FR2729930A3 - TEMPORARY CONTAINER FOR PRINTING INK - Google Patents

Abstract

The temporary container (10, 24; 50) described and claimed is composed of an outer packaging (22) of rigid material in the form of a straight prism, and of an inner packaging (24) of flexible material in the form of a straight prism. 'a bag that can be hermetically sealed. The horizontal section of the container is preferably an isogonal octagon derived from a square where the angles have been cut. This configuration allows the inner packaging to conform well to the walls of the outer packaging, and it provides better resistance and stability of the container. To fill this packaging preferably with intaglio printing ink, and its closure, a specific method is proposed.

Description

- 1 - Temporary container for printing ink The present invention

  belongs to the field of printing inks. More particularly, it refers to a container or temporary container which can contain a predetermined quantity of ink, this container being transportable and disposable and the materials of which can be

  destroyed or recovered, respectively.

  Until now, printing inks, in particular intaglio printing inks in the form of an extremely viscous and thixotropic paste, have been transported from the ink manufacturer to the user in cans, usually steel, containing about 25 kg of ink. These canisters are heavy by themselves, they are expensive, and they also occupy a lot of space on the transport pallets; the result is that a pallet shipment has a poor relationship between the volume and the weight of the load. In addition, the volume of air remaining in the container creates the risk

  that a skin forms on the surface of the ink.

  There is no question of emptying the contents of the container into the printer's ink tanks by flow because the paste is too viscous; we must place a tray with a hole in the middle on the surface of the ink contained in the container, the tray is pressurized, and a pump in

  back and forth sucks the ink through the hole in the tray.

  Since the container must be pressurized, light containers cannot be used; it is necessary that the container withstands the pressure. In addition, it is very painful to clean the container after emptying - which always leaves a significant amount of ink which can be about 500 g in the container -, and this cleaning requires a lot of time and solvent or other cleaning product. he

  it is out of the question to throw away the container after emptying.

  - 2 The object of the present invention is to create a temporary packaging for the transport of printing inks, in

  particular, but not exclusively, size inks

  gentle, which removes all the disadvantages listed above. This object is achieved by the temporary container according to the invention which is defined in independent claim 1, special executions being the subject

dependent claims.

  The container of the invention consists of two parts, to

  namely an outer packaging and an inner packaging.

  The inner packaging is flexible, preferably hermetically sealed and impermeable to gases and light,

  and made from a sheet of synthetic material.

  The outer packaging supports the weight of the ink that is contained in the inner packaging; it is a straight prism, that is to say a solid body (which is naturally hollow to form the container) having two equal and parallel polygonal bases, the lateral edges of the body being perpendicular to the bases. The bases can be square, pentagonal, hexagonal, octagonal etc .; for the reasons which will be explained below, an octagonal base with equal angles is preferred, the opposite sides of which have the same length; they are not necessarily regular octagons; on the contrary, a certain non-regular form of the octagon is preferred, which will be described

lower.

  The outer packaging is preferably made of cardboard, especially corrugated cardboard, although any other solid and resistant material can be used, for example reinforced plastics, such as those made from plastic waste. This outer packaging contains the inner packaging which is preferably a tube made of a flexible composite sheet, closed by folding and heat sealing and, when filled with printing ink, closed in the same way at the top, but this time under vacuum. The composite sheet preferably comprises a layer of polyethylene or any other polyolefin inside, coming into contact with the ink, this layer naturally having to be inert with respect to the ink. Then, this inner layer is covered with a sheet impermeable to gases, in particular to oxygen and water vapor, to the

  light and, a fortiori, all liquids.

  Generally, metals such as aluminum are used for this layer, but it is in principle also possible to use highly pigmented plastics, for example carbon black. Finally, an outer layer was provided in this composite sheet; this outer layer protects the aluminum foil and is made of polyester or any other flexible and resistant material such as polyurethanes. If light protection is not required, you can

  omit the intermediate layer described.

  As regards the thicknesses, the internal layer has a thickness of between 70 and 100 μm, the intermediate layer, preferably of aluminum, between 9 and 12

  pm, and the outer layer between 8 and 15 = m.

