ES2757976B2 - FLUID OR SEMI-FLUID FEED METHOD - Google Patents

Description

DESCRIPTION

Fluid or semi-fluid feeding method

SCOPE

The present invention refers to a device for feeding fluid or semi-fluid products used for the decoration, personalization or polychromatic finishing of objects, preferably with a flat surface.

By way of example only, but not limiting, said flat surface objects can be made of ceramic material such as, for example, ceramic tiles and plates or other similar objects.

The present invention also relates to a method of feeding said fluid or semi-fluid products and to a decoration machine comprising said feeding device.

With the term "fluid or semi-fluid product" is understood, for example, an enamel, an ink or a paint, that is to say any fluid or semi-fluid coloring product capable of providing a certain coloration to the object to be decorated.

STATE OF THE ART

Devices for feeding fluid or semi-fluid products are known that comprise a mixing bowl, configured to contain and keep the product stirring, a pump unit fluidly connected to the bowl through a first tube, and a dispenser, fluidly connected to the pumping unit through a second tube, and by means of which the fluid / semi-fluid product is applied to the object to be decorated.

In particular, the dispenser has a suitably designed outlet section to obtain a constant and defined spray area, which depends on the shape and size of the object to be decorated, and on the decoration to be printed on it.

In the ceramic sector, fluid / semi-fluid coloring products used for tile decoration typically have a fairly high density and viscosity. high, thus promoting adhesion to the surface to be colored of the fluid / semi-fluid product after the coloring process.

On the other hand, fluid / semi-fluid coloring products contain, in suspension, microparticles which may also have abrasive characteristics, for example to provide the object in question with an intended surface roughness.

Especially in this case, the fluid / semi-fluid coloring product sprayed at high pressure and speed can cause wear phenomena, or structural damage to both the second tube and the dispenser.

In fact, the latter is particularly subject to wear as it has a narrow outlet section, in order to conveniently direct the flow of the fluid / semi-fluid product to the object to be decorated.

A drawback of the systems of the known art is determined by the fact that fluid or semi-fluid coloring products, due to their characteristics mentioned in the previous paragraphs, that is, viscosity, presence of abrasive particles, deform, by widening it, the section of dispenser outlet.

This widening modifies the spray area on the object to be decorated that is reached by the fluid / semi-fluid coloring product, compromising the aesthetic result of the decoration.

Known feeding devices may also comprise a pressure sensor of the fluid / semi-fluid product, configured to detect the value of the pressure of the fluid / semi-fluid in the lower part of the pumping unit, that is, inside the second tube. .

The pressure sensor is typically connected to a management and control unit, which serves to manage the operation of said pumping unit.

The management and control unit is configured to receive the pressure value detected by the pressure sensor and can produce an operational signal that will be sent to the pump unit, in order to keep the pressure of the fluid / semi-fluid product constant in the inside the second tube, so that the feeding device works at a constant pressure.

In particular, the management and control unit typically comprises a proportional integral derivative (PID) circuit that elaborates the operating signal that will be sent to the pump unit based on the difference between the pressure detected by the pressure sensor and a value of predefined reference.

The solutions of the known technique that we have just described have some drawbacks.

A drawback of fluid / semi-fluid feeding devices that work at constant pressure resides in the fact that due to the deformation, that is, the widening of the outlet section of the dispenser, the pressure of the fluid inside the second tube tends to decrease progressively over time.

Consequently, the management and control unit automatically generates an operating signal to increase the pressure of the fluid / semi-fluid product, to compensate for the pressure drop and to bring the pressure back to the predetermined reference value.

This operational signal determines an increase in the flow of fluid / semi-fluid, which, in addition to not guaranteeing the aesthetic purpose of the decoration, is sprayed in greater quantity, with a significant economic waste.

Another drawback, related to the waste of fluid / semi-fluid coloring product, is that the costs for its disposal increase, since it is a highly polluting chemical product.

In order to guarantee the aesthetic performance of the product, constant maintenance of the dispensers is therefore necessary.

Maintenance, in the current state of the art, is only carried out when the malfunction of the dispensers is verified, which in this case occurs as a result of the visual detection of the damaged dispenser by an expert operator.

Damage detection can also occur indirectly, thanks to visual analysis, always by an expert operator, of the spray area generated on the surface of the object to be decorated.

