FIELD OF THE INVENTION
[0001] The present invention concerns a device, and the relative method, for grinding tubular
fabrics, particularly hosiery fabrics or suchlike.
[0002] By the term grinding, we mean a treatment to finish fabrics suitable to give the
feel of the fabric particular aesthetic effects, for example, ageing, pre-washing
or the so-called peach-skin effect.
BACKGROUND OF THE INVENTION
[0003] It is known that the grinding of a fabric is performed by drawing the textile material
in contact with a plurality of rollers, covered on the surface with abrasive material
such as abrasive paper, diamond paper, filaments or other. Instead of rollers brushes
can be used or other similar means, or even plates covered with abrasive material.
[0004] The action of the abrasive material on the fabric produces a partial removal of fibrous
material, causing the formation of a surface down that is more or less accentuated
according to the final result or characteristics of feel to be obtained. Grinding
is normally performed on dry textile material or even, in some cases, on material
that has been previously wet or dampened.
[0005] The various known grinding devices for tubular fabrics include various disadvantages,
to a greater or lesser extent, including the need for complex accessory components
for widening and/or stretching the fabric, great spaces occupied if several passes
of the fabric on the abrasive elements are required, low productivity, poor uniformity
in the treatment, especially if the fabric has extensive surfaces, and other problems.
[0006] To be more exact, a problem that businessmen working in this field complain of in
particular is that deriving from the signs and marks that are impressed on the outer
face of the fabric by the widening elements arranged along the grinding path, for
example between one brush/roller and the next, in order to keep the tubular fabric
correctly widened and tensioned.
[0007] One purpose of the present invention is to achieve a grinding device for a tubular
fabric that limits to a minimum the need for accessory devices, that reduces the operating
times, increases productivity and reduces the overall bulk given the same number of
grinding passes.
[0008] Another purpose is to guarantee a high uniformity of the grinding action even when
the fabric to be treated has extensive surfaces.
[0009] Another purpose is to reduce to a minimum the contact between the fabric and the
widening elements, thus preventing the risk of marks or signs being made on the fabric.
[0010] Applicant has devised, tested and embodied the present invention to overcome the
shortcomings of the state of the art and to obtain these and other purposes and advantages.
SUMMARY OF THE INVENTION
[0011] The present invention is set forth and characterized in the main claims, while the
dependent claims describe other characteristics of the present invention or variants
to the main inventive idea.
[0012] In accordance with the above purposes, a device for grinding a tubular fabric according
to the present invention comprises a support and transport element on which said tubular
fabric is able to be positioned in order to be widened, supported and fed in a determinate
direction, and grinding elements arranged around said support and transport element
and able to be taken into contact with the outer surface of the tubular fabric, positioned
on the support and transport element, in order to achieve a grinding action on said
outer surface.
[0013] In a preferential form of embodiment, the support and transport element comprises
at least an inlet element, the function of which is to open and progressively dilate
the tubular fabric as it advances.
[0014] In a first embodiment, said inlet element comprises a widening device, for example
of a magnetic, mechanical or other type, which consists of at least a pair of arms
on which the tubular fabric is positioned. The arms can be selectively brought closer
to each other or distanced from each other in order to widen or narrow the tubular
fabric to the desired extent, for example according to the size, and in order to guarantee
at the same time that the desired tension is maintained.
[0015] According to a variant, the inlet element comprises a shaped element with a divergent
conformation starting from the inlet of the tubular fabric.
[0016] Downstream of the inlet element, the support and transport element comprises a supporting
and guiding structure on which the tubular fabric advances, and around which the grinding
elements are arranged.
[0017] In a first embodiment, the supporting and guiding structure consists of a plurality
of frames, disks or rings, arranged in succession and distanced from each other along
the path on which the tubular fabric is fed; the tubular fabric is progressively positioned
thereon so as to be accompanied from inlet to outlet of the grinding zone.
[0018] In a preferential embodiment, all the frames lie on respective planes substantially
parallel to each other. According to a variant, the frames have an asymmetrical geometric
configuration with respect to at least an axis; for example they are rectangular in
shape and are arranged with a different orientation on respective lying planes in
order to modify the arrangement of the faces of the tubular fabric with respect to
the grinding elements.
[0019] In another preferential embodiment, the frames are made in such a manner as to be
able to vary their section size; for example they are made in two or more parts, the
ends of which are telescopically associated. In this way, it is possible to modify
the transit section as required by the size of the tubular fabric, and also to adjust
the tension of the tubular fabric according to the type of processing to be done and
the grinding result to be obtained.
