EP3902950B1

EP3902950B1 - A shrinking machine

Info

Publication number: EP3902950B1
Application number: EP20715195.2A
Authority: EP
Inventors: Franco Bertoldo
Original assignee: Red Carpet Srl
Current assignee: Red Carpet Srl
Priority date: 2019-03-04
Filing date: 2020-02-26
Publication date: 2024-01-17
Anticipated expiration: 2040-02-26
Also published as: EP3902950A1; IT201900003121A1; CN113508200A; EP3902950C0; WO2020178670A1; CN113508200B

Description

Definitions

In the present patent, the term "textile item" means any type of continuous and non-continuous fabrics such as, for example, orthogonal fabrics, knitted fabrics, non-woven fabrics, and so on.

Field of Application

The present invention applies to the textile industry, and, in particular, relates to a shrinking machine for textile items.
More in detail, the present invention relates to the shrinking portion of a shrinking machine.

Background

During the manufacturing process, a textile item is subjected to longitudinal tension, which causes the temporary lengthening thereof. Therefore, the need is felt to eliminate the aforesaid lengthening in order to prevent the textile item from spontaneously recovering it during or after the packaging of the final product. In fact, this aspect irremediably would compromise the quality of the product itself.
To this end, textile item shrinking machines are known to induce the recovery of the longitudinal lengthening and achieve its stabilization.
Among such known machines, we can distinguish shrinking machines comprising a flexible and extensible conveyor belt, usually made of rubber, arranged in a closed loop around a series of rollers, which manage, among other things, its movement. Notably, there are an inlet roller, an outlet roller and a tensioning roller, arranged in contact with the inner side of the belt.
There is also a stretching roller interposed between the inlet roller and the outlet roller, and having a diameter considerably greater than these. The textile item to be treated is passed in a stretching channel identified between the stretching roller and the conveyor belt. The thrust exerted by the latter on the textile item against the stretching roller achieves the desired stretching.
During the passage between the tensioning roller and the inlet roller, the conveyor belt undergoes an elongation obtained by imposing a rotation speed on the tensioning roller lower than the one of the inlet roller. The moment the conveyor belt loses contact from the inlet roller, it tends to contract until it returns to its previous condition.
Such phenomenon is then used to shrink the textile item. In fact, it is sufficient to deposit it on the conveyor belt before its contraction and hold it close to the belt itself to have it shrunk. The foregoing occurs in the stretching channel.
Besides, conveniently, stretching and shrinking occur simultaneously so as to make the latter more effective and long lasting.
However, the contraction of the conveyor belt already begins in the last portion in contact with the inlet roller. This typically occurs before entering the stretching channel, i.e. before the textile item is held close to the conveyor belt. The result is a loss of shrinking capability, since the contraction of the belt begins before the instant when it is transferred also to the textile item.
To compensate for this drawback, according to the known art, the difference in the rotation speed of the inlet and tensioning rollers is increased so as to increase the elongation of the belt.
However, strong tractions imposed on the conveyor belt often lead to the formation of ripples thereon, which affect the textile item compromising its quality.
Furthermore, the tension to which the conveyor belt is subjected favours the slipping of the belt itself on the inlet roller with subsequent loss of shrinking on the textile item.
The documents US 2015 050460 A1 , US 3 469 292 A , DE 718 624 C , and US 2006 112526 , wherein different solutions for lengthening the conveyor belts are presented, are also known. However, such documents do not resolve the drawbacks relating to the loss of shrinking capability of the belts due to an early contraction.

