[DESCRIPTION]

[Invention Title]

APPARATUS AND METHOD FOR TINTING OF LEATHER

[Technical Field]

The present invention relates to an apparatus for tinting, and in particular, to an

apparatus and a method for the tinting of leather.

[Background Art]

Leather is typically produced by a series of processes including the beam house

process, performed on pelt or skin obtained from the hide of an animal; the tanning

process, which performs tanning on the leather to increase its flexibility and heat-

resistance; the neutralizing, tinting, and fatliquoring processes; and the finishing process,

which includes drying and coating. These procedures improve the durability and the

settling property, to yield the final leather product.

Leather products are used in a variety of fields, with various animal hides and

corresponding tanning methods used in each field. Moreover, in recent times the

processes of finishing leather have come to include not only the overall tinting to a

specific color, but also various other finishing treatments such as embossing and suede-

treatment, etc.

The tinting of leather according to prior art is performed using dye or paint. Most

of these tinting materials are materials previously used in dyeing fabrics, with the

appropriate tinting methods used according to the type of leather, tanning method, and

usage.

Since leather has different properties for each type, the actual working of leathers

depends greatly on experience. For example, even when tinting leather in a single color,

certain leather products may require long working times, complicated procedures, or

several repetitions of the same operation. Thus, it was difficult to mass-produce dyed

products of an identical design, or to dye leather to form detailed or polychromatic

images.

Meanwhile, the tinting of textiles according to prior art included: smoothing out a

textile by means of a plurality of drive rollers and feeding to a conveyor device;

performing tinting with a printing unit by a screen printing method, etc., on the textile

attached to and conveyed by the conveyor device; and then drying in a drying box to

complete the tinting process.

During this process, the textile is made to adhere to the conveyor device by coating

the surface of the conveyor device with adhesive and applying heat to the surface of the

conveyor device, to allow a smooth printing operation on the textile, while at the end

portion of the conveyor device, the surface coated with adhesive is cleaned to prevent

dust and foreign substances, etc., from sticking to the surface of the conveyor device.

If this conventional textile tinting apparatus may also be used for tinting leather, an

inexpensive and convenient means of mass production may be obtained, as no

additional equipment is necessary.

However, there are problems in using the conventional textile tinting apparatus in

that, first, it is difficult to use conventional drive rollers, since leather products have

greater thickness than do textiles, have lower uniformity in thickness, and unlike textiles

are fed in single sheets; second, the tinting of leather is not completed as quickly as the

tinting of textiles; and third, the tinted leather is subject to shrinkage when dried in the

drying box.

[Disclosure]

[Technical Problem]

The present invention aims to provide an apparatus and method for the tinting of

leather, with which the tinting of leather may be performed inexpensively and

conveniently using conventional textile tinting equipment, without using an apparatus

exclusively for tinting leather.

[Technical Solution]

One aspect of the invention provides a leather tinting apparatus comprising a drive

roller; a conveyer belt adjacent to the drive roller which conveys leather fed from the

drive roller; a printing unit positioned at an upper portion of the conveyor belt which

performs tinting on the leather; and a drying unit positioned after the printing unit in the

direction of conveyance of the conveyor belt, wherein the drive roller comprises two

rollers elastically supported by each other which include elastic material.

The drive roller may comprise a first roller; a second roller in rolling contact with

the first roller; a drive part supplying rotational force on the first roller or the second

roller; a frame joined to the rotational axis of the second roller with an elastic body

interposed in-between; an adjustment axis screw-joined to the frame which has one end

in contact with the rotational axis and the other end protruding out of the frame; and a

handle joined to the other end of the adjustment axis.

Adhesive may be coated onto the surface of the conveyor belt, where the adhesive

may preferably include any one or more of acetone, thinner, and toluene. The conveyor

belt may comprise a heat supply device in its interior.

Also, the leather tinting apparatus may further comprise a control part for adjusting

the conveyance speed of the conveyor belt or the tinting speed of the printing unit,

where the control part may adjust the tinting speed in correspondence with the

conveyance speed or adjust the conveyance speed in correspondence with the tinting

speed.

