EP3607131B1

EP3607131B1 - A shrinking machine

Info

Publication number: EP3607131B1
Application number: EP18718915.4A
Authority: EP
Inventors: Davide MANZARDO
Original assignee: Red Carpet Srl
Current assignee: Red Carpet Srl
Priority date: 2017-04-07
Filing date: 2018-03-26
Publication date: 2023-10-04
Anticipated expiration: 2038-03-26
Also published as: IT201700038489A1; CN110494605A; CN110494605B; EP3607131A1; WO2018185601A1

Description

Field of application

The present invention is applicable to the textile field and, in particular, relates to a shrinking machine for fabrics.
More in detail, the present invention relates to the shrinking portion of a shrinking machine.

State of the art

During the processing process, a fabric is subjected to a certain tension, which causes its temporary elongation. The need therefore arises to eliminate the aforesaid elongation in order to prevent the fabric from spontaneously recovering it during or after the packaging of the final product. In fact, this aspect irremediably compromises the quality of the product itself.
To this end, fabric shrinking machines are known to induce recovery of elongation and stabilize the fabric after processing.
Among such known machines we can distinguish shrinking machines comprising a felt belt arranged in a closed loop around a series of rollers which manage, among other things, its movement.
In particular, there are an inlet roller and an outlet roller, arranged in contact with the inner side of the loop, and an intermediate cylinder interposed between the aforementioned rollers and of considerably greater diameter than these, arranged in contact with the outer side of the loop so as to create a concavity in the latter.
The fabric to be treated is made to pass between the belt and the intermediate cylinder. There is also a flexible sheet, generally of Teflon-coated glass fibre, called "shoe", arranged between the inlet roller and the intermediate cylinder so as to keep the fabric in contact with the belt on a trajectory stretch that develops around the inlet roller upstream of the intermediate cylinder.
The aforesaid flexible sheet has the advantage of easily adapting to variations in thickness of the fabric, such as those at the seams, while maintaining the fabric adhering to the belt.
The inlet roller, the intermediate cylinder and the flexible sheet define a trajectory for the fabric which comprises a first stretch with a concavity facing the inlet roller and an immediately following stretch with a concavity facing the intermediate cylinder, i.e. opposed to that of the previous stretch. Advancing along the aforementioned trajectory, the fabric is kept in contact with the surface of the felt belt and undergoes the same surface deformations of the latter.
More precisely, during the passage between the inlet roller and the intermediate cylinder, the felt belt reverses its curvature so as to shrink its outer surface. The aforementioned compression is transmitted to the fabric and causes its shrinking.
The intermediate cylinder is heated, generally by means of steam injected into a cavity of the cylinder itself, so as to heat the fabric during shrinking so as to make the latter more effective and durable.
Since the greater the difference in speed between the convex trajectory stretch and the concave stretch, the greater the shrinking potential of the machine, in order to try to increase the effect of fabric shrinking, an attempt was made to reduce to a minimum the diameter of the inlet roller and to increase belt thickness. With this last modification, in particular, the shrinking force exerted by the belt on the fabric is increased. However, it is not possible to overcome certain physical limits, because the inlet roller, if too small, tends to flex, ruining the quality of the fabric and risking compromising the same machine. Moreover, in the case of the flexible belt, it is not possible to excessively increase its thickness as it tends to break when subjected to traction and subsequent compression.
Moreover, there are some types of fabric that fail to adhere correctly to the felt belt, thereby generating a "shrinking rejection" effect which manifests itself in folds on the fabric coming out of the machine.
Documents EP 0 364 024 A1 , EP 0 950 748 A1 , WO 2007/027909 A2 , EP 3 118 359 A1 and EP 1 055 764 A2 are known. All of them teach to have the sheet that keeps the fabric in position until after the inlet point, with only one tensioning elements arranged at the first end of the sheet before the inlet point. The second end of the sheet is free.

