WO2005035141A1

WO2005035141A1 - Method for the continuous application of a compound on a moving body and a corresponding system

Info

Publication number: WO2005035141A1
Application number: PCT/IT2004/000562
Authority: WO
Inventors: Enrico Faccin
Original assignee: Cos.T.A. S.R.L.
Priority date: 2003-10-13
Filing date: 2004-10-08
Publication date: 2005-04-21
Also published as: ITVI20030202A1

Abstract

The invention concerns a method for the continuous application of a compound on a body (C) to be treated moving along a rectilinear advance direction (1) and a system for the implementation of said method. The compound is applied to the body (C) with several passes that are performed following application axes (2a, 2b) that are neither orthogonal, nor parallel to the advance direction (1), in order to deposit stripes (3) of compound parallel to one another.

Description

METHOD FOR THE CONTINUOUS APPLICATION OF A COMPOUND ON

A MOVING BODY AND A CORRESPONDING SYSTEM.

The invention concerns a method for the continuous application of a compound on a moving body to be treated, particularly suitable for the application of chemical preparations like, for example, paints or glues, on hides or films or dies used in leather upgrading processes and a corresponding system.

It is well known that in leather processing it is necessary to apply continuously chemical compounds like paints, lacquers, resins, adhesives or other substances on the surface of moving products. This operation is generally carried out through a spraying process that involves the use of a particularly expensive and sophisticated nozzle that makes it possible to adjust the dimensions of the area that will be covered by the spray.

The known method for the continuous application of a compound on a body to be treated that moves along a straight advance direction requires that the spraying nozzle passes repeatedly on the surface to be treated, following an application axis that is orthogonal to the above mentioned advance direction.

A first example of application of the method described above is represented by leather upgrading systems.

These processes require that a film of synthetic material, on which veins reproducing the aesthetic characteristics of high-quality leather are stamped, is glued onto low-quality leather.

More precisely, the glue is applied onto the film using a spraying systems that implements the method described above.

This system, also called spraying booth, substantially comprises a conveyor belt on which the film to be treated is laid and a spraying unit, positioned above the film and installed on a moving carriage.

The spraying unit comprises the above mentioned nozzle that sprays the product used for the treatment directing it onto the surface to be treated.

The moving carriage is installed on a rail that is orthogonal with respect to the film advance direction, and along which the carriage moves alternately to and from according to the input of a control unit.

After setting the conveyor belt advance speed and the width of the film to be treated in the control unit, the operator starts the system.

The control unit thus provides for operating the nozzle and moving the carriage to and from, along the direction orthogonal to the film advance direction, depositing the compound on the surface to be treated.

A first drawback of the method and system described is constituted by the fact that the movements of the nozzle don't cover the whole surface to be treated.

A further drawback is constituted by the fact that the compound or product sprayed isn't distributed uniformly on the film surface.

In particular, the combination of the movements of the advancing film and of the carriage determines a distribution of the product as shown in Figure 1.

As it can be observed, the compound is sprayed in stripes F with specific width

L, depending on the characteristics of the nozzle used and on the pressures set. On the treated surface S it is therefore possible to observe areas N that haven't been reached by the sprayed product, areas D on which the product is present in the desired quantity, or areas P covered by twice the desired quantity of sprayed product.

Another drawback connected to the previous one is constituted by the fact that, in the process described above, the non-uniform distribution of the sprayed product doesn't allow the film to be perfectly glued onto the hide.

A further inconvenience is constituted by the fact that the considerable accelerations and decelerations to which the moving carriage and the nozzle integral with it are subjected interrupt, in correspondence with the reversal points, the supply of compound to the nozzle, thus further increasing the lack of homogeneity in the compound layer sprayed onto the treated surface.

The purpose of this invention is to overcome the drawbacks described above.

In particular, it is a first goal of the invention to obtain a method for the continuous application of a compound on a moving body, which allows the whole surface involved to be treated.

It is a further goal of the invention to propose a method for depositing and obtaining a homogeneous and uniform layer ©f preparation on the whole surface treated.

It is a further aim of the invention to propose a method that makes it possible to deposit and obtain a localised, homogeneous and uniform layer of preparation on any area, even a delimited one, of the treated surface.

It is a further aim to propose a method that, in comparison with the known method, should be more efficient in terms of quantity of compound used per unit of surface. It is a further goal of the invention to propose a method that, in comparison with the known method, allows the surface area treated per unit of time to be increased.

