MXPA00004180A - Laser beam cutting method for cutting laminates for applying to the skin - Google Patents

Abstract

The invention relates to a method for cutting laminates for applying to the skin, comprising the following steps:a laminate consisting of at least one film and at least one other layer is prepared;the laminate is conveyed to a cutting area of a laser beam cutting device where it is kept flat with a stress of between 0.1 N/m and 1 x 104 N/m and the laser beam is used to cut through or into the laminate.

Description

METHOD OF CUTTING BY LASER RAY FOR CUTTING LAMINATES THAT WILL BE APPLIED ON THE SKIN Field of the Invention The invention relates to a method for cutting laminates to be applied to the skin. These laminates have at least one sheet and at least one other layer and are suitable for medical-pharmaceutical application on the skin.

Background of the Invention The manufacture of patches from. of material in the form of a continuous sheet (laminate) is generally made, for example, according to DE-A 41 10 027, by mechanically carving or sectioning the laminate. The contour cutter is constituted in this case by a strip cutting die introduced for example and fixed in a wooden template. When punching, the strip cutter is brought over the continuous rolling sheet - depending on the structure of the laminate, with variable dynamics - and the laminate layers are traversed to a predetermined cutting depth. The strip cutting die will preferably be in position REF .: 119363 completely horizontal with respect to the continuous sheet of laminate, in such a way that the laminate is crossed at the same time and with the same depth in all points along the strip cutting die. In the production process and due to the constant repetition of these stages there is a deviation - according to the material, more or less premature and strong - with respect to the ideal conditions mentioned above. The reasons are, on the one hand, the wear of the strip cutting die and, on the other hand, also the non-ideal fixation of the same on the aforementioned template, as well as other factors, such as, for example, the not exactly horizontal placement of the stamp on the laminate. As a result, the number of defective punching processes is increased, so that the laminate layers that are to be separated are not completely separated. The subsequent separation of the excess part of the laminate presents, therefore, enormous difficulties, which means a greater number of material waste. For this reason, it is necessary to change regularly the strip cutting dies after a certain time, which implies an increase in costs due to the preparation times of the necessary machines and the start-up losses. In addition, the prints themselves are subject to non-negligible wear and require regular maintenance. From WO-A 95/17304, a method is known for custom cutting labels using laser beam, which are applied on packages. WO-A 97/11841 describes a method for manufacturing self-adhesive labels. These self-adhesive labels are cut from a material in the form of a continuous sheet by means of a cutting head with laser beam; the material is kept below the cutting head, by means of a depression fixing device.

Description of the Invention What is intended with the present invention is to offer a method for cutting laminates to be applied to the skin which, compared to similar methods known, involves less wear for the tools, less waste of material and in general lower costs - due to the fact that it is possible to eliminate, among other things, the preparation times of the machine. The method must be particularly highly variable, so that it is no longer necessary, for example, to develop an own die for each form of punching of the laminate. This problem is solved by a method for cutting laminates to be applied on the skin, which comprises the following steps: - a laminate consisting of at least one sheet and at least one other layer is available, - the laminate is brought to a cutting area of a cutting device by laser beam, remaining flattened in the cutting zone, under a voltage ranging between 0.1 N / m and 1 x 104 N / m, - is notched or sectioned with laser beam.

In the method according to the invention, the tension under which the laminate is maintained for application on the skin ranges between 600 and 3000 N / m, in particular between 1000 and 2000 N / m. The adjustment of this tension can be done using the usual devices that can also be found outside the cutting area. Among these devices used according to the invention are, in particular, cyclically-operated clamp-type devices, which are located in front of and / or behind the cutting zone, which transport the material, for example by overcoming the braking action of a coupling of the coupling. Laminating dispensing device or having different advance lengths, with the particularity that the forward feed in the direction of the feed has a somewhat longer path than the rear. According to another aspect of the invention, a method for cutting the aforementioned medical pharmaceutical laminates is presented, which comprises the following steps: a laminate consisting of at least one sheet and at least one other layer is provided, the laminate it leads to a cutting area of a laser beam cutting device, being flattened in the cutting area, by means of a fixing device, - it is notched or it is cut with a laser beam.

Of course, it is also possible to combine the two methods according to the two main aspects of the invention - as described above.

The aforementioned fixing device is an adjustable retaining device, similar to a frame, optionally mounted on bearings, more or less the "active fixing frame" described below (FIG. 2A, B), or a retaining device having perforations in the upper face, with the particularity that the relative superficial proportion of the perforations, referred to the surface of the upper face of the fixing device, located opposite the laser beam, is greater than 50%. Preferably, this proportion is greater than 90%, in particular greater than 99%. Preferably, the perforations are alveolar in shape. Other preferred fastening devices are a transparent cover device, for example glass, plastic, such as Plexiglas, etc., which has a different absorption band from the laminate. Also used according to the invention are devices which are combinations of the retention device, similar to a frame, mentioned above, of the retention device with perforations or of the transparent cover device.