Currently, therefore, it is only possible to instrumentally detect the presence of wear phenomena of the dispensers that modify the outlet section of the latter, with a visual control of an operator, because the pressure value of the fluid / semi-fluid product, in the inside of the second tube, detected by the pressure sensor, is immediately corrected by the management and control unit in the way we have described.

Another drawback is that machine stops may occur at unforeseeable moments in the decoration cycle and with a non-constant cadence, which prevents effective and fast scheduled maintenance interventions and requires the blocking of industrial decoration cycles.

An objective of the present invention is to produce a device for feeding fluid or semi-fluid products that allows one or more of the drawbacks indicated to be solved.

Another objective of the present invention is to produce a device for feeding fluid or semi-fluid products that allows the wear status of the dispenser to be automatically monitored and eventually reported on associated malfunctions.

Yet another objective of the present invention is to produce a device for feeding fluid or semi-fluid products that can apply the intended decoration to the objects in question.

Yet another objective of the present invention is to realize a device for feeding fluid or semi-fluid products capable of minimizing the waste of fluid / semi-fluid coloring product used for decoration.

Another objective of the present invention is to produce a device for feeding fluid or semi-fluid products that allows for the incorporation of predictive maintenance. In this way, it is possible to anticipate a possible breakdown, or the moment when the wear of the dispenser is about to exceed a limit value, above which the device for supplying the fluid / semi-fluid coloring product cannot provide the objects in question the desired decoration.

In this way, maintenance interventions can be conveniently programmed, with the consequent reduction of machine downtime and increased productivity.

In order to obviate the drawbacks of the known technique and to achieve these and other purposes and advantages, the Applicant company has studied, experimented and carried out the present invention.

EXHIBITION OF THE INVENTION

The details and characteristics of the invention are set out in the independent claims.

An advantage of the feeding device according to the invention is that, by keeping the flow rate of the product in the second tube constant, the pressure measuring means provides a pressure signal indicating the state of wear of the dispenser.

Advantageously, the pressure measuring means quickly detects if there have been breakdowns or malfunctions of the dispenser.

Therefore, according to the invention, a device for feeding fluid or semi-fluid products can be obtained that minimizes product waste and reduces the possibility of causing aesthetic defects in the decoration, with the consequent increase in productivity.

By way of example only, said device for feeding fluid or semi-fluid products can be used to decorate ceramic tiles and plates.

According to the present invention a method for decorating objects is obtained, and an object decoration machine, where it is envisaged to use a feeding device according to the present invention.

ILLUSTRATION OF THE DRAWINGS

These and other characteristics of the invention will become clear in the following description of embodiments, provided by way of example, not limiting, in relation to the attached figure that schematically illustrates a device for feeding fluid or semi-fluid products according to the present invention.

It is understood that elements and features of one embodiment can be conveniently incorporated into other embodiments without new specifications.

DESCRIPTION OF FORMS OF REALIZATION

With reference to figure 1, a device for feeding fluid or semi-fluid coloring products can be seen, indicated as a whole with the reference number 10.

According to embodiments of the invention, the fluid or semi-fluid feeding device 10 is configured to dispense a fluid / semi-fluid L on at least one surface of a flat object O to decorate the latter, that is, to provide it with certain characteristics, by a For example, a certain decoration or a desired surface roughness.

The fluid / semi-fluid product L can have a precise pigmentation to give the decoration a certain color, and can be chosen from a group comprising enamels, inks, paints or other similar or assimilable fluid / semi-fluid products.

The fluid / semi-fluid product L can have a variable density between approximately 1000 kg / m3 and 2000 kg / m3 and a variable viscosity between approximately 0.368 and 1.106 poise.

Furthermore, the fluid / semi-fluid product L may contain, dispersed within it, solid microparticles configured to provide particular characteristics to the surface of the flat object O.

The feeding device 10 is configured to decorate objects made of different materials or better yet, the object O can be made of ceramic, metallic, plastic, paper or other material, including fabrics.

The flat object O, in the illustrated example presented as a square-shaped ceramic tile, is typically placed on conveyor means 28, configured for example as belts or conveyor belts of the known art that make it advance in the direction indicated in the figure by arrow F.

Said feeding device 10 comprises at least one reservoir 11, with a sufficient capacity, suitable to contain the fluid / semi-fluid product L.

The reservoir 11 can be configured as a closed or open tank at the top, or it can be associated with a lid (not shown) in order to avoid drying, or partial drying, of the fluid / semi-fluid product L.

