum value of <NUM>°, around the motorized roller <NUM>, optionally heatable, whose outer surface has a low coefficient of friction, the percentage of frictional compaction of the textile manufactured product <NUM>, pressed by the elastic ring <NUM>, against the aforementioned second roller <NUM> is adjusted accordingly.

From experimental tests carried out on knitwear and fabric articles of various weights and of various structures it was found that in order to accurately adjust the percentage of compaction of each single textile manufactured product <NUM>, pressed between the roller <NUM> and the elastic ring <NUM> during the contraction phase, the adjustable speed of the motorized roller <NUM> can be lower, equal to or higher than the adjustable speed of the first roller <NUM>.

The adjustable winding angle of the tensioned elastic ring <NUM> around the motorized roller <NUM>, from <NUM>° up to <NUM>°, combined with the adjustable tension of the same ring, consequently adjusts the contact surface of the textile manufactured product <NUM> sandwich-pressed between the elastic ring <NUM> and the second roller <NUM>, but also adjusts the pressure, advantageously up to a value of about <NUM>/cm<NUM>, exerted by the tensioned elastic ring <NUM> against the surface of the same textile manufactured product <NUM>; the adjustable pressure is indispensable to avoid, in the phase of compaction by friction of the textile manufactured product <NUM> against the motorized roller <NUM>, the uneven sliding of the same manufactured product around said roller. Furthermore, varying the contact surface of the textile manufactured product <NUM> pressed against the motorized roller <NUM> contributes to varying the percentage of compaction of the manufactured product itself.

The pressure exerted by the elastic ring <NUM> against the surface of the textile manufactured product <NUM>, wound for a stretch around the motorized roller <NUM>, is adjusted by the ring itself; for example, if the elastic ring <NUM> has undergone in the first stretch YX a percentage of elongation with relative tension of <NUM>% and the subsequent percentage of contraction in the second stretch XY is <NUM>%, the pressure exerted by the ring <NUM> against the surface of the textile manufactured product <NUM> will be moderate, because said ring comes out slightly tensioned from the roller <NUM>; vice versa, if the elastic ring <NUM> has undergone in the first stretch YX a percentage of elongation with the relative tension of <NUM>% and the subsequent percentage of contraction in the second stretch XY is <NUM>%, the pressure exerted against the textile manufactured product will be high, because the elastic ring <NUM> comes out still strongly tensioned by the roller <NUM>. The percentage of elongation in the first stretch YX, with the relative tension of the elastic ring <NUM> and the subsequent percentage of contraction of the same ring, in the second stretch XY, can be adjusted independently. With the same percentage of elongation with the relative tension and the subsequent percentage of contraction of the elastic ring <NUM>, by varying the winding angle of the same elastic ring <NUM> around the motorized roller <NUM>, the percentage of compaction of the textile manufactured product <NUM> varies.

With the same winding angle of the elastic ring <NUM> around the motorized roller <NUM>, by varying the percentage of elongation with the relative tension and the subsequent percentage of contraction of the same elastic ring <NUM>, the percentage of compaction of the textile manufactured product <NUM> varies.

The percentage of elongation with the relative tension in the first stretch YX, the subsequent percentage of contraction in the second stretch XY, as well as the winding angle of the elastic ring <NUM> around the motorized roller <NUM>, offer an infinite number of possible adjustments to be chosen based on the characteristics of the textile manufactured product <NUM>, which may vary according to the weight, chemical composition, elasticity and structure of the manufactured product, in addition to the percentage of compaction required.

In addition to the percentage of compaction deriving from the friction of the textile manufactured product <NUM> against the roller <NUM>, the percentage of compaction of the same manufactured product is further increased by exploiting the elasticity of the ring <NUM>; in fact, the side of the ring <NUM> which turns in contact against the textile manufactured product <NUM> and against the roller <NUM> contracts, while the outer side of the same ring lengthens.

Below are some examples of device adjustment:.

The compacted textile manufactured product <NUM> then exits the device <NUM> (outlet B).

The compaction adjustment, from a minimum value of <NUM>% up to a maximum value of <NUM>% of the paper or of a textile manufactured product <NUM>, with a weight that can vary from a minimum value of <NUM>/m<NUM> up to a maximum value of <NUM>/m<NUM>, takes place by setting:.

Claim 1:
DEVICE (<NUM>) FOR CONTINUOUSLY COMPACTING A TEXTILE MANUFACTURED PRODUCT (<NUM>) OR PAPER, which comprises:
- a first motorized roller (<NUM>), a second motorized roller (<NUM>) and a third motorized roller (<NUM>), arranged in sequence;
- means that are adapted to cause a speed variation of all the three motorized rollers (<NUM>, <NUM>, <NUM>);
- an elastic ring (<NUM>) wound around said rollers to transport and support the textile manufactured product (<NUM>) or the paper to be compacted;
- at least one roller (<NUM>) adapted to act as a pre-tensioning means for applying a predetermined longitudinal tension to the elastic ring (<NUM>), which is longitudinally elastically deformable;
being provided for the elastic ring (<NUM>) to be accompanied as wound for a stretch around the first motorized roller (<NUM>), then wound for a stretch around the second motorized roller (<NUM>) and finally wound for a stretch around the third motorized roller (<NUM>),
being moreover provided for the textile manufactured product (<NUM>) or the paper to be fed respectively between the elastic ring (<NUM>), both wound for a stretch around the first motorized roller (<NUM>), and the second motorized roller (<NUM>) and then transported interposed between the elastic ring (<NUM>) and the second motorized roller (<NUM>),
said device being characterized in that
- the second motorized roller (<NUM>) is optionally heated, and the outer surface thereof has a low coefficient of friction;
- means are provided that are adapted to allow the variation of the winding angle of the elastic ring (<NUM>) around the second motorized roller (<NUM>), said winding angle being able to assume a value comprised between <NUM>° and <NUM>°;
- two further idle pressing rollers (<NUM>, <NUM>) are also provided, respectively opposite at substantially punctual points (Y, X) to the first and third motorized roller (<NUM>, <NUM>), the elastic ring (<NUM>) being also provided to slide between the pair of opposite rollers formed by the first motorized roller (<NUM>) and a first idle pressing roller (<NUM>), and the pair of opposite rollers formed by the third motorized roller (<NUM>) and a second idle pressing roller (<NUM>) being thus compressed between said opposite rollers, thus defining two independent stretches (YX) and (XY).