-
The present invention relates to an apparatus for rolling
up compressible fibrous materials.
-
In particular, the invention relates to formation of
rolls starting from bands or ribbons of compressible
fibrous materials such as mineral-fibre felts intended
for use typically in the building field for heat
insulation and/or soundproofing of walls, attics and so
on.
-
It is known that mineral-fibre felts, such as felts made
of glass wool, are widely used for heat insulation or
soundproofing purposes in a variety of fields and, as
above mentioned, they particularly apply to the building
field.
-
The insulation capabilities, both as regards heat
insulation and soundproofing, of felts made of glass wool
depend, as known, on the felt thickness.
-
On the other hand, in order to make mineral-wool ribbons
commercially desirable, packaging techniques capable of
greatly minimizing the volume taken up by felts have been
increasingly widespread.
-
From the above it appears that, on the one hand, the
glass wool felt thickness is required to be maximum
during setting up so, as to ensure high performance in
terms of heat insulation/soundproofing and, on the other
hand, there is an opposite requirement of minimizing the
volume taken up by the felts in order to enable an easy
and cheap transportation of same.
-
In order to meet these requirements, different packaging
techniques have been set up in the past which consist in
rolling up the glass wool ribbon under compressed
conditions, so as to form a cylindrical roll capable of
being stably housed in an outer envelope of paper or
plastic material so that transportation of same can take
place without taking up too much room.
-
Possibly, from the point of view of bulkiness, it is
certainly useful that the felt thickness should be
reduced as much as possible although, on the other hand,
the springing-back capability of the product, when the
latter is disengaged from package and then installed, is
to be taken into due account too.
-
In order to ensure an efficient reduction in volumes and
at the same time an efficient material spring-back on
installation, it is absolutely necessary that:
- 1. the whole ribbon submitted to packaging should be
compressed in a uniform manner and to an extent as much
as possible closest to the springing-back limit of the
product;
- 2. during packaging, tearing and in particular
delamination of the fibrous material should be avoided,
as this would involve unevenness and structural
discontinuity in the fibrous material and, as a result,
unevenness in the subsequent operating behaviour of same.
-
-
In an attempt to reach the above mentioned results, the
following packaging techniques involving roll formation
have been presently used.
-
According to one technique, the glass wool ribbon is led
through a space delimited by two conveyor belts and a
pressure roller. In particular, the conveyor belts are
inclined and converge towards each other so as to define
a predetermined solid angle, whereas the pressure roller
is disposed within the solid angle formed by the two
above mentioned belts at a given distance from the ideal
corner defined by the latter. The conveyor belts and
roller draw the felt in a rotation movement about itself.
In particular the pressure roller is displaced in such a
manner that the space in which the glass wool roll is
being formed progressively increases. Depending on the
different embodiments, the pressure roller is suitably
counterbalanced and is allowed to move freely during
formation of the glass wool roll (packaging by passive
compression), or it is moved by appropriate drive means
and control members following a law previously set by the
apparatus (rolling up by active compression).
-
Obviously, apparatuses provided with an active control on
the pressure roller are capable of performing a
continuous adjustment of the action exerted by the roller
on the felt, so that an as much as possible uniform
compression and felt processing is carried out during the
whole rolling-up operation.
-
A rolling-up apparatus providing an active compression
control is disclosed widely and in detail in European
Patent No. EP-0 140 785, to which please refer for
further information.
-
Practically, in accordance with teachings in the
European Patent No. EP-0 140 785, rolling up is
controlled by an active intervention of the pressure
roller imposing a predetermined thickness, which is
preferably constant or slightly decreasing during
rolling, to each coil of the felt being rolled up, in
order to substantially achieve a uniform compression over
the whole felt length, so that, during the installation
step, a product having a uniform spring-back and, as a
result, constant insulation features over the whole
longitudinal extension thereof, is correspondingly
obtained.
-
While rolling-up apparatuses provided with an active-compression
roller have been widely used, they however
have highlighted some serious drawbacks.
-
Firstly, compression carried out by the roller takes
place by suitably managing the radial position of the
roller relative to the glass wool roll being formed and
the peripheral speed of the pressing roller itself. It is
well apparent that, since arrangement of sophisticated
and precise devices for controlling the roller position
and speed depending on the number of rolled-up coils is
required, the packaging apparatus can become, on the
whole, very complicated.
-
Still more important is the fact that said pressure
roller, by working on the coils being formed, exerts a
compression action on the last rolled-up coil and this
action necessarily also affects, deforms and presses
coils already submitted to compression in the preceding
steps. This inevitably gives rise to the fact that the
pressure roller is substantially unable to ensure a
really uniform treatment of the fibrous material being
processed, over the whole longitudinal extension of said
material.