The drying unit may comprise one or more electric heaters, one or more fans

positioned behind the electric heaters, and a reflective board behind the fans

surrounding the fans and the electric heaters. The leather tinting apparatus may further

comprise a cleaning device after the drying unit in the direction of conveyance of the

conveyor belt, which cleans the surface of the conveyor belt.

Also provided is a method of tinting leather comprising (a) feeding the leather, by

inserting the leather between two rollers, which are elastically supported by each other

and which include elastic material; (b) attaching the leather on a conveyor belt and

conveying; (c) tinting the leather by means of a printing unit positioned at an upper

portion of the conveyor belt; and (d) drying the leather by supplying heat to the leather.

It may be preferable to have adhesive coated on the surface of the conveyor belt,

including any one or more of acetone, thinner, and toluene. It may be preferable to

adjust the conveyance speed of the conveyor belt and the tinting speed of the printing

unit to be in correspondence.

An operation of cleaning the surface of the conveyor belt may further be included

after the operation (c) or the operation (d).

Also provided is leather tinted by such method of tinting leather.

[Advantageous Effects]

According to the present invention comprised as above, leather can be tinted

inexpensively and conveniently, simply by replacing the drive roller for feeding leather

and the drying unit for drying the tinted leather in a conventional textile tinting

equipment.

[Description of Drawings]

Fig. 1 is a side view of a leather tinting apparatus according to an embodiment of

the present invention.

Fig. 2 is a plan view of a leather tinting apparatus according to an embodiment of

the present invention.

Fig. 3 is a side view of a drive roller in a leather tinting apparatus according to an

embodiment of the present invention.

Fig. 4 is a front view of a drive roller in a leather tinting apparatus according to an

embodiment of the present invention.

Fig. 5 is a plan view of a printing unit in a leather tinting apparatus according to an

embodiment of the present invention.

Fig. 6 is a longitudinal cross section of a drying unit in a leather tinting apparatus

according to an embodiment of the present invention.

Fig. 7 is a latitudinal cross section of a drying unit in a leather tinting apparatus

according to an embodiment of the present invention.

Fig. 8 is a flowchart illustrating a leather tinting method according to an

embodiment of the present invention.

[Mode for Invention]

Hereinafter, embodiments of the apparatus and method for the tinting of leather,

according to the invention will be described in more detail with reference to the

accompanying drawings. In the description with reference to the accompanying

drawings, those components are rendered the same reference number that are the same

or are in correspondence regardless of the figure number, and redundant explanations

are omitted.

Fig. 1 is a side view of a leather tinting apparatus according to an embodiment of

the present invention, and Fig. 2 is a plan view of the leather tinting apparatus according

to an embodiment of the present invention. Referring to Figs. 1 and 2, a drive roller 10,

conveyor belt 20, printing unit 30, drying unit 40, cleaning device 50, and control part

60 are illustrated.

The leather tinting apparatus of the present invention is an improvement of the

conventional textile tinting apparatus such that renders it suitable for leather products,

with modifications and replacements mainly in the leather feeding portion, the tinting

process control part 60, and the portion for drying.

That is, the leather tinting apparatus of the present invention is composed of a drive

roller 10 for feeding the leather to be tinted, a conveyor belt 20 which conveys the

leather fed from the drive roller 10, a printing unit 30 for performing the tinting

procedures on the conveyed leather, and a drying unit 40 for drying the tinted leather.

The order of the components along the route in which the leather is conveyed by

the conveyor belt 20, is the drive roller 10, the conveyor belt 20 and printing unit 30,

and then the drying unit 40. As the printing unit 30 is the unit that performs tinting, by

methods such as screen-printing, from above the leather being tinted, it is preferably

located at an upper portion of the conveyor belt 20.

As the leather tinting apparatus according to the present invention, unlike the

conventional textile tinting apparatus, deals with leather, which is supplied in single

sheets and which has a great thickness and large deviations in thickness, the structure of

the drive roller 10 for feeding the object of tinting is made different from that of prior

art.

In other words, whereas the drive roller 10 according to prior art applied a tensile

force on the textile by means of a plurality of rollers, in order to convey the

unidirectionally extending textile in a smoothly stretched out state, the drive roller 10

according to the present invention deals with single sheets of leather, so that it is

difficult to apply tensile forces on the leather, and the leather is fed in a mode such as of

rolling by means of a drive roller 10 comprising a pair of rollers.

