DESCRIPTION

The invention relates to a device for continuously compacting a textile manufactured product or paper, according to the general part of claim 1.

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 70 mm 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 DE 718624 describes a plant for compacting textile manufactured products, wherein a tensioned elastic ring turns around a first motorized roller, then it winds 180° 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 EP 1657340 Al describes (the cited references are to this document) a device for continuously compacting a textile manufactured product (device 1), which comprises a first motorized roller, a second motorized roller and a third motorized roller (motorized rollers 4 and 5 and drum 7) - see paragraphs [0049] and [0050]), arranged in sequence; an elastic ring 3 wound around said rollers to transport and support the textile manufactured product 2 to be compacted (see paragraph [0042]); at least one roller (idle roller 6)) adapted to act as a pre-tensioning means for applying a predetermined longitudinal tension to the elastic ring (see paragraph [0047]), 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 5, then wound around the second motorized roller 7 and finally wound around the third motorized roller 4 (see fig. 2), 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 [0043]). The device of the document EP 1657340 Al further comprises means adapted to vary the speed of all three rollers (see paragraphs [0048] - [0050]).

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 180 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 EP 1489216 A2, EP 1860224 A2 and WO 2020183410 Al.

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 1. 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:

- fig. 1 shows a schematic view of the invention, in a first operating mode thereof;

- fig. 2 shows a schematic view of the invention, in a second operating mode thereof.

As visible in both figures, the device referred to in the invention, indicated as a whole with the reference number 1, provides that paper or a textile manufactured product 101, such as a fabric or a knit or yarns or a non-woven fabric composed of cellulosic fibres or fibres of animal origin or of synthetic fibres or of artificial fibres or of various mixed fibres, with a weight that can vary from a value of 10g/m ² up to a value of 500 g/m ² , is continuously compacted in said device 1. In Fig. 1, it can be seen that in its first operating mode an elastic ring 102, which has a thickness that can vary from 10 mm up to about 70 mm even if advantageously the thickness can vary from 20 mm up to about 30 mm, a ring 102 composed of a stretchable material such as natural or synthetic rubber with a hardness that can vary from 40 Shore up to about 50 Shore, said stretchable material can be elongated up to 100%. The ring 102 is wound in contact for a stretch around a first motorized roller 103 having a rubberized outer surface, and then it is wound, with a winding angle of about 180°, in contact with and around a second motorized roller 104, 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 105, which has a rubberized outer surface; again thereafter, it is tightened (see point Y) between said third roller 105 and a pressing roller 106 and is then wound in contact around a tensioning roller 107 of the elastic ring 102. Finally, the ring 102 is tightened (see point X) between the first roller 103 and a pressing roller 108 and is then wound back into contact around the first roller 103.

The outer surface of the two sides of the ring 102 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 104 is advantageously covered with a mini layer of polytetrafluorethylene or ceramic.

In fig. 2 a further operating mode of the device according to the invention is visible, wherein the winding angle of the elastic ring 102 around the motorized roller 104 is conversely about 60°; by adjusting the raising or lowering of the motorized roller 104, a winding angle of the elastic ring 102 around the roller 104 is obtained, which varies from a maximum value of 180°, up to a minimum value of 0°; by varying the winding degree of the elastic ring 102 around the motorized roller 104, the contact surface of the elastic ring 102 against the motorized roller 104 varies accordingly.

In a variant of Fig. 2, not shown, in order to keep the distance between the rollers 103 and 104 unchanged, as the value of the winding degree of the ring 102 around the roller 104 varies, with said elastic ring interposed in contact between the two said rollers, the raising or lowering of the roller 104 does not take place in a perpendicular direction, but in an oblique direction.

In a variant of Fig. 1 and Fig. 2, not shown, upstream of the motorized roller 103, there is a series of motorized rollers, around which the elastic ring 102 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 102.

The pressure exerted by the pressing rollers 106 and 108 against the motorized rollers 103 and 105 effectively divides the elastic ring 102 into two independent stretches, YX and XY. Along the first stretch YX, the tensioning roller 107 adjusts the elongation with the relative tension of the elastic ring 102 which, consequently, generates a pressure up to a maximum value of about 3 kg/cm ² , which the same ring can exert for the stretch wound against the surface of the roller 104. The subsequent adjustable contraction of the same ring 102, wound for a stretch around the motorized rollers 103, takes place along the second stretch XY, 104 and 105; the diameter of the roller 104 can advantageously vary from a value of 200 mm up to a value of 300 mm, 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 108 and 106 can be placed laterally or above the motorized rollers 103 and 105.

As visible in the figures, the device 1 provides that a textile manufactured product 101, which can be dried, but also wet or even heated, is continuously fed (inlet A) between the tensioned elastic ring 102, supported by the first roller 103 and the second motorized roller 104, optionally heatable, whose outer surface has a low coefficient of friction.

In the second stretch XY, the percentage of contraction of the ring 102 is adjusted by the difference in speed between the motorized rollers 103, 104 and 105; the lower adjustable speed of the motorized roller 105 with respect to the adjustable speed of the rollers 103 and 104 effectively guarantees the adjustable percentage of contraction of the tensioned elastic ring 102, 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 102, but may also be lower.

