[0001] The invention relates to a device and method for sealing packages of rolled-up fabrics,
in particular plastics packages.
[0002] It is known that packing sheets, generally made of plastic material, polyethylene
for example, are currently wrapped around fabric rolls.
[0003] These packing sheets are clamped and locked to the rolled-up position in many cases
with the aid of clips or staples of metal material.
[0004] Said clips are bent upon themselves in the same manner as common staples for holding
paper sheets together.
[0005] The staples are applied to the end portions of the packing sheets which are disposed
close to the ends of the rolls and folded in a layered or pleated form.
[0006] This known technique has the merit of being simple and cheap and also of holding
said end portions of the packing sheets steadily, so that they practically form end
bunches in the rolls, which bunches are also very useful for grasping the fabric rolls
when they are arranged in a stack.
[0007] In fact, when several rolls are arranged in a stack, withdrawal of a single roll
when it is not located uppermost is possible only by making the same slide in a direction
parallel to its wrapping axis, and in this case the grasping point enabling said withdrawal
is exactly said end bunch.
[0008] Beside the above advantages, this known technique also has some drawbacks.
[0009] In fact, due to the rules of law obliging to carry out a differentiated disposal
of refuse, metal staples need to be separated from the packing sheets of plastic materiale
before sending the latter to the dump.
[0010] Therefore a specific intervention on the staples is necessary in order to separate
them from the plastics sheets. This operation is time-consuming and therefore increases
costs.
[0011] The increase in costs may have an important incidence if we consider that, when a
great number of rolls is to be handled, which usually happens in some industries in
the textile field, it is sometimes necessary to assign appropriate staff to this operation
of separating the different parts of the packaging before getting rid of them.
[0012] Another drawback is connected with the fact that the above metal staples do not enable
achievement of a hermetic seal of the packages.
[0013] In fact the application of said staples involves the steps of bending them and turning
their ends towards the central portion of same and therefore, once said staples have
been bent, their profile is like that of a butterfly, that is the staple ends are
expanded due to the presence of curved loops formed by said bending.
[0014] Practically the known metal staples in use produce on the layers they tighten a greater
squashing at the central area than at the ends where said curved loops are present.
Due to said unevenness in squashing, a perfect sealing cannot be ensured.
[0015] It is also to be noted that known metal staples not only are incapable of ensuring
a perfectly sealed closure, but in some cases they may even become slack and slipping
off the package, thereby practically causing a complete opening of same.
[0016] Another drawback is connected with the variable thickness of the layered or pleated
portions, to which said staples are applied. In fact it may be necessary to provide
for the use of a wide variety of staples belonging to different size classes depending
on the packages to be sealed by them.
[0017] In order to obviate some of the above drawbacks, it is possible to carry out closure
of rolled-up-fabric packages by adopting sealing techniques for the sheets that do
not use additional elements such as said staples.
[0018] For example the end portions of said packages may be heat sealed, but this process
is restricted to fabric rolls which are not very heavy since in this case breakages
in the packaging material are likely to occur.
[0019] Said packing sheets may also be sealed by ultrasonic welding, but this technique
involves high costs for installation and in addition is of difficult adjustment.
[0020] The package ends may also be closed by adopting the technique of heat shrinkage by
hot air. This known technique however is not widely applied because in some cases
the material to be packed can be damaged.
[0021] In addition, heat-sealing, ultrasonic welding and heat-shrinkage reduce the sizes
of said end bunches and therefore manual handling of rolls is made more difficult.
[0022] Under this situation, the technical task underlying the present invention is to devise
a sealing device and a method capable of substantially eliminating the above drawbacks.
[0023] The technical task specified is substantially achieved by a device and method for
sealing rolled-up-fabric packages, in particular plastics packages, as claimed in
Claims 1 and 5.
[0024] The features and advantages of the invention will be hereinafter described with reference
to a preferred embodiment of same, with the aid of the accompanying drawings, in which:
Figure 1 is an exploded view of the component parts of the device of the invention, one of
said parts being shown in face elevation and the other in top view and overturned;
Figure 2 is a top view, partly in section, of the component parts shown in Fig. 1, in an assembled
condition;
Figure 3 is an elevational front view partly in section of the device of Fig. 1 in an operating
position; and
Figures 4 and 5 show two operating steps in succession for applying the device of Fig. 1 to a rolled-up-fabric
package.