While the thickness of a textile is generally 0.2 to 0.3 mm, the typical thickness of

leather is 2 to 3 mm, and as leather has a great thickness as well as large deviations in

thickness in different portions, the leather may be supplied in a mode such as of rolling

by means of a pair of rollers, to achieve an effect comparable to the effect of the

plurality of rollers in a conventional textile tinting apparatus.

That is, the drive roller 10 according to the present invention smoothens out the

leather to be tinted and reduces the deviations in thickness, while it supplies the leather

in single sheets to the conveyor device for tinting.

To this end, the drive roller 10 according to the present invention is preferably

composed of two rollers, which are elastically supported by each other and which

include elastic material, joined together in rolling contact. Detailed descriptions on the

structure of the drive roller 10 will be provided later.

Fig. 3 is a side view of a drive roller in a leather tinting apparatus according to an

embodiment of the present invention, and Fig. 4 is a front view of the drive roller in a

leather tinting apparatus according to an embodiment of the present invention. Referring

to Figs. 3 and 4, a drive roller 10, first roller 12, second roller 14, rotational axis 15,

elastic body 16, adjustment axis 17, frame 18, and handle 19 are illustrated.

The drive roller 10 is a component for feeding the leather in a mode such as of

rolling, a basic composition of which includes two rollers that are in rolling contact

elastically. As mentioned earlier, each roller includes elastic material such as rubber.

Thus, when a rotational force is applied to both or one of the two rollers and the

leather is inserted between the two rollers, a gap is formed between the two rollers

because they are elastically supported by each other, and the leather is fed in through the

gap in a mode such as that of rolling.

Each roller includes elastic material such as rubber, and since they contact each

other elastically, each of the rollers press the leather while the leather is fed in, whereby

the leather is stretched smooth and deviations in its thickness are reduced.

Not only does leather, which is the object of tinting, have a great thickness, it may

also have substantially varying thicknesses according to its type, so that in order to feed

leathers of various thicknesses into the tinting apparatus, it is desirable that the drive

roller 10 be composed to allow the adjustment of the gap between the two rollers.

To this end, the frame 18 is joined to the rotational axis 15 of the first roller 12 or

the second roller 14, the adjustment axis 17 having one end in contact with the

rotational axis 15 and the other end protruding out of the frame 18 is screw-joined to the

frame 18, and the handle 19 for rotation is joined to the other end of the adjustment axis

17.

Thus, the adjustment axis 17 may be rotated by rotating the handle 19, and as the

adjustment axis 17 screw-joined with the frame 18 is moved relative to the frame 18, to

widen the gap between the two rollers, the handle 19 is rotated such that the adjustment

axis 17 moves out of the frame 18, and to close the gap between the two rollers, the

handle 19 is rotated such that the end of the adjustment axis 17 touches the rotational

axis 15 and presses the rotational axis 15.

When the adjustment axis 17 is moved by the rotation of the handle 19 such that

the end of the adjustment axis 17 is moved in a direction away from the rotational axis

15, in order to make the rotational axis 15 of the first roller 12 or second roller 14 move,

in a manner that increases the gap between the two rollers, while maintaining contact

with the end of the adjustment axis 17, it is desirable that the first roller 12 or second

roller 14 be joined with the frame 18 with an elastic body 16 positioned in-between.

Thus, the elastic body 16 pulls the rotational axis 15, and the adjustment axis 17

pushes rotational axis 15, so that the gap between the two rollers may be adjusted by

operating the handle 19.

However, the present invention is not necessarily limited to using the above

composition for adjusting the gap between rollers, and it is to be appreciated that any

composition may be used for adjusting the gap between the two rollers within a scope

apparent to those skilled in the art, such as a combination of an elastic body 16, e.g. a

spring, etc., for pushing the rotational axis 15, and an adjustment axis 17 joined to the

rotational axis 15 for pulling the rotational axis 15.

