KR20200094158A - Plant for drying pre-treated flexible sheet products - Google Patents

Abstract

A drying plant (1) for drying a pretreated flexible sheep product having at least one side in which a layer of chemical compound has been previously deposited, the system (1) for supplying sheet products in one direction (L) A supply means (2), a drying means (3) for drying the product to be supplied, said drying means being each chamber for applying an alternating electromagnetic field in the RF range and a chamber designed for the supply means (2) to pass through the chamber. A control for controlling the drying means 3 and the generator 11 and/or the applicator 10, having at least an open operating unit 5 with at least one applicator 10 connected to the 11. Unit 16 is included. The field has an oscillation frequency in the range of 300 kHz to 300 MHz, preferably 27.12 MHz, and is provided with at least one blowing means 18 and/or at least one suction means 19 for delivering hot air. The control unit 16 is configured to change the speed of the supply means or the application time of the electromagnetic field. Sensor means are additionally provided for detecting one or more physical and/or thermodynamic parameters of the operating unit 5 and the temperature of the sheet and controlling the means 2, 18, 19 in isolation or in combination with each other, said means 2, 18, 19) perform complete drying of the chemical compound layer.

Description

Plant for drying pre-treated flexible sheet products

The present invention is generally used for drying pre-treated flexible sheet products, such as industrial hides, skins, imitation leathers or leather derivatives, which find applications in the tanning field in general. It is about a plant.

After a variety of tanning, re-tanning and dyeing treatments, the leather often exhibits surface defects due to poor preservation of the leather after naturally formed or peeled off (through scratching, barbed wire or contact with thorns) due to animal survival. It is known to indicate.

In this case, once the leather has dried, it undergoes a surface treatment process, commonly known as a finishing step, whereby such defects are eliminated or less visible for better use of the leather.

During the chemical finishing step, chemical compounds, which are generally in liquid form, are deposited on the leather, forming a grain side layer that can be of varying thickness or elastic or rough depending on the finishing step and the type of leather.

The compound is initially deposited by a predetermined amount on the particle side of the leather, and subsequently dried to form a layer that bonds with the fiber, whereby it is integrated with the leather.

Finishing chemical compounds are usually applied using sprays or rotating rollers that come into contact with the leather when it is supplied.

Moreover, the drying process for chemical compounds is usually carried out using one oven or infrared, catalytic gas and more often a hot air operated tunnel.

For this purpose, the plant for the surface treatment of leather includes one or more drying units, hot air is delivered to the drying units by a high flow compressor and blower, and the flow rate can reach several thousand m ³ /h. Drying temperatures in these installations typically range from 80°C to 160°C.

The first disadvantage of these plants is the high hot air flow to dry the leather and the high manufacturing energy costs associated with plant operation.

An additional disadvantage is that the dried leather, as described above, has a very high surface temperature and is not easy to handle and stack.

Thus, the completely dry leather can be cooled by using a cooling device, for example, a cold air cooler, which has a high power consumption.

Another disadvantage is that the high temperature drying process is not uniform and tends to change the "hands" of the leather, ie harder and less soft than in the unfinished state.

Finally, the shrinking effect of the hot drying process will result in shrinking of the leather, thereby resulting in a significant reduction in the useful leather area and a reduction in the final intrinsic value of the treated leather.

To at least partially eliminate this disadvantage, leather drying plants have been developed that use electromagnetic fields whose frequencies are within the radio frequency range.

EP2935631 by the applicant of the present invention discloses a plant for drying a leather having a pair of operating units each comprising a radio frequency electromagnetic field applicator located in a chamber and connected to each high-frequency AC voltage generator.

That is, the two operating units are configured to dry different finishing chemical compounds previously deposited on the leather by one or more deposition units.

The first disadvantage of such a facility is that such a plant does not allow the feedback reaction control of the operation of the generator and applicator depending on the operating state of the drying unit.

An additional disadvantage is that the leather has to go through two drying processes for an optimal finish. This disadvantage entails an increase in overall processing costs.

