HK1196584B - Method for producing a structure and product produced by the method - Google Patents

Description

Method for producing a structure and product produced according to said method

Technical Field

The invention relates to a method for producing at least one structure under the action of laser light on at least one wall part of a container wall of a plastic container product, preferably produced by means of a blow molding, filling and sealing method. The invention further relates to a product produced according to the method, in particular in the form of such a container.

Background

Devices and methods for producing hollow containers (e.g. ampoules) made of plastic have many embodiments in the prior art and are widely used in packaging systems for liquid or pasty products, for example, in conjunction with known packaging systemsThe systems act together. A similar blow moulding, filling and sealing method for manufacturing a receptacle, such as a container or ampoule, is disclosed for example in EP0359971B 1.

It is also prior art to provide the container products thus manufactured with an external structure. For this purpose, DE10328198a1 discloses an embossing method, in which the relevant structures are produced on the container product or on a component that can be separated from the container product by embossing, wherein the embossed structures and, for this purpose, the structures produced by the recesses form markings which show characteristic data relating to the plastic container. In particular, this may relate to a code number which may allow, inter alia, to deduce the production location and date and the type and amount of the respective container contents, and possibly also the expiry date of the container contents.

The characteristic data may also exist unencrypted for the information of the end consumer circle. The characteristic data are formed for this purpose in the form of alphanumeric symbols or characters. Such characteristic data are preferably arranged directly on the container product in a region which surrounds the interior of the container product with the fluid or other medium. In this case, the embossing process should be carried out accordingly carefully in order to avoid complete pressing through of the container product, which may result in the container contents becoming unusable.

US3,627,858A describes a method for producing a foamed surface region on a thermoplastic wall plastic part made of polystyrene, polyamide and the like, wherein the plastic part is first acid-etched in a medium and then locally coated with CO having a wavelength of 10.6 μm₂Laser heating to form a foamed region on the plastic part, which can thus be formedAnd forming the manufactured structural mark.

DE19645871a1 describes a method for producing shaped bodies, in which at least two plastic granules of different colors are mechanically mixed, for example by hot-pressing or two-component injection molding or multi-component injection molding, wherein laser inscription is subsequently produced in that: the plastic material in the character area is "vaporized".

The known methods for producing structures in plastic parts are still in need of improvement in terms of shortening of the method duration and in terms of the accuracy of the structures to be produced and the clarity to be identified.

Disclosure of Invention

Starting from this prior art, the object of the present invention is to provide a method for producing a corresponding structure in such a plastic container product, which can be carried out in a particularly simple and reliable manner and which leads to a clearly distinguished, visible structure. The object of the invention is also to provide a product having a corresponding structure, which can preferably be produced according to the method of the invention.

According to the invention, the corresponding structure to be produced is at least considered by means of laser action

-a laser power of the laser light source,

-the duration of action of the laser light,

the type of plastic material and

type of desired structure

In this case, the linear recesses are formed in the one wall part in such a way that the recesses are bounded on the edge side and, as the linear recesses run, are each delimited by a projection, which is produced at least partially under the influence of the inherent material stress of the plastic material.

A recess with a wave-shaped cross section is thus formed in the container wall, which recess is bounded on both sides by projections extending linearly with respect to the remaining container wall. In this case, a material displacement takes place by laser action in the direction of the linear projections formed thereby in the case of the formation of the recesses. By means of the laser action, the container wall composed of plastic material is locally heated, and in the case of which the plastic fibers or such molecular chains are not interrupted in the region of the linear depressions and the plastic material in the region of the depressions is not significantly evaporated either by means of the laser action, the heated plastic material is discharged outwards on the edge side under the action of the laser, so that a wave comprising a central trough and a crest following on the edge side, viewed in cross section, is generated. The discharge of the plastic material in the direction of the linear projections or wave crests takes place under the influence of the material stresses inherent in the plastic material heated in this respect, capillary and/or surface tension effects likewise being able to act.

