[0001] The present invention relates to a device for moistening a continuous textile material.
[0002] In the textile industry different methods for treating textile materials are used.
One of them consists in moistening using water or aqueous solutions.
[0003] Generally, the moistening of continuous textile materials such as, for example, woven
fabrics, knitted fabrics, non-woven fabrics, etc. is performed using one of the three
following techniques:
- mechanical application of a liquid;
- physical absorption of moisture in the vaporous state;
- extraction of a predetermined quantity of liquid with conversion into the vaporous
state.
[0004] The first of these techniques uses mechanical means able to spray the liquid in the
form of a stream of droplets and transfer it onto the surface of the textile material
to be moistened. The size of the droplets, their distribution in the stream and their
speed of transfer depend essentially on their form and the mode of operation of the
spraying means.
[0005] Italian patent application No. M193A001126 describes a moistening apparatus comprising
a rotating roller and a cylindrical brush, rotating parallel to said roller and in
contact therewith. The roller is partially immersed in a tank containing the liquid
to be applied to a textile material which travels at a certain distance from the roller.
The roller removes the liquid from the tank and the cylindrical brush collects it
from the surface of the roller and projects it, forming a stream of droplets directed
towards the textile material.
[0006] In order to moisten the textile material simultaneously on both sides, it is envisaged
using two apparatuses.
[0007] In this apparatus, the regulation of the quantity of liquid removed and sprayed depends
on the variation in the portion of the roller immersed in the liquid and the speeds
of rotation of the roller and the brush.
[0008] It consists of a fairly approximate regulating system which does not allow the quantity
of liquid which strikes the fabric to be precisely determined.
[0009] In fact, the dimensions of the droplets and the distribution and the direction of
the stream of droplets have a wide range of variation since they depend on many factors
such as, for example, the configuration of the brush, the orientation of the bristles
of the brush and the manner in which the bristles pick up the liquid from the roller
and project it within the stream of droplets.
[0010] The first negative consequence is that the textile material is struck in an irregular
manner by the stream of droplets and the moistening action is not uniform. The second
negative consequence, which is linked mainly to the relatively large size of the droplets
thus produced, relates to the lack of penetration of the liquid inside the structure
of the textile material. In fact, the larger the droplets, the more they will tend
to accumulate on the surface of the textile material and form rivulets. Thus the liquid
remains on the surface of the textile material without being absorbed by the latter
and the textile material is partly wetted but not moistened.
[0011] Therefore, this apparatus is unable to ensure precision, repeatability and efficiency
of the moistening operation.
[0012] EP-0,723,609-B1 describes an apparatus for the conditioning of continuous textile
materials which constitutes an application of the second moistening technique described
further above. The apparatus uses, as treatment means, moisture in the vapour state
conveyed by an air flow. The apparatus comprises a fan able to produce an air flow
through a textile material and moistening means for moistening at least a part of
the air flow. The moistening means comprise a series of nozzles which spray jets of
water towards a saturator.
[0013] The conditioning process comprises a first stage involving transfer of the moisture
from the air flow to the surface of the textile material and from the latter into
the textile structure (moistening) and a second stage involving absorption of the
moisture by the fibres (actual conditioning).
[0014] This apparatus has a structure and a mode of operation which are very complex and
which result in the apparatus being particularly costly and therefore disadvantageous
from an economic point of view.
[0015] An application of the third moistening technique described further above consists
in a known apparatus which operates by extracting moisture from a wet textile material
until a predetermined quantity is left therein. This extraction of moisture is performed
using energy supplied by a radiofrequency generator and is therefore, basically, a
process of controlled evaporation of the liquid from the wet textile material.
[0016] The apparatus makes use of the properties of radiofrequencies in order to cause evaporation
of the moisture from the innermost zones of the textile material and interrupts this
action when the desired level of residual moisture is reached.
[0017] This apparatus, in addition to being complex, has a high energy consumption due to
the very large amount of power used by the radiofrequency generator.
[0018] The object of the present invention is to provide a device for moistening a continuous
textile material which is able to achieve, in a simple and efficient manner, penetration
of a predetermined quantity of liquid inside the structure of the textile material.