It is a further aim of the invention to implement a system for the continuous application of a compound on a moving body to be treated, which should implement the method that is also the object of the invention.

It is a further aim of the invention to carry out a system that can be installed on or inserted in continuous production lines.

It is another goal of the invention to carry out a system particularly suited to treat finished or semi-finished products in the sector of natural or imitation leather processing.

It is a further aim of the invention to carry out a system that can be introduced in particular, but not necessarily, in continuous production lines for the processing of semi-finished items for the production of natural or imitation leather. It is a further aim of the invention to carry out a system that is easy to manage and to configure, capable of treating bodies or products even with different geometrical and dimensional characteristics.

The last but not least aim of the invention is to carry out a simple and reliable system that could uses a single spraying nozzle. The aims mentioned above have been achieved through the implementation of a method for the continuous application of a compound on a body to be treated, said body moving along a substantially rectilinear advance direction, which, according to the main claim, is characterised in that said compound is applied to said body with one or more passes, following application axes that are neither orthogonal, nor parallel to said advance direction, in order to deposit stripes of compound substantially parallel to one another.

To advantage, this allows the layer of compound deposited onto the treated surface to be checked, as will be better explained below.

The system for the continuous application of a comppund on a body to be treated positioned on a conveyor unit that makes it advance along a substantially rectilinear direction, which is also object of the invention, comprises a frame and means for the application of said compound, positioned above said conveyor unit and is characterized in that said means for the application of said compound is associated to said frame through moving means suited to move said means for the application of said compound along application axes that are neither orthogonal, nor parallel to the body advance direction, in order to deposit stripes of compound that are substantially parallel to one another. The aims and advantages mentioned above will be explained in greater detail in the description of some among many possible applications of the invention, given by way of illustration and not by way of limitation, with reference to the attached drawings, wherein:

- Figure 1 shows a surface to which a compound has been applied by means of a continuous application method of the known type;

- Figures from 2 to 5 show in sequence the various phases of application of the compound with the proposed method; - Figure 6 is an axonometric view of a system for the continuous application of a compound on a moving body, said system being the object of the invention;

- Figure 7 is a plan view of the system represented in Figure 6;

- Figure 8 is a plan view of a variant of the system shown in Figure 6;

- Figure 9 is a plan view of the system shown in Figure 8 during an operating phase;

- each of the Figures from 10 to 13 shows a plan view of a position taken by the system shown in Figure 6 during a complete work cycle;

- Figure 14 is a plan view of a position taken by the system shown in Figure 6 in a different operating mode. The method for the continuous application of a compound or product on a moving body will be now described referring to Figures from 2 to 5. According to the invention, while the body to be treated C advances along a rectilinear advance direction 1, the compound or product is applied to the surface to be treated S of the body C using suitable means, indicated as a whole by 4, with one or more passes following an application axis 2a that is neither orthogonal nor parallel to the advance direction 1, in such a way as to deposit stripes 3 of preparation substantially parallel to one another. In particular, the application axis 2a forms with the advance direction 1 of the surface to be treated S an angle A determined as a function of the advance speed Va of the body C and of the speed Vs with which the pass on the surface to be treated is carried out along direction 2a.

This angle A corresponds to the arc cosine of the ratio between the advance speed Va of the body C and the speed Vs at which the pass of the nozzle for the application of the compound is carried out (A=arc cos(Va/Vs)). To advantage, this makes it possible to obtain on the treated surface S product stripes 3, visible in Figure 3, substantially orthogonal to the advance direction 1 of the body C, with defined width 5 and all parallel to one another. By checking the width of the stripes obtained with the means 4 it is thus possible to precisely check the layer of preparation deposited on the body C. In fact, it is possible to obtain partially overlapping stripes or stripes that don't overlap.

In the example shown in Figure 5 the stripes 3 overlap by half of their width 5. Thus an homogeneous layer of material is distributed on the body C, on its whole surface S, with controlled thickness that is twice the thickness obtained with one pass. In fact, there are neither areas without compound, nor areas on which one pass only has been carried out.

Again according to the invention, the method requires that once the first pass has been performed, the following pass is carried out by moving the means 4 in the opposite direction, along a second application axis 2b that intersects the first axis 2a and forms with the advance direction 1 the same angle A, as shown in detail in Figures 4 and 5.

In particular, the two sections of the axes 2a, 2b along which the passes are carried out substantially intersect at their medial point 5 and the passes are carried out by the application means moving in accordance with the advance direction of the body C.