[0025] Referring to the drawings, the device of the invention has been identified by reference
numeral 1.
[0026] It applies to a package 2 consisting of a wrapping sheet of plastic material such
as polyethylene for example, gathered at its ends so as to form end portions 3 folded
in a pleated configuration.
[0027] The device 1 comprises a first clamping element consisting of a clip in the form
of a staple 4, that is having a substantially U-shaped configuration comprising a
central portion 5 and two side arms 6 parallel to each other.
[0028] Staple 4 is arranged around a sealing area 3a disposed at an end portion 3 of said
package.
[0029] Also provided is a second clamping element consisting of a plate 7 provided with
gauged holes 7a to be coupled by force with the side arms 6 of staple 4, so as to
define therewith a body fixedly embracing the sealing area 3a. Actually, said first
and second clamping elements comprise means for mutual engagement by forced fitting
adapted to define an irremovable clamping.
[0030] As discernible from the drawings, staple 4 is provided on its side arms with locking
portions 8 consisting of a series of extensions insertable in the gauged holes 7a,
said gauged holes being such sized, relative to the locking portions 8, that the plate
7 once fitted can be removed therefrom only if it is broken or greatly torn.
[0031] In detail, the locking portions 8 are formed on external regions of the side arms
6 turned outwardly from staple 4, so that the locking portions 8 of a side arm 6 do
not face the locking portions of the other side arm 6.
[0032] In this manner, fitting movements of the plate 7 on the staple 4 are prevented when
a localized pressure is exerted on the plate itself at a middle region thereof, that
is the region between the two gauged holes 7a, as better clarified in the following.
[0033] In addition, the locking portions 8 turned outwardly of staple 4 enable the formation
of a wide and smooth seat 4a, at the inside of said staple, into which the package
to be clamped can be introduced easily and without any risks of tearing.
[0034] Each of the locking portions 8 is saw-toothed and exhibits an inclined face 8a with
respect to the central portion 5, and a transverse face 8b substantially parallel
to said central portion 5.
[0035] The inclined faces 8a promote a forced insertion of the plate 7, if conveniently
pushed at the gauged holes 7a, whereas the transverse faces 8b fixedly hook the plate
7, once it has been conveniently fitted.
[0036] The first and second locking elements 4 and 7 define opposite clamping surfaces,
9a and 9b respectively, between which the sealing area 3a is squashed, within the
seat 4a.
[0037] One feature of the invention is that the first and second clamping elements 4 and
7 are made of rigid or semirigid plastic material. Therefore the clamping surfaces
9a, 9b are pre-shaped on the elements themselves.
[0038] Advantageously, the selected plastic material is the same material as used for the
manufacture of package 2: for example, if the packing sheets are made of polyethylene,
the first and second clamping elements 4 and 7 will be of polyethylene as well.
[0039] Use of the device is as follows.
[0040] Staple 4 is positioned on the sealing area 3a of a package 2 so that it embraces
said area between the side arms thereof 6, within the smooth seat 4a.
[0041] At this point plate 7 can be arranged so that its gauged holes 7a are disposed on
the side arms 6 and pushed towards the central portion 5.
[0042] The thurst action must be exerted at the ends of plate 7 or at the gauged holes 7a
so that a forced fitting of the plate itself may be allowed, due to the presence of
the inclined faces 8a.
[0043] A thrust exerted on the middle portion of plate 7 practically does not enable a forced
fitting, in that the inclined faces 8a are located externally of staple 4.
[0044] In this manner the package is best clamped at the most critical areas and a better
seal is achieved.
[0045] The plate 7 is moved close to the central portion 5 until it completely compacts
the package pleats between the clamping surfaces 9a, 9b.
[0046] The locking portions 8 stop the plate 7 to the final position reached and prevent
slipping off of same.
[0047] The clamping surfaces 9a and 9b clamp the sealing area 3a by muving close to each
other and therefore the staple 4 can be conceived of large sizes as regards the length
of both the central portion 5 and side arms 6.