Presentation of the invention

The object of the present invention is to overcome at least partially the drawbacks highlighted above by providing a shrinking machine which allows the correct processing also of difficult fabrics which in the known machines tend to refuse shrinking.
Said object, as well as others which will become clearer below, are achieved by a shrinking machine according to the following claims, which are to be considered as an integral part of this patent.
In particular, the machine comprises at least one flexible belt for supporting and transporting the fabric. This belt is arranged in a closed loop around at least one inlet roller and at least one outlet roller. There is also at least one intermediate body located near the flexible belt between the two inlet and outlet rollers. In this sense, a stretch of the outer surface of the intermediate body identifies with a corresponding stretch of the flexible belt a sliding channel for the fabric.
The flexible belt, therefore, during its sliding around the inlet roller, sees at least its outer surface extend. In this situation, it receives the fabric, supporting it. Subsequently, the same flexible belt is subjected to a lower curvature, if not null or inverted, as in the case of the drawings. The result is a compression of the same outer surface of the flexible belt which causes a shrinking of the fabric. The latter, therefore, is shrunk.
The aforementioned sliding channel allows first of all to keep the fabric in contact with the flexible belt during its shrinking. Furthermore, since the intermediate body is typically heated, in the channel there is a heat transfer to the tissue in order to stabilize its shrinking. In other words, the shrunk fabric is ironed in the channel.
According to the invention, the machine also comprises at least one sheet arranged in contact with the flexible belt starting from at least one point corresponding to the inlet roller and terminating at a point next to the channel inlet point.
According to the invention, the shrinking machine also comprises at least one pair of tensioning elements of the sheet arranged at the end portions of the sheet itself.
Advantageously, therefore, the sheet, being tensioned, exerts a greater pressure on the fabric in the expansion stretch of the flexible belt.
This makes it possible to increase the adhesion of the fabric in the stretch of greater extension of the flexible belt and, consequently, to increase the shrinking effect exerted on the fabric after the point of belt curvature decrease, i.e. after the starting point of fabric shrinking.
Still advantageously, the greater pressure exerted by the sheet on the fabric towards the flexible belt allows to make correctly adherent to the latter also the difficult fabrics which in the state of the art "refuse" shrinking.
According to a further aspect of the invention, the outer surface stretch of the intermediate body in correspondence with the conveying channel is convex and arranged in contact with the flexible belt. As a consequence, the corresponding stretch of the latter assumes a concave conformation and thus also the sliding channel. In other words, the flexible belt is subjected not only to a decrease in its curvature, but rather to a bending inversion.
Advantageously, this makes it possible to further increase the shrinking effect of the fabric in addition to what has already been obtained by tensioning the aforesaid sheet.

Brief description of the drawings

Further features and advantages of the invention will become more evident in light of the detailed description of a preferred but not exclusive embodiment of a shrinking machine according to the invention, illustrated by way of non-limiting example with the aid of the accompanying drawings, wherein:

FIG. 1 represents a shrinking machine according to the invention in schematic view;
FIG. 2 represents a detail of the shrinking machine of FIG. 1.