The laminate suitable for the application on the skin can be fumigated, according to the invention with an inert gas during the cutting process. If certain materials are used, unwanted oxidation processes during cutting can be avoided in this way. In addition, by supplying inert gas during the cut, the material that evaporates can be eliminated or vacuumed, thereby avoiding any negative impact on the surface of the laminate. Said negative incidences may consist for example in that the vaporized or otherwise detached particles combine with the surface of the laminate and exert an undesired negative influence on their properties. The term previously used "evaporate, vaporize" must be understood in this context, in a broad sense. With this term, it is not only indicated that a solid material passes to the vapor phase in the laser cutting process, but also refers to particles present in solid phase, having a size of the order of μm or even nm or even smaller (also called microparticles or nanoparticles hereinafter). The inert gas used according to the invention can be, in what follows, a gas such as nitrogen, argon or helium, etc. The feeding and fumigation with inert gas during cutting can be used in particular to reinforce the flat position of the laminate on the said fixing device. This can be done, for example, by overpressure. The gas can be fed parallel to the laser beam and then sucked, for example by applying depression. For this, the retention device having perforations according to the invention can be used. On the other hand, the feeding of the gas can also be carried out laterally, for example through nozzles, which are located above, parallel to the laminate. The flattened position can also be reinforced, as is natural, by applying a depression in the laminate, below the cutting area. For this purpose, the device with perforations mentioned above is particularly suitable. In the event that the laminate is placed on this device to proceed with the cut, the laminate can be kept flat, applying a depression to the laminate through the perforations that are below.