  The outer packaging has a polygonal section. An object of the present invention was to create a packaging which takes up the least space on a well-known transport pallet and is used all over the world, especially in Europe where its dimensions are standardized; these pallets have a loading surface of 80 cm by 120 cm. This aim which has just been defined must however take into consideration the fact that an inner packaging, normally of circular section, must be placed in the outer packaging. However, space on a pallet is best used by square packaging; but in these square packages, a circular bag is difficult to insert, and despite its flexibility, it adapts very little to the interior walls of the package which may also burst because it contains empty volumes, not occupied by the bag containing the ink. On the other hand, an outer packaging with a circular section, therefore a drum, would be best suited to the bag that forms the interior packaging, but a lot of space would be lost not only on the pallets but also in the warehouses. It has therefore been found, according to an important aspect of the invention, that an octagonal prism shape has many advantages although any other polygonal shape is also usable. The octagonal shape is a good compromise between the circular shape and the square shape. We can use a regular octagon but, in order to better use the space on a pallet, we have found that a special octagon is particularly advantageous; it is a square whose angles are cut in such a way that the new edges thus formed are shorter than the remaining sides which come from the primitive square. In other words, we pushed away two orthogonal pairs

  edges of a regular octagon outwards.

  For example, if we look at the width of the standard pallet which is 80 cm, or the length of a subdivided pallet which is also 80 cm, we divided this measurement by three to obtain approximately 26 cm. This dimension is that of the primitive square. Then, since the tank intended to receive the inner packaging has a diameter of 30 cm, the four corners of the square are cut so as to obtain a new diagonal of 30 cm, the original diagonal being approximately 36.8 cm, so we cut twice 3.4 cm on the diagonal. The octagon thus -5- thus formed alternately, a first side of (26 - 2 * 4.8) = approximately 16.4 cm and a second side of 2 * 3.4 = approximately 6.8 cm . These measures are fairly approximate given the manufacturing tolerances of corrugated articles. The angles between the sides are equal and have the value of that of the regular octagon, at

know 135.

  As a general rule, the ratio between the first and second sides should be between 2: 1 and 5: 1, preferably between 2: 1 and 3: 1, and more preferably

still stands at around 2.4: 1.

  With regard to the space sacrificed for cutting the corners of the primitive square, a suitable limitation for this

  space is Q 10% of the area of the primitive square.

  After a simple calculation, we arrive at the following two relations: x = f (Q / 2) 0.22 and b / d = [2 * x / (1-2 * x) 0.556; where: x = the total fraction cut from the diagonal of the primitive square; b = the width of the second sides 36 a / b,

  d = the width of the first sides 34 a / b.

  If the quotient b / d is between 1: 2 and 1: 5, as mentioned above, then x is between 0.21 and 0.11

  approximately, and Q between 0.088 and 0.024 approximately.

  It has been found, surprisingly, that the crushing resistance of such a packaging is much greater than that of a square packaging and essentially equal to that of a circular packaging, the dimensions being chosen to be comparable. It is especially the vertical edges which are reinforced, which ensures stacking of the containers. To fill the container according to the invention, it is first possible to place the inner packaging, closed at the bottom by heat-sealing or heat-sealing, in the outer packaging and then fill the container. Then, the inner packaging is closed in the same way, this time under vacuum, and the outer packaging is also closed by folding and sticking the closure tabs. But you can also fill and close the inner packaging first and then slide it, using a short conical tube with a

  appropriate diameter, in the outer packaging.

  To empty the container according to the invention, one can proceed according to two methods, the choice of which depends on the use: progressive (slow) for ready-to-use inks which feed a printing machine; or fast for basic inks for manufacturing

fine tint inks.

  -7- In the first case, the emptying is done by a suction pump comprising a thrust plate and the action of a reciprocating piston; this device is known. The bag is removed from its carton by tearing the carton using a tab provided for this purpose in the lower half of the carton, and the bag is placed in a solid cylindrical container of stainless steel, specially studied and having a corresponding internal diameter the diameter of the bag. We make a circular opening on the top of the bag. The pump plate comes to rest on the bag from the top and forces it to press against the wall of the container, and then the piston begins its action of extraction of the ink by suction. The bag gradually crashes. At the end, it is collected at the bottom of the container in the form of a thin cake containing another 250

g to 500 g of ink.

  In the second case, the cardboard is opened in the same way, by prepared tearing of the cardboard and the bag is placed in a solid cylindrical container specifically studied, having a central circular hole at the bottom and a circular disc pierced with a circular hole also , but of smaller diameter over it. The container with the bag in it is put on a press, then the bag is drilled at the bottom through the hole in the disc. Then the press plate exerts a strong pressure on the bag and pushes the ink out through the bottom and falling into a tank placed below the press. The circular hole of the disc which is smaller than that of the container ensures that the container does not get dirty. One can also provide several interchangeable discs having holes of different diameters depending on the fluidity of the ink to be extracted. When you do not want to empty the bag completely, you can leave it in the container with the hole and close the hole with a suitable cap, for example a

  plastic as used for cardboard tubes.