-
Finally, also important is the fact that the pressure
roller, in addition to exerting a given radial action on
the coils of the fibrous material, certainly also exerts
a tangentially-directed strong action. This inevitably
gives rise to tangential stresses at the contact areas
between the fibrous material and the pressure roller
surface, which stresses very often cause delaminations of
the fibrous material, breakage of many fibres and, as a
result, a substantial incapability of springing back of
the material at the delamination regions.
-
It is finally to point out that typically rolling-up
devices involving an active compression produce an action
on the perimeter of the roll being formed that gives rise
to some deformation in the shape of the transverse
section of said roll, which deformation may jeopardise
the final step of applying an outer paper sheath to the
roll for blocking the fibre roll once the latter has
reached the desired diameter sizes, or make this final
step difficult.
-
Under this situation, it is a fundamental object of the
present invention to provide a new apparatus for
packaging fibrous compressible materials in the form of
rolls, which is capable of improving the traditional-apparatus
behaviour.
-
In particular, it is a fundamental object of the
invention to provide an apparatus capable of ensuring
rolling up of compressible fibrous materials while
minimizing the delamination problem of the material,
achieving a high and uniform compression of the material
being processed and finally allowing an as much as
possible cylindrical roll to be obtained, i.e. a roll
devoid of marked deformations in its transverse section.
-
It is also a further object of the invention to provide
an apparatus which is of simple structure, easy operating
control and, as a result, easy and cheap installation.
-
The foregoing and further objects that will become more
apparent in the progress of the following description are
substantially achieved by an apparatus for rolling up
compressible fibrous materials in accordance with the
features recited in the appended claims.
-
Further features and advantages will be more fully
understood from the detailed description of a preferred,
non-exclusive embodiment of an apparatus for rolling up
compressible fibrous materials in accordance with the
present invention. This description will be taken
hereinafter, by way of non-limiting example, with
reference to the accompanying drawings, in which:
- Fig. 1 is a diagrammatic side view showing an apparatus
in accordance with the present invention;
- Fig. 2 shows a portion of the apparatus seen in Fig. 1,
in more detail.
-
With reference to the drawings, an apparatus for rolling
up compressible fibrous materials in accordance with the
present invention has been generally identified by
reference numeral 1.
-
In particular, it is to note that apparatus 1 will be
adapted for use in rolling up materials such as mineral-fibre
ribbons or bands, such as felts made of glass
wool.
-
Apparatus 1 comprises at least one conveyor member 2, and
at least one deflection member 3, preferably consisting
of respective conveyor belts such disposed as to define
a solid angle (Y) of predetermined opening.
-
More specifically, as shown in the accompanying drawings,
the conveyor belt 2 has a corresponding operating stretch
4a, the horizontal one in this case, over which the
ribbon of compressible fibrous material 5 to be rolled up
is placed. In turn, the deflection member (belt) 3
operates at an end region 2a of the conveyor belt 2 and
has a respective operating stretch 4b defining a solid
angle (Y) with the mentioned operating stretch 4a; a
roller 6 is disposed within the angle (Y) and, in
cooperation with the conveyor belt 2 and deflection belt
3, it defines a rolling-up space 7 inside which a roll 8
of fibrous material is being gradually formed.
-
It is to note that the conveyor belt 2 causes movement of
the compressible fibrous material 5 in a predetermined
direction and feeding speed, diagrammatically shown by
arrow 9, towards the rolling-up space 7. As the roll of
fibrous material 8 is being formed and hence its radial
sizes increase, the above mentioned roller 6 moves away
from the ideal corner 10 of the solid angle (Y) defined
by the conveyor belt 2 and deflection belt 3. It will be
recognized that roller 6 placed inside the solid angle
(Y) is rotatable about a rotation axis 11 orthogonal to
the feeding direction 9 of the fibrous material 5 and
parallel to the ideal corner 10 defined by the solid
angle extending between the conveyor belt 2 and
deflection belt 3. In other words, the rotation axis of
roller 6 is substantially parallel to the ideal rolling-up
axis of the fibrous material.
-
In an original manner, apparatus 1 also comprises a
precompression device 12 operating upstream of the
rolling-up space 7 relative to the feeding direction 9 of
the fibrous material being processed 5; the
precompression device 12 is active on the compressible
fibrous material ribbon to cause a predetermined
compression of said ribbon before it comes to the
rolling-up or packaging space 7.
-
In more detail, the precompression device 12 operates
close to the conveyor belt 2 and is active on the
fibrous material on the opposite side relative to the
operating stretch 4a of said conveyor belt.