Meanwhile, by using elastic material such as rubber for the material of each of the

rollers, leather of varying thicknesses may be fed in a mode such as of rolling, even

when there is no such composition for adjusting the gap between the two rollers.

Therefore, the two "elastically supported" rollers of the present invention

collectively includes the case in which an elastic body 16 is joined with an adjustment

axis 17, the case in which rollers including elastic material are joined to have rolling

contact, and the case where both of the two cases above apply.

Fig. 5 is a plan view of a printing unit in a leather tinting apparatus according to an

embodiment of the present invention. Referring to Fig. 5, a printing unit 30, a printing

area 32, a printing area 32, and printing arms 34 are illustrated.

The printing unit 30 of a leather tinting apparatus according to the present

invention utilizes a printing unit 30 for tinting textiles according to prior art, and its

basic composition and printing mode are the same as those of prior art. That is, the

tinting of textiles according to prior art is performed by applying heat on a conveyor

belt 20 coated with adhesive to activate the adhesive and feeding the textile, so that the

textile is attached to the conveyor belt 20 and secured such that the textile does not

move during the tinting procedure, and then tinting the leather located in the printing

area 32 by a method such as silk-screening, etc., using printing arms 34.

In the case of leather tinting, however, there is less risk of the leather moving

during the tinting procedure, due to the thickness and weight of the leather itself, and

the leather has a superior ability to adhere to the conveyor belt 20, so that there is less

need for attaching and securing the leather onto the conveyor belt 20. Coating the

conveyor belt 20 with adhesive may be a cause of dust or foreign substances sticking to

the conveyor belt 20, which can incur malfunctioning in the machinery or degrading of

tinting quality.

Thus, the conveyor belt 20 in a leather tinting apparatus of the present invention

may also have adhesive coated on its surface for securing the leather to be tinted, and

may have a heat supply device installed in its interior to supply heat. However, since

leather does not require as strong an adhesion as do textiles, as was discussed earlier, it

is desirable to use a diluted form of conventional adhesive. For diluting the adhesive,

such materials as acetone, thinner, and toluene, etc., are mixed with the adhesive.

Using diluted adhesive does not present a problem in securing the leather to be

tinted, while decreasing the amount of dust or foreign substances sticking to the surface

of the conveyor belt 20, and either eliminates the need to clean the belt surface at the

end of the belt or makes the cleaning very easy.

Since the tinting of leather may require a longer time than for regular textiles, it is

desirable to set the conveyance speed of the conveyor belt 20 to be lower than that for

textiles, and to set the tinting speed of the printing unit 30 to be higher than that for

textiles. To this end, it is desirable to further include a control part 60 which adjusts the

conveyance speed of the conveyor belt 20 and the tinting speed of the printing unit 30.

Although a conventional tinting device does include a control panel for ON/OFF

control of the drive roller 10, conveyor belt 20, and printing unit 30, etc., it is desirable

to include a control part 60 that is able to control the conveyance speed and tinting

speed to be in correspondence, for tinting leather according to the present invention.

The control part 60 is preferably a processing unit capable of internal computations,

such as a computer, and controls the speed of the motor supplying driving power to the

conveyor belt 20 or the printing unit 30 such that the conveyance speed and tinting

speed of the leather are in correspondence.

As the computer thus controls the conveyance speed and the tinting speed, the

conveyor belt 20 and the printing unit 30 are controlled to be in correspondence simply

by inputting the appropriate values according to the type of the leather being tinted and

the form of tinting, etc., so that the tinting quality is maintained, and no problems occur

in mass production.

Fig. 6 is a longitudinal cross section of a drying unit in a leather tinting apparatus

according to an embodiment of the present invention, and Fig. 7 is a latitudinal cross

section of the drying unit in a leather tinting apparatus according to an embodiment of

the present invention. Referring to Figs. 6 and 7, a drying unit 40, electric heaters 42,

fans 44, and a reflective board 46 are illustrated.

The leather tinting apparatus of the present invention utilizes conventional textile

tinting equipment, and textiles typically go through a drying procedure in a drying box.

A drying box generally supplies heat up to 110 to 150 degrees Celsius to form a space

for drying the textiles, and if the drying procedure is performed for leather in such a

drying box, the properties of the leather cause it to shrink.