According to the proposed method, the means 4 is then brought back to the initial position represented in Figure 2 and the operations described above are cyclically repeated.

It is important to observe that the angle A can also be expressed as a function of other parameters, provided that the stripes 3 are parallel to one another and if desired orthogonal to the advance direction 1 of the body C. Simple trigonometric equations, in fact, show that the angle A is equal also to the arc tangent of the ratio between the product of the number of passes to be carried out per unit of time M mμltiplied by the width R of the surface S of the body C and the speed of advancement Va of the surface to be treated (A=arc tg (M*R/ Va)).

The application of said method allows the means 4 to cover the whole surface S to be treated by means of repeated passes. This allows the preparation to be applied to any area of the surface S, even if limited, thus making it possible to obtain, as desired, treated and non-treated areas, substantially of any geometrical form, by simply operating and stopping the means 4 while this moves along the axes 2a and 2b.

This way drawings or graphical reproductions of any shape and dimension can be obtained on the surface S. The system for the continuous application of a product on a body to be treated, suited also to implement the method described above, is represented as a whole in Figures 6 and 7, where it is indicated by number 100.

It comprises a frame 101 to which the means for the application of the compound, indicated as a whole by 104, is associated, said means being positioned over the conveyor unit 103 on which the body to be treated C is located.

The conveyor unit 103, which may belong to the system 100 or not, is generally constituted by a conveyor belt 105 that sets the body C moving at a speed Va along a rectilinear advance direction 106. According to the invention, the means 104 for the application of the preparation is associated to the frame 101 through moving means, indicated as a whole by 107, suited to move the means 104 along directions 102a, 102b that are neither orthogonal, nor parallel to the advance direction 106 of the body C to be treated, in order to deposit stripes of preparation 103, visible in Figures 11, 12 and 13, substantially parallel to one another.

In particular the moving means 107 comprises guide means, constituted by a moving rail 110, supporting a carriage 111 to which the means 104 for the application of the preparation is associated. The rail 110, defining the rectilinear axis 102a, 102b along which the passes for the application of the compound are carried out, is supported at its ends by two moving elements 112.

Said moving elements 112 move along corresponding guides 113 in coordination, in order to rotate the rail 110 around a vertical axis 115 passing through the medial point of the rail 110 itself. In particular, the guides 113 allow the elements 112 to move along curved trajectories constituted by arcs of circumference.

This makes it possible, as will be described below, to arrange the rail 110 at any angle A with respect to the advance direction 106 to move the means 104 to the various positions, represented in Figures from 2 to 5, necessary to implement the method described. The movements of the various parts of the system are controlled by a control unit that is not represented and is provided with suitable means for interfacing with the operator, which make it possible to check and set the operating parameters of the system, according to the description provided above.

Motion is transmitted to the various moving parts of the system 100 by power units, constituted by electric motors, through drive members of the known type, such as belts, chains, joints, etc.

As regards the means for the application of the preparation 104, this is preferably, but not necessarily, constituted by a spray unit comprising one or more adjustable nozzles. Each nozzle is fed by a corresponding feeding unit, not represented, which may also comprise a volumetric pump, depending on the type of preparation to be applied.

Alternatively, said means 104 may be constituted by an atomizer that directs the product onto the surface S to be treated or by a brush or an equivalent tool. A first variant, indicated as a whole by 200 in Figure 8, is differentiated from the previous one by the fact that the moving elements 112 move in coordination on the relevant linear or rectilinear guides 120 parallel to the advance direction 106 of the body C, in such a way as to allow the rail 110 to travel along a direction parallel to the advance direction 101 of the body C. The trajectories 102a, 102b, rectilinear but inclined according to angle A with respect to the advance axis 106 of the body C in this case are obtained by properly coordinating the movements of the carriage 111 and of the elements 112 through the control unit, as shown in Figure 9. More precisely, the carriage 111 is moved along the direction orthogonal to the advance direction 106 at a speed Vo, while at the same time the elements 112 are moved parallelly to the same direction 106 at a speed Vp. According to the invention, the speeds Vo and Vp are such as to move the means 104 along the direction 102a at the speed Vs, respecting the conditions explained above (A=arc cos(Va/Vs) or A=arc tg (M*R/ Va)). A further executive variant is differentiated from the preceding ones due to the fact that the system comprises also a unit for detecting the geometrical shape of the surface S to be treated. This unit, substantially of known type, comprises systems for the acquisition and processing of images that cooperate with the control unit to supply the information regarding the width R of the surface S, useful to control the operation and stop of the means 104. According to a further variant, the advance speed Va of the body C is detected with apposite electric transducers constituted, for example, by encoders cooperating with the control unit.