On the other hand, the tank 11 can be equipped with means for removing 12, of a type known in the art, the fluid / semi-fluid product L contained therein.

According to possible embodiments, the reservoir 11 may have inside spaces separated from each other to allow one or more fluids / semi-fluids L.

According to possible embodiments, the tank 11 can incorporate thermoregulatory means configured to control the density and viscosity of the fluid / semi-fluid product L.

The supply device 10 also comprises a pumping unit 13 associated with the reservoir 11 through a first tube 14.

The first tube 14 allows the passage of the fluid / semi-fluid product L from the reservoir 11, located at a first end 24 of the first tube 14, to the pumping unit 13, located at a second end 25 of the first tube 14.

The pumping unit 13 is designed to send the fluid / semi-fluid product L to at least one dispenser 15 by means of a second tube 16.

The second tube 16 conducts the fluid / semi-fluid product L from the pump unit 13, located at a first end 26 of the second tube 16, to at least one dispenser 15, located at a second end 27 of the second tube 16.

According to one aspect of the invention, the dispenser 15 is configured to spray a predetermined quantity of fluid / semi-fluid product L at least on a part of the surface of the flat object O that it is desired to decorate.

Typically, the delivery of the fluid / semi-fluid product L is done from above, since the dispenser 15 is located at the top and is oriented substantially perpendicular to the surface of the object O to be decorated.

The dispenser 15 can have at least one outlet section 17 suitably designed and dimensioned to obtain a spray zone 18 chosen on the surface of the flat object O to be decorated.

The spray zone 18 has dimensions, a shape and a position relative to the object O to be decorated, which are determined in the design phase, and which correspond directly to the outlet section 17.

In some embodiments, the dispenser 15 may have a plurality of outlet sections 17, distinct from each other and selectively selectable, in order to obtain different shapes of the spray area 18.

Although in the illustrations of the embodiments the spray area 18 has an elliptical shape, other shapes, such as circular, square, rectangular or others of varying perimeter may be envisaged.

Due to the phenomenon of wear, after a variable time interval that depends on the operating hours of the feeding device 10, the dispenser 15 may have a larger outlet section 17 with respect to the corresponding section in the initial operating conditions.

For this reason, a spray area 18 is obtained with a shape and dimensions other than those desired and, consequently, an incorrect decoration of the flat object O is obtained.

The supply device 10, according to the present invention, also comprises pressure measurement means 19, associated with the second tube 16, configured to detect the pressure value of the fluid / semi-fluid product L in said tube.

According to the embodiments of the present invention, the supply device 10 comprises a management and control unit 20, configured to manage the operation of the pumping unit 13.

In particular, the control unit 20 is configured to generate an operational signal that will be sent to the pump unit 13.

Such a signal can be generated, for example, by a proportional integral (PI) controller or a proportional integral derivative (PID) circuit.

According to one aspect of the invention, the pressure measurement means 19 may be operatively associated with the management and control unit 20, as illustrated in figure 1.

In this case, the management and control unit 20 can include memorizing means, not illustrated, configured to memorize the pressure values of the fluid / semi-fluid product L measured by the pressure measurement means 19 in predetermined time intervals, in order to assess the evolution of the pressure of the fluid / semi-fluid product L inside the second tube 16 for a long time.

According to a variant embodiment, not illustrated, said pressure measurement means 19 can be independent, that is, not associated with the management and control unit 20.

In this case, the pressure measurement means 19 can be configured as a pressure gauge provided with display means, not illustrated, configured to allow the visualization of the instantaneous value of pressure of the fluid / semi-fluid L by an operator.

According to possible embodiment variants, the display means can be physically connected to the pressure measurement means 19 or associated with a mobile device, used by the operators, with a wireless connection to the pressure measurement means 19.

According to a characteristic aspect of the present invention, the feeding device 10 also comprises flow measurement means 21, preferably associated with the second tube 16 to measure the value of the flow rate of the fluid / semi-fluid product L.

According to the embodiments, the flow measurement means 21 may also be located in the first tube 14, immediately above the pump unit 13 (see the broken line in Figure 1) and associated with the pump unit. management and control 20, to which they send the detected flow value of the fluid / semi-fluid product L.

By way of non-limiting example, the flow measurement means 21 may be chosen from a group comprising volumetric lobe, geared, nutating disc, electromagnetic meters.

In a possible mode of use of the supply device 10, the management and control unit 20, through the values measured by the flow measurement means, acts on the pumping unit 13 in order to have a controlled flow of the fluid / semi-fluid L inside the second tube 16.