-
As shown in Figs. 1 and 2, the precompression device
comprises at least one conveyor mat 13 having at least
one portion 13a active on the fibrous material and
exerting a compression action thereon, which action is
directed perpendicularly to the feeding direction (see
face 9) of the fibrous material towards the rolling-up
space 7. More specifically, the conveyor mat 13 of the
precompression device has a rectilinear active portion
13a converging towards the operating (rectilinear too)
stretch 4a of the conveyor belt 2, as the ribbon moves
closer to the rolling-up space 7.
-
Practically, an acute precompression angle α is formed
between the active portion 13a of the conveyor mat 13 and
the operating stretch 4a of the first conveyor belt 4,
which angle fundamentally defines the percentage of
maximum compression to be imparted to the material being
processed.
-
In this connection it is to note that, if ribbon-like
materials of different thicknesses (S1, S1) or different
features in terms of compressibility are wished to be
processed, movement means (not shown) adapted to
angularly shift said mat so as to vary said
precompression angle (α) may optionally be associated
with the conveyor mat itself (see Fig. 2).
-
In order to carry out a compression action on the
material being processed which is directed exclusively
perpendicularly to the material itself without tangential
stresses being exerted thereon, the active portion 13a of
the precompression device 12 is moved at a peripheral
speed V1 of contact with the material being processed
having a component V1p parallel to the peripheral speed
V2 of the operating stretch 4a of the conveyor belt 2 and
of same modulus, direction and way as the speed V2 of
stretch 4a. Clearly, for carrying out the desired
compression, the peripheral speed V1p of the active
portion 13a of the precompression device also has a
component V1o orthogonal to the peripheral speed V2 of
the operating stretch 4a of the first conveyor. This
orthogonal component V1o will have a modulus to be fixed
depending on requirements and in particular on opening of
angle (α).
-
In all cases it is however essential that during feeding
and compression of the material being processed the
precompression device does not substantially exert any
tangential action on the material to be packaged.
-
It is also to note that the movement means associated
with the precompression device 12 can also include slides
or similar devices for advantageously moving the device
itself away from the rolling-up space 7, as the material
is wound in a roll (see Fig. 1).
-
Practically, the movement means will be managed by a
control unit for moving the precompression device 12 away
from the packaging space and keep a minimum distance d
between an outer perimetric edge 8a of the roll being
packaged and the precompression device, constantly
unchanged. It is to note that the first conveyor belt 2,
the deflection belt 3 and the conveyor mat defining the
precompression device can be activated by respective
power units 14, 15, 16 or by a single power unit after
interposition of kinematic connecting members, depending
on the practical and construction requirements that are
each time present.
-
At all events, the power unit or power units active on
the conveyor belts and conveyor mat, suitably managed by
a Central Processing Unit (CPU) 17, will be adapted to
enable the peripheral speed of the different conveyors to
be varied so as to obtain particular production rates or
compression control effects in accordance with laws set
in by the user during rolling up.
-
In operation, it is to note that the roller operating
within the solid angle (Y) defined between the first and
second conveyors is constantly guided in such a manner
that it exhibit its rotation axis constantly disposed at
the flat surface 18 bisecting the same above mentioned
solid angle.
-
At all events, this roller can be counterbalanced by
substantially exerting a constant compression action
without particular and accurate electronic managements
being required, because the compression control of the
ribbon during rolling up substantially relies on the
precompression device 12.
-
Finally, the apparatus in reference comprises at least
one auxiliary unit 19 for feeding sheet material 20,
which operates above the first conveyor belt 2, for
example. Unit 19 is shiftable from a non-operating
condition to an operating condition in which this
auxiliary feeding unit is capable of sending a sheet
material such as paper or plastic film, to the packaging
station to carry out a final packaging of the fibrous-material
roll, once the latter has reached the desired
radial sizes.
-
The invention achieves important advantages.
-
First of all, due to the presence of the precompression
device consisting of a conveyor mat the speed of which
can be such managed, in terms of modulus and direction;
that a mere compression action on the compressible
material to be rolled up is exerted, said material is not
submitted to any delamination action and can be packaged
at high precompression values without any structural
damage.
-
Obviously the above involves a perfect springing back of
the fibrous material in use, so that it can offer
improved heat insulation and soundproofing properties.
-
It is also to note that the apparatus in reference can be
easily installed and fundamentally enables the whole
compression action to be exerted upstream of the
packaging space, an active and constant managing of the
compression exerted by roller 6 operating between the
first and second conveyor belts being substantially
unnecessary.
-
In addition, since the compression action takes place on
the material being not yet rolled up, this compression
action does not give rise to any deformation in the shape
of the roll 8 being formed, neither, during processing,
does it modify the precompression already imparted to the
rolled-up coils.