To the surprise of the person skilled in the art of the use of laser technology for plastic materials, he could obtain greatly improved results without, as shown in the prior art, having to foam (US3,627,858A) the plastic material with a laser in order to form the structure and without substantially evaporating the plastic material (DE19645871a1) to obtain a structure which always protrudes relative to the other wall portions of the container wall, seen from the linear protrusion, which involves producing a structure which is also clearly visible and clearly perceptible in this respect on the respective container.

Since the material filled into the container may be a sensitive fluid pharmaceutical product which should be filled under sterile clean room conditions and which reacts sensitively to atmospheric oxygen, in particular with regard to its service life, it is ensured by the method according to the invention that the plastic material is not damaged in this way, in particular not evaporated or converted into the form of bubbles, and that the basic structure (e.g. the fibers or molecular chains of the plastic material) is not damaged by the action of the laser light, so that despite the structure, the container wall is not weakened or altered such that atmospheric oxygen or other media which damage the interior of the container may accidentally penetrate the plastic container wall to an increased extent. However, in order to reliably protect the container contents, the corresponding linear recesses should reduce the thickness of the container wall by no more than 50%.

With the above method, structures are produced in the container wall which are clearly visible from the outside, which structures are suitable for forming letters, numbers, dots and also for obtaining braille in accordance with the braille alphabet, according to the thread guide. Furthermore, a corresponding structure can be provided as a groove on the container wall or on the lid, for example, in order to improve the feel. A simple, reliable and flexible method for producing structures for each type of plastic product, but preferably for container products, is thus provided.

In particular, it is advantageous if both the structure produced in each case in the one wall part and at least the next adjacent wall part form a continuously extending, in itself homogeneous and bubble-free container wall which is closed off from the surroundings. In this way, the later inclusion of impurities into the container walls does not occur, and the diffusion of particles from the surroundings through the container walls remains reduced to a minimum, so that the container contents which may have been in the container when the structure was produced neither become unusable when the structure was produced nor during subsequent storage.

Advantageously, the respective wall portion of the container wall is also heated by the above-mentioned forming method, in particular the blow-moulding method, under the action of the laser. This allows a rapid process sequence and an advantageous use of the heated and thus softer structure of the container wall for generating the desired waveform.

The linear recesses can merge at a connecting location, such as a node location or an intersection location, which is bounded outwardly by the edge-side projections, except for the intersection region of the respective recesses.

Particularly advantageously, the laser intensity for producing the structure can be reduced when the mark formation speed is reduced or the wall portion is irradiated with the laser for the second time. This measure ensures that the corresponding linear depressions are formed with a substantially uniform depth and in any case prevent the container wall from burning through.

Advantageously, at least two linear recesses running parallel to one another can be provided at least in sections in the region of the nodal point and/or of the intersection point, which recesses delimit between them a further projection, which is arranged on the same level or on a different level with respect to the level of the further projections on both sides. By this measure, the node positions and/or the intersection positions can be constructed simply and stand out well visible. In particular, the laser beam does not have to hit exactly the already previously produced recesses of the already produced wave structure.

It is particularly advantageous if, at the same time, a further structure is formed in the wall section facing the interior of the container opposite the wall section with the structure, which further structure follows the one structure in such a way that a projection is provided or formed at the location of the respective recess and a recess is provided or formed at the location of the respective projection. This results in a uniform support and a uniform container wall in the sense of the desired homogenization.

Each structure advantageously passing CO₂Laser light is generated. In the context of the solution according to the invention, it has been shown that such a laser is particularly well suited for producing structures in plastic products on the basis of its frequency spectrum and its intensity.

In a particularly advantageous manner, the structures are produced by means of laser action in plastic container products composed of polyolefin plastic material. In particular, the structure can also be used to produce so-called coextruded wall portions of the receptacle, at least two plate-like or layer-like wall portions abutting one another. The material of the outer wall part layer of the co-extruded plastic product can accordingly be selected such that the structure can be produced particularly advantageously and reliably in terms of process engineering in such a wall part, wherein the at least one layer, which is formed in the composite body with the co-extruded layer, preferably of another plastic material, in the form of a locking device can prevent impurities from migrating into the interior of the receptacle. What is able to satisfy the good tactile sensation and/or readability of the structure to be produced is that on the linear recess in the container wall portion, only on one wall side linear projections parallel to the linear recess appear, which however requires accurate laser insert technology.