The operation of the system proposed is described below with reference to the first system illustrated.

The operator, after setting in the control unit the advance speed Va of the conveyor belt 105 and the width of the surface of the body C to be treated, or alternatively the speed Va, the number of passes per unit of time M and the width

R of the surface S, starts the system 100. The control unit thus provides for calculating the angle A and consequently positioning the rail 110 according to this angle, as shown in Figure 10.

Successively, as the body C, in this case constituted by a film to which a layer of compound must be applied, approaches, it operates the nozzle 104, moving the carriage 111 forward at speed Vs. A first stripe 103 with width 105, substantially orthogonal to the advance direction 101, to which a first layer of preparation is applied, is thus obtained on the surface S, as shown in Figure 11.

After the first pass, the control unit operates the elements 112, rotating the rail

110 on axis 115, until it reaches the position represented in Figure 12, thus getting ready for the successive pass. The carriage 111 is now moved in the opposite direction, that is, backwards, thus obtaining a second stripe 103, whose width is equal to the width of the first stripe.

It can be easily observed that the second stripe is parallel to the first one and partially overlaps it. After the second pass the control unit, proceeding as described above, brings the rail back to its initial position represented in Figure 10, thus starting the operating cycle again.

It must be observed that, by properly choosing and adjusting the means 104, it is possible to vary the width 105 of the stripes 103 of preparation deposited at each pass.

This makes it possible to precisely check the layer of product deposited and also to avoid the overlapping of stripes obtained with successive passes.

In fact, it is sufficient to adjust the nozzle so that the width 105 of the stripe 103 is substantially equal to the distance 121 between the median axes of the stripes 103 obtained with two successive passes, in order to prevent the stripes 103 themselves from overlapping.

This is also useful to compensate for the advance of the body C during the time interval necessary to move the nozzle from the "end-of-passage" position, visible in Figures 11 and 13, to the successive start position shown in Figures 10 and 12. According to a further operating mode, the control unit operates and stops the means 104 for the application of the preparation in such a way as to obtain discontinuous or interrupted stripes of preparation, of the type represented in Figure 14. As stated above, this allows drawings or graphic patterns of any type to be obtained on the surface S of the body C, in this case constituted by a hide.

In particular in this case the operator, using the interface means, will provide for introducing also the information regarding the geometrical shape that he wants to obtain on the surface S. Besides calculating the angle A, as described above, the control unit will also provide for calculating the moments at which the means 104 must be operated and stopped.

As stated above, the system and the method proposed are particularly useful to carry out treatments such as painting, spreading and application of glues or compounds on hides, films or dies to be applied to the leather being processed. According to the above, it is clear that the method and the system proposed make it possible to check the thickness of the preparation that is applied on the surface to be treated, thus reaching the goals set.

Even though the invention has been described making reference to the drawings attached hereto, upon implementation modifications may be carried out, which are all included in the same inventive concept described in the claims below and are therefore protected by this patent.

Claims

CLAIMS 1) Method for the continuous application of a compound to a body (C) to be treated that is moving along a substantially rectilinear advance direction (1), characterized in that said compound is applied to said body (C) with one or more passes according to application axes (2a, 2b) that are neither orthogonal, nor parallel to said advance direction (1) in order to deposit stripes (3) of compound substantially parallel to one another. 2) Method according to claim 1), characterized in that said application axes (2a, 2b) form with said advance direction (1) an angle (A) equal to the arc cosine of the ratio between the advance speed (Va) of said body (C) and the speed (Vs) at which the pass is carried out along said application directions (2a, 2b) in order to apply said preparation (A=arc cos(Va/Vs)). 3) Method according to claim 1), characterized in that said application axes (2a, 2b) form with said advance direction (1) an angle (A) equal to the arc tangent of the ratio between the product of the number of passes carried out per unit of time (M) multiplied by the width (R) of the surface to be treated of said body (C) and the advance speed (Va) of said surface to be treated (A=arc tg (M*R/ Va)). 4) Method according to claim 1), or 2), or 3), characterized in thiat said application axes (2a, 2b) intersect and form with said advance direction (1) the same angle (A). 5) Method according to claim 4), characterized in that said passes are cyclically repeated following said axes (2a, 2b), moving according to said direction of advance (1). 6) Method according to any of the previous claims, characterized in that said stripes (3) are substantially orthogonal to said advance direction (1). 7) Method according to any of the previous claims, characterized in that said stripes (3) substantially overlap by half of their width (5). 8) Method according to any of the previous claims, characterized in that said stripes (3) are orthogonal to said advance direction (1) of said body (C). 9) Method according to any of the previous claims, characterized in that said stripes (3) are continuous. 10) Method according to any of the previous claims, characterized in that at least one of said stripes (3) isn't continuous. 11) Method according to any of the previous claims, characterized in that said compound is applied by spraying. 12) System (100, 200) for the continuous application of a compound to a body (C) to be treated positioned on a conveyor unit (103) that makes it advance