Among the laminates used according to the invention for applying to the skin, it is understood in principle all the multilayer monolayer laminates, whose materials are such that they are suitable for carrying them for a long time on the skin. These materials are not only those known as "Tapes" such as Hansaplast®, Leukosilk®, Leukoplast®, etc., but also the materials commonly used for patches, in particular patches containing active principle, such as percutaneous therapeutic systems (TTS). These percutaneous therapeutic systems are described in K. Heilmann "Therapeutic Systems - Concept and Implementation of Scheduled Drug Administration" (4th Edition 1984). These TTS generally consist of a back layer, a deposit or matrix of one or more layers and optionally a separable protective layer in the form of a sheet. The back layer may be formed of flexible or non-flexible material. The substances used for their manufacture are polymeric substances, such as polyethylene, polypropylene, polyethylene terephthalate, polyurethane or polyamide. Other materials that can be used are polyvinylalcohol, styrene-diene block copolymers, polyvinyl chloride, polyethacrylates, to mention just a few more examples. Naturally, combinations of the mentioned materials can also be used. Other materials that can be used are also metallized films, such as for example aluminized sheets, alone or coated with a polymer substrate. In addition, surface textile structures are also used, at least as long as the aforementioned components of the tank or matrix can not pass through said structure. For the separable protective sheet, the same materials can be used in principle, although it must also have an adhesion-reducing coating. This adhesion-reducing coating can be achieved by special siliconization. The reservoir or the matrix which may have, as already indicated, one or several layers, generally contains, in addition to one or more active ingredients, other auxiliary substances as additives as well as a polymeric material. Polymers such as polyisobutylene, polyvinyl alcohol ester, polyacrylic and polymethacrylic ester, natural rubber, styrene, isoprene and styrene-butadiene polymer, silicone polymers, resinous components such as saturated or unsaturated hydrocarbon resins, abietil derivatives can be used. -alcohol and ß-pinene, plasticizers such as phthalic ester, triglycerides and fatty acids. The matrix polymer material may also be based on polymers such as rubber, block-like, synthetic, rubber-like homopolymers, copolymers or polymers, polyurethanes, ethylene copolymers or polysiloxanes. The aforementioned abutments - also called auxiliary substances - are divided, according to their function, into plasticizers, binders, agents that favor resorption, stabilizers or fillers. These substances, which must be physiologically harmless, are known to the artisan. For the laminates used in the method according to the invention, in particular for the laminates from which TTS are manufactured, it is possible in principle to use all the active pharmaceutical ingredients which pass through the skin. Suitable active ingredients are in the groups of: parasympatholytic (for example scopolamine, atropine, benazidazine), cholinergic (for example physostigmine, nicotine), neuroleptics (for example chloropromazine, haloperidol), inhibitors of mono-aminooxidase (for example tranylcypromine, selegiline), sympathomimetics (for example ephedrine, D-norpseudoephedrine, salbutamol, fenfluramine), sympatholytics and antisimpatico-tonic (for example propanolol, timolol, bupranolol, clonidine, dihydro-ergotamine, naphazoline), anxiolytics (eg example diazepam, Triazolam), local anesthetics (for example lidocaine), central analgesics (for example fentanyl, sufentanil), antirheumatics (for example indomethacin, piroxicam, lornoxicam), coronary therapeutics (for example glycerol trinitrate, dinitrate of isosorbide) estrogen, progestagens and androgens, antihistamines (for example diphenhydramine, c lemastine, terfenadine) prostaglandin derivatives, vitamins (for example vitamin E, cholecalciferol) and cytostatics. The lamination can be carried out in the cutting zone continuously or in cycles. The feeding speed of the laminate is regulated, preferably by computer. All other parameters of the laser lamination cutting process according to the invention, such as laser power, cutting speed, etc., are also regulated with the aid of a computer. In addition, the laser cutting process can be carried out continuously or by pulses. The movement of laser beam is done using mirrors, prisms and / or beam splitters, with controllable movement. In particular, a device carrying the device that emits the laser beam and can be moved in two directions (X, Y coordinates) (plotter guide) is used for this purpose. All common lasers are used for this purpose. Among these are: excimer laser (F2, ArF, KrF, XeCl, CO, C02), gas laser, (Ar, HeNe) solid-body laser, semiconductor laser. The laser beam is preferably focused on the laminate with the help of a lens system. In case of continuous feeding of the laminate, the feeding speed according to the invention and / or the movement of the laser is regulated, so that the chosen cutting shape is independent of the transport speed. The depth of cut of the laser beam can be adjusted to be constant or variable. In this way, a type of "perforation" can be achieved. Furthermore, in the method according to the invention, the depth of cut of the laser beam can be determined, that is to say up to what depth the notched laminate is notched, so that, independently of the possible variation in the thickness of the laminate, it is always notched until a certain depth. Accordingly, the depth of cut in a multilayer laminate can vary along the cutting direction. Even if the laminate itself does not have a regular thickness, but has more or less enhanced areas, as can occur in the case of the TTS, it is thus achieved that along the entire cutting line always be carved up to the same defined depth. In this way, the thickness of the rest of the laminate that is not notched remains constant. And in particular, also in the laser cutting method according to the invention, the intensity distribution profile of the laser beam can be adjusted or modulated. In this way, the thermal load of the piece can be controlled and its properties influenced. For example, the use of an intensity profile that is weakly reduced towards the sides may have the advantage that, in the edge areas, along the cut edge, certain thermal modifications of the material produced in the desired form are produced. It is working. Thus, for example, the viscosity of the material in the area to be cut can be influenced in a desired manner. In the case of simple sectioning, on the other hand, the load along the cut edge can be minimized by modulating the intensity profile. This is achieved by using a sharp edge intensity profile if possible. The distribution profile of the intensity of the laser beam necessary to achieve these properties of the cut edge, however, also depends on the rolling material used and can not be determined in advance in a general way. In a given laminate, the technician can determine, by means of routine tests, the intensity distribution of the laser beam necessary to achieve certain properties of the cut edge. DESCRIPTION OF THE FIGURES The method according to the invention is explained in more detail on the basis of the figures, as well as the following examples: Figure 1 shows a device used according to the invention, which places the laminate (0) flattened on the base (5); applying overpressure in the cutting zone (8). This is done with a special cutting head (2) (figure A, side view, IB seen in plan or section), which is carried on the laminate. The cutting head has a central channel (9), through which the laser beam (1) is carried. Air or a special process gas (3) can optionally be passed through this channel through a side feed or purge hole (7). The gas is directed, at high pressure, to the laminate "(0) to be cut and compresses it, in the cutting area (8) against a support (5) .This way, the laminate is fixed in this way. zone in flat position Another channel (6) that annularly surrounds the central channel (9) and has a separate supply or purge hole, allows eventually to suck the vapors or gases (4) in the form of particles that originate in the process of The orifices (6) and (7) can optionally be used as a supply and / or purge orifice, for example, in a special embodiment of the device, another process gas can be fed through the orifice (6). Furthermore, the hole (7) can serve as a suction channel, Figure 2 shows in cross-section the fixing device according to the invention in the form of an active fixing frame mounted on bearings in side view (top) (FIG. 2A) or plant (below) (Figure 2B). The roller has two pairs of rollers (5) mounted eccentrically and vertically to each other, and the rollers of a pair are positioned parallel to each other. The bearings (9) of the rollers form a rectangular frame; the perforation of the frame releases at its narrowest part, transversely to the laminate (8), at least 80% of the width of the laminate. If the laminate (8) is fixed or held in the plane of the laminate, the lowering of the frame, that is to say of the rollers (5) means that, due to the eccentric housing (6) of the rollers (5), the laminate ( 8) be transported from point of contact A or A ' (figure 2A, B) in the direction of point B (figure 2B).