[0020] In a preferential embodiment, each of said frames is made in at least two parts that
can be separated in independent manner, so that each frame can be dis-assembled from
the relative central shaft without requiring that it be removed axially. This considerably
facilitates and accelerates the operations to re-adapt the support and transport element
if the format of the tubular fabric to be treated has to be changed.
[0021] In a further preferential embodiment, the widening device is kinematically connected
to at least some of the frames so that, when adjustment is made at inlet to the device
to bring closer/distance the widening device, all the frames connected to the widening
device are in turn adjusted dimensionally in a coordinated manner. Advantageously,
this adjustment is made automatically, by driving a command member. In a further variant,
the command member is governed by a programmable control unit in which various adjustment
parameters can be set according to the tubular fabric to be treated and the treatment
to be done.
[0022] In a second embodiment, said supporting and guiding structure consists of a supporting
body or core, with a substantially continuous shape, which has a substantially constant
section between inlet and outlet of the tubular fabric. According to a variant, it
has a progressively widening or narrowing section from inlet to outlet of the tubular
fabric.
[0023] In a first form of embodiment, the supporting body or core has a polygonal section
with plane sides, so that the grinding elements, advantageously each associated with
a relative side of said supporting body or core, can act on a relative substantially
plane face of the tubular fabric.
[0024] In a preferential embodiment, the supporting body or core has a quadrangular, square
or rectangular section, and at least one grinding element is associated with each
of the faces thereof. According to evolutionary variants of the invention, the supporting
body or core has a triangular, pentagonal, hexagonal section, etc.
[0025] According to these embodiments, a preferential formulation of the invention provides
that at least some of the grinding elements associated with different faces of the
supporting body or core are arranged on different levels along the support and transport
element. The grinding elements that lie on different levels are arranged angled one
with respect to the other according to the angle formed between two adjacent faces
of said supporting body or core.
[0026] In the event that the supporting body or core has a quadrangular section, grinding
elements cooperating with adjacent faces of the supporting body or core are arranged
superimposed one on top of another along the direction of feed of the tubular fabric
and are orthogonal to each other in twos.
[0027] Advantageously, the grinding elements have their axis lying on a plane substantially
orthogonal to the plane on which the axis of feed of the tubular fabric lies.
[0028] In another form of embodiment, the supporting body or core has a substantially circular
section and at least the inlet end, advantageously also the outlet end, has a progressively
tapered section; thanks to this, the tubular fabric entering the device can be progressively
widened and put under tension in correspondence with the cylindrical part where contact
with the grinding elements occurs.
[0029] According to a variant, the supporting body or core has a constant section and cooperates,
at least upstream, with a widening element with a divergent conformation.
[0030] According to this embodiment with a cylindrical supporting body or core, there are
at least two grinding elements, advantageously three or more, arranged angularly distanced
from each other following at least a circumference around said cylindrical body and
associated with respective drive means able to make them rotate according to an axis
of rotation.
[0031] In a first embodiment, said grinding elements have an angularly fixed position with
respect to the support and transport element.
[0032] According to a variant, said grinding elements are mounted on an annular support
suitable to rotate, with an axis of rotation substantially coinciding with the longitudinal
axis of the support and transport element, in order to induce a revolutionary movement
of the brushes, while they are rotating on their own axis, around said support and
transport element. In this way, the action of even a limited number of grinding elements
can cover the whole circumference of the tubular fabric while it is advancing longitudinally
on the support and transport element.
[0033] In a preferential embodiment, the device comprises two or more groups of grinding
elements, arranged at different heights along the longitudinal development of the
support and transport element, each group comprising a plurality of grinding elements
arranged angularly distanced around the support and transport element.
[0034] According to this embodiment, in the case of angularly fixed grinding elements, those
present on a first annular support are advantageously arranged angularly offset with
respect to those present on an adjacent annular support, so as to cover the whole
surface of the tubular fabric passing through without leaving strips or bands that
are not treated.
[0035] In a first embodiment, which is applied both to supporting bodies with a polygonal
section and also to those with a circular section, the support and transport element
has an outer surface substantially continuous for the whole of its development, so
as to function as a supporting and positioning plane for the tubular fabric for the
whole of its extension.