Drawings

The invention is explained in detail below with the aid of the figures. The figures show:

FIG. 1 is a side view of an ampoule-shaped plastic container provided with an outer structure in the form of text according to the method according to the invention, without an associated cover part;

FIG. 2 includes a side view of the container with the lid component shown partially cut away, rotated 90 relative to FIG. 1;

FIG. 3 shows the resulting structure with the number "4" as an example according to the numbering order of FIG. 1; and

shown in the form of a photograph are:

FIG. 4 is a top view of the structure of FIG. 3 at position A;

FIG. 5 is a top view of the structure of FIG. 3 at position B;

FIG. 6 is a top view of the structure of FIG. 3 at position C;

FIG. 7 is a cross-section of the structure of FIG. 3 at position A, shown partially along line X-X of FIG. 4;

FIG. 8 is a cross-section of the structure of FIG. 3 at position B, shown partially along line Y-Y of FIG. 5; and

fig. 9 is a cross-section of the structure of fig. 3 at position C, shown partially along line Z-Z of fig. 6.

Detailed Description

In the drawings a plastic container product or receptacle in the form of an ampoule 1 is shown. Ampoule 1 has a container body 3, to which a neck part 5, to which only a cover part 7 shown in fig. 2 is screwed, is connected to the top. The neck part 5, the lid part 7 and the closure part 9 at the end of the neck part 5 are constructed in a manner known from DE102005025760a 1. In fig. 2, the initial position of the cover part 7 is shown, which corresponds to the delivery state of the ampoule 1. As is known from the above-mentioned documents, the cover part 7, when screwed further on, forms an opening device for the purpose of releasing the ampoule contents by piercing the closure part 9 by means of the piercing insert of the cover part 7.

As an example of a container product provided with an outer structure by means of the method according to the invention, an ampoule 1 for a 10 ml filling is shown in the drawing on double scale in relation to the natural dimensions. Ampoule 1 has a non-circular, substantially oval configuration of container body 3, and the narrower side of container body 3 is visible in fig. 1. On the central wall portion 11 of this side a structure in the form of a marking 13 is applied, which in the present example comprises six code numbers 123456. These code numbers are formed by laser action. Preferably, the laser device (not shown) is arranged as a self-sufficient laser stationBetween the manufacturing equipment and the punching equipment, the punching equipment removes edge waste on the ampoule belt and/or separates the ampoules. The laser station may be connected withThe systems work together in coordination. Temporally and spatially withIn laser stations in which the system works in close relation, the plastic of ampoule 1 can still have an elevated temperature, preferably in the range of approximately 45 ℃, depending on the process, due to the residual heat, which is advantageous for producing a structure in container wall 29.

Fig. 1 shows the marking 13 as a structure produced in the container wall section 11, it being possible on the basis of the readable code description 123456 by laser action which is also described further below to form other structures in the container, for example for improving the tactile impression of the container product. Fig. 2 thus shows, for example, a groove 15 produced on the cover part 7 of the ampoule 1 by the action of a corresponding laser, which groove improves the handling of the cover part 7.

The production of the structure 13 is explained further below with the aid of fig. 3 to 9. As can be seen in fig. 3, the reference numeral "4" in accordance with the code 123456 in fig. 1 is intended here to be produced as a structure produced by laser action as a linear recess 17 in the wall portion 11 of the container wall 29 of the plastic container product, taking into account at least the laser power, the duration of action of the laser and the type of plastic material. Here, the recess should have projections 27 on both sides, on the edge side and following the course of the linear recess 17, which projections are produced under the influence of the material-inherent stresses of the plastic material. In this particular example, a vertical line 19 of the number "4" is first generated that seamlessly merges into the oblique pull-down line 21 and into a horizontal transverse line 23 that intersects the vertical line 19. The structure of the linear depressions 17 with its two projections 27 and the edge regions 25 adjoining the projections at the positions A, B and C is shown in fig. 4 to 6 in a photograph-like top view, respectively, wherein the linear depressions 27 intersect at the positions B and C if the laser produces the structure 17 during the method.

