METHOD AND PLANT FOR SORTING OF TEXTILE PRODUCTS

Technical field

This invention relates to a plant for sorting textile products.

In particular, the invention relates to a plant for sorting textile products which is able to recognise many characteristics of the individual products and direct them towards specific relative collectors.

The invention also relates to a method for sorting textile products.

Background art

Historically, the recovery and recycling of textile products has been entrusted to the so-called "sorting machines", particularly expert workers who were able to discern the composition of an item of clothing or other textile product at a glance or at the most helping themselves by touching the product with their fingers. Over the years, together with the spread of a certain level of wellbeing in many countries, the recycling and recovery of waste or second-hand textile products has declined, also due to the poor economic sustainability of a substantially manual activity, characterised therefore by high costs and execution times and consequently limited profitability.

Whilst, on the one hand, the activity of manual selection of the recovery textile products has been increasingly reduced, on the other hand, there has been a considerable increase, due, precisely, to the increase in wellbeing, in the mass of waste textile materials, thus creating a significant problem regarding the correct use or re-use of these materials.

It should also be noted that the demands of fashion, which are so rapidly changing, mean that many new items of clothing, which are unsold at the end of the season, cannot find any real outlet on the market since they are perceived by possible buyers as not very attractive because they are out of fashion, therefore also ending up as a waste item.

It is very clear that this combination of factors has led in recent years to the production of enormous quantities of textile waste that are very hard to place, and are very often destined for incineration.

The increasingly pressing ecological demands, combined with a more mature awareness by many buyers of the importance of limiting the environmental impact due to the disposal of used or waste textile products, have led to the spreading of a greater awareness, in recent years, regarding the issues of recovery and recycling of textile materials.

Recent input, including from the institutions, has meant that not longer are only charities and non-profit associations interested in the re-use of used or discarded textile products, triggering a virtuous process, involving businesses and consumers, focused on the recovery and re-use of textile products.

In particular, for example in Italy, the issue of recycling used clothing, both in terms of actual recycling and re-use, is finding a wide response, with this resulting in the need for a considerable upgrade of the plants designed for their treatment.

In particular, with regard to the recycling of the raw materials which make up the textile materials, their sorting activities are essential in order to be able to direct homogeneous quantities of material towards those who are responsible for giving new life to these materials.

As mentioned above, the action of operators who manually deal with the sorting of textile materials has now become decidedly uneconomic and inefficient.

An example of a sorting plant is described in patent document US2022161298A1.

Aim of the invention

The aim of the invention is to provide a sorting plant and method which is able to overcome the drawbacks connected with the prior art methods for sorting recovered textile materials.

Another aim of the invention is to provide a method for sorting textile products which is effective and practical and inexpensive to implement.

According to the invention, these aims and others are achieved by a method and a plant for sorting textile products comprising the technical features described in the accompanying claims.

Brief description of the drawings

The technical features of the invention, according to the above-mentioned aims, are clearly described in the appended claims and its advantages are apparent from the detailed description which follows, with reference to the accompanying drawings which illustrate a nonlimiting example embodiment of it, and in which:

- Figure 1 is a schematic side elevation view of an embodiment of the sorting plant according to the invention;

- Figure 2 is a schematic plan view from above of the plant of Figure 1;

- Figure 3 is a perspective view from above of a detail of the plant of the previous drawings;

- Figure 4 is a schematic side elevation view of the detail of Figure 3;

- Figure 5 shows a cross-section along the plane C-C indicated in Figure 4;

- Figure 6 is a perspective view from above of a further detail of the plant of the previous drawings;

- Figure 7 is a schematic side elevation view of the detail of Figure 6.

Detailed description

As illustrated in the drawings 1 and 2, the numeral 1 denotes in its entirety a plant for sorting textile products (not illustrated) made in accordance with the invention.

The sorting plant 1, hereinafter for brevity also referred to as the plant 1, extends longitudinally along a first predetermined direction DI.

With reference to Figures 1 and 2, the plant 1 has a zone 2 for loading the above-mentioned and not illustrated textile products.