[0019] The invention relates to a device for moistening a continuous textile material comprising
a distribution roller capable of rotating, immersed, at least partially, in a prechosen
liquid and an application roller capable of rotating and driven by said textile material,
said application roller being adjacent to said distribution roller, characterized
in that said distribution roller has a cylindrical wall provided with a spongy and
yielding external layer able to absorb said liquid, and said application roller has
a substantially non-absorbent cylindrical wall around which said textile material
is wound, said wall of said application roller supporting said textile material being
able to engage with and compress a prechosen first portion of said external layer
of said distribution roller so as to impregnate said textile material with said liquid
and thus moisten it.
[0020] According to one embodiment, said application roller is displaceable with respect
to said distribution roller so as to vary the surface area of said first compressed
portion of said external layer and thus regulate the moistening rate of said textile
material.
[0021] According to another embodiment, said device also comprises a metering roller capable
of rotating, adjacent to said distribution roller, said metering roller having a substantially
non-absorbent cylindrical wall able to remain in contact with and compress a prechosen
second portion of said external layer of said distribution roller in order to extract
a part of said liquid from said external layer.
[0022] Preferably, said metering roller is displaceable with respect to said distribution
roller so as to vary the surface area of said second compressed portion of said external
layer and thus regulate the rate of absorption of said liquid by said external layer.
[0023] Typically, said distribution roller is operationally connected to motor means capable
of causing it to rotate.
[0024] Advantageously, said external layer consists of expanded rubber with an absorbent
structure.
[0025] Preferably, said expanded rubber is of the cellular type with an absorbent structure.
[0026] Preferably, said cylindrical wall of said distribution roller is provided with an
internal layer of non-absorbent material.
[0027] Advantageously, said non-absorbent material consists of expanded rubber with a non-absorbent
structure.
[0028] Typically, said expanded rubber is of the cellular type with a non-absorbent structure.
[0029] Preferably, said cylindrical wall of said application roller consists of a layer
of synthetic-fibre felt.
[0030] Typically, said cylindrical wall of said metering roller consists of a layer of synthetic-fibre
felt.
[0031] The device according to the invention has the advantage that it allows direct transfer
of the liquid to the textile material by means of the mutual engagement of the distribution
and application rollers and the textile material located between them and in direct
contact with both of them. This favours an optimum absorption and uniform distribution
of the liquid inside the structure of the textile material.
[0032] Another advantage consists in the possibility of regulating, with precision, the
quantity of liquid absorbed by the textile material by varying the degree of penetration
of the application roller into the cylindrical wall of the distribution roller.
[0033] A further advantage consists in the possibility of regulating the quantity of liquid
which is absorbed by the distribution roller and ensuring its uniform distribution
by varying the degree of penetration of the metering roller into the cylindrical wall
of the distribution roller.
[0034] In addition to this, the device according to the invention is simple, practical,
has a low cost and very low energy consumption.
[0035] Further characteristic features and advantages of the invention will now be illustrated
with reference to the embodiments shown by way of a non-limiting example in the accompanying
drawings in which:
Fig. 1 is a front view of a device for moistening a continuous textile material, provided
in accordance with the invention;
Fig. 2 is a cross-sectional view along the plane indicated by II-II in Fig. 1.
[0036] Figs. 1 and 2 show a device 1 for moistening a continuous textile material 2. The
device 1 comprises a tray 3, containing a liquid 4, such as water or a suitable aqueous
solution. The device 1 also comprises a distribution roller 6 and an application roller
8. The distribution roller 6 is at least partially immersed in the liquid 4 and the
application roller 8 engages with it, as will be shown further below. The device 1
also comprises a metering roller 9 which also engages with the distribution roller
6, as will be illustrated further below. The distribution roller 6, the application
roller 8 and the metering roller 9 are rotatably supported on side panels 5 and 5'
of the tray 3 by means of respective shafts 22, 11 and 12. The shafts 22, 11 and 12
are parallel.
[0037] The distribution roller 6 has a cylindrical wall 7 comprising a spongy and yielding
external layer 7a made of liquid-absorbent material and a yielding internal layer
7b made of non liquid-absorbent material. The external layer 7a consists, for example,
of expanded rubber which is preferably synthetic and of the cellular type with an
absorbent structure. The internal layer 7b consists, for example, of expanded rubber
of the cellular type with a non-absorbent structure.
[0038] The application roller 8 and the metering roller 9 have a respective non-absorbent
cylindrical wall 88 and 89 consisting, for example, of a layer of synthetic-fibre
felt.