[0036] According to a variant, the support and transport element has a discontinuous surface
so that at least along part of its development the grinding elements act on a tubular
fabric that is not totally supported and can thus exert a deeper and more effective
action.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] These and other characteristics of the present invention will become apparent from
the following description of some preferential forms of embodiment, given as a non-restrictive
example, with reference to the attached drawings wherein:
- fig. 1 is a schematic lateral view, partly in section, of a first form of embodiment
of a device for grinding a tubular fabric according to the invention;
- figs. 2 and 3 show respectively the sections from II to II and from III to III of
fig. 1;
- fig. 4 is a schematic perspective view of the device in fig. 1;
- fig. 5 is a schematic lateral view of a second form of embodiment of the device according
to the invention;
- fig. 6 is a view from above of a variant of the device in fig. 5;
- fig. 7 shows a section from VII to VII of fig. 5.
DETAILED DESCRIPTION OF SOME PREFERENTIAL FORMS OF EMBODIMENT
[0038] With reference to the attached figures, a grinding device 10 according to the invention
for grinding a tubular fabric 11 comprises a frame 12, in this case extending vertically,
inside which a support and transport element 13 is arranged for the tubular fabric
11.
[0039] Around the support and transport element 13 there are grinding groups 15, comprising
in this case brushes 21, arranged one on top of the other along the longitudinal development
of the support and transport element 13. The brushes 21 have an abrasive or filamentary
covering in order to perform the grinding action on the tubular fabric 11 passing
along the support and transport element 13.
[0040] The brushes 21 are associated both with motor means, not shown here, so as to be
made to rotate on their axis at least when they are in contact with the surface of
the tubular fabric 11, and also with movement means, of a known type and not shown
here, able to move them selectively from a position of contact to a position distanced
from the tubular fabric 11 passing through, as shown by the arrows in figs. 2, 3 and
4.
[0041] In correspondence with the lower part and the upper part of the frame 12, two groups
of drawing rollers are provided, respectively an inlet roller 16 and an outlet roller
17, able to feed the tubular fabric 11 from inlet to outlet of the support and transport
element 13. The outlet roller 17 is associated with a relative motor 32.
[0042] In the first embodiment shown in figs. 1-4, the support and transport element 13
has a supporting and guiding structure 31, consisting of a plurality of little frames
28, with a quadrangular section, in this case square or rectangular, so as to define
four substantially plane working surfaces 31a, 31b, 31c, 31d (fig. 4); relative grinding
brushes 21 cooperate which each of them.
[0043] According to the variants shown in figs. 5 and 6, the support and transport element
13 consists of a continuous supporting body 31, with a desired section, in this case
circular.
[0044] To be more exact, the brushes 21 are arranged in superimposed pairs on several levels
along the supporting and guiding structure 31, each pair having brushes 21 arranged
with an axis substantially parallel to each other, the brushes 21 of superimposed
pairs having a reciprocally orthogonal axis.
[0045] The brushes 21 of each pair can be arranged on the same level (fig. 1) or slightly
offset along the support and transport element 13.
[0046] Each brush 21 is arranged so as to cover, with an axis substantially orthogonal to
the direction of feed of the tubular fabric 11, a relative surface 31a-31d of the
supporting and guiding structure 31. When the supporting and guiding structure 31
has a triangular, pentagonal, hexagonal section or other, there can be one brush 21
for every level and the angle formed between the brushes 21 of adjacent levels will
be greater or less than 90° according to the different cases.
[0047] The little frames 28 are mounted on a supporting shaft 30 by means of flanges 29.
In this case, each little frame 28 is made in two independent halves, respectively
128a and 128b (figs. 2 and 3), so that each of them can be removed laterally and autonomously
from the supporting shaft 30 without requiring them to be removed axially, which would
entail long and complex operations to dismantle and disconnect the other operating
groups of the grinding device 10.
[0048] According to an advantageous variant, as will be seen hereafter in detail and as
indicated by the arrows in figs. 2 and 3, the two halves 128a and 128b of each little
frame 28 can be mounted on the supporting shaft 30 in an independently adjustable
manner, at least in a lateral direction, according to the size of the tubular fabric
11 to be treated and the value of tension that is to be imparted thereto during processing.
[0049] Upstream of the supporting and guiding structure 31 the support and transport element
13 has a widening element 19, the function of which is to open and progressively dilate
the tubular fabric 11 entering, until it becomes gripped by the lower part of the
supporting and guiding structure 31.