Adjacent to the loading zone 2, the plant 1 comprises a first detecting station 3 where the structure and the color of the individual textile product are detected. The term "structure" means the type of connection of the yarn in a textile product, classified into three different types: knitted structure, non-knitted structure, weft and warp structure.

For the purposes of this description, a non-knitted structure is considered to be that of a fabric which, performed on particular frames, does not allow the threads used, following a breakage, to detach, that is to say, it prevents the break up of the fabric.

The first detecting station 3 comprises a video camera 4 for detecting the structure and color of a textile product.

The video camera 4 is a color video camera.

The video camera 4 is a video camera which acts in the visible spectrum.

According to an embodiment, the video camera 4 is a matrix video camera, that is to say, which is able to produce a two-dimensional image of the captured scene. Advantageously, this type of video camera is used for capturing images of the static type, that is to say, when the textile product is stationary, even though for a limited period of time, in the capturing field of the video camera.

According to other embodiments, the video camera 4 is a linear video camera.

Advantageously, this type of video camera is used for acquiring images of the non-static type, that is to say, when the textile product is moving in the field of acquisition of the video camera.

As illustrated in Figures 3 to 5, with reference to the detail of the first detecting station 3, the first detecting station 3 comprises a support plane 5 for supporting the above-mentioned and not illustrated textile products to be sorted.

With reference to Figure 3, on the above-mentioned support plane 5 there is a window 6, advantageously made of glass or other transparent scratchproof material.

As illustrated in Figures 4 and 5, the video camera 4 is positioned below the window 6 for capturing the single textile products resting on the window 6.

The first detecting station 3 also comprises an lighting means 7 having a circular crown shape extending around the above-mentioned video camera 4.

In other words, the video camera 4 is substantially positioned at the centre of the circular crown defined by the lighting means 7.

The lighting means 7 having the shape of a circular crown defines, for the sorting plant 1, respective first lighting means configured to illuminate the above- mentioned and not illustrated textile products from below, through the window 6.

As illustrated in Figures 1 and 2, the sorting plant 1 comprises a belt conveyor 8 extending longitudinally along the above-mentioned first direction DI and designed to advance the above-mentioned textile products in succession.

The belt conveyor 8 is of substantially known type and comprises a belt 9 looped around respective pulleys of which at least one is motor-driven.

The advancement direction of the belt 9 of the belt conveyor 8 is represented in the accompanying drawings by the arrow F. The above-mentioned textile products, not illustrated, are therefore also advanced along the plant 1 in the direction of the arrow F.

As clearly illustrated in Figures 1 and 2, the belt conveyor 8 extends from the first detecting station 3 immediately downstream thereof in the direction indicated by the arrow F.

Again downstream of the first station 3 in the direction of the arrow F, the plant 1 comprises a second detecting station 10.

The second detecting station 10 is configured to detect the composition of a individual textile product, that is to say, the composition of the yarn(s) making up the individual textile product.

For this purpose, as illustrated in Figure 1 and in more detail in Figures 6 and 7, the second detecting station 10 comprises a hyperspectral video camera 11 designed to frame the individual textile products and acquire respective images.

The operation of the above-mentioned hyperspectral video camera 11 is explained in more detail below.

As illustrated in Figures 6 and 7, at the second detection station 10, the plant 1 has a plurality of linear lighting units 12 positioned parallel with each other and with a second direction D2 perpendicular to the above-mentioned first direction DI.

The above-mentioned plurality of lighting units 12 defines, for the plant 1, respective second lighting means 13 for illuminating a region 14 with a linear extension for acquiring the image by the hyperspectral video camera 11. Advantageously, according to the embodiment illustrated, each lighting unit 12 comprises a plurality of lighting bodies 15 positioned aligned in succession according to the above-mentioned direction D2.

The second detecting station 10 comprises a frame 16 for supporting the hyperspectral video camera 11 and the lighting units 12.