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 that allows the proper shrinking of textile items using the technique of elongation of the conveyor belt.
Notably, an object of the present invention is to provide a shrinking machine that allows the degree of shrinking achieved to be improved by optimizing the contraction imparted by the conveyor belt to the textile item.
Another object of the present invention is to provide a shrinking machine that allows the contraction of the conveyor belt before the textile item is held thereon to be avoided.
A further object of the present invention is to avoid the formation of ripples in the conveyor belt during the elongation step.
Another object is to avoid the slipping of the conveyor belt on the inlet roller as a result of the tension of the belt.
Said objects, as well as others that will become more manifest below, are achieved by a shrinking machine according to the following claims, which are to be considered as an integral part of the present patent.
Notably, the machine comprises at least one elastically flexible and extensible conveyor belt for transporting and treating a textile item. Such belt, generally made of rubber, is arranged in a closed loop around a plurality of rollers for its movement.
There is at least one stretching roller whose at least one section of the outer surface identifies, with a corresponding section of the conveyor belt, a stretching channel for the textile item having an inlet and an outlet.
According to an aspect of the invention, among the above-mentioned plurality of rollers, there is at least one inlet roller arranged alongside the stretching roller to define the inlet of the stretching channel. There is also at least one tensioning roller operatively placed upstream of the inlet roller and rotating with a rotation speed of the surface lower than the rotation speed of the surface of the inlet roller.
As a result, the conveyor belt undergoes an elongation induced by the difference in rotation speed of the surfaces of the rollers long before reaching the inlet of the stretching channel. In this situation, it receives the textile item, supporting it.
As far as the inlet roller is concerned, according to another aspect of the invention, it has at least one annulus made of a compressible material, generally rubber. The stretching roller, moreover, is arranged at least during operation against the inlet roller, compressing at least partially the annulus.
Advantageously, the compression of the annulus of the inlet roller enables to have a wide contact area between the annulus and the conveyor belt.
Still advantageously, the compression of the annulus is maximum at the axis connecting the centre of the inlet roller to the centre of the stretching roller. As a result, still advantageously, the contraction of the belt occurs only downstream of such axis.
Still advantageously, the compression of the annulus of the inlet roller allows the inlet of the stretching channel to be moved operatively upstream of the above-mentioned axis connecting the rotation centres of the inlet roller and the stretching roller.
Still advantageously, therefore, the textile item is held against the conveyor belt before the latter has begun the contraction step, increasing the shrinking effect of the textile item compared to what occurs in the known art.
Still advantageously, the compressible material, which forms the outer surface of the inlet roller, increases the friction between the conveyor belt and the roller itself, improving the slip resistance.
According to another aspect of the invention, the shrinking machine also comprises at least one guiding roller operatively arranged between the inlet roller and the tensioning roller.
Advantageously, the guiding roller allows the belt to be guided from the tensioning roller to the inlet roller, while avoiding that the belt itself may form ripples or corrugations, which would then affect the textile item.

Brief Description of the Drawings

Further features and advantages of the invention will be 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 a schematic view.

Detailed Description of Some Preferred Embodiments

With reference to the mentioned figure, a shrinking machine 1 of textile items T is described, wherein textile item T means, as previously defined, any type of continuous and non-continuous fabrics.
It comprises an elastically flexible and extensible conveyor belt 2, for supporting and transporting a textile item T. Such conveyor belt 2 is typically made of an elastic material, generally rubber. This feature must not be regarded as limiting for the invention, since the belt 2 may be made up of any material having features of elasticity and flexibility sufficient to serve the purpose.
According to the embodiment which is being described, the conveyor belt 2 is arranged in a closed loop around a plurality of rollers 3 for its movement. Among them, an inlet roller 4 and a stretching roller 5 are identified. A section of the outer surface 6 of the latter identifies, with a corresponding section 7 of the conveyor belt 2, a stretching channel 8 for the textile item T. The channel 8 has an inlet 9 and an outlet 10.
In this channel 8, the conveyor belt 2 pushes the textile item T against the stretching roller 5. The latter is heated, generally by steam injected into a cavity of the stretching roller 5 itself, so as to heat the textile item T.
The shrinking machine 1 also comprises one tensioning roller 14 operatively placed upstream of the inlet roller and rotating 4 with a rotation speed of the surface lower than the rotation speed of the surface of the aforementioned inlet roller 4.
Advantageously, the conveyor belt 2, during its sliding between the tensioning roller 14 and the inlet roller 4, undergoes an elongation induced by the difference in rotation speed of the two rollers 4, 14. The belt 2 is then lengthened and at this stage receives the textile item T. As a result, the contraction that the conveyor belt 2 undergoes upon detachment from the inlet roller 4 will induce shrinking of the textile item held against the belt 2 by the stretching roller 5.
In the embodiment which is being described, the stretching roller 5 is not always placed against the inlet roller 4, but is movable along an axis X connecting a first rotation centre 11 of the inlet roller 4 to a second rotation centre 12 of the stretching roller 5.
Therefore, advantageously, the stretching roller 4 may be moved from the contact position to facilitate maintenance interventions or not to damage the belt when the machine is stopped. Obviously, such aspect should not be regarded as limiting for different embodiments of the invention wherein, for example, the inlet roller is movable with respect to the stretching roller, or wherein both are static in contact with each other.
According to another aspect of the invention, the inlet roller 4 has a annulus 13 made of a compressible material, generally but not necessarily composed of rubber.
According to another aspect of the invention, during operation the stretching roller 5 is arranged against the inlet roller 4, partially compressing the annulus 13 made of a compressible material.
Advantageously, the compression of the annulus 13 of the inlet roller 4 enables to deform an initial section of the stretching channel 8 and, therefore, to move the inlet 9 of the stretching channel 8 operatively upstream of the axis X connecting the rotation centres of the inlet roller 4 and stretching roller 5. That is, the contact between the inlet roller 4 and the stretching roller 5 does not identify a single point of tangency, but a section in which the stretching roller 5 is secant to the circular area of the inlet roller 4.
Still advantageously, the textile item T is held against the conveyor belt 2 before the latter is no longer in contact with the inlet roller 4, i.e. before the conveyor belt 2 has started the contraction step. This allows a greater shrinking of the textile item T compared to what occurs in the known art, wherein the textile item is held against the conveyor belt only after the contraction step of the latter has started.
Furthermore, still advantageously, since the textile item T is heated by the stretching roller 5, a more effective and long lasting shrinking is achieved.
According to the known art, as mentioned above, conveyor belt is often operated with particularly high tensioning values so as to achieve a greater lengthening of the belt and, therefore, to achieve an increased and more effective shrinking of the textile item. This way, as previously pointed out, it happens that belt slips on the inlet roller, which affects the textile item by compromising its quality.
Advantageously, with the present invention, the presence of a annulus 13 made of a compressible material increases the friction between the conveyor belt 2 and the inlet roller 4, improving the slip resistance that can occur during the elongation step of the belt 2.
According to the embodiment of the invention which is being described, the tensioning roller 14 also has an outer crown 15 made of rubber or other material which advantageously increases the friction with the belt 2, further reducing the risk of the slipping thereof along its trajectory. Obviously, such feature, too, should not be regarded as limiting for the invention.
According to a further aspect of the invention, the shrinking machine 1 also comprises a guiding roller 16 interposed between the tensioning roller 14 and the inlet roller 4.
Advantageously, the presence of the guiding roller 16 keeps the conveyor belt 2 stretched and shortens the air path between the tensioning roller 14 and the inlet roller 4. As a result, the generation of ripples on the belt 2 is eliminated, improving the quality of the textile item T.
According to another aspect of the invention, the shrinking machine 1 comprises an additional guiding roller 17, operatively placed upstream of and near the tensioning roller 14. Advantageously, the presence of the additional guiding roller 17, also together with the action of the guiding roller 16, allows the surface of the conveyor belt 2 in contact with the tensioning roller 14 to be increased. This way, the friction between the belt 2 and the tensioning roller 14 is increased, enhancing the slip resistance.
However, such aspects of the invention should not be regarded as limiting for different embodiments. Notably, according to some alternative embodiments
not shown in the figures, there may be multiple guiding rollers and multiple tensioning rollers. By contrast, according to other alternative embodiments, the additional guiding roller is not provided. Likewise, according to a particular alternative embodiment, the guiding roller is not provided, too.
In light of the foregoing, it is understood that the shrinking machine of the invention achieves all the intended objects.
Notably, it allows the proper shrinking of the textile items to be achieved using the technique of elongation of the conveyor belt by optimizing the contraction imparted by it on the textile item.
On closer inspection, in fact, it allows the textile item to be held against the conveyor belt before the latter begins to contract.
The shrinking machine of the invention also allows the formation of ripples in the conveyor belt during the elongation step to be avoided.
Furthermore, it allows the slipping of the conveyor belt on the inlet roller as a result of the tension of the belt to be avoided.