[0050] The widening element 19 consists (figs. 1 and 4) of a pair of arms 33 on which the
tubular fabric 11 is positioned, each of which cooperates with a relative block 34,
arranged outside and in proximity with a relative arm 33. On the arms 33 and the blocks
34 respective magnetic elements 35 and 36 are mounted, the function of which is to
determine a reciprocal attraction between the block 34 and the relative arm 33, with
the tubular fabric 11 positioned between them.
[0051] Wheels, respectively lower 37 and upper 38, mounted on the blocks 34, are commanded
by a motor 40 and contribute to the feed of the tubular fabric 11, while support and
guide wheels 39 are mounted on the arms 33. The motor 40 and the motor 32 of the outlet
roller 17 are independently commanded, so that it is possible to adjust to the desired
value the tension of the tubular fabric 11 passing through, possibly modifying it
also during the treatment according to needs.
[0052] The blocks 34 are mounted on respective screw-type shafts 41, connected to respective
motors 42. Driving the motors 42 in one direction of rotation or the other determines
a corresponding reciprocal distancing or drawing closer of the blocks 34 according
to the entity of the widening to be imparted to the tubular fabric 11 at inlet to
the grinding device 10.
[0053] The arms 33 are mounted on the supporting shaft 30 on which the little frames 28
are also mounted, and are connected to it, in this case, by means of a relative rack
43 which engages on a sprocket 44 solid with the supporting shaft 30.
[0054] In turn, the individual components 128a and 128b of each little frame 28 are also
mounted on the supporting shaft 30 by means of a respective rack 43 which engages
on a relative sprocket 44 solid with the supporting shaft 30.
[0055] The drive of the motors 42 is advantageously governed by a control unit in which
working programs can be set according to the type and size of the tubular fabric 11
to be treated and the type of grinding treatment to be done.
[0056] Thanks to this configuration, it is possible to set the value of widening to be imparted
to the tubular fabric 11 at inlet to the grinding device 10 by acting on said motors
42, which make the respective screw-type shafts 41 rotate in the pre-determined direction,
and displace the relative blocks 34 in the corresponding manner. The presence of the
mating magnetic elements 35 and 36 causes the arms 33 to remain magnetically attracted
by the relative blocks 34, and hence to be displaced laterally in a corresponding
manner, moving the relative racks 43 and therefore making the relative sprocket 44
rotate.
[0057] The rotation of the sprocket 44 of the widening element 19 makes the supporting shaft
30 rotate, and hence all the sprockets 44 associated with each little frame 28. By
means of the respective pairs of racks 43, motion is then transferred simultaneously
from the widening element 19 to all the little frames 28, that is, to the whole supporting
and guiding structure 31, which therefore widens and narrows according to the command
imparted by the control unit which regulates the drive of the motors 42.
[0058] This command system allows, in a relatively simple and economical manner, to adapt
on each occasion the geometry of the supporting and guiding structure 31 to the specific
operating situation, according to the type of tubular fabric 11 to be treated and
the operating result to be obtained.
[0059] Once the desired parameters of width and tension to be imparted to the tubular fabric
11 have been set, and which, moreover, can be modified even during the grinding process,
the tubular fabric 11 is positioned on the widening element 19 and on the little frames
28, and the operation to feed it is begun, by driving the motors at inlet 40 and at
outlet 32.
[0060] The tubular fabric 11, fed by the inlet rollers 16 in a closed and flattened form,
is progressively widened on the widening element 19 and is arranged, widened and dilated,
on the supporting and guiding structure 31, so as to be subjected to the grinding
action performed by the brushes 21, in the meantime brought into contact with the
tubular fabric.
[0061] For the inlet step, it may be provided to use a segment of discard or an added segment
applied on the tubular fabric 11 to be ground.
[0062] Each brush 21 acts on a relative substantially plane face of the tubular fabric 11,
which can be either completely supported below, in the case of a continuous supporting
body 31 such as that shown in fig. 5, or simply supported between two points, as in
fig. 1, with the brushes 21 penetrating in greater depth into the surface of the tubular
fabric 11.
[0063] The tubular fabric thus ground is discharged by the outlet rollers 17. It comes within
the field of the invention that a same face of the tubular fabric 11 can be subjected
to several grinding passes in the grinding device 10, or that the tubular fabric 11
can be turned over and returned to the grinding device 10 so that the opposite face
can be ground.