Because this is car out synchronously in the 4 directions of the fixing plane, a fixing of the laminate takes place in this way. When the rollers (5) of the fixing frame are at rest, a stop (7) prevents the rollers from hanging down and thus guarantees the direction of the transport process when the rollers are lowered. Another embodiment (not shown) of the active fixing frame comprises only a pair of fixing rollers arranged in parallel, so that the fixing of the material is only car out in the transport direction of the laminate or transversely thereto. Figure 3 shows in plan view an embodiment of the fixation device with perforations, that is to say a vacuum table (3). The fixing device shown is configured so that it is particularly suitable for cutting the laminate (1). The perforations (2), which can be seen as ovals in the plan view, have in cross section, in their narrowest area a width corresponding to at least three times the diameter of the laser beam. Preferably, the width of the perforation oscillates between 3 times and 100 times the diameter of the laser beam. The total proportion of the perforations in the surface of the upper face opposite the laser beam is greater than 90%, in the represented embodiment, very particularly preferred, in which the perforations are only separated from one another by narrow arms (4). ) of for example metals such as aluminum, this proportion is more than 99%. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (14)

1. R E I V I N D I C A C I O N S Having described the invention as above, the content of the following claims is claimed as property: 1.
2. Method for cutting laminates for application on the skin, characterized in that it comprises the following steps: - a laminate consisting of at least one sheet and at least one other layer is provided, the laminate is brought to a cutting area of a device of cutting by laser beam, keeping flattened "in the area of cut, under a voltage ranging between 0.1 N / m and 1 x 104 N / m ', -needed or sectioned with laser beam. claim 1, characterized in that the tension ranges between 600 and 300 N / m, preferably between 1000 and 2000 N / m 3.
3. Method for cutting laminates intended to be applied on the skin, characterized in that it comprises the following stages: laminate consisting of at least one sheet and at least one other layer, the laminate is brought to a cutting area of a cutting device by laser beam, being flattened in the cutting area, by means of a fixing device, notch or It is sectioned with laser beam.
4. Method according to claim 3, characterized in that the fixing device is a retaining device in the form of a frame, optionally with ball bearing, a retaining device having perforations in the upper face, the relative surface proportion of which, referred to in FIG. surface of the top face, exceeds 50%, a transparent cover device or a combination of these devices.
5. Method according to one of the preceding claims, characterized in that inert gas is applied during cutting.
6. Method according to one of the preceding claims, characterized in that the flattened clamping is achieved or reinforced using overpressure or depression.
7. Method according to one of the claims 3 to 6, characterized in that the surface proportion of the perforations, referred to the upper face presenting the perforations, is greater than 90%, preferably greater than 99%.
8. Method according to claim 7, characterized in that the perforations in the cross section have in their narrowest zone a diameter corresponding to at least three times the value of the diameter of the laser beam.
9. Method according to one of claims 3 to 8, characterized in that the fixing device contains essentially a thermo-resistant material, preferably: Al, asbestos, Keviar, glass, metals or their alloys or plastics.
10. 10. Method according to one of the preceding claims, characterized in that, in the case of continuous feeding of the laminate, the feeding speed and / or the movement of the laser beam cutting device are regulated so that the chosen cutting shape is independent of transport speed. Method according to one of the preceding claims, characterized in that by measuring the thickness of the laminate and adjusting accordingly the other parameters of the method, preferably the power of the laser and / or the speed of advance, the depth of cut is carried out just one layer determined of the laminate. Method according to one of the preceding claims, characterized in that the laminate is notched with a variable cutting depth and the variable cutting depth is achieved by modifying the power of the laser beam and / or the relative feed speed of the laminate. Method according to one of the preceding claims, characterized in that the material that evaporates during the cutting process is removed. Method according to one of the preceding claims, characterized in that at least one of the other layers contains at least one active ingredient. METHOD OF CUTTING BY RAYO L BEING TO CUT LAMINATES THAT WILL BE APPLIED ON THE SKIN SUMMARY OF THE INVENTION The invention relates to a method for cutting laminates to be applied to the skin, which comprises the following steps: a laminate consisting of at least one sheet and at least one other layer is available; laminate is brought to a cutting area of a laser cutting device, keeping flattened in the cutting area, under a voltage ranging from 0.1 N / m to 1 x 104 N / M, is notched or sectioned with laser beam.