Detailed description of some preferred embodiment examples

With reference to the mentioned figures and, in particular, to Figs. 1 and 2, described herein is a shrinking machine 1 for fabrics T.
It comprises a flexible belt 2 with which the fabric T to be shrunk is arranged in contact. Said belt 2 is arranged in a closed loop around some rollers 3 among which an inlet roller 4 and an outlet roller 5 are identified. The first corresponds to the point from which the fabric T is arranged in contact with the flexible belt 2, while the second identifies the maximum point of the path of the fabric T on the same belt 2 . By reaching the outlet roller 5, the fabric T is taken from the flexible belt 2 to be conveyed to other processing steps.
For the shrinking of the fabric T, the machine 1 comprises an intermediate body 7 arranged next to the flexible belt 2 between the inlet roller 4 and the outlet roller 5. On the outer surface 8 of the intermediate body 7, a stretch 9 can therefore be identified which, with a corresponding stretch 10 of the flexible belt 2, forms a sliding channel 11 for the fabric.
Therefore, the flexible belt 2, during its sliding around the inlet roller, sees at least its outer surface extend. In this situation, it receives the fabric T, supporting it. Next, the same flexible belt 2 is subjected to at least one curvature decrease. As a consequence, the same outer surface of the flexible belt 2 is shrunk, which induces a shrinking of the fabric T.
The aforementioned sliding channel 11 advantageously allows, first of all, to keep the fabric T arranged in contact with the flexible belt 2 during its shrinking. Furthermore, since the intermediate body 7 is typically heated, in the channel 11 there is a heat transfer to the fabric T in order to stabilize its shrinking. In other words, the shrunk fabric is ironed in the channel 11.
From the drawings it can be observed that the stretch 9 of the intermediate body 7 which shares the construction of the channel 11 is convex. Moreover, the intermediate body 7 is arranged in contact with the flexible belt 2 in the corresponding stretch 10. In this way, the corresponding stretch 10 is shaped with a concavity 15 which in substance is immediately downstream of the convexity 16 generated by the inlet roller 4. Consequently, the flexible belt 2, in the transition from the convexity 16 to the concavity 15, also undergoes a bending inversion which ends the shrinking effect exerted on the fabric T. In other words, advantageously, the fabric T, which is arranged in contact with the belt 2 in its extended stretch corresponding to the convexity 16, starting from a surrounding area of the curvature inversion point, is substantially shrunk by the narrowing of the belt 2 in the concavity 15.
The intermediate body 7 contributes to shrinking, primarily by favouring the change in curvature of the belt 2. Moreover, it is generally heated to perform the ironing of the fabric T mentioned above so as to stabilize shrinking over time.
In order to ensure the best possible adhesion of the fabric T to the belt 2 in correspondence with the inlet roller 4 (that is, in the stretch of maximum extension of the belt 2), the shrinking machine 1 also comprises a sheet 18 arranged in contact with the flexible belt 2 a starting from a point of the latter in correspondence of the inlet roller 4 and terminating at a subsequent inlet point 19 of the sliding channel 11 which, in the described embodiment, corresponds to the curvature inversion point of the flexible belt 2. This sheet 18 is supported by a special first cylinder 20 arranged near the inlet roller 4. Obviously, the presence of the first cylinder must not be considered limiting for the invention, the sheet being supported by any other type of component.
Advantageously, therefore, the sheet 18 keeps the fabric T in position until after the inlet point 19, i.e. up to the shrinking area of the fabric T itself.
Since the action of the sheet 18 results in a pressure exerted on the fabric T towards the belt 2, according to the embodiment which is described, the starting point of this action is located laterally to the inlet cylinder 4 positioning the first cylinder 20 at least sideways to the same inlet cylinder 4.
Advantageously, therefore, the fabric T is also shaped with a convexity 22. This convexity 22 exerts a pressure action on the fabric T which accentuates its adherence to the belt 2.
However, as said, despite this expedient, the sheet 18 is not always able to correctly adhere the fabric T to the belt 2, especially in the case of difficult fabrics.
For this reason, according to the invention, the machine 1 also comprises a pair of tensioning elements 25 of the sheet 18 arranged at the end portions of the sheet 18 itself.
This advantageously allows increasing the thrust force exerted by the sheet 18 on the fabric T towards the belt 2. This force allows to adhere to the belt 2 also fabrics T that usually "refuse" shrinking.
Still advantageously, this pressure makes it possible to increase the adhesion of the fabric T in the stretch of greater extension of the flexible belt 2 and, consequently, to increase the shrinking effect exerted on the fabric T in the subsequent compression of the belt 2.
Since the increase in pressure exerted is in fact discharged on the flexible belt 2 and on the underlying inlet roller 4, this feature could force to increase the dimensions of the inlet roller 4 to avoid possible unwanted bending. This increase in size, however, would decrease the shrinking effect exerted on the fabric T.
To avoid this, according to another aspect of the invention, the shrinking machine 1 comprises a support body 26 of the inlet roller 4. In the embodiment that is described, the support body 26 is constituted by a support roller 27 located below the inlet roller 4, but this aspect must not be considered limiting for the invention.
Likewise, the number and the form of execution of the flexible belts, of the rollers, of the intermediate bodies, of the sheets and of the tensioning elements must not be considered as limiting.
With regard to the latter, according to another aspect of the invention, a first of them consists of the first cylinder 20 which supports a first end portion of the sheet 18 retaining it.
According to a further aspect of the invention, a second 30 of the tensioning elements 25 is constituted by means for fixing the second end portion of the sheet to the outer surface 8 of the intermediate body 7 . The embodiment of the aforesaid fixing means is indifferent to the scope of protection of the present patent, since they can consist of adhesives, screw means, joints made on the intermediate body or other.
What is evident in the first instance is that, according to this embodiment, the intermediate body 7 is a fixed and non-moving element. In this sense, the embodiment of such intermediate body 7, represented in the figures and constituted by a cylinder, must not be considered as limiting the invention. In particular, the intermediate body 7 can have any shape and profile.
However, even these aspects of the invention should not be considered as limiting. In particular, according to an embodiment variant not shown in the figures, the second tensioning element comprises means for thrusting the second end portion of the sheet against the outer surface of the intermediate body. In this sense the latter could be rotating and therefore shaped like a cylinder or similar.
A further embodiment of the machine of the invention, not shown in the figures, shows the second tensioning element comprising a second cylinder to which the second end portion of the sheet is stably coupled. In particular, the second cylinder is arranged operatively downstream of the intermediate body, for example near the outlet roller. Even in this case, obviously, the intermediate body can be rotating.
Since, from what has been said, it is clear that an important aspect of the shrinking machine 1 of the invention is the increase of the pressure exerted by the sheet 18 on the fabric T against the flexible belt 2 at least in correspondence with the inlet roller 4, the same sheet 18 is subject to greater stresses that could compromise its integrity.
For this reason, according to a further aspect of the invention, the sheet 18 is constituted by a metal mesh.
Advantageously, this embodiment allows to considerably increase the tensioning of the sheet 18 and its consequent effects on the fabric T.
Still advantageously, it improves the wear resistance over time of the sheet 18 with respect to the known sheets even in the absence of tensioning.
Typically, the metal mesh is of the type woven on a loom, to optimize its flexibility, but also this aspect must not be considered limiting for the invention.
In any case, the same mesh is appropriately subjected to abrasion treatment with abrasive paste that not only smooths out any protrusions, but also fills any depressions, reducing the roughness. Finally, typically, a polishing treatment is carried out to obtain the best possible result.
In light of the foregoing, it is understood that the shrinking machine of the invention achieves all the prefixed purposes.
In particular, it allows the correct processing also of difficult fabrics which, in the known machines, tend to refuse shrinking.
On closer inspection, it also enables the improvement of the shrinking degree of fabrics subjected to processing.
The invention may be subject to many changes and variations, which are all included in the appended claims. Moreover, the materials may be different depending on the needs, without departing from the scope of protection of the invention defined by the appended claims.