The lighting units 12 are pivoted on the frame 16 so as to be angularly adjusted, about respective axes of oscillation parallel to the above-mentioned second direction D2, so as to achieve an optimum lighting of the filming area of the hyperspectral video camera 11. As illustrated in Figure 2, the sorting plant 1 comprises a plurality of selecting elements 17 located at predetermined positions along the conveyor belt, downstream of both the above-mentioned first and the second detecting stations 3 and 10 in the advancement direction F of the belt 9.

The selecting elements 17 are, as described in more detail below, designed to remove individual textile products from the belt conveyor. In order to collect the above-mentioned and not illustrated textile products removed from the belt conveyor 8 by the selecting elements 10, the plant 1 comprises a plurality of collection containers 18 positioned at the selecting elements 17.

In other words, the above-mentioned collection containers 18 are positioned at the side of the belt conveyor 8, below the belt conveyor, for collecting the removed textile products by gravity. According to the embodiment illustrated, the selecting elements 17 comprise pneumatic nozzles 19 designed to generate respective jets of air for striking the above- mentioned and not illustrated textile products advanced by the belt conveyor 8 and causing the removal from the surface of the belt 9 and the subsequent selective falling into a respective collection container 18.

The pneumatic nozzles 19 are supplied in known manner by a pneumatic system of substantially known type and not illustrated or described further.

Advantageously, according to the embodiment illustrated, each selecting element comprises three pneumatic nozzles positioned adjacent to each other in succession along the advancement direction F.

Each nozzle 19 is controlled by a respective electrically controlled valve not illustrated.

The three nozzles 19 of each selecting element 17 are advantageously controlled for emitting air under pressure simultaneously or in succession, as a function of the consistency of the textile product and/or its extension along the belt 9, in order to optimise the removal from the belt 9.

Advantageously, the sorting plant 1 comprises a collection container 18 positioned at an end 8a of the belt conveyor 8 for collecting any textile products not previously removed and/or in any case not intended for other collection containers 18 positioned along the conveyor 8.

The plant 1 comprises, not illustrated, a computerised command and control unit operatively connected to the video camera 4, to the hyperspectral video camera 11, to the pneumatic nozzles 19 of the selecting elements 17, as well as to an encoder, also not illustrated, which controls the movement of the belt 9.

In other words, the computerised command and control unit is configured for processing the images acquired by the first and second video cameras 4, 11 and detecting stations 3, 10 and selectively controlling the selecting elements 17.

In use, the above-mentioned and not illustrated textile products are transferred to the loading zone 2. Advantageously, an operator positioned close to the loading zone 2 singles out the textile products and positions them, one by one, on the window 6 in such a way that they are illuminated by the lighting means 7 and the video camera 4 captures the textile product and acquires a matrix image.

Once the image of a significant portion of the textile product has been acquired, a circumstance which is advantageously indicated to the operator by an acoustic and/or luminous signal, the operator moves the textile product on the belt 9 of the belt conveyor 8, upstream of the second detecting station 10.

With the advancement of the belt 9 in the direction of the arrow F, the textile product passes beneath the hyperspectral video camera 11 and is captured by this. The hyperspectral video camera 11 is of the linear type, that is to say, it scans strips or segments and therefore, during the passage of the textile product, it makes a succession of scans.

Once all the textile product has been scanned, the computerised command and control unit executes a processing by means of which the background is eliminated from the image, and a region of interest (ROI) is selected from the image of the textile product.

The above-mentioned scanning is performed whilst the above-mentioned lighting units 12 strike the region of interest with respective light beams.

A plurality of strips or segments is advantageously acquired on the region of interest (since, as mentioned, it is a linear video camera).

Advantageously, by way of an example, the number of strips acquired is approximately five hundred.

In a substantially known manner, the hyperspectral video camera 11, also by the processing performed by the computerised control unit, forms the emission spectrum of each pixel of each strip acquired.

The computerised command and control unit stores a plurality of reference spectra, each relating to a predetermined composition of yarns.