In fact, if the flow rate of the fluid / semi-fluid product L is constant, if the outlet section 17 increases due to wear, there is a decrease in the pressure of the fluid / semi-fluid product L inside the second tube 16, which is detected by the pressure measuring means 19.

According to an embodiment, through the display means associated with the pressure measurement means 19, an operator can check the change in the pressure value and, consequently, stop the feeding device 10 to replace the dispenser 15 .

Alternatively, according to a variant, the management and control unit 20, through the pressure measurement means 19, is capable of evaluating whether the pressure value of the fluid / semi-fluid product L is approaching a preset threshold value and consequently it can automatically stop the feeding device 10 and indicate the need to replace the dispenser 15.

Other embodiments of the invention also relate to a method of feeding fluids or semi-fluids L related to the embodiments of the feeding device 10 described above, which provides:

- the suction by the pumping unit 13 of the fluid / semi-fluid product L, located in the tank;

- the transfer of the fluid / semi-fluid product L from the reservoir 11 to the dispenser 15, through connection tubes;

- the measurement of the flow rate of the fluid / semi-fluid product L inside a section of the connection tubes comprised between the pumping unit and the dispenser 15 through the flow measurement means 21;

- control of the flow of the fluid / semi-fluid product, thanks to the actuation of the pumping unit by the management and control unit, based on the values measured by the flow measurement means, to keep the product flow constant fluid / semi-fluid at least in said section of the connection tubes;

- the monitoring of the pressure of the fluid / semi-fluid product inside said section through the pressure measurement means.

Other embodiments also relate to a decorating machine for decorating flat objects O, for example ceramic tiles.

According to the invention, the decoration machine (not shown) comprises at least one feeding device 10 for fluid or semi-fluid products according to the present invention, and is provided with conveyor means 28 that move the objects O in the direction indicated by the arrow F .

It is clear that modifications and / or parts can be added to the feeding device 10, to the corresponding feeding method and to the corresponding decorating machine, without departing from the scope of the present invention.

It is also understood that, although the invention has been described with reference to specific examples, a person skilled in this field will obviously be able to make many other equivalent forms of a feeding device 10, of the corresponding feeding method and of the corresponding machine for decorate, having the characteristics expressed in the claims and therefore included in the scope of protection defined by the latter.

Claims (1)

1. Method for feeding fluid or semi-fluid products into a device for feeding fluid or semi-fluid products for the decoration of ceramic flat-surface objects, comprising a tank (11) suitable for containing a fluid / semi-fluid product (L), dispensing means (15) of said fluid / semi-fluid product, a pumping unit (13) connected to said reservoir (11) and to said dispensing means (15) through connection tubes (14, 16) and configured to transfer said product fluid / semi-fluid (L) from said reservoir (11) towards said dispensing means (15), pressure measurement means (19) associated with said connection tubes (14, 16), said feeding device being characterized by the fact that comprising a management and control unit (20) is configured to control said pumping unit (13) and monitor the state of wear of the dispensing means (15) and further comprising measuring means of the flow rate (21) of the fluid / semi-fluid product (L), configured to control the flow of the fluid / semi-fluid product and connected to said management and control unit (20), so that the latter controls said pumping unit (13) to maintain a substantially constant flow rate of said fluid / semi-fluid product (L), being configured to monitor the state of wear of dispensing means (15) and report malfunctions associated with said wear, which provides for the phases of: - sucking, by means of the pumping unit (13), said fluid / semi-fluid product (L), located in said tank (11); - transferring said fluid / semi-fluid product (L) from said reservoir (11) towards said dispensing means (15), with connection tubes (14, 16); characterized by the fact that the method also foresees the phases of: - measuring the flow rate of the fluid / semi-fluid product (L) inside a section of said connection tubes (16) comprised between said pumping unit (13) and said dispensing means (15) through said means for measuring the flow rate (21); - control the flow of the fluid / semi-fluid product, by actuating said pumping unit (13) by said management and control unit (20), depending on the values detected by the flow measurement means (21) , to keep the flow rate of the fluid / semi-fluid product constant at least in a section of said connection tubes (14, 16) extending between said pumping unit (13) and said dispensing means (15); - monitoring the pressure of the fluid / semi-fluid product (L) inside said section through said pressure measurement means (19), so that the pressure measurement means (19) provide a pressure signal indicating the state of wear of the dispensing means (15).