Another disadvantage is that the electrode is placed in a drying unit in a conventional geometry that cannot be changed to optimize the application of an electromagnetic field on the leather when it is supplied.

Still another drawback is that the use of a single radio frequency limits the drying efficiency of chemical compounds and leather and causes the accumulation of residual moisture in the drying unit.

In light of the prior art, the technical problem solved by the present invention is the combined adjustment and control of the various thermal and hydrodynamic parameters of the plant for effective and rapid drying of the finished chemical compound after the finished chemical compound is deposited on the product. Is to guarantee.

The object of the present invention is to solve the above-mentioned problem by providing a drying plant for drying a highly effective and relatively cost-effective pretreated flexible sheet product.

It is a particular object of the present invention to provide a plant that allows combined feedback response control and adjustment of the sheet product drying component as described above.

It is a further object of the present invention to provide a plant for quickly and effectively drying the finished chemical compound irrespective of the amount of compound deposited on the sheet product as described above.

Another object of the present invention is to provide a plant capable of optimizing the overall energy cost as described above.

Still another object of the present invention is to provide a plant as described above that can use a combination of different drying modes.

A further object of the present invention is to provide a plant capable of removing residual moisture accumulated in the drying unit as described above.

Still another object of the present invention is to provide a plant capable of optimizing the application efficiency of the product by adjusting the electromagnetic field applicator as described above.

As will be explained more clearly below, these and other purposes are fulfilled by a plant for drying the pre-treated flexible sheet product as defined in claim 1, in which the sheet product is transferred onto the sheet product. It has at least one side with a chemical compound layer deposited on it.

The plant includes supply means for supplying a sheet product in the longitudinal direction and drying means for drying the supplied product.

The drying means has at least one operating unit with a chamber, the supply means passing through a chamber having at least one applicator in the chamber and connected to each generator to apply an AC electromagnetic field within the RF range. And is designed to dry the chemical compound deposited on the product during the treatment step.

The plant also includes at least one control unit that controls the generator and/or applicator. The AC electromagnetic field has an oscillation frequency in the range of 300 kHz to 300 MHz, preferably 27.12 MHz, with tolerances in the allowed ISM band, and/or at least one blowing means 18 for transmitting hot air and/or At least one suction means 19 is provided.

The blowing means is controlled to deliver hot air at a predetermined temperature, and the suction means is configured to suck moisture removed from the chamber during drying. The control unit is configured to change the speed of the supply means or the time of application of the electromagnetic field, and the sensor means can determine the thermodynamic parameters of one or more physical and/or at least one operating unit, such as the temperature in the chamber and/or the temperature of the residual moisture and leather. It is provided in the chamber to detect and also control the feeding means, and the blowing means and the suction means are separated or combined with each other to ensure complete drying of the chemical compound layer.

Advantageous embodiments of the invention are defined according to the dependent claims.

For further features and advantages of the present invention see the detailed description of some preferred and non-exclusive embodiments of a plant for drying a pre-treated flexible sheet product such as an industrial leather, skin, artificial leather or leather derivative according to the present invention. This will become clearer, which is described as a non-limiting example with reference to the accompanying drawings:
1 is a perspective view of a drying plant of the present invention;
2 is a side view of the plant of FIG. 1;
3 is a front view of the plant of FIG. 1;
4 is an exploded side view of the plant of FIG. 1;
5 is an exploded side view of the plant of FIG. 4.

Referring to the figure, a plant for drying a pre-treated flexible sheet product such as industrial leather, skin, artificial leather or leather derivatives is shown, which is generally indicated by the number 1.

Leather is known to include a particle side and a flesh side, with a layer of a finished chemical compound previously deposited on either side, preferably on the side of the particle.

The process of drying the chemical compound carried out by the plant 1 of the present invention imparts special aesthetic and tactile properties to the leather.