In short, the computerised command and control unit compares the curves representing the spectra detected and the reference spectra, identifying, with greater or lesser approximation, the composition of each strip. Once the composition of all the strips acquired (for example, the above-mentioned five hundred strips) has been established by comparison with the reference spectra, a processing of these compositions is performed by means of a dedicated algorithm and a deviation of the spectrum from the reference spectra is calculated, in order to identify the overall composition of the textile product. Purely by way of example, some reference spectra inserted in the memory of the computerised command and control unit are listed below: pure wool, pure cotton, polyester, nylon, wool blend with wool from 50 to 70%, wool blend with wool from 70 to 80%, wool blend with wool from 80 to 90%, synthetic blends mixed with elastomers.

Upon completion of the step of acquiring images and processing them, the path of the textile product continues on the belt 9 of the belt conveyor 8.

Since the computerised command and control unit has, as seen above, assigned a very precise composition to the yarn from which the textile product is made, the same computerised unit, by means of the above-mentioned encoder connected to the belt conveyor 8, knows the exact position of the textile product at each moment of its advancement on the belt 9.

Thanks to this, the computerised control unit controls the selecting elements 17 by activating the specific pneumatic nozzles 19 positioned at the station assigned to the specific combination of color, structure and composition of the individual textile product.

In other words, each collection container 18 is assigned to a specific combination of color, structure and composition and the pneumatic nozzles 19 positioned close to it are activated upon the passage of a textile product corresponding to that specific combination in such a way as to cause the falling precisely in that collection container 18.

Depending on the categories identified (color, structure, composition) and the number of classes prepared for each category, the number of collection containers 18 positioned along the belt conveyor 8 clearly varies.

For example, with ten composition classes, eight in color and three of structure there should be forty (8x10x3=40) collection containers 18 in order to be able to house all the relative possible combinations.

Since this might cause the conveyor belt 8 to extend considerably and, as a result, make the plant excessively bulky as a whole, it is possible to proceed to sorting one after another, for example, with single, successive passes, each relating to one of the categories listed above: color, structure and composition.

In this way, the number of collection containers 18 necessary for operation of the plant would be defined by the maximum number of classes established between all the categories. In accordance with the above-mentioned example, the number of containers required would be ten, that is to say, determined by the ten composition classes planned.

Advantageously, as shown in Figures 1 and 2, the collection container 18 provided at the end 8a of the conveyor is designed to collect textile products not assigned to specific collection containers 18, for example not recognised as belonging to classes provided for a particular selection set up.

The invention, as mentioned above, also relates to a method for sorting textile products.

The method comprises the following steps:

- detecting the texture and color of a textile product, by means of a camera 4 designed to frame individual textile products and acquire images thereof, - detecting the composition of the textile product by means of a hyperspectral camera 11 designed to frame individual textile products and acquire relative images of them,

- advancing the textile product by means of a belt conveyor 8,

- providing a plurality of selecting elements 17 arranged at specified positions along the belt conveyor 8 and designed to remove the textile product from the belt conveyor 8,

- processing the images captured by the above-mentioned video cameras 4, 11 and selectively control the selecting elements 17.

The method comprises the step of selectively collecting the textile products removed from the belt conveyor 8 using a plurality of collection containers 18 positioned at the plurality of selecting elements 17.

The step of detecting the composition of the textile product advantageously comprises the step of acquiring the emission spectrum of the textile product using the hyperspectral video camera 11 and in that the processing step comprises the step of comparing the emission spectrum acquired with a plurality of reference spectra. The plant 1 according to the invention and the relative sorting method overcome the above-mentioned drawbacks and achieve important advantages.

A first advantage linked to the invention is due to the fact that it provides a plant designed for the sorting of textile products which is able to operate in a substantially automatic manner, without requiring a particular experience of the operators in the various steps for selecting the products.

Another advantage linked to the sorting plant, and relative sorting method, according to the invention is due to its versatility, being able in effect to easily adapt to the specific requirements of the user, easily modifying the categories and the classes for selecting textile products to be sorted.