By adjusting the percentage of contraction of the elastic ring 102, which rotates with an adjustable winding angle, from a minimum value of 0° up to a maximum value of 180°, around the motorized roller 104, optionally heatable, whose outer surface has a low coefficient of friction, the percentage of frictional compaction of the textile manufactured product 101, pressed by the elastic ring 102, against the aforementioned second roller 104 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 101, pressed between the roller 104 and the elastic ring 102 during the contraction phase, the adjustable speed of the motorized roller 104 can be lower, equal to or higher than the adjustable speed of the first roller 103.

The adjustable winding angle of the tensioned elastic ring 102 around the motorized roller 104, from 0° up to 180°, combined with the adjustable tension of the same ring, consequently adjusts the contact surface of the textile manufactured product 101 sandwich-pressed between the elastic ring 102 and the second roller 104, but also adjusts the pressure, advantageously up to a value of about 3 kg/cm ² , exerted by the tensioned elastic ring 102 against the surface of the same textile manufactured product 101; the adjustable pressure is indispensable to avoid, in the phase of compaction by friction of the textile manufactured product 101 against the motorized roller 104, the uneven sliding of the same manufactured product around said roller. Furthermore, varying the contact surface of the textile manufactured product 101 pressed against the motorized roller 104 contributes to varying the percentage of compaction of the manufactured product itself.

The pressure exerted by the elastic ring 102 against the surface of the textile manufactured product 101, wound for a stretch around the motorized roller 104, is adjusted by the ring itself; for example, if the elastic ring 102 has undergone in the first stretch YX a percentage of elongation with relative tension of 30% and the subsequent percentage of contraction in the second stretch XY is 20%, the pressure exerted by the ring 102 against the surface of the textile manufactured product 101 will be moderate, because said ring comes out slightly tensioned from the roller 105; vice versa, if the elastic ring 102 has undergone in the first stretch YX a percentage of elongation with the relative tension of 100% and the subsequent percentage of contraction in the second stretch XY is 20%, the pressure exerted against the textile manufactured product will be high, because the elastic ring 102 comes out still strongly tensioned by the roller 105. The percentage of elongation in the first stretch YX, with the relative tension of the elastic ring 102 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 102, by varying the winding angle of the same elastic ring 102 around the motorized roller 104, the percentage of compaction of the textile manufactured product 101 varies.

With the same winding angle of the elastic ring 102 around the motorized roller 104, by varying the percentage of elongation with the relative tension and the subsequent percentage of contraction of the same elastic ring 102, the percentage of compaction of the textile manufactured product 101 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 102 around the motorized roller 104, offer an infinite number of possible adjustments to be chosen based on the characteristics of the textile manufactured product 101, 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 101 against the roller 104, the percentage of compaction of the same manufactured product is further increased by exploiting the elasticity of the ring 102; in fact, the side of the ring 102 which turns in contact against the textile manufactured product 101 and against the roller 104 contracts, while the outer side of the same ring lengthens.

By way of example:

Below are some examples of device adjustment: in the case of a winding angle of 90° of the elastic ring 102 around the motorized roller 104, combined with an average percentage of elongation and relative tension of the same ring, a subsequent average percentage of contraction of the elastic ring 102 may be sufficient to compact an elastic manufactured product, consisting in particular of a knit; in the case of a winding angle of 120° - 150° of the elastic ring 102 around the motorized roller 104, combined with a medium/high percentage of elongation and relative tension of the same ring, a subsequent medium percentage of contraction of the elastic ring 102 is suitable for compacting a synthetic textile manufactured product; in the case of compacting a dense and heavy cotton or wool fabric, where a smooth surface of the manufactured product is also required, the winding angle of the elastic ring 102 around the motorized roller 104 will be about

180°, all this combined with a high percentage of elongation and relative tension of the same ring, a subsequent medium/low percentage of contraction of the elastic ring 102 being suitable for compacting the fabric.

The compacted textile manufactured product 101 then exits the device 1 (outlet B). The compaction adjustment, from a minimum value of 1% up to a maximum value of 100% of the paper or of a textile manufactured product 101, with a weight that can vary from a minimum value of 10g/m ² up to a maximum value of 500g/m ² , takes place by setting:

- the winding angle of the elastic ring 102 around the motorized roller 104 adjustable between 0° and 180°.

- the percentage of elongation in the first stretch YX, up to a value of 100%, of the elastic ring 102 composed of a stretchable material such as natural or synthetic rubber, said percentage of elongation with the relative tension of the elastic ring 102 being adjusted by means of at least one tensioning roller 107.

- the subsequent percentage of contraction of the elastic ring 102 in the second stretch XY, with a percentage less than or equal to the percentage of elongation of said elastic ring in the first stretch YX, with the textile manufactured product 101 kept pressed between the elastic ring 102 and the motorized roller 104, said percentage of contraction of the elastic ring 102 being adjusted by the adjustable speed of each of the motorized rollers 103, 104 and 105.

In a variant of the device referred to in the invention, not shown in the figures, in the second stretch XY the number of motorized rollers can also be greater than 3, without however departing from the scope of the invention.