The finishing chemical compound can be deposited by known deposition means, such as spray or roll deposition means. The rule deposition means may apply one layer to the layer of chemical compound on at least one side of the sheet product with a surface density ranging from 0.01 g/m ² to 500 g/m ² , preferably from 5 g/m ² to 150 g/m ² It is configured to deposit.

For example, the deposited chemical compound can act as a base, color and finish coating, and can be selected from the group comprising polymer compounds such as acrylic and polyurethane resins, inorganic compounds such as iron oxide, pigments and natural compounds.

In a preferred embodiment of the invention, the plant 1 comprises supply means 2 for supplying sheet products in the longitudinal direction L and drying means 3 for drying the product when it is supplied.

As is known per se, the feeding means 2 can comprise an annular belt or wire conveyor 4 with a belt or wire tensioned by an end roller, the conveyor feeding for sheet products to its upper section. Form a plane (π).

Moreover, the drying means 3 comprises at least one operating unit 5 with a chamber 6 through which the supply means 2 pass.

That is, the chamber 6 can be at least partially closed and defined by a boxed structure 7 with an inlet 8 and an outlet 9 for passage of the supply means 2.

4 and 5, the drying chamber 6 has an oscillation frequency in the range of 300 kHz to 300 MHz to dry the chemical compound deposited therein during the treatment step, regardless of the surface density of the product therein. It includes at least one applicator 10 connected to a high frequency voltage generator 11 to apply an AC electromagnetic field.

Preferably, the generator 11 is configured to have a value of 27.12 MHz with a tolerance in the ISM band where the oscillation frequency of the electromagnetic field is allowed.

Thereafter, the electromagnetic field applied to the flexible sheet product supplied to the operation unit 5 can heat the chemical compound to a predetermined temperature.

The generator 11 is in a group comprising a power triode, an inverter-controlled power triode, a modular electronic power amplifier, a converter power amplifier with possible solid-state technology, or combinations thereof. Can be selected.

The applicator 10 comprises at least one series of electrodes arranged in the drying chamber 6 and connected to a pair of terminals of the generator 11.

In a first embodiment of the present invention, not shown, the electrode comprises at least a pair of substantially parallel plates made of a conductive material each having an anode and a cathode function to apply a radio frequency electromagnetic field. It can contain.

The plate is arranged at an adjustable distance below and above the supply plane π to selectively change the intensity of the electromagnetic field applied to the product during the processing step.

Alternatively, the electrode comprises first and second series 12 and 13 of transverse bars made of a conductive material, which are respectively connected to the first and second terminals of the generator 11. .

One series of electrodes 12 are connected in parallel and have a cathode function, and the other series of electrodes 13 are also connected in parallel and have an anode function.

As described above for the plate, the bars 12 and 13 are also arranged at an adjustable distance, whereby the electromagnetic field strength can be adjusted.

For example, as shown in the figure, the bars 12 of one series are fixed to the longitudinal beams 14 respectively moving in the vertical direction by suitable driving means 15, so that the first bars are bars of another series. It can be moved toward or away from (13).

In the second embodiment of the present invention, as well illustrated in FIGS. 4 and 5, the first and second series 12, 13 can be disposed below or above the feed plane π of the conveyor 4. .

That is, the first series bar 12 is offset from the second series bar 13 in the longitudinal direction and alternates with the second series bar 13, and each first series bar 12 is adjacent to the second series bar ( In combination with 13), each applicator 10 can be formed.

Also in a third alternative embodiment, not shown, one series bar 12 may be disposed below the supply plane π and another series bar 13 may be disposed above the supply plane π.

As in the second embodiment, the first series bar 12 is offset from the second series bar 13 in the longitudinal direction regardless of whether it is disposed below or above the feed plane and alternates with the second series bar 13.

Also in this embodiment, each bar of the first series bar 12 disposed below or above each of the bars with a second series bar 13 disposed below or above and offset longitudinally from the first series. The applicator 10 is formed.

Moreover, the plant comprises a generator 11 and/or applicator 10 and/or supply means 2 for complete drying of chemical compounds previously deposited on at least one side of the sheet product in the operating unit 5. ) At least one control unit (16) configured to control.