[0039] The textile material 2 is wound around the application roller 8 and is located between
it and the distribution roller 6. Thus, the textile material 2 is in contact with
the cylindrical walls 7 and 88 of both the rollers 6 and 8. The textile material 2
travels in the direction of the arrows A, driven by known movement means, not shown,
and causes rotation of the application roller 8 in the direction of the arrow B and
the distribution roller 6 in the direction of the arrow C.
[0040] The cylindrical wall 99 of the metering roller 9 is in contact with the cylindrical
wall 7 of the distribution roller 6. The distribution roller 6 rotates in the direction
of the arrow C and causes rotation of the metering roller 9 in the direction of the
arrow D.
[0041] According to a variant, the distribution roller 6 is driven by means of a gearmotor
21 keyed to one end of the shaft 22 and arranged on the outside of one of the side
panels 5 and 5' of the tray 3.
[0042] The ends of the shafts 11 and 12 are slidably supported in the side panels 5 and
5' of the tray 3 by means of movable supports 13, 13' and 14, 14'. The supports 13,
13' and 14, 14' are slidable in pairs of guides 19, 19' and 20, 20', respectively,
mounted on the side panels 5 and 5' and are operationally connected to hydraulic or
pneumatic pistons 15, 15' and 16, 16', respectively. The cylinders 15, 15' and 16,
16' are operated by electric or pneumatic actuators 17, 17' and 18, 18', respectively.
The supports 13, 13' and 14, 14' are operated so as to slide in the direction of the
arrows E so as to cause translation of the shafts 11 and 12 of the rollers 8 and 9
with respect to the side panels 5 and 5'. In this way, the rollers 8 and 9 vary their
distance from the roller 6 and their cylindrical walls 88 and 99, respectively, compress
a portion 77 and a portion 177, respectively, of the cylindrical wall 7 of the roller
6. The surface areas of the compressed portions 77 and 177 depend on the distance
between the roller 6 and the rollers 8 and 9.
[0043] An instrument 10 for checking and regulating the level of the liquid 4 is housed
inside the tray 3. The instrument 10 consists, for example, of a level measuring rod
23 which is displaceable vertically in the direction of the arrows F with respect
to a graduated element 24.
[0044] A sensor 25, for example of the conductive type, which detects the presence or absence
of liquid and activates introduction thereof into the tray 3 using known means, not
shown, in order to keep the level at the set value, is inserted at the bottom end
of the rod 22.
[0045] According to a variant, the instrument 10 may comprise a float and minimum or maximum
level switches, or other means suitable for controlling and regulating the level of
the liquid 4.
[0046] When the device 1 is in operation, the continuous textile material 2 to be moistened
travels in the zone of engagement between the cylindrical wall 7 of the distribution
roller 6 and the cylindrical wall 88 of the application roller 8 being in contact
with both the cylindrical walls. The distribution roller 6 removes a certain quantity
of the liquid 4 from the tray 3. The liquid absorbed by the external layer 7a of the
roller 6 is regulated by the metering roller 9 by means of compression of the portion
177. The compression of the portion 177 causes a partial extraction of the liquid
from the external layer 7a and uniform distribution thereof. Then, the external layer
7a of the roller 6 comes into contact with the textile material 2 which is pressed
by the cylindrical wall 88 of the roller 8 against the portion 77. Thus, the entire
structure of the textile material 2 is impregnated with the liquid 4.
[0047] As a result of the action of the actuators 18, 18' which effect the displacements
of the pistons of the cylinders 16, 16' and the supports 14, 14', the cylindrical
wall 99 of the metering roller 9 is moved towards or away from the cylindrical wall
7 of the distribution roller 6. In this way, the cylindrical wall 99 penetrates more
or less deeply into the external layer 7a and compresses a more or less extensive
portion 177, causing partial expulsion of the liquid 4 so as to regulate the quantity
absorbed by the layer 7a and homogenise the distribution thereof.
[0048] A similar action is performed by the actuators 17, 17' which effect the displacements
of the pistons of the cylinders 15, 15' and the supports 13, 13' By means of these
displacements, the cylindrical wall 88 of the application roller 8 is moved towards
or away from the cylindrical wall 7 of the distribution roller 6. In this way, the
cylindrical wall 88 penetrates more or less deeply into the external layer 7a and
compresses a more or less extensive portion 77 so as to remove from the layer a predetermined
quantity of liquid which impregnates the textile material 2 located between the rollers
6 and 8.