Claims

A shrinking machine for fabrics (T), comprising:
- at least one flexible belt (2) for supporting and transporting a fabric (T), said flexible belt (2) being arranged in a closed loop around at least one inlet roller (4) and at least one outlet roller (5);

- at least one intermediate body (7) of which at least one stretch (9) of the outer surface (8) identifies with a corresponding stretch (10) of said flexible belt (2), between said two rollers (4, 5), a sliding channel (11) for the fabric (T),

- at least one sheet (18) having a first end portion and a second end portion, said at least one sheet (18) being arranged in contact with said flexible belt (2) starting from at least one point corresponding to said inlet roller (4) and ending in a point subsequent to the inlet point (19) of said sliding channel (11), said inlet point (19) of said sliding channel (11) corresponding to the curvature inversion point of the flexible belt (2);
said shrinking machine being characterised in that it comprises:
- at least one pair of tensioning elements (25) of said sheet (18) comprising a first tensioning element and a second tensioning element (30) arranged at the end portions of said sheet (18), said second tensioning element (30) being positioned at said second end portion of the sheet (18).
Shrinking machine according to claim 1, characterised in that said at least one stretch (9) of said outer surface (8) of said intermediate body (7) is convex and arranged in contact with said corresponding stretch (10) of said flexible belt (2) to invert the curvature of said flexible belt (2).
Shrinking machine according to claim 1 or 2, characterised in comprising a support body (26) for said inlet roller (4).
Shrinking machine according to any of the foregoing claims, characterised in that a first element of said pair of tensioning elements (25) comprises a first cylinder (20) to which a first portion of said end portions of said sheet (18) is firmly coupled.
Shrinking machine according to claim 4, characterised in that said first cylinder (20) is arranged at least laterally to said inlet roller (4).
Shrinking machine according to any of the preceding claims, characterised in that said
second element (30) of said pair of tensioning elements (25) comprises means for fixing the second of said end portions of said sheet (18) to said outer surface (8) of said intermediate body (7).
Shrinking machine according to any one of claims 1 to 5, characterised in that said
second element of said pair of tensioning elements comprises means for thrusting said second end portion of said sheet against said outer surface of said intermediate body.
Shrinking machine according to any one of claims 1 to 5, characterised in that said
second element of said pair of tensioning elements comprises a second cylinder which is stably connected to said second end portion of said sheet, said second cylinder being operatively arranged downstream of said intermediate body.
Shrinking machine according to any one of the preceding claims, characterised in that said sheet (18) is a metal mesh.
Shrinking machine according to claim 9, characterised in that said metal mesh is of the type woven on a loom, abraded with abrasive paste and polished.