For example, the control unit 16 sets the speed of the supply means 2 to a predetermined value in the range of 0.01 m/min to 30 m/min, preferably in the range of 6 m/min to 15 m/min, or the time for applying the electromagnetic field Or it can be configured to change the intensity.

Moreover, the control unit 16 may include a control algorithm and a memory portion installed in the control unit. The memory portion may store data and information corresponding to a plurality of drying programs.

The software can be configured to select the most suitable drying program depending on the specifics of the sheet product being processed.

Additionally, as is well illustrated in Fig. 1, the control unit 16 comprises interface means 17, which are configured to be operated by an operator for the management of the control unit.

Advantageously, the operating unit 5 may comprise at least one air injection means 18 and/or at least one suction means 19 in fluid communication with the drying chamber 6.

The spraying means 18 and the suction means 19 can also be connected to the control unit 16 to control the drying temperature of the sheet product and further to dry the chemical compound.

The injection means 18 can be controlled to deliver hot air at a predetermined temperature, and the suction means can be configured to suck moisture removed during drying from the chamber 6.

Sensor means, not shown, are further provided in the drying chamber 6 and can be connected to the control unit 16.

The sensor means are configured to detect one or more physical and/or thermodynamic parameters of the operating unit 5, for example the temperature of the chamber and/or the temperature of the leather and/or residual moisture in the chamber 6.

Moreover, the control unit 16 comprises at least one generator 11, an applicator 10, and at least one separated from or combined with each other based on a possible physical and/or thermodynamic parameter detected by the sensor means. It can be configured to control the supply means 2 either manually or automatically.

Thus, the change in the operating conditions of the above-described components by the control unit 16 will be faster and more accurate compared to existing plants.

The temperature of the sheet product as a result of the drying process performed by the operating unit 5 is determined according to the environmental conditions of the use of the plant 1.

This feature enables immediate handling and loading of the sheet product by the operator after drying, greatly reducing the overall processing time.

In addition, this feature makes it possible to avoid the use of cold air coolers with high cost and maintenance requirements in the downstream part of the operating unit.

Leathers, skins and artificial leathers that are subjected to steps by the above-described plant are less prone to reducing useful leather areas after treatment, even increasing useful leather areas, and having initial softness without being affected by various processing steps. Turned out.

In the embodiment of the figure, the system 1 comprises a plurality of operation units 5A, 5B, 5C with one operation unit downstream of another operation unit in the longitudinal direction of the supply L.

Obviously, the number of units 5A, 5B, 5C may also be different from that shown in the drawings without departing from the scope of the present invention.

The units 5A, 5B, 5C can be connected to the supply means 2 described above, otherwise the operator may have to manually transfer the sheet product from one operating unit to another at the end of each drying process.

Each unit 5A, 5B, 5C has at least one respective generator 11A, 11B, 11C, one respective applicator to generate an electromagnetic field of suitable strength within each chamber 6A, 6B, 6C. (10A, 10B, 10C) and one possible control unit (16A, 16B, 16C).

Additionally, each operating unit 5A, 5B, 5c may include respective blowing means 18A, 18B, 18C and/or suction/drying means 19A, 19B, 19C and/or sensors , They are configured to operate as described above for at least one operating unit, and are connected to the control units 16A, 16B, 16C.

Within the concept of the invention disclosed in the appended claims, the plant of the invention is capable of numerous modifications and variations. Without departing from the scope of the present invention, all details of the present invention can be replaced by other technically equivalent parts, and the material can be changed according to different needs.

Although the plant has been described with specific reference to the accompanying drawings, the numbers referenced in the present disclosure and claims are used only for better clarity of the present invention and are not intended to limit the claimed scope in any way.

Industrial availability

In particular, the present invention can be applied industrially, since the present invention can be produced on an industrial scale in a tanning factory that processes surfaces of leather, skins, artificial leather and derivatives.