' along a substantially rectilinear direction (106), comprising a frame (101) and means (104) for the application of said compound positioned above said conveyor unit (103), characterized in that said means (104) for the application of said compound are associated to said frame (101) through moving means (107) suitable for moving said means (104) for the application of said compound along application axes (102a, 102b) that are neither orthogonal, nor parallel to the advance direction (106) of said body (C), in order to deposit stripes (103) of compound substantially parallel to one another. 13) System (100, 200) according to claim 12), characterized in that said application axes (102a, 102b) form with said advance direction (106) an angle (A) equal to the arc cosine of the ratio between the advance speed (Va) of said body (C) and the speed (Vs) at which the pass along the application directions (102a, 102b) is performed to apply said compound (A=arc cos(Va/Vs)). 14) System (100, 200) according to claim 12), characterized in that said application axes (102a, 102b) form with said advance direction (1) an angle (A) equal to the arc tangent of the ratio between the product of the number of passes performed per unit of time (M) multiplied by the width (R) of the surface to be treated of said body (C) and the advance speed (Va) of said surface to be treated (A=arc tg (M*R/ Va)). 15) System (100, 200) according to claim 12), or 13), or 14), characterized in that said application axes (102a, 102b) intersect and form the same angle (A) with said advance direction (106). 16) System (100, 200) according to claim 12), or 13), or 14) or 15), characterized in that said passes are cyclically repeated along said axes (102a, 102b) by the application means (104) moving according to said advance direction (D- 17) System (100, 200) according to any of the claims from 12) to 16), characterized in that said moving means (107) comprise guide means supporting at least one carriage (111) to which said means (104) for the application of said compound is associated. 18) System (100, 200) according to claim 17), characterized in that said guide means comprise at least a moving rail (110) supported by moving elements (112) that ensure its rotation around a substantially vertical axis (115). 19) System (100, 200) according to claim 17), characterized in that said guide means comprise at least one moving rail (110) supported by moving elements (112) suited to allow said at least one rail (110) to travel along a direction substantially parallel to said advance direction (106) of said body (C). 20) System (100, 200) according to claim 18) or 19), characterized in that said moving elements (112) move along corresponding guides (113) integral with said frame (101). 21) System (100, 200) according to any of the claims from 12) to 17), characterized in that it comprises said conveyor unit (103). 22) System (100, 200) according to claim 21), characterized in that said conveyor unit (103) comprises at least one conveyor belt (105). 23) System (100, 200) according to any of the claims from 12) to 22), characterized in that said means (104) for the application of said compound comprises a spray unit. 24) System (100, 200) according to claim 23), characterized in that said spray unit comprises at least one nozzle fed by a corresponding feeding unit. 25) System (100, 200) according to claim 23), characterized in that said spray unit comprises at least one atomizer. 26) System (100, 200) according to any of the claims from 12) to 25), characterized in that it comprises at least one control unit suited to operate and/or stop said means (104) for the application of said preparation, in order to obtain continuous and/or non-continuous stripes (103) and to coordinate its movements along said application axes (102a, 102b). 27) System (100, 200) according to claim 26), characterized in that said at least one control unit comprises interface means for the operator. 28) System (100, 200) according to claim 26) or 27), characterized in that it comprises a unit for detecting the advance speed (Va) of said body (C), said unit cooperating with said at least one control unit. 29) System (100, 200) according to any of the claims from 26) to 28), characterized in that it comprises at least one unit for detecting the geometrical shape of the surface (S) to be treated of said body (C), said unit cooperating with said at least one control unit. 30) Method for the continuous application of a compound to a moving body to be treated and corresponding system substantially as described with reference to the attached drawings.