[0064] In the embodiment shown in figs. 5 and 6, where the same numbers identify components
equal or equivalent to those described heretofore, the support and transport element
13 has a supporting body 31 with a substantially circular section with the ends 19
and 20 tapered so as to facilitate respectively the operations to attach and detach
the tubular fabric 11 to/from the support and transport element 13.
[0065] The support and transport element 13 is supported below and stabilized above by respective
toroidal elements 23, cooperating with the tapered ends 19 and 20.
[0066] The grinding brushes 21 are arranged, with an axis of rotation substantially orthogonal
to the direction of feed of the tubular fabric 11, around the support and transport
element 13, and are mounted rotatable on relative rings 26 by means of respective
levers 25. Thanks to the levers 25, the brushes 21 can be distanced from the support
and transport element 13 in the step when the tubular fabric 11 is positioned, and
taken into contact with the tubular fabric 11 when the grinding cycle is started.
[0067] The rings 26 are arranged parallel with each other, coaxial with each other and with
the support and transport element 13 and can be either fixed or rotating, in the second
case to guarantee that the whole outer surface 11a of the tubular fabric 11 is ground,
even with a limited number of brushes 21. With fixed rings 26, the brushes 21 mounted
on two adjacent rings 26 are angularly offset so as to guarantee that the outer surface
11a of the tubular fabric 11 advancing on the support and transport element 13 is
completely covered.
[0068] According to the variant shown in fig. 7, at least some of the brushes 21 are mounted
on the relative rings 26 with an axis of rotation substantially parallel to the direction
of feed of the tubular fabric 11.
[0069] According to another variant, articulated means are provided, not shown here, suitable
to direct in a desired manner the individual brushes 21 in order to move them from
a substantially horizontal position to a substantially vertical position or in any
other suitable intermediate position.
[0070] It is clear, however, that modifications and/or additions of parts or steps may be
made to the grinding device 10 and the relative grinding method as described heretofore,
without departing from the field and scope of the present invention.
[0071] For example, the tubular fabric 11 can be introduced into the frame 12 from above
downwards, or it can make alternate working cycles first in one direction and then
in the other. The supporting and guiding structure 31 can also have an elliptical
transverse section, or other type. In these cases the arrangement of the brushes 21
has to be planned accordingly, so as to ensure that grinding is performed on all the
outer surface 11a of the tubular fabric 11. The supporting and guiding structure 31
can also have a shaped outer surface, so as to improve the conditions of contact between
the tubular fabric 11 and the grinding brushes 21.
1. Device for grinding a tubular fabric (11), characterized in that it comprises a support and transport element (13) on which said tubular fabric (11)
is able to be positioned in order to be widened, supported and made to advance in
a determinate direction, and grinding elements (21) arranged around said support and
transport element (13) and able to be brought into contact with the outer surface
(11a) of said tubular fabric (11) positioned on said support and transport element
(13), in order to perform a grinding action on said outer surface (lla).
2. Device as in claim 1, characterized in that said support and transport element (13) comprises a supporting and guiding structure
(31) for said tubular fabric (11), and a widening element (19) arranged at least upstream
of said supporting and guiding structure (31) in cooperation with the inlet of the
tubular fabric (11) into the device (10).
3. Device as in claim 2, characterized in that said widening element (19) is in a single piece with said supporting and guiding
structure (31).
4. Device as in claim 2, characterized in that said widening element (19) is a separate element from said supporting and guiding
structure (31).
5. Device as in claim 2, characterized in that said supporting and guiding structure (31) consists of a plurality of little frames
(28) mounted one on top of the other on a central shaft (30) and able to define a
discontinuous frame which confers the desired widened form to the advancing tubular
fabric (11).
6. Device as in claim 5, characterized in that each of said little frames (28) is made in two parts (128a, 128b) able to be displaced
laterally one with respect to the other.
7. Device as in claim 6, characterized in that said parts (128a, 128b) are able to be separated from each other.
8. Device as in claim 6, characterized in that each of said parts (128a, 128b) is associated to said shaft (30) by means of a mechanical
system (43, 44) able to convert a rotation of said shaft (30) into a movement of lateral
displacement of the parts (128a, 128b) one with respect to the other and in respectively
opposite directions.
9. Device as in claims 4 and 5, characterized in that said widening element (19) includes widening means (33) able to be adjusted at least
laterally, said widening means (33) being kinematically connected to said shaft (30)
by means of a mechanical system (43, 44) in order to transmit a received command of
lateral displacement to all said little frames (28).