  - 8 - In the drawing, there is shown an embodiment of the container according to the invention: FIG. 1 shows a perspective view of a preferred container; fig. 2 is a perspective view of the inner packaging still contained in the outer packaging which has been torn and partially removed; fig. 3 is a top view of the outer packaging of the container; fig. 4 shows the filling of the container; and

  fig. 5 shows the closure of the container.

  We can see in fig. 1 the body 10 of the outer packaging of the container according to the invention. This packaging is made of corrugated cardboard and made in a known manner from a flat pattern. The pattern is folded and then glued along the edge 12. The tear-off tab 14 ends in this edge 12. Upwards, the packaging is closed by four glued flaps of which only the two upper flaps 16, 18 are seen. In addition, the corrugated cardboard packaging has tabs 20 which, when pushed in, grip openings, the tabs being stamped in the carton and partially perforated so that they remain

attached to the body 10.

  Fig. 2 shows the inner packaging 24, namely a bag made of a composite sheet as described above. The bag can be an extruded tube or pipe with circular section; in the present example, it is obtained by 9 - gluing two lengths of superimposed composite sheet along their edges, and it is closed at the top by laying the tube flat and gluing the sheet together, thus forming a closure strip 26 The bag 24 is still standing in the torn lower part 22 of

the outer packaging 10.

  Finally, fig. 3, which is a schematic view from above of the container according to the present example, shows the original (fictitious) square 30 which served as the basis for drawing the octagon 32. This octagon comprises two pairs of long edges 34a, 34b , opposite by the center, and two pairs of short edges 36a, 36b, also opposite by the center. The linear dimension 38 is that which determines the size of the container, for example on a pallet, and the linear dimension 40 is the distance from the opposite short edges 36a, 36b which determines the capacity of the inner packaging 24. The latter is symbolized by the dotted outline 42. We see that the inner packaging

  adapts well to the inner walls of the outer packaging.

  The wafer that forms after emptying the bag and crushing it, can be subjected to ink and aluminum recovery treatments at least. The outer packaging 10 can be burnt without leaving harmful or otherwise dangerous residues, for example in installations

  garbage incineration. It can also be recycled.

  In this way, the invention has the additional advantage that the new temporary container is non-polluting and respects the environment. This container is advantageously applicable for units for making ink from 10 kg to 100 kg, and more specifically for

  conventional 25 kg units.

- 10 -

  The container is filled so that no air pocket forms between the ink and the wall of the bag. Because it is known that inks based on vegetable oil form a skin in contact with oxygen in the air. The formation of air pockets is prevented by a method of mechanical filling and automatically controlled by a computer which maintains an almost constant distance, throughout the operation, between the

  ink surface and the filling nozzle.

  In addition, intaglio printing inks, for which the packaging according to the invention has been particularly designed, have a high viscosity, for example more than 3 Pa s at 40 C, and often more than 7 Pa s. Therefore, these inks cannot be poured as liquids and only fill a space such as packaging very slowly, which is unacceptable for an industrial process. This problem is also

  solved by this mechanical filling method.

  A preferred installation for implementing this filling process according to FIGS. 4 and 5 essentially consists of a support 51 for the packaging 50 and a nozzle 53. At the orifice 55 of the nozzle 53 is a valve 54 provided inside with movable blades 56. The blades 56 serve to close the orifice 55 and shown in the open state. The ink 57 flows under pressure through the nozzle 53 and

  is added to the ink 58 already arrived in the packaging 50.

  By a movement of the nozzle 53 and / or of the support 51 controlled by the computer, the distance between the orifice 55 and the surface of the ink 58 in the package 50 is kept constant throughout the filling. Likewise, a flat, that is to say minimal, surface of ink 58 is obtained, as well as close contact of the bag 24 and the packaging.

exterior 10.

- he -

  To avoid the formation of skins during storage of the filled packages, the bag 24 is sealed under vacuum. The best way is to heat-seal the bag. Good quality welding is only obtained

  if the surfaces of the bag remain free of traces of ink.