Claims (10)

A drying plant (1) for drying a pre-treated flexible sheet product having at least one side with a previously deposited chemical compound layer, said plant (1) comprising:
-A supply means (2) for supplying the sheet product (M) in the longitudinal feed direction (L);
-As a drying means (3) for drying the product when the product is supplied, the drying means (3) is provided with a chamber (6) designed for the supply means (2) to pass through and inside the operating unit (5) Has at least one operating unit 5 with at least one applicator 10, which is connected to each generator 11 for application of an AC electromagnetic field in the RF range during the processing step The drying means (3) for drying the chemical compound deposited on the product;
-In the drying plant (1) comprising at least one control unit (16) for controlling the generator (11) and/or the applicator (10),
The AC electromagnetic field has an oscillating frequency in the range of 300 kHz to 300 MHz, preferably 27.12 MHz, with a tolerance in the allowed ISM band, and/or at least one blowing means 18 for transmitting hot air and/or At least one suction means 19 is provided in the chamber 6, the blowing means 18 is controlled to deliver hot air at a predetermined temperature, and the suction means 19 are removed from the chamber 6 Configured to suck the extracted water during the drying step, the control unit 16 is configured to change the speed of the supply means 2 or to change the application time of the electromagnetic field,
One or more physical and/or thermodynamic parameters of the at least one operating unit 5, for example the temperature in the chamber and/or the temperature of the residual moisture and leather, respectively, and also controls the feeding means 2 In order to do so, a sensor means is provided in the chamber 6, characterized in that the blowing means 18 and the suction means 19 are separated or combined with each other to allow complete drying of the chemical compound layer,
Drying Plant (1). According to claim 1,
The electromagnetic field generator 11 is at least one of a power triode, an inverter-controlled power triode, a modular electronic power amplifier, a converter power amplifier, an amplifier with solid-state technology, or a combination thereof. Characterized in that it is selected from the group comprising:
Drying Plant (1). According to claim 1,
The supply means (2)
Characterized in that it comprises a belt or wire conveyor (4) having a belt or wire tensioned by an end roller and forming a supply plane (π) in its upper section.
Drying Plant (1). The method of claim 2 or 3,
The applicator 10 is characterized in that it comprises at least one electrode series disposed in the chamber 6 and connected to a pair of terminals of the generator 11,
Drying Plant (1). According to claim 4,
The electrode comprises at least a pair of substantially parallel plates made of a conductive material each having an anode and a cathode function for application of the radio frequency electromagnetic field, the plate comprising the supply plane ( Characterized in that the supply plane (π) is located below and above each at an adjustable distance from π),
Drying Plant (1). According to claim 4,
The electrode comprises first and second series (12, 13) of transverse bars made of a conductive material, wherein the series (12, 13) of transverse bars are connected to the first and second terminals of the generator (11). Each connected and configured such that the bars are located at an adjustable distance from each other,
Drying Plant (1). The method of claim 6,
The bars of the first and second series (12, 13) are located below or above the conveyor (4), the bars of the first series (12) are offset in the longitudinal direction from the bars of the second series (13) and the first Characterized by alternating with the bars of the 2 series (13),
Drying Plant (1). The method of claim 6,
The bars of the first series 12 are located below the supply plane π, the bars of another series 13 are located above the supply plane π, and at least the bars of the first series 12 are Characterized by being offset in the longitudinal direction from the bars of the at least one second series (13) and alternately with the bars of the at least one second series (13),
Drying Plant (1). The method according to any one of claims 1 to 8,
A plurality of operation units 5A, 5B, 5C having one operation unit downstream of another operation unit in the supply direction L,
Drying Plant (1). The method of claim 9,
At least each of the operating units 5A, 5B, 5C can be connected to at least one control unit 16A, 16B, 16C to generate an electromagnetic field of suitable intensity within the respective chambers 6A, 6B, 6C Comprising one respective generator 11A, 11B, 11C and/or one respective applicator 10A, 10B, 10C,
Drying Plant (1).

Images