10. Device as in claim 9, characterized in that said widening means comprise at least a pair of arms (33) on which said tubular fabric
(11) is positioned, and relative blocks (34) arranged facing a relative arm (33) and
outside the tubular fabric (11).
11. Device as in claim 10, characterized in that on said arms (33) and on said blocks (34) mating magnetic elements (35, 36) are provided
able to exert a force of reciprocal attraction between arm (33) and relative block
(34), said tubular fabric (11) being located between them.
12. Device as in claim 11, characterized in that said blocks (34) are associated with respective motor means (42) able to move them
laterally according to the desired widening to be imparted to said tubular fabric
(11).
13. Device as in claim 12, characterized in that said motor means (42) are associated with a programmable control unit in order to
set programs to adjust the widening and tension of the tubular fabric (11) that vary
at least according to the type of tubular fabric (11) and the treatment to be performed.
14. Device as in claim 10, characterized in that driven wheels (37, 38) are mounted on said blocks (34) in order to feed said tubular
fabric (11).
15. Device as in claim 10, characterized in that supporting and guiding wheels (39) for said tubular fabric (11) are mounted on said
arms (33).
16. Device as in any claim from 1 to 4 inclusive, characterized in that said supporting and guiding structure (31) has a substantially constant section between
inlet to and outlet from the device (10).
17. Device as in any claim from 1 to 4 inclusive, characterized in that said supporting and guiding structure (31) has a section that widens or narrows between
inlet to and outlet from the device (10).
18. Device as in any claim hereinbefore, characterized in that said supporting and guiding structure (31) has a polygonal section defining a plurality
of substantially plane faces (13a-13d).
19. Device as in claim 18, characterized in that a relative grinding element (21) is associated with each of said substantially plane
faces (13a-13d).
20. Device as in claim 19, characterized in that said grinding elements (21) are arranged with their axis lying on a plane substantially
orthogonal to the plane on which the axis of feed of said tubular fabric (11) lies.
21. Device as in claims 18 to 20, characterized in that at least the grinding elements (21) associated with adjacent faces of said supporting
and guiding structure (31) are arranged longitudinally on different levels of said
supporting and guiding structure (31).
22. Device as in any claim from 1 to 4 inclusive, characterized in that said supporting and guiding structure (31) has a substantially circular section wherein
the inlet end for the tubular fabric (11) has a progressively divergent section and
defines said widening element (19).
23. Device as in claim 22, characterized in that said supporting and guiding structure (31) has the outlet end (20) for said tubular
fabric (11) with a progressively convergent section.
24. Device as in claim 1, characterized in that said grinding elements (21) are arranged angularly distanced following at least a
circumference around said support and transport element (13) and associated with respective
drive means able to make them rotate according to an axis of rotation.
25. Device as in claim 24, characterized in that said grinding elements (21) have an angularly fixed position with respect to said
support and transport element (13).
26. Device as in claim 24, characterized in that said grinding elements (21) are mounted on an annular support (26) suitable to rotate,
with an axis of rotation substantially coinciding with the longitudinal axis of said
support and transport element (13), in order to induce a revolutionary movement of
said grinding elements (21), while they are rotating on their own axis, around said
support and transport element (13).
27. Device as in any claim from 24 to 26 inclusive, characterized in that it comprises two or more groups (15) of grinding elements (21), arranged at different
heights along the longitudinal development of said support and transport element (13),
each group (15) comprising a plurality of grinding elements (21) arranged angularly
distanced around said support and transport element (13).
28. Device as in claim 27, characterized in that in the case of angularly fixed grinding elements (21), the grinding elements (21)
of a first group (15) are arranged angularly offset with respect to the grinding elements
(21) present on a second adjacent group (15), so as to cover the whole surface of
the tubular fabric (11) passing through without leaving untreated bands or strips.
29. Method for grinding a tubular fabric (11), characterized in that it comprises a first step wherein said tubular fabric (11) is positioned on a support
and transport element (13) in order to be widened and positioned with respect to grinding
means (15), and at least a second step wherein grinding means (15), comprising a plurality
of grinding elements (21) arranged around said support and transport element (13),
are taken into contact with the outer surface (11a) of said tubular fabric (11), positioned
on said support and transport element (13), in order to perform said grinding.