  To ensure excellent maintenance of the cleanliness of the bag in the area to be welded, suitable methods and equipment have been developed. It is well known that inks based on resin and vegetable oils easily form threads which soil tools and equipment

  used to handle them. Also, the valve 54 comprises-

  it has a suitable closing mechanism fitted with a very efficient thread cutter which ensures that the bag is not stained with ink on arrival and departure from its filling position under the nozzle, along a chain filling. According to fig. 4, the orifice 55 is closed by inserting the blades 56. In other words, the valve 54 cuts the wire in the manner of a sphincter which widens to allow a fluid to pass and which

closes when the flow is stopped.

  Likewise, the vacuum has been designed to be very fast. By this speed, the ink which could flow under the effect of atmospheric pressure and be placed in the area of the bag which must be welded, does not have time to move before a sufficient vacuum of air n has been obtained

and that the welding is carried out.

  Fig. 5 shows the condition fulfilled and evacuated the packaging after the air has been rapidly sucked in via the vacuum duct 60. Since the ink has not deformed due to its viscosity, the inner bag 24

  of the packaging matches the almost solid ink mass 58.

  Above ink 58, the bag closed tightly under the

- 12 -

  atmospheric pressure and thus forms the probing zone 62. The filling method and devices represent only preferred examples, and the specialist can develop modifications without departing from the scope of the invention.

- 13 -

Claims (14)

Claims   1. Temporary container for printing inks, in particular for intaglio printing inks, characterized in that it is composed of an outer packaging (10) made of rigid material having the shape of a straight prism, and an inner packaging (24) of flexible material   in the form of a bag which can be hermetically closed.   2. Container according to claim 1, characterized in that the outer packaging (10) is made of cardboard, preferably corrugated cardboard, and of octagonal cross section. 3. Container according to claim 2, characterized in that this octagonal section is formed by a square (30) whose four angles are cut at 45, the width of the second sides (36a, 36b) thus formed being smaller than the width of the first sides (34a, 34b) remaining of the square primitive (30).   4. Container according to claim 3, characterized in that the ratio between the width of the first sides (34a, 34b) and the width of the second sides (36a, 36b) is between 2: 1 and 5: 1, preferably between 2 : 1 and 3: 1, more   preferably about 2.4: 1.   5. Container according to claim 3 or 4, characterized in that the distance between two opposite second sides is at a fraction of the diagonal of the square (30) equal to or greater than 0.78, this fraction being preferably in the range of 0.78 to 0.90.   6. Container according to one of claims 2 to 5,   characterized in that it is adapted to be transported on a standard European pallet or a subdivision of a - 14 -   such a pallet, having a width or length dimension, respectively, of 80 cm, the sides of said primitive square having a length of approximately 26 cm and the distance between the opposite sides of a pair of second sides (36a, 36b) , formed by cutting the original square, being 30 cm approx.   7. Container according to any one of the claims   above, characterized in that the inner packaging consists of a bag formed by two superimposed lengths of a flexible sheet, joined by gluing or welding of the longitudinal edges.   8. Container according to one of claims 1 to 7,   characterized in that the material of the inner packaging (24) is a composite sheet of synthetic material containing a layer impermeable to gases and preferably also to light and that the composite sheet consists of an inner layer of polyolefin, having a thickness between 70 and 100 wm, an aluminum intermediate sheet with a thickness between 9 and 12 pm, and an outer polyester layer of a   thickness between 8 and 15 pm.   9. Container according to any one of claims   2 to 8, characterized in that the outer packaging (10) of corrugated cardboard is equipped with a peripheral tear-off tab (14) comprising a gripping tab and located in   the lower half of the prism which constitutes the packaging.   10. Container according to any one of claims   above, characterized in that it is filled with printing ink, in particular intaglio printing ink. - 15 -   11. Container according to one of claims 1 to 10,   characterized in that the inner packaging is closed by   heat sealing or vacuum sealing.   12. Method of filling the container according to one of   Claims 1 to 11, characterized in that the ink is   introduced under pressure by a nozzle (53), and that the distance from the orifice (55) of the nozzle (53) is kept approximately constant during the entire filling.   13. The method of claim 12, characterized in that to complete the filling, the orifice (55) is closed by a valve (53) arranged close to the orifice (55) and comprising a closure means acting in the manner a wire cutter.   14. Method of filling the container according to one of   claims 1 to 11 or according to claims 12 or 13,   characterized in that after filling the container (50), the container is evacuated fairly quickly, so that the ink does not deform substantially during this time, so that the inner packaging (24) follows the mass of ink (58) and closes above the ink (58) by   creating an ink free area (26) that can be welded.