Such shrinkage not only degrades the tinting quality, but also incurs irreparable

damage to the leather product itself. Therefore, with the leather tinting apparatus

according to the present invention, the leather is dried using a drying unit 40 comprising

electric heaters 42, fans 44 located behind the electric heaters 42, and a reflective board

46 which surrounds the fans 44 and electric heaters 42 from behind the fans 44.

The electric heaters 42 generate heat that creates a temperature at which shrinkage

does not occur for leather, and the fans 44 generate an air current that passes the electric

heaters 42 to facilitate the drying of the leather. The reflective board 46 reflects the

radiant heat from the electric heater 42 in the direction of the leather.

By thus positioning the drying unit 40 after the printing unit 30 in the conveyance

direction of the conveyor belt 20, the leather is dried after being tinted to complete the

tinting process. Of course, the drying unit 40 used in a leather tinting apparatus

according to the present invention is not necessarily limited to the composition

described above, and any composition may be used that is apparent to those skilled in

the art, as long as it does not cause the tinted leather to shrink.

Meanwhile, for the tinting of leather according to the present invention, a more

diluted adhesive than the conventional adhesive may sufficiently secure leather to the

conveyor belt 20, as described earlier, whereby the surface of the conveyor belt 20 may

be readily cleaned, and in some cases may not require cleaning at all.

Thus, a cleaning device 50 may further be included after the drying unit 40 in the

conveyance direction of the conveyor belt 20, and the cleaning device 50 may provide

sufficient cleaning with a lower rotation speed or a fewer number of brush rollers than

in prior art.

Fig. 8 is a flowchart illustrating a leather tinting method according to an

embodiment of the present invention.

The present invention relates to a leather tinting apparatus which is modified from

a conventional tinting apparatus to be suitable for tinting leather fed in single sheets,

and a leather tinting method using this is also provided. That is, with a leather tinting

method according to the present invention, the leather to be tinted is first fed in (100),

by inserting the leather into the drive roller 10 composed of two rollers elastically

supported by each other and including elastic material. As the composition of the drive

roller 10 is the same as that described earlier, detailed descriptions on this will not be

provided.

Next, the leather fed into the drive roller 10 is attached to the conveyor belt 20 and

conveyed (110). The reason for attaching the leather onto the conveyor belt 20, as

described earlier, is so that the object of tinting does not move, however, with the

present invention, the adhesive used in conventional textile tinting may be used diluted

with acetone, thinner, or toluene, etc.

Next, the leather is tinted (120) by means of the printing unit 30 positioned at an

upper portion of the conveyor belt 20. The case of a printing unit 30 in conventional

textile tinting may be applied for the printing unit 30 and its tinting method.

Finally, heat is supplied to dry the leather (130) tinted by means of the printing unit

30. As described earlier, since heat may cause leather to shrink, the drying unit 40 for

drying the leather preferably has a composition capable of supplying heat to the leather

by means of the fans 44 and the reflective board 46 to such an extent where shrinkage of

the leather does not occur.

Since the tinting of leather may require a longer time than for the tinting of textiles,

it is desirable to set the conveyance speed of the conveyor belt 20 to be lower, and to set

the tinting speed of the printing unit 30 to be higher, and to this end, it is desirable to

control the conveyance speed of the conveyor belt 20 and the tinting speed of the

printing unit 30 to be in correspondence.

Meanwhile, since the leather tinting method of the present invention uses more

diluted adhesive than that of prior art to secure the leather to the conveyor belt 20,

cleaning the surface of the conveyor belt 20 may be performed more readily than in

conventional textile tinting. Therefore, an operation of cleaning the surface of the

conveyor belt 20 (140) may further be included after performing tinting on the leather or

after drying the tinted leather, and as described earlier, the cleaning device 50 may

provide sufficient cleaning with a lower rotation speed or a fewer number of brush

rollers than in prior art.

[Industrial Applicability]

While the spirit of the invention has been described in detail with reference to the

foregoing embodiments, the embodiments are for illustrative purposes only and do not

limit the invention. It is to be appreciated that those skilled in the art can change or

modify the embodiments without departing from the scope and spirit of the invention.