Claims

A shrinking machine for textile items (T), comprising:
- at least an elastically flexible and extensible conveyor belt (2) for supporting and transporting a textile item (T), said conveyor belt (2) being arranged in a closed loop around a plurality of rollers (3) for its movement;

- at least one stretching roller (5) whose at least one section of the outer surface (6) identifies, with a corresponding section of said conveyor belt (2), a stretching channel (8) for the textile item (T) having an inlet (9) and an outlet (10);

- at least one inlet roller (4) arranged alongside said stretching roller (5) to define said inlet (9) of said stretching channel (8);

- at least one tensioning roller (14) operatively placed upstream of said inlet roller (4) and rotating with a rotation speed of the surface lower than the rotation speed of the surface of said inlet roller (4) so as to induce an elongation in said conveyor belt (2) at least between said tensioning roller (14) and said inlet roller (4),
characterized in that:
- said inlet roller (4) comprises at least one annulus (13) made of a compressible material;

- said stretching roller (5) being arranged, at least during operation, against said inlet roller (4), compressing at least partially said annulus (13) made of a compressible material so as to deform at least an initial section of said stretching channel (8) and move said inlet (9) of said stretching channel (8) operatively upstream of an axis (X) connecting a first rotation centre (11) of said inlet roller (4) to a second rotation centre (12) of said stretching roller (5).
The shrinking machine according to claim 1, characterized in that said stretching roller (5) is movable with respect to said inlet roller (4) according to said axis (X) connecting said rotation centres (11; 12).
The shrinking machine according to claim 1 or 2, characterized in that said elastic material is rubber.
The shrinking machine according to any one of the preceding claims, characterized in that said tensioning roller (14) has at least one circular crown (15) made of rubber.
The shrinking machine according to any one of the preceding claims, characterized in that it comprises at least one guiding roller (16) operatively arranged between said inlet roller (4) and said tensioning roller (14).
The shrinking machine according to any one of the preceding claims, characterized in that it comprises at least one additional guiding roller (17) operatively upstream of said tensioning roller (14).