[0048] In this manner it can be fitted on a sealing area 3a of substantially any size.
[0049] It is pointed out that the adaptability of the device to any type of rolled-up-fabric
package is not to the detriment of the hermetic seal of same in that, even if the
package occupies only one portion of the room included between the side arms 6, the
greater pressure necessarily exerted exactly at said side arms prevents the pleats
from opening or moving to the free space.
[0050] A sealing method for packing rolled up fabrics is put into practice by said device.
[0051] According to the method in question the sealing area 3a is submitted to opposite
pressures exerted by substantially parallel and opposite surfaces, corresponding to
the clamping surfaces 9a, 9b.
[0052] Mutual approaching of the clamping surfaces performs a squashing action on the pleats
of the sealing area 3a and causes a given orientation of said pleats which will tend
to be arranged in tight contact with each other taking substantially parallel positions.
[0053] Pleats are only subjected to compression and any twisting stress is reduced.
[0054] In addition, according to one aspect of the method shown in Fig. 3, the clamping
efforts 10 are exerted close to the end edges of the sealing area 3a.
[0055] Thus a slight outwardly-convex bending of the clamping surfaces may be caused and
at all events a squashing pressure which is higher exactly at the end regions of said
pleats, where they form folding loops and where an appropriate seal is more likely
to be lacking if the pleats occupy only part of the room included between the clamping
surfaces.
[0056] Practically the greatest clamping action is exerted exactly at the most critical
areas for the achievement of a hermetic seal.
[0057] The invention achieves important advantages.
[0058] The use of component parts made of the same plastic material as the packages reduces
costs for disposal because packages and clampers are homogeneous and do not need to
be mutually separated.
[0059] In addition, the device is adapted for packages which are very different from one
another as regards size and thickness, because closure takes place between two opposite
surfaces that can be conceived of large sizes and variably spaced apart from each
other.
[0060] The sealing action does not cause twistings of the package, but a mere compression
of same, thereby avoiding risks of tearings.
[0061] In addition compression is particularly marked exactly at the edge pleats which are
more critical for a hermetic sealing.
[0062] It is pointed out that the device and method are very simple and involve low costs.
1. A sealing device for packages of rolled-up fabrics, in particular for packages of
plastic material, characterized in that it comprises:
- a substantially rigid clamping element (4), made of plastic material and adapted
to partly encircle a sealing area of said one package;
- and a second clamping element (7) of plastic material to be engaged with said first
clamping element (4) according to a plurality of positions, so as to completely enclose
said sealing area,
- said first and second clamping elements (4, 7) defining pre-shaped and opposite
clamping surfaces (9a, 9b) between which said sealing area is squashed, and
- said first and second clamping elements (4, 7) comprising means for mutual engagement
by forced fitting (7a, 8) adapted to define an irremovable engagement.
2. A device according to Claim 1, wherein said first and second clamping elements (4,
7) are made of the same plastic material as that of said packages.
3. A device according to Claim 1, wherein said first clamping element (4) exhibits, at
the inside thereof, a substantially smooth seat (4a) for said package and wherein
said means for mutual engagement by forced fitting (7a, 8) is disposed externally
of said seat (4).
4. A device according to Claim 1, wherein said second clamping element (7) is a plate
to be forcedly coupled with said first clamping element (4).
5. A device according to Claim 4, wherein said first clamping element (4) is a substantially
U-shaped element or staple the side arms (6) of which are provided with locking portions
(8) of a saw-tooth configuration, and wherein said plate (7) exhibits a pair of gauged
holes (7a) conveniently sized relative to said locking portions (8) so as to form
therewith an irremovable clamping when said plate (7) is engaged with said clamping
element (4).
6. A device according to Claim 5, wherein said locking portions (8) of a saw-tooth configuration
are disposed on regions of said side arms (6) turned outwardly of said first clamping
element (4).
7. A sealing method for packages of rolled-up fabrics, in particular for plastics packages,
characterized in that it consists in submitting a sealing area of said package to
a clamping action generated by moving opposite clamping surfaces close to each other
so as to form, in said package, pleats folded over according to substantially parallel
lying planes, and wherein said opposite clamping surfaces are moved close to each
other by clamping stresses applied close to the edges of said sealing area.