[0049] Operation of the actuators 17, 17' and 18, 18', which is manual or electrically or
pneumatically assisted, imparts an adjustable and predetermined axial translatory
movement to the cylinders 15, 15' and 16, 16' which in turn cause sliding of the supports
13, 13' and 14, 14' in the respective pairs of guides 19, 19' and 20, 20', thus effecting
the displacement of the shafts 11 and 12 perpendicularly with respect to their axes
and causing the respective rollers 8 and 9 to move towards or away from the lining
7 of the roller 6.
[0050] As the liquid 4 is used up and its level inside the tray 3 diminishes, the sensor
25, at the bottom end of the rod 23, supplies a signal to the means for introduction
of the liquid into the tray for restoration of the set level.
[0051] The continuous textile material 2 is driven forwards, as mentioned further above,
by motor means and, in turn, causes rotation, by means of contact, of the rollers
8 and 6. The roller 6 transmits the movement, by means of contact, to the roller 9
so that the rollers 6, 8 and 9 rotate idle and substantially at the same speed as
the textile material.
[0052] As mentioned, the roller 6 may be rotationally driven by the gearmotor 21 keyed to
one end of the shaft 22. The speed of the gearmotor 21 and the roller 6 is adjustable
and, preferably, is equal to the speed of feeding of the textile material 2 so that
the roller 6, the textile material 2 and the roller 8 have the same speed, while the
roller 9 is driven rotationally, as a result of contact, by the roller 6.
[0053] This variant is advantageous in that the motor-driven roller 6 assists the advancing
movement of the textile material and minimises the longitudinal tension particularly
in the case of textile materials which are sensitive to elongation stresses.
[0054] The device according to the invention is low-cost and compact and occupies a limited
amount of space. It may form an accessory which can be combined upstream or downstream
with any machinery in which the textile material undergoes prior or subsequent treatment.
1. Device (1) for moistening a continuous textile material (2) comprising a distribution
roller (6) capable of rotating, immersed, at least partially, in a prechosen liquid
(4) and an application roller (8) capable of rotating and driven by said textile material
(2), said application roller (8) being adjacent to said distribution roller (6), characterized in that said distribution roller (6) has a cylindrical wall (7) provided with a spongy and
yielding external layer (7a) able to absorb said liquid, and said application roller
(8) has a substantially non-absorbent cylindrical wall (88) around which said textile
material (2) is wound, said wall (88) of said application roller (8) supporting said
textile material (2) being able to engage with and compress a prechosen first portion
(77) of said external layer (7a) of said distribution roller (6) so as to impregnate
said textile material (2) with said liquid (4) and thus moisten it.
2. Device (1) according to Claim 1, characterized in that said application roller (8) is displaceable with respect to said distribution roller
(6) so as to vary the surface area of said first compressed portion (77) of said external
layer (7a) and thus regulate the moistening rate of said textile material (2).
3. Device (1) according to Claim 1, characterized in that it also comprises a metering roller (9) capable of rotating, adjacent to said distribution
roller (6), said metering roller (9) having a substantially non-absorbent cylindrical
wall (99) able to remain in contact with and compress a prechosen second portion (177)
of said external layer (7a) of said distribution roller (6) in order to extract a
part of said liquid (4) from said external layer (7a).
4. Device (1) according to Claim 3, characterized in that said metering roller (9) is displaceable with respect to said distribution roller
(6) so as to vary the surface area of said second compressed portion (177) of said
external layer (7a) and thus regulate the rate of absorption of said liquid (4) by
said external layer (7a).
5. Device (1) according to Claim 1, characterized in that said distribution roller (6) is operationally connected to motor means (21) capable
of causing it to rotate.
6. Device (1) according to Claim 1, characterized in that said external layer (7a) consists of expanded rubber with an absorbent structure.
7. Device (1) according to Claim 6, characterized in that said expanded rubber is of the cellular type with an absorbent structure.
8. Device (1) according to Claim 1, characterized in that said cylindrical wall (7) of said distribution roller (6) is provided with an internal
layer (7b) of non-absorbent material.
9. Device (1) according to Claim 8, characterized in that said non-absorbent material consists of expanded rubber with a non-absorbent structure.
10. Device (1) according to Claim 9, characterized in that said expanded rubber is of the cellular type with a non-absorbent structure.
11. Device (1) according to Claim 1, characterized in that said cylindrical wall (88) of said application roller (8) consists of a layer of
synthetic-fibre felt.
12. Device (1) according to Claim 3, characterized in that said cylindrical wall (99) of said metering roller (8) consists of a layer of synthetic-fibre
felt.