At the position a of the vertical beam of "4", a linear recess 17 is formed. The recess has a straight course. The recess 17 is substantially U-shaped and reminds of a wave trough. The recess is bounded on the edge by a projection 27, which can also be referred to as a peak. These peaks 27 are elevated with respect to the remaining container wall 29 (see fig. 7). The maximum depth T of the linear recess 17 is about 1/6 of the thickness D of the remaining container wall 29 in this region. The maximum height H of the projection 27 is about 1/12 of the thickness D of the container wall 29.

The outer contour of the container wall 29 with the wall portion 11, viewed from the left to the right in the projection plane of fig. 7, rises slightly until it reaches the highest point of the left projection 27, which is the first peak, then merges into the U-shaped course of the linear recess 17, which is the trough, and on the opposite side merges with a shape which is as symmetrical as possible into the right projection 27, which is a further, second peak, which extends from the maximum possible height H and then again extends flat. On the opposite inner side 31, the container wall 29 is thickened in the region of the linear recess 17 in order to form a flat rib 33. The rib 33 has recesses 35 on both sides. In this connection, therefore, a further structure 33, 35 is formed on the wall portion 31 facing the interior of the container opposite the wall portion 11 comprising the structure 13, which further structure follows the one structure 13 in such a way that a projection 33 is formed at the location of the respective recess 17 and a recess 35 is formed at the location of the respective projection 27. However, it is clear from the cross-sectional view according to fig. 7 that the projections 33 and the respective outwardly adjoining recesses 35 have a smaller imprint than the waves on the outer circumferential side of the container wall 29. In order to clarify the geometry of the opposing arrangement, in fig. 7, in addition to an imaginary horizontally extending line, an imaginary vertical axis L is drawn, by means of which an average depth T of the recesses 17 is provided in the upper region.

In the corner region (position B) or in the intersection region (position C), the advance speed of the laser must correspondingly be increased or the laser intensity must be reduced in order to prevent the laser from being introduced too deeply into the container wall 29. The linear depressions 17 also do not necessarily intersect in these regions, so that usually two linear depressions 17 can be arranged extending parallel to one another, as is shown in particular by the cross-sectional views according to fig. 8 and 9.

The structure thus produced in the corner region (position B) of the number "4" (see fig. 8) has two recesses 17, 37 of different depth running parallel to one another, each recess being separated from one another by an intermediate projection 39. The central projection 39 can be designed such that it also projects beyond the edge-side projection 27 with the greatest height H, as can be seen in fig. 9 for a node (position C). Advantageously, such intermediate projections 39 and further recesses 37 are avoided; however, the control of the laser tool does not exclude the parallel channel guidance, which is caused by production tolerances, when the laser light is guided within the intersection region. This also applies in principle to nodal or intersecting positions (position C), wherein, for the sake of simplicity of illustration, the double guidance of the linear depressions and projections in fig. 5 and 6, seen from above in the viewing direction of fig. 8 and 9, is omitted for the sake of simplicity.

The linear recesses 17, 37 merge at a connecting location, such as a nodal or intersection location (location C), see fig. 6 and 9, and are delimited outward by the edge-side projection 27, except for the intersection region 41 of the respective linear recess 17, 37. In the junction region 41, the respective recess 17, 37 can have a maximum depth, which is shown in particular in the diagram according to fig. 5. However, it is also possible according to the illustration according to fig. 6 to cause increased melting of the plastic material in such a connecting region of the respective recess 17, so that a ball is then formed which can function as a reinforcing element, but which can also contain a corresponding recess in the intersection region 41. Ultimately here depending on the laser input power into the plastic material.

Both the structure 13 produced with the one wall portion 11 and at least the next adjacent wall portion 43, which is also in the form of the edge region 25, form a continuously extending, in itself homogeneous and bubble-free container wall 29 of the ampoule 1, which is closed off from the surroundings.

It has proven advantageous for the linear depressions 17, 37 to be arranged parallel to the fiber orientation and thus parallel to the extrusion direction of the plastic material in the container wall 29. In this way, the structures 13, 15 can be formed with less energy input. In this way, too, the shape of the respective structures 13, 15 is produced more reliably and faithfully to the shape. The linear recesses 17, 37 are preferably filled with CO₂Laser light is generated. Such lasers have a frequency range that is ideally tunable to the plastic itself. In practice especially of the order of 100 watts of CO₂Lasers have proven feasible, which in principle operate at 40% laser power.

The method according to the invention is suitable not only for plastic products 1 made of polyolefins, but also for other plastics, in particular plastics that appear transparent, such as Polyethylene (PE) or polypropylene (PP).

Claims (16)

1. A method for producing at least one first structure (13, 15) on at least one wall portion (11) of a container wall (29) of a plastic container product (1) under the action of laser light, wherein the first structures (13, 15) are each produced by means of laser light at least under consideration

-a laser power of the laser light source,

-the duration of action of the laser light,

the type of plastic material and

type of desired structure

In the case of (11), the linear recesses (17, 37) are formed in such a way that they are bounded at the edges and, as the linear recesses (17, 37) run, are each bounded by a projection (27, 39) which is produced under the influence of the inherent material stress of the plastic material, characterized in that the container wall composed of plastic material is heated locally by the action of the laser, while in the region of the linear recesses (17, 37) the plastic fibers or such molecular chains are not interrupted and the plastic material in the region of the linear recesses (17, 37) is not significantly evaporated by the action of the laser.

2. A method according to claim 1, wherein said plastic container product (1) is manufactured by means of a blow moulding, filling and sealing method.

3. Method according to claim 1, characterized in that both the first structure (13, 15) produced in each case in the one wall part (11) and at least the immediately adjacent wall part (43) are designed as a continuously extending, in an outwardly closed manner with respect to the surroundings, container wall (29) which is uniform in itself and is free of gas bubbles.

4. A method according to claim 2, characterized in that the respective wall portion (11) of the container wall (29) is also heated by the blow-moulding, filling and sealing method under the influence of the laser light.

5. A method according to claim 4, characterized in that the respective wall portion (11) of the container wall (29) is heated by blow-moulding under the influence of laser light.

6. A method according to one of claims 1 to 3, characterized in that the linear recesses (17, 37) merge in the joining position, except for the intersection region (41) of the respective linear recesses (17, 37), which is bounded outwardly by the edge-side projection (27).

7. Method according to claim 6, characterized in that the connection location is a node location (B) or an intersection location (C).

8. A method as claimed in any one of claims 1 to 3, characterized in that the laser intensity is reduced when the mark formation speed is reduced or the wall portion (11) is irradiated a second time.

9. A method according to one of claims 1 to 3, characterized in that at least two linear recesses (17, 37) extending parallel to one another are provided at least partially in the region of the nodal point (B) and/or of the intersection point (C), each linear recess delimiting between them a further projection (39) which is arranged on the same level or on a different level with respect to the level of the further projection (27).

10. A method according to any one of claims 1 to 3, characterized in that a second structure (33, 35) is formed in a wall portion (31) of the container wall (29) facing the interior of the container, opposite the wall portion (11) of the container wall (29) with the first structure (13, 15), which second structure follows the first structure (13, 15) in such a way that a projection (33) is provided or formed at the location of the corresponding linear recess (17) and a recess (35) is provided or formed at the location of the corresponding projection (27) following the linear recess.

11. A method according to any of claims 1 to 3, characterized in that each first structure (13, 15) is passed through CO₂Laser light is generated.

12. A method according to any one of claims 1 to 3, wherein the first structures (13, 15) are produced in the plastic container product (1) consisting of polyolefin by means of laser action.

13. A product manufactured according to the method of one of claims 1 to 12, the product having at least one first structure, characterized in that the first structure at least partially comprises a linear recess (17, 37) made in a wall portion (11) of the product, which linear recess is bounded on at least one edge side thereof and, as the linear recess (17, 37) runs, at least partially by a projection (27, 39).

14. The product of claim 13, wherein the product is in the form of a container.

15. The product of claim 14, wherein the product is in the form of an ampoule.

16. Product according to claim 13, characterized in that the linear recesses are bounded on adjacently opposing edge sides and, as the recesses (17, 37) run, at